JP2015063071A - Ink supply device of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink supply device of a printer that is capable of shortening time until a concentration is stabilized when a graph value has been changed.SOLUTION: In changing a graph value from Gb to Ga(Gs=Ga-Gb), the graph value is temporarily set as Gz1 and output is performed for a predetermined S number of times of a temporary cycle, and subsequently Ga is to be outputted. The temporary graph value Gz1 for one cycle is obtained from Gz1=Ga+{(γ*Gs)/ε} where a concentration correction coefficient is γ and ε is a natural number. When Gz1 is positive and less than one round of an ink call roller Gm, Gz1=Ga+{(γ*Gs)/ε} is applied while S=ε. When Gz1 exceeds one round of the ink call roller Gm, Gz1=Gm is applied while S=(γ*Gs)/(Gm-Ga). When Gz1 is negative, Gz1=0% is applied while S=(γ*Gs)/Ga.

Description

  The present invention relates to an ink supply apparatus for a printing press, and more particularly to an apparatus for supplying ink from an ink fountain through an ink fountain roller, an ink call roller, and a plurality of ink kneading rollers to a printing surface.

  As this type of ink supply device, a plurality of ink call rollers divided in the length direction of the ink fountain roller are arranged in the vicinity of the ink fountain roller constituting the ink fountain, and each ink call roller is an ink fountain roller. Can be switched individually between the calling position that contacts the ink and the non-calling position away from the ink fountain roller, and the control device switches the position of the required ink calling roller at each predetermined calling timing. The ink circumference is controlled from the ink fountain roller to the ink call roller by controlling the rotation angle of the ink fountain roller from the contact with the ink fountain roller to the separation of each ink call roller. What is made in this way is known (Patent Document 1). The rotation angle of the ink fountain roller is controlled by controlling the time from the output of the switching command to the calling position to the ink calling roller until the output of the switching command to the non-calling position.

  In this apparatus, the ink that has come out of the ink fountain onto the surface of the ink fountain roller is transferred to the ink call roller while the ink call roller is switched to the call position, and the ink transferred to each ink call roller. Is transferred to the ink kneading roller while the ink calling roller is switched to the non-calling position. Then, by controlling the circumferential length of the ink to be called for each ink call roller, the amount of ink supplied to the ink kneading roller, that is, the printing surface is controlled for each ink call roller.

  The reason why the ink amount is controlled for each ink calling roller is that the optimal ink amount varies depending on the position in the width direction depending on the pattern of the printed material. The ink amount for each ink calling roller is the pattern area ratio of the printed material. Is set according to

  The target value of the ink amount is displayed in% as a “graph value” for each color and for each ink calling roller, and the ink fountain roller is based on the “graph value” preset according to the pattern area ratio of the printed matter. The circumference of the ink that is called from the ink call roller to the ink call roller (specifically, the ON / OFF time of the switching valve that moves each ink call roller) is controlled.

JP 2011-73415 A

  In the conventional ink supply device of a printing press, adjustment is performed by raising and lowering the graph value in order to set the density to an appropriate value at the time of printing. However, when the graph value is raised and lowered, the density immediately stabilizes. For example, when the graph value is increased, the ink holding amount of the roller of the printing press slowly increases, and the density increases accordingly, so it takes time until the density stabilizes after the graph value is increased. There was a problem that it took.

  An object of the present invention is to solve the above problems and provide an ink supply device for a printing press that can shorten the time until the density is stabilized when the graph value is changed.

  In the ink supply device of the printing press according to the present invention, a plurality of ink calling rollers divided in the length direction of the ink fountain roller are arranged in the vicinity of the ink fountain roller constituting the ink fountain, It is designed to be individually switched between a calling position that contacts the ink fountain roller and a non-calling position that moves away from the ink fountain roller. Based on the graph value set according to the pattern area of the printed matter by the controller, a predetermined value is set. The ink fountain roller is controlled by changing the position of the desired ink fountain roller at each call timing with a certain interval, and the ink fountain roller rotation angle from the contact with the ink fountain roller to the separation is controlled for each ink call roller. By controlling the circumference of the ink that is called from the ink fountain roller to the ink calling roller When the graph value is changed from Gb to Ga (Gs = Ga−Gb) in the ink supply device of the printing press, the graph value is temporarily set as Gz1 and output for a predetermined number of provisional cycles is performed. Later, Ga is assumed to be output, and the provisional graph value Gz1 for one cycle is obtained by Gz1 = Ga + {(γ × Gs) / ε}, where γ is a density correction coefficient and ε is a natural number. When Gz1 is positive and is smaller than the ink calling roller one revolution Gm, Gz1 = Ga + {(γ × Gs) / ε} for the provisional cycle number S = ε. When Gz1 exceeds Gm for one revolution of the ink calling roller, the provisional graph value Gz1 for 3.1 cycles is set as Gz1 = Gm during the provisional cycle number S = (γ × Gs) / (Gm−Ga). Is negative, Gz1 = 0% during the provisional cycle number S = (γ × Gs) / Ga.

  When the graph value is changed, it is not reflected in the density until the ink holding amount of the roller is changed. Therefore, in the conventional control, the concentration does not change immediately, and the target concentration is reached after a sufficient time has passed. In the ink supply device of the printing press according to the present invention, when the ink amount is increased so that the ink holding amount of the roller immediately changes when the graph value is changed, the ink amount more than the difference is rapidly increased for a certain time. When the amount of ink supplied is reduced, the output of the ink calling roller is stopped for a certain period of time. Thereby, it is possible to shorten the time until the density is stabilized when the graph value is changed.

  According to the ink supply device of the printing press of the present invention, as described above, when the ink amount is increased so that the ink holding amount immediately changes when the graph value is changed, the difference is rapidly increased by a certain time. When the ink amount is reduced and the ink amount is reduced, the output of the ink calling roller is stopped for a certain period of time, so the time until the density stabilizes when the graph value is changed can be shortened. .

FIG. 1 is a schematic side view of a main part of an ink supply device of a printing press showing an embodiment of the present invention. FIG. 2 is a partially cutaway plan view of the ink transfer roller unit of FIG. FIG. 3 is a cross-sectional view of FIG. FIG. 4 is a block diagram showing a control device of the ink supply device. FIG. 5 is a flowchart showing a main part of the control device of the ink supply device. FIG. 6 is a diagram illustrating an example of density change.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 is a left side view schematically showing a part of an ink supply device of a printing press, FIG. 2 is a partially cutaway plan view showing an enlarged part of FIG. 1, and FIG. 3 is an enlarged cross-sectional view of FIG. FIG. In the following description, the right side of FIG. 1 and FIG. 3 (lower side of FIG. 2) is the front, the left side of FIG. 1 and FIG. 3 (upper side of FIG. 2) is the rear, and the left and right when viewed from the front are left and right. .

  As shown in FIG. 1, an ink fountain roller (41) is arranged so as to be close to the rear end portion of the ink fountain member (40), thereby forming an ink fountain (42), and an ink fountain member (40 ) And an ink path (43) having a predetermined gap is formed between the rear end portion and the surface of the ink fountain roller (41).

  The first ink kneading roller (44) of the plurality of ink kneading rollers (44) (46) is arranged behind the ink fountain roller (41), and the ink fountain roller (41) and the ink kneading roller (44) are arranged. In between, the ink calling roller unit (45) is disposed adjacent to both. As shown in FIG. 2, the roller unit (45) is an aggregate of a plurality (seven in the drawing) of ink calling rollers (15) divided in the axial direction of the rollers (41) and (44). Ink calling rollers (15) are arranged at small intervals in the axial direction. The axes of these rollers (15) (41) (44) are parallel to each other and extend in the left-right direction. The ink fountain roller (41) and the ink kneading roller (44) are rotatably supported by the frame (7) of the printing machine, and are continuously driven in the direction of the arrow in FIG. Rotated. For example, the rotation speed of the ink fountain roller (41) is about 1/10 of that of the ink kneading roller (44).

  The left and right ends of the linear support member (6) parallel to the rollers (41) and (44) are fixed to the frame (7), and a plurality of movable members (8) are attached around the support member (6). Yes. The support member (6) has a prismatic shape having a slightly larger front-rear width than a vertical width. The movable member (8) has a short cylindrical shape, and the movable member (8) is formed with a relatively large square hole (9) penetrating in the axial direction. A plurality of movable members (8) are arranged in the axial direction between a pair of short cylindrical fixed members (10) fixed to the frame (7) so as to face each other and penetrated through the support member (6). The support member (6) is passed through the hole (9) of the movable member (8). The vertical width of the hole (9) of the movable member (8) is substantially equal to the vertical width of the support member (6), and the upper and lower surfaces of the hole (9) are in sliding contact with the upper and lower surfaces of the support member (6). Further, the front and rear width of the hole (9) is slightly larger than the front and rear width of the support member (6), and the movable member (8) has a rear surface of the hole (9) with respect to the support member (6). The front end position in contact with the rear surface and the rear end position in which the front surface of the hole (9) contacts the front surface of the support member (6) can be moved back and forth. On the upper surface of the hole (9) of the movable member (8) that is in sliding contact with the support member (6), a corner groove (11) is formed over the entire length of the movable member (8).

  As will be described later, each movable member (8) is positioned in the axial direction with respect to the support member (6), and between the movable members (8) and between the fixed members (10) at both ends, A slight gap is provided in the axial direction. Therefore, each movable member (8) can move individually in the front-rear direction with respect to the support member (6).

  An inner ring of a ball bearing (12) that is a rolling bearing is fixed to the outer periphery of each movable member (8). A metal sleeve (14) is fixed to the outer periphery of the outer ring of each ball bearing (12), and a rubber thick cylindrical ink call roller (15) is fixed to the outer periphery of the sleeve (14).

  A short cylindrical dust-proof member (16) is fitted between the outer peripheries of adjacent movable members (6). The dust-proof member (16) is made of an appropriate rubber-like elastic material such as natural rubber, synthetic rubber, or synthetic resin, for example, and flange portions (16a) that slightly protrude inward are integrally formed at both ends thereof. These flange portions (16a) are fitted into annular grooves (17) formed on the outer peripheral surface of the portion near the left and right ends of the movable member (8), whereby the dustproof member (16) is moved to the movable member (8). It is fixed to. A similar dustproof member (16) is fitted between the outer peripheries of the movable member (8) at the left and right ends and the fixed member (10) adjacent thereto.

  On the support member (6) side between each movable member (8) and the support member (6), a roller position switching device (19) for switching the position of the ink calling roller (15) is provided as follows. .

  A cylinder portion (20) is formed by forming a hole extending from the front to the rear a little at the portion of the support member (6) corresponding to the axial central portion of the movable member (8), and from the rear surface to the front a little. An extended spring accommodating hole (21) is formed. The center of the cylinder part (20) and the center of the spring accommodating hole (21) are on one straight line in the front-rear direction near the center of the movable member (8) in the vertical direction. A short cylindrical piston (22) is inserted into the cylinder part (20) through an O-ring (23) so as to be slidable back and forth. A ball (24) as an urging member is slidably inserted in the spring accommodating hole (21), and a compression coil spring (25) that urges the ball backward is inserted.

  Recesses (26) and (27) are formed on the front surface of the hole (9) of the movable member (8) facing the center of the piston (22) and the rear surface of the hole (9) facing the center of the ball (24), respectively. Is formed. The width of each recess (26) and (27) in the axial direction of the movable member (8) is constant. The cross-sectional shape of each of the recesses (26) and (27) in the cross section orthogonal to the axis of the movable member (8) is uniform, and forms an arc shape centering on a straight line parallel to the axis. A taper-shaped protrusion (22a) is formed at the center of the end face of the piston (22) facing the recess (26), and the protrusion (22a) is fitted into the recess (26). Note that the length of the piston (22) excluding the protrusion (22a) is slightly shorter than the length of the cylinder part (20), so that the protrusion even when the piston (22) is most retracted into the cylinder part (20). Most of (22a) protrudes from the front surface of the support member (6). On the other hand, a part of the outer periphery of the ball (24) is fitted in the recess (27).

  At the rear part of the support member (6), the ball (24) is always brought into pressure contact with the rear surface of the hole (9) of the movable member (8) by the elastic force of the spring (25), and the ball (24) has an outer periphery. The portion is fitted into the recess (27) and is brought into pressure contact with the front and rear edges of the recess (27). On the other hand, at the front part of the support member (6), the front surface of the support member (6) or the piston (22) is brought into pressure contact with the front surface of the hole (9) of the movable member (8), and the protrusion ( Most of 22a) is in the recess (26). In this way, most of the protrusion (22a) of the piston (22) and a part of the ball (24) are always fitted in the recesses (26) and (27), so that the support member (6) The movable member (8) is positioned in the axial direction.

  The support member (6) is formed with a circular air supply hole (28) extending in the axial direction from the left end and closed in the vicinity of the right end, and the left end opening end of the hole (28) is connected through an appropriate pipe. Connected to a compressed air source (29).

  A switching valve (solenoid valve) (30) is mounted on the upper surface of the supporting member (6) facing the groove (11) of the movable member (8), and the two ports of the switching valve (30) are connected to the supporting member ( The air supply hole (28) and the cylinder part (20) communicate with each other through the communication holes (31) and (32) formed in 6). Further, the electric wire (33) of the switching valve (30) is drawn out through the groove (11) and connected to the control device (34).

  In a state where the switching valve (30) is energized (on state), the cylinder part (20) is connected to the air supply hole (28) via the switching valve (30), and in a state where the energization is stopped (off state) The cylinder part (20) is communicated with the atmosphere through the switching valve (30). Then, by individually switching the energization state of the switching valve (30) of each switching device (19) by the control device (34), the position in the front-rear direction of each ink calling roller (15) is switched individually.

  When the switching valve (30) is switched to the OFF state, the cylinder (20) is brought into communication with the atmosphere, so that the piston (22) can move freely within the cylinder (20). For this reason, the movable member (8) is moved to the rear side via the ball (24) by the spring (25). As a result, the movable member (8) and the ink calling roller (15) are switched to the rear end position (non-calling position), and the ink calling roller (15) is separated from the ink fountain roller (41) and the ink kneading roller (44 ).

  When the switching valve (30) is switched on, the cylinder part (20) communicates with the air supply hole (28) and further through the compressed air source (29), so that the cylinder part (20) is compressed. Air is supplied. For this reason, against the force of the spring (25), the piston (22) protrudes forward from the support member (6), and thereby the movable member (8) is moved forward. As a result, the movable member (8) and the ink calling roller (15) are switched to the front end position (calling position), and the ink calling roller (15) moves away from the ink kneading roller (44) and presses against the ink fountain roller (41). To do.

  A position switching detection sensor (35) composed of a magnetic sensor is fixed in an embedded manner on the lower surface of the support member (6) that is in sliding contact with the bottom wall of the hole (9) of the movable member (8), and a movable member ( A permanent magnet (36) is fixed in an embedded manner to the bottom wall of the hole (9) of 8). The lower surface of the sensor (35) is flush with the lower surface of the support member (6) or slightly inward (upper side). The upper surface of the permanent magnet (36) is flush with the bottom wall surface of the hole (9) of the movable member (8) or slightly inside (lower). In the state where the movable member (8) is switched to the rear end position, the sensor (35) is opposed to the central portion in the front-rear direction of the permanent magnet (36), and in the state where the movable member (8) is switched to the front end position, The sensor (35) is detached rearward from the permanent magnet (36). Therefore, the output of the sensor (35) varies depending on the position of the movable member (8), and the position of the movable member (8), that is, the ink calling roller (15), can be determined from the output of the sensor (35).

  The ink in the ink fountain (42) passes through the ink passage (43) and exits to the outer peripheral surface of the ink fountain roller (41). The film thickness of the ink that appears on the surface of the ink fountain roller (41) corresponds to the size of the gap of the ink passage (43), and by adjusting the size of the gap of the ink passage (43), the ink fountain roller (41 The film thickness of the ink coming out on the surface is adjusted. Usually, the size of the gap of the ink passage (43) is adjusted so that the ink film thickness becomes equal for all the ink calling rollers (15). The ink that has appeared on the outer peripheral surface of the ink fountain roller (41) is transferred to the ink call roller (15) while the ink call roller (15) is switched to the front end position, and each ink call roller (15). The ink transferred to is transferred to the ink kneading roller (44) while the ink calling roller (15) is switched to the rear end position. The ink transferred to the ink kneading roller (44) is further supplied to the printing surface via a plurality of other ink kneading rollers (46) as shown in FIG. Also, the output of the sensor (35) detects whether or not the switching of the ink call roller (15) is normal, and if the ink call roller (15) is not switched normally, an alarm is issued. It is done.

  In the printing machine, the controller (34) calls the ink by switching the position of the required ink call roller (15) at each call timing with a predetermined interval, and for each ink call roller (15), Ink to be called from the ink fountain roller (41) to the ink call roller (15) by controlling the rotation angle (contact rotation angle) of the ink fountain roller (41) from contact with the ink fountain roller (41) until it leaves. As a result, the amount of ink supplied to the printing surface is adjusted by the position in the width direction.

  The contact rotation angle is controlled by the time from the output of the switching command (contact command) to the calling position to the ink calling roller (15) until the output of the switching command (non-contact command) to the non-calling position (contact command). Time).

  When the picture to be printed is shown, the picture area ratio is read using a picture area reader, and a graph value corresponding to the ink supply amount is calculated. It is converted into the contact length with the roller (41) and used for the above-described ink supply control. The graph value is the target value of the ink amount indicating how much ink of a predetermined color is used for each ink calling roller (15), and 0% is maximum when the predetermined color is not used. When used, 100% is displayed in%. Accordingly, 30%, 40%, 10%, and the like are set according to the pattern area of the portion corresponding to each ink calling roller (15). Based on the graph value displayed in%, the calling time of the ink calling roller (15) (the contact time between the ink fountain roller (41) and the ink calling roller (15), that is, the time for turning on the switching valve (30)) is controlled. Is done. If 8 colors are used, 8 plate cylinders (8 ink call roller units (45)) are used, and the graph values are for each color (each plate cylinder = ink call roller unit (45)). Set for each ink call roller (15).

  By performing such control, the density of each color should be constant at any position, but actually, the density value is different for each ink call roller (15). Therefore, when the density is low, the graph value of each ink call roller (15) that supplies ink to this position is raised, and when the density is high, the value of each ink call roller that supplies ink to this position is increased. It is preferable to lower the graph value.

  In this embodiment, the density value is fed back by the control device (34) of the ink supply apparatus as described below, so that the density value is maintained at an appropriate value.

  FIG. 4 is a block diagram showing the control device (34) of the ink supply device. In FIG. 4, the printing press is provided with a density measuring device (50) so as to measure the density of the printed matter.

  In order to measure the density, a density measurement patch is installed on the printing plate, and the density of the portion corresponding to the patch is measured. What is necessary is just to use a well-known thing as a density | concentration measuring apparatus (50), and a density | concentration value can be calculated | required as an arithmetic mean value of the RGB component of the part made into the density | concentration measurement location. In the above ink supply device, a plurality of plate cylinders are used corresponding to a plurality of colors, and an ink call roller unit (45) as an aggregate of a plurality of ink call rollers (15) corresponding to each plate cylinder. ) Are installed, the density value is measured for each of the ink call rollers (15) of all the ink call roller units (45). The concentration measurement is preferably performed online, but may be performed offline. In any case, the obtained density value is fed back to the control device of the ink supply device in the order of printing.

  The control device (34) of the ink supply apparatus includes a density target value setting means (51), a graph value setting means (52), a density expected value calculation means (53), a graph fluctuation value calculation means (54), Control graph value calculation means (55) and switching valve on / off means (56) are provided.

  The graph value setting means (52) and the switching valve on / off means (56) are conventional parts, and the graph value setting means (52) is set with graph values for each color for each ink calling roller (15). The switching valve ON / OFF means (56) controls the ON time of the switching valve (30) (see FIGS. 2 and 3) based on the graph value.

  Conventionally, based on the graph value Gb stored in the graph value setting means (52), the ON time of the switching valve (30) in the switching valve ON / OFF means (56) is set so as to be this graph value Gb. The on / off signal is output to the switching valve (30).

  In this embodiment, the graph value Gb stored in the graph value setting means (52) is changed by the control graph value calculation means (55), and the switching valve on / off means is changed by the graph value Ga after the change. The ON time of the switching valve (30) in (56) is determined.

  The graph value Ga after the fluctuation is obtained as follows based on the measured concentration value Xn obtained by the concentration measuring device (50).

  First, the expected density value calculation means (53) obtains the expected density value Y based on a plurality of density measurement values. For example, the density changes as shown in FIG. In the illustrated example, the density is gradually decreasing, the first time, the second time, and the third time. At this stage, whether the convergence is 1.85 or 1.80, 1.75 It is unclear whether it will converge. If the target value is 1.80, and if the nth (final) expected density value Y is 1.85, the graph value may be lowered so that the density becomes lighter, and the expected density value Y is 1.75. For example, the graph value may be increased so that the density is high.

  The expected concentration value is obtained by acquiring one or a plurality of measurement values and using the plurality of measurement values.

  When the concentration is measured twice or more (n times), the expected concentration value is obtained as follows.

First, the standard deviation σ is obtained using all the measured values (X ₁ , X ₂ ,..., Xn) of n times of measurement. The average value for n times is Xa.

σ ² = {(X ₁ −Xa) ² + (X ₂ −Xa) ² +... + (Xn−Xa) ² } / n
Next, from the standard deviation σ, a deviation value T of the final (n-th) measurement value of the n measurement measurements is calculated.

T = {10 × (Xn−Xa) / σ}
By calculating this T, it is possible to determine how much the final (n-th) measured concentration is in the total measured n times.

  Next, the predicted density value Y is calculated using the predicted density coefficient α.

Y = Xn + {T × | Xn−Xa | × α
In the case of the same measurement value n times, Y = X ₁ = (X ₂ = Xn). Further, even if a single measurement, and Y = _{X 1.}

  The graph fluctuation value calculation means (54) uses the predicted density value Y to obtain the graph value as follows.

  When the ink density target value (reference value) is K, the ink excess / deficiency ratio L is calculated from the following equation.

L = (Y−K) × 100 / K (%)
Here, the graph fluctuation value Gs is calculated using the graph value correction coefficient β. The graph value before the change is Gb.

Gs = Gb × L × β ÷ 100 (%)
It becomes.

  In the control graph value calculation means (55), the changed graph value Ga is obtained by Ga = Gb + Gs. The graph value Ga after the change is used as a control graph value instead of the preset graph value Gb, and the on-time of the switching valve (30) is controlled based on the control graph value Ga. Is done.

  The density prediction coefficient α and the graph value correction coefficient β are set to 1, for example, and may be set to appropriate values empirically. The expected value can be adjusted by changing the value of α, and the graph fluctuation value can be adjusted by changing the value of β. β may be a different value between the predicted density value Y> the target density value K and the predicted density value Y <target density value K.

  By the above density correction, the density is converged to the target value. Here, depending on the case, there is a problem that it takes time to converge and it takes a long time to obtain an appropriate density (a lot of printed matter having an inappropriate density is generated). Therefore, in the control graph value calculation means (55), the temporary graph value Gz1 for one cycle is output a predetermined number of temporary cycles S times before the changed graph value Ga.

  The main part of a control program for outputting the provisional graph value Gz1 for one cycle for a predetermined number of provisional cycles S is shown in the flowchart of FIG.

  As shown in the flowchart of FIG. 5, in the graph value change control, when there is an instruction to change the graph value (S1), the temporary graph value Gz1 for one cycle and the number of cycles for executing this are set to S, Using the graph value Gb before the change, the graph value Ga after the change, and the density correction coefficient γ, the graph value difference Gs before and after the change is obtained as Gs = Ga−Gb, and the amplified ink amount Gr is set as Gr = γ × Gs. The provisional graph value Gz is obtained as Gz = Ga + Gr = Ga + (γ × Gs) (S2).

  The provisional graph value Gz1 for one cycle is obtained by Gz1 = Ga + {(γ × Gs) / ε}, assuming that the amplified ink amount Gr is output in ε cycles (S3).

  Since Gs = Ga−Gb and Ga <Gb and Ga> Gb are possible, Gz1 can be either positive or negative, and in the case of positive, provisional graph value = amplification graph value. Thus, the provisional graph value for one cycle = the supply ink amount for one cycle is a value larger than Ga. The amount of ink supplied for one cycle cannot exceed the amount of ink Gm supplied by one revolution of the ink calling roller (15). Therefore, when Gz1 is positive, it is necessary to determine whether Gz1 exceeds or does not exceed the ink amount Gm supplied by one revolution of the ink calling roller (15). When Gz1 is negative, there is no supply of negative ink amount. Therefore, the supply amount of ink amount is set to 0%, and the number of cycles for supplying 0% of ink amount is calculated according to the value of Gz1. Is done.

  First, it is determined whether Gz1 ≧ 0 (S4). If Gz1 <0, the process proceeds to step (S7). If Gz1 ≧ 0, it is determined whether Gz1 ≦ Gm ( S5). If Gz1 ≦ Gm, the provisional graph value Gz1 for one cycle is determined as Gz1 = Ga + {(γ × Gs) / ε}, and this is output for ε cycles (S6). This completes the step of tentatively amplifying the output, and then shifts to the post-change graph value that is the same as the conventional output (S9).

  In the step of determining whether Gz1 ≦ Gm (S5), if Gz1 ≦ Gm is not satisfied, that is, if Gz1> Gm, the ink call roller (15 which is the maximum amount that can supply the temporary graph value Gz1 for one cycle) ) Is the ink amount Gm (Gz1 = Gm) supplied by one round. In this case, the amplification amount of the ink amount supplied in one cycle is (Gm-Ga), and the total ink amount necessary for amplification is Gr = γ × Gs. Therefore, the cycle number S necessary for amplification is S = ([Gamma] * Gs) / (Gm-Ga) (S8). This completes the step of tentatively amplifying the output, and then shifts to the post-change graph value that is the same as the conventional output (S9).

  If Gz1 <0 in the step (S4) for determining whether or not Gz1 ≧ 0, the temporary graph value Gz1 = 0 for one cycle is set in step (S7). In this case, the amount of ink used (reduced) in one cycle is Ga, and the total amount of ink that needs to be reduced is Gr = γ × Gs. Therefore, the number of cycles S required for reduction is S = (γ XGs) / Ga. This completes the step of tentatively amplifying the output (amplifying the decrease amount), and thereafter, shifts to the post-change graph value that is the same as the conventional output (S9).

  Thus, in the ink supply device of this embodiment, the output of... Gb.fwdarw.Gz1... Gz1 .fwdarw.Ga. In the case where the ink amount is decreased even when the ink amount is increased by obtaining the provisional graph value Gz1 for one cycle and the corresponding provisional cycle number S by the above calculation in three cases. Even so, the time until the concentration is stabilized when the graph value is changed can be shortened.

  In the above flowchart, Gz1 = 0 is included in Gz1 ≧ 0, and Gz1 = Gm is included in Gz1 ≦ Gm. However, Gz1 = 0 is included in Gz1 ≦ 0. Even if the case of Gz1 = Gm is included in Gz1 ≧ Gm, exactly the same result (the values of Gz1 and S are the same) is obtained.

  In the above, the printed matter may be a thing other than paper, for example, a can.

(15) Ink call roller
(34) Control device
(41) Ink fountain roller
(42) Inkwell

Claims (1)

In the vicinity of the ink fountain roller constituting the ink fountain, a plurality of ink call rollers divided in the length direction of the ink fountain roller are arranged, and each ink call roller contacts the ink fountain roller and the ink fountain roller. It can be switched individually to a non-calling position away from the roller, and is required for each call timing at a predetermined interval based on the graph value set by the control device according to the pattern area of the printed matter. The ink call roller is switched from one ink fountain roller to the ink call roller by controlling the rotation angle of the ink fountain roller from contact with the ink fountain roller to the separation. Ink supply device for a printing press designed to control the circumference of the ink to be called Oite,
When changing the graph value from Gb to Ga (Gs = Ga−Gb), the graph value is temporarily set as Gz1, and after outputting for a predetermined number of provisional cycles, Ga is output. Is obtained by Gz1 = Ga + {(γ × Gs) / ε}, where γ is a density correction coefficient and ε is a natural number,
1. When Gz1 is positive and smaller than the ink calling roller one revolution Gm, Gz1 = Ga + {(γ × Gs) / ε} during the provisional cycle number S = ε,
2. When Gz1 exceeds Gm for one revolution of the ink calling roller, Gz1 = Gm for the provisional cycle number S = (γ × Gs) / (Gm−Ga),
3. Ink supply device for printing press, characterized in that Gz1 = 0% during temporary cycle number S = (γ × Gs) / Ga when provisional graph value Gz1 for one cycle is negative.

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