JPH04344283A - Printing device - Google Patents

Abstract

PURPOSE:To ensure that data is printed at an optimal printing density by using a control device for determining a printing density based on ink temperature and set printing speed or time required to up the resumption of a printing process in addition to the ink temperature and printing speed, and controlling the printing density to the determined level, and also using a printing density setting device which sets the density determined under the control of the control device. CONSTITUTION:CPU 31 determines an optimal stable printing density based on data on printing speed entered from a control panel 33, ink temperature from a thermister 34 and time from a previous printing finish to a printing start this time from a timer 35. Next, CPU 31 controls a drive device(printing density setting device) so that the pressure contact force of a press roller on a drum becomes a pressure contact force which corresponds to a determined printing density. A press drive device 37, based on this control, makes the pressure contact force of the press roller on the drum a value corresponding to the determined printing density. If this control is performed in the fuzzy control mode, a program volume can be reduced.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and more particularly to a printing apparatus with improved print density. [0002] As a conventional printing device, Japanese Patent Laid-Open No. 2-2
As seen in Japanese Patent No. 45371, there is a printing device equipped with a printing density adjustment mechanism corresponding to printing speed. With this print density adjustment mechanism, when the print speed information is locked, the print speed is fixed, and from then on, key input is made to the print speed setting key provided on the operation panel (print speed setting input).
Even if there is, the print density is adjusted in response to the print speed setting input. [0003] However, the above-mentioned conventional printing apparatuses do not take into account temperature changes and the time left for printing since the previous printing, which are considered factors that affect print density. Unevenness in print density inevitably occurs due to these factors. The present invention has been made in view of the above situation, and it is an object of the present invention to provide a printing apparatus that can maintain a desired print density. [0005] A printing apparatus according to claim 1 includes a setting means for setting printing speed information, a temperature measuring means for measuring the temperature of printing ink, and a setting means. and a first control means that determines the print density based on the information on the printing speed and the temperature of the printing ink from the temperature measurement means and performs control to achieve the determined print density; The present invention is characterized by comprising a print density setting means for setting the print density to the determined print density based on the control. The printing apparatus according to the second aspect of the present invention includes a setting means for setting printing speed information, a temperature measuring means for measuring the temperature of the printing ink, and a temperature measuring means for measuring the temperature of printing ink, and a temperature measuring means for measuring the temperature of printing ink from the end of the previous printing to the start of the current printing. Based on information such as the printing speed, printing ink temperature, and time from the end of the previous printing to the start of the current printing from the time measurement means for measuring time, the setting means, the temperature measurement means, and the time measurement means. a second control means that determines the print density and performs control to set the print density to the determined print density; and a print density that sets the print density to the determined print density based on control from the second control means. The present invention is characterized by comprising a setting means. A printing apparatus according to a third aspect of the present invention is characterized in that fuzzy control is applied to the determination of print density by the first control means. A printing apparatus according to a fourth aspect of the present invention is characterized in that fuzzy control is applied to the determination of print density by the second control means. [Operation] In the printing apparatus configured as described above, the first control means is configured to control the printing speed based on the printing speed information from the setting means for setting the printing speed information and the printing ink temperature information from the temperature measuring means. The printing density is determined, and control is performed to achieve the determined printing density. The print density setting means sets the print density to the determined print density based on the control from the first control means. The second control means also receives the printing speed information from the setting means for setting the printing speed information, the printing ink temperature information from the temperature measuring means, and the previous print end information from the time measuring means. The print density is determined based on the time information from the time to the start of the current printing, and control is performed to achieve the determined print density. The print density setting means sets the print density to the determined print density based on the control from the second control means. [0011] Thereby, it is possible to print at the optimum print density according to the printing speed, the temperature of the printing ink, and the standing time (the time from the end of the previous printing to the start of the current printing). Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a simplified explanatory diagram showing the configuration of an embodiment of the printing apparatus of the present invention, and FIG. 2 is a simplified explanatory diagram of the main part of FIG. In FIG. 1, reference numeral 1 denotes a document placed at a predetermined position at the top, and this document 1 is transported by a transport mechanism (not shown) and moved over a fluorescent lamp 2 placed on the left side of the top.
The document is ejected to the document tray 3 on the left side. At this time, the light from the fluorescent lamp 2 illuminates the surface of the document 1, and the reflected light is input to the CCD imaging device 6 via the mirror 4 and lens 5, where it is photoelectrically converted. The image signal photoelectrically converted by the CCD imaging device 6 of the image scanner section is supplied to the printer section. In the printer section, a conveyance roller drive motor (not shown) is driven, the conveyance roller is rotationally driven, and the master 7 is sent out toward the drum 8 . Then, in the printer section, the master 7 is combed by a thermal head 9 in accordance with the supplied image data, and the image data is sequentially written on the master 7, while the written master 7 is wound around the drum 8 one after another. The master 7 that was used for the previous printing and was wrapped around the drum 8 is stripped off by a discard mechanism (not shown) and sent to the left in accordance with a command from the CPU 31 in FIG. Will be discarded. Next, the master 7 to which the image data has been written
When wrapped around the drum 8, it is placed on the paper feed table 10,
The printing paper 12 whose both sides are positioned by the paper feed side plates 11 is taken in by the paper feed roller 13, and is fed between the master 7 wound around the peripheral surface of the drum 8 and the press roller 15 via the separation roller 14. go. The press roller 15 constitutes a press drive device (not shown) as a printing density setting means, is driven by a motor of the press drive device, and is driven by a drum 8.
This is to set the pressure contact force to the set pressure contact force. [0015] Also, an ink pack 16 containing ink is provided.
A cylindrical rod 18 whose one end is connected to the drum 8 via a connecting member 17 and whose other end is closed is disposed in the center of the drum 8 in the axial direction of the drum 8. This rod 18 has holes formed at regular intervals so that ink 19 from the ink pack 16 drips through the holes. Inside the drum 8, as shown in FIG. 2(a), an ink roller 23 and a gap adjustment roller 24 connected to the ink roller 23 are disposed. The ink roller 23 is disposed so that its outer circumferential surface contacts the inner circumferential surface of the drum 8, and is rotatable around a central axis. Further, the gap adjustment roller 24 extends along the generatrix direction of the ink roller 23 with a predetermined gap d from the outer circumferential surface of the ink roller 23, and the gap adjustment roller 24 is rotated with the rotation of the drum 8. The ink 19 dripped from the holes of the rod 18 is rotated in the same direction as the drum 8.
is supplied to the inner peripheral surface of the drum 8 through the gap d. That is, the ink 19 dropped from the hole of the rod 18
As the ink roller 23 rotates, this ink roller 2
3 and the gap adjustment roller 24, the ink is metered at that time and forms a printing ink layer of uniform thickness on the outer peripheral surface of the ink roller 23, and this printing ink layer is As the drum 23 rotates, it is supplied to the inner peripheral surface of the drum 8. FIG. 2(b) shows the inner peripheral surface of the drum 8.
The screen 22 is inserted through the hole 20 of the stainless steel member 21 of
It penetrates into the paper and is used for printing. As shown in FIG. 2(b), the outer peripheral portion 8a of the drum 8 is made of a stainless steel member (made of SUS0.2) in which holes 20 of φ0.3 to φ0.5 are opened at regular intervals.
21 and a screen 22 on the peripheral surface thereof, and the master 7 is wound around the peripheral surface of the screen 22 on the outer peripheral portion 8a as shown in the figure. At the center of the drum 8 is a press drive device (not shown) for pressing the printing paper 12 onto the drum 8.
is provided. In the present invention, as described later, FIG.
The CPU 31 determines the optimum stable printing density based on the temperature of the ink 19 and the set printing speed information, or based on these and the standing time (the time from the end of the previous printing to the start of the current printing). is determined, and the press drive device is controlled to achieve the determined printing density, and therefore to set the pressing force F of the press roller 14 against the drum 8 to a pressing force corresponding to the determined printing density. The press drive device is
Under the control of the CPU 31 in FIG. 3, the pressing force of the press roller 15 against the drum 8 is controlled to correspond to the printing density information. Mask 7 with image data written
is fed toward the drum 8, and a portion of the tip of the master 7 is clamped by a clamp mechanism (not shown). The master 7 is then wound around the outer peripheral surface of the drum 8. Next, after ink is applied to the master 7 from the outer circumferential surface of the drum 8, printing is performed by pressing the printing paper 12 against the outer circumferential surface of the drum 8 around which the master 7 is wound by the pressing force of the press roller 15. There is. As a result, the optimum printing density is achieved in accordance with the temperature of the ink 19, printing speed information, and standing time. [0020] It should be noted that the printed printing paper 1 on which printing has been completed
When the paper sheets 1 are peeled off from the drum 8 by a paper peeling claw (not shown), they are sent to the lower left side in FIG. Ru. FIG. 3 is a block diagram of the electrical configuration of an embodiment of the printing paper shown in FIG. In the figure, numeral 31 is a CPU serving as a first control means and a second control means of the present invention. 32 is a ROM in which programs for controlling various mechanisms within the printing apparatus are stored. Reference numeral 33 denotes an operation panel provided with printing speed setting keys and the like as printing speed information setting means of the present invention. 34 is a thermistor provided on the rod 18 for measuring the temperature of the ink, and the thermistor 34 constitutes the temperature measuring means of the present invention. The thermistor 34 may be provided in the ink pack 16. Further, 35 is a timer as a time measuring means for measuring the time from the end of the previous printing to the start of the current printing (referred to as the standing time). When the rotation of the drive motor of the drum 8 stops due to the end of the previous printing, the timer 35 starts operating in conjunction with this, and then when the start button on the operation panel 33 is turned on due to the start of the current printing. By resetting the timer 35, the idle time is measured. Further, 36 is a RAM that stores printing speed information set by the printing speed setting key, the standing time measured by the timer 35, ink temperature information measured by the thermistor 34, etc. as needed. Further, 37 is a press drive device as a printing density setting means. The CPU 31 determines the printing density based on the printing speed information set by the printing speed setting key, the ink temperature information measured by the thermistor 34, and the standing time measured by the timer 35, and prints the determined printing density. In order to achieve the desired density, the press drive device 37 is controlled so that the pressing force F of the press roller 15 against the drum 8 corresponds to the determined printing density information. The CPU 31 is connected via a bus 38 to the aforementioned ROM 32, operation panel 33, thermistor 34, timer 35, RAM 36, press drive device 37, and other various devices (not shown). Next, the operation of the printing apparatus will be briefly explained using FIGS. 1 to 3. First, the original 1 is placed at a predetermined position on the top of the printing device. Next, the printing speed is set using the printing speed setting key provided on the operation panel 33. Next, the start button provided on the operation panel 33 is turned on. As a result, based on a command from the CPU 31, the master 7 used for the previous printing and wrapped around the drum is released from the clamped state, and is peeled off from the outer peripheral surface of the drum 8 by a peeling mechanism (not shown). , are discarded in the reject box 26. In addition, CPU31
is optimally stabilized by fuzzy control, which will be described later, based on the set printing speed information entered using the printing speed setting key on the operation panel, the ink temperature information from the thermistor 34, and the standing time information from the timer 35. Determine the print density. A transport roller drive motor (not shown) is driven by a command from the CPU 31, and the feed roller is rotationally driven. sent to. Then, the leading end of the master 7 is clamped by a clamp mechanism (not shown), and the drum drive motor is driven by a command from the CPU 31. Then, the drum 8 is driven to rotate clockwise, and the master 7 is wound around the outer peripheral surface of the drum 8. Further, when the start button is turned on, the fed printing paper 12 is supplied to the outer peripheral surface of the drum 8 and passed between the wrapped master 7 and the press roller 15. Next, the CPU 31 controls the press drive device 37 so that the pressing force of the press roller 15 against the drum 8 is set to a value corresponding to the determined printing density so that the printing process with the determined printing density is executed. . The press drive device 37 is C
Based on the control of the PU 31, the printing pressure of the ink roller 23 and the press roller 15, that is, the pressing force of the press roller 15 against the drum 8, is set to a value corresponding to the determined printing density. In this way, under the control of the CPU 31, the drum 8 and the press drive device 37 (press roller 15) are driven, the paper feed mechanism, the ink roller 23, etc. are operated, and printing is performed. The operation of the printing apparatus has been described above. Next, how the CPU 31 determines print density using fuzzy reasoning will be described in detail below. As described above, the CPU 31 uses the set printing speed information, ink temperature information, and standing time information to
Optimal and stable printing density (I/D) through fuzzy reasoning
Determine. Based on the determined printing density information, the printing pressure of the press roller 15 (pressing force F of the press roller 15 against the drum 8) corresponding to the determined printing density is determined. First, the "suitable temperature" for the printing device
, "low" and "high" are as shown in FIG. 4, and the contents of FIG. 4 are stored in the ROM 32 in advance. Further, the relationship between temperature and print density is as shown in FIG. 5, and this relationship is stored in the ROM 32 in advance. Also,
The relationship between printing speed and printing density is as shown in Figure 6.
This relationship is stored in the ROM 32 in advance. Further, the ranges of "moderate", "light" and "dark" in printing density are as shown in FIG. 7, and the contents of FIG. 7 are stored in the ROM 32 in advance. In addition, the ranges of "low speed", "medium speed", and "high speed" in the printing speed are as shown in FIG. 8, and the contents of FIG.
It is stored in 32. The relationship between the pressure applied by the press roller 15 (abbreviated as printing pressure) and the printing density is as shown in FIG. 9, and this relationship is stored in the ROM 32 in advance. Further, the printing pressure of the press roller 15 and the degree of the printing pressure are shown in FIG.
The contents of FIG. 10 are stored in advance in the ROM 32.
is stored in. (A) First, the CPU 31 determines the printing speed (V)
The optimum stable printing density is determined based on the temperature (T) and the press roller 15 corresponding to the determined printing density.
The printing pressure (pressing force of the press roller 15 against the drum 8) is determined as follows. The printing pressure adjustment rule based on the combination of printing speed (V) and temperature (T) is as shown in FIG. 11, and the table shown in FIG. 11 is stored in the ROM 32 in advance. The printing pressure adjustment rules shown in FIG. 11 can be expressed as the following nine fuzzy rules. IF T=C AND V=L THEN
PF=Z IF T=C AND V=M
THEN PF=S IF T=C AN
D V=H THEN PF=vS IF
T=G AND V=L THEN PF=W
IF T=G AND V=M THEN
PF=Z...(1) I
F T=G AND V=H THEN P
F=S IF T=H AND V=L T
HEN PF=vW IF T=H AND
V=M THEN PF=W IF T=H
AND V=H THEN PF=Z 00
39] The printing pressure adjustment rule shown in FIG. 11 is a rule for stably maintaining printing density in a stable region, and if printing processing is performed according to this rule, printing can be performed at an optimum and stable printing density. Therefore, you don't have to worry about anything else by following this rule (resolving the trade-off relationship). Next, as a specific example, the optimum press roller 1 for printing at an ink temperature of 15°C and a printing speed of 5 will be described.
The case of calculating the printing pressure of No. 5 will be explained below. First, the CPU 31 selects a fuzzy rule to be applied using the membership functions shown in FIGS. 4 and 8 stored in the ROM 32 as follows. In other words, if the ink temperature is 15°C, the appropriate temperature (G
) is 0.7 and the grade low (C) is 0.3.
...(2) The grade of high (H) is determined as 0. On the other hand, printing speed 5 is determined by the membership function shown in FIG. 8, as shown in FIG.
High speed (H) grade is 1 Medium speed (M) grade is 0
...(3
) The low speed (L) grade is determined as 0. Next, the CPU 31 calculates (2), (3)
By applying this relationship to the table of FIG. 11 stored in the ROM 32, the corresponding IF-THEN rule is determined as follows. That is, in the table of FIG. 11, (2), (3
), the round frame parts 41 to 43 shown in FIG. 14 are considered, and the round frame parts 41 and 42 and the round frame part 43
The overlapping parts (shaded parts in the figure) 44 and 45 are the applicable parts. Expressing these overlapping parts 44 and 45 using the IF~THEN rule, IF T=C AND V=H THEN
PF=VS...(4) IF
T=G AND V=H THEN PF=S
It will be like this. These two rules (two of the nine rules shown in (1) above) are applied to this specific example. Therefore, the CPU 31 performs IFT
=C(0.3) AND V=H(1)
THEN PF=VS(0.
3×1) ...(5) IF
T=G(0.7) AND V=H(1)
THEN PV=S(0
．． 7×1) is obtained as the output value. Next, the CPU 31 converts the output value of (5) into R
Using the relationship shown in FIG. 10 stored in the OM 32, the points are concentrated at one point (determining the center of gravity) as follows. That is, strongly (
The center of gravity of S)=0.7 and very strongly (VS)=0.3 is determined from the relationship shown in FIG. 15 using the following equation (6). PF (printing pressure) = 18 x 0.7 + 21 x 0.3/0.
7+0.3 =18.9(
kg)
...(6) [0045] Therefore, C
The determined output determined by the PU 31, that is, the printing pressure (PF) of the press roller 15 is 18.9 kg, and this determined output is the value at the position indicated by the arrow 46 in FIG. (B) Next, the CPU 31 determines the printing speed (V)
In addition to temperature (T) and standing time, the optimum stable printing density is determined, and the optimum pressure applied to the press roller 15 (press roller 1
The optimum pressing force F) for the drum 5 to be applied to the drum 8 is determined as follows. That is, the coefficient m of the maximum applied pressure of the press roller 15 and the coefficient k of the maximum applied pressure of the press roller 15 in the normal state are determined based on the length of the standing time and the number of sheets printed, and from these results, the coefficient m of the maximum applied pressure of the press roller 15 in the normal state is determined. The pressure applied to the press roller this time is determined in the following manner. The relationship between the standing time and the coefficient is as shown in FIG. 17, and this relationship is stored in the ROM 32 in advance. Further, the applicable range of the leaving time is as shown in FIG. 18, and the contents of FIG. 18 are stored in the ROM 32 in advance. Also, the applicable range in terms of the number of sheets printed is shown in Figure 19.
The contents of FIG. 19 are stored in the ROM 32 in advance. Further, the fuzzy rule of the coefficient k of the stable region result based on the combination of the standing time (ST) and the number of sheets printed (N) is as shown in FIG. 20, and the table of FIG. 20 is stored in the ROM 32 in advance. [0049] In the table of Fig. 20, the number of printed sheets is "
"Very many" means, for example, 40 or more. The number of sheets printed (N) is "Low (L)", "Normal (M)", "
The relationship between the amount of time (B) and the standing time (ST) is expressed as IF~TH.
Expressed using EN rules, it is as follows. IF N=L AND ST=S THE
N k=I IF N=L AND ST=
M THEN k=lI IF N=L A
ND ST=L THEN k=Z IF
N=M AND ST=S THEN k=v
I IF N=M AND ST=M TH
EN k=I...(7)
IF N=M AND ST=L THEN
k=lI IF N=B AND ST=S
THEN k=vvI IF N=B A
ND ST=M THEN k=vI IF
N=B AND ST=L THEN k=
Further, the coefficient k and its degree of the stable region result obtained from FIG. 20 are as shown in FIG. The contents of FIG. 21 are stored in the ROM 32 in advance. [0051] Next, the coefficient k of the stable region result when the standing time is taken into consideration in addition to the printing speed and temperature described above is determined as follows. That is, based on the standing time and the number of sheets printed, the coefficient k of the above-mentioned stable region result is determined using the membership functions shown in FIGS. 18 and 19 and the fuzzy rule shown in FIG. The coefficient k obtained from FIG. 20 is applied to FIG. 21 to obtain the value k1 of k. Next, press roller maximum applied pressure (
Using m=1-k, the coefficient m of full power) is m=1-
Find it as k1. The applied pressure (PF) of the press roller 15 in the normal state determined in the above-mentioned specific example is 18.9 kg,
The coefficient k1 of the stable region result obtained as above and the maximum applied pressure (full power) of the press roller (here 23k
g) and the coefficient m1 of the full power obtained as described above, the center of gravity is obtained as in the following equation (8) in the same manner as described above. PF (printing pressure) = (23 x m1) + (18.9 x k1
) /m1+k1

...(8) [0052] In this way,
The pressure applied by the press roller 15 (pressing force of the press roller 15 against the drum 8) (PF) is applied every time one sheet is printed. Depending on the number of sheets printed, the value of k (k1
) is found, the value of m (m1) is found, and these m
1, k1 into equation (8) and press roller applied pressure (
This is because PF) can be found. However, as the number of printed sheets increases, k=vv1 from FIGS. 19 and 20, and k=vv1(1) from FIG. 21, that is, k1=1, m1
= 0, and only the calculation results in the stable region are available. Cases (A) and (B) have been described above, but in this embodiment, according to the flowchart of FIG. 16, the press roller corresponding to the optimum and stable printing density is Find the applied pressure (PF). The program for the processing flow in FIG. 16 is stored in advance in the ROM3.
It is stored in 2. The CPU 31 executes the method (A) or (B) for determining the pressure applied to the press roller according to the program of the processing flow shown in FIG. 16 stored in the ROM 32. That is, it is checked whether printing is to be performed immediately after cutting (step S1), and if printing is to be performed immediately, the pressure applied to the press roller (PF) is determined according to the stable region algorithm described in (A) above (step S2). . In addition, even if printing is not done immediately after cutting (if it has been left unattended since the previous printing finished), if the unattended time is less than 1 hour (referred to as 1H), press according to the stable region algorithm in (A) above. Roller applied pressure (P
F) is determined (steps S1, S2, S3). Also, if you do not print immediately after cutting (if you leave it unattended),
If the standing time is 1 H or more, the pressure applied to the press roller (PF) is determined according to the above-mentioned leaving algorithm (B) (including the stable region algorithm) (steps S1, S3, S4). The CPU 31 controls the press drive device 37 so that the pressure applied to the drum 8 by the press roller 15 is equal to the pressure applied to the press roller (PF) determined as described above. This makes it possible to print at an optimal and stable printing density. In this embodiment, the CPU 31 adjusts the pressure applied to the press roller in order to obtain an optimum and stable printing density, but the present invention is not limited to this.
The CPU 31 controls the press drive device 37 to shift the position of the press roller 15, and as shown in FIG. Alternatively, the pressure applied to the press roller may be adjusted in conjunction with the adjustment of the offset amount a. [0056] As described above, by using the printing apparatus of the present invention, the following effects can be obtained. (1) Print at an optimal and stable print density that matches the printing ink temperature and set printing speed, or these and the standing time (time from the end of the previous printing to the start of the current printing). be able to. (2) The first control means is based on the set printing speed information and printing ink temperature information, and the second control means is based on the set printing speed information, printing ink temperature information, and standing time information. In each case, the printing density setting means is controlled in order to achieve the optimum and stable printing density, but by performing this control using fuzzy control, past experience and knowledge can be easily established as a rule, and the program volume can be reduced. Can be done cheaply.

[Brief explanation of drawings]

FIG. 1 is a simplified explanatory diagram showing the configuration of an embodiment of a printing apparatus according to the present invention.

FIG. 2 is a simplified explanatory diagram of the main parts of FIG. 1;

FIG. 3 is a block diagram showing the electrical configuration of the printing apparatus shown in FIG. 1;

FIG. 4 is a diagram showing an applicable temperature range for a printing device.

FIG. 5 is a diagram showing the relationship between temperature and print density.

FIG. 6 is a diagram showing the relationship between printing speed and printing density.

FIG. 7 is a diagram showing the applicable range of printing density.

FIG. 8 is a diagram showing the applicable range of printing speeds.

FIG. 9 is a diagram showing the relationship between the applied pressure of the press roller 15 and print density.

FIG. 10 is a diagram showing the applied pressure of the press roller 15 and the degree of the applied pressure.

FIG. 11 is a diagram showing fuzzy rules for adjusting applied pressure based on a combination of printing speed (V) and temperature (T).

12 is a diagram showing how to determine the grade at a temperature of 15° C. from the membership function of FIG. 4. FIG.

13 is a diagram showing how to obtain a grade at a printing speed of 5a from the membership function of FIG. 8. FIG.

FIG. 14 is a diagram illustrating how to select a corresponding adaptive rule from the table of FIG. 11;

15 is a diagram illustrating a method of determining the pressure applied to the press roller using FIG. 10. FIG.

FIG. 16 is an operation flowchart showing the configuration of an embodiment of the printing apparatus shown in FIG. 1;

FIG. 17 is a diagram showing the relationship between the standing time and the coefficient.

FIG. 18 is a diagram showing the applicable range in terms of the standing time.

FIG. 19 is a diagram showing the applicable range based on the number of printed sheets.

FIG. 20 is a diagram illustrating fuzzy rules for stable area result coefficients based on combinations of standing time and number of sheets printed.

FIG. 21 is a diagram showing coefficients of stable region results and their degrees.

FIG. 22 is a diagram showing the applied pressure of the press roller 15 and the degree of the applied pressure when determining the center of gravity.

[Explanation of symbols]

1 Manuscript 6 CCD imaging device 7 Master 8 Drum 9 Thermal head 12 Printing paper 15 Press roller 23 Ink roller 31 CPU 32 ROM 33 Operation panel 34 Thermistor 35 Timer 36 RAM 37 Press drive device

Claims (4)

[Claims] 1. Setting means for setting printing speed information, temperature measuring means for measuring the temperature of printing ink, and information on the printing speed and the temperature of the printing ink from the setting means and the temperature measuring means. a first control means that determines the print density based on and performs control to achieve the determined print density, and based on the control from the first control means,
1. A printing apparatus comprising: a print density setting means for setting a print density to the determined print density. 2. Setting means for setting printing speed information, temperature measuring means for measuring the temperature of printing ink, and time measuring means for measuring the time from the end of the previous printing to the start of the current printing. and the printing density is determined based on each information of the printing speed, the temperature of the printing ink, and the time from the end of the previous printing to the start of the current printing from the setting means, the temperature measuring means, and the time measuring means. , a second control means that performs control to achieve the determined print density;
A printing apparatus comprising: a print density setting means for setting the print density to the determined print density based on control from the second control means. 3. The printing apparatus according to claim 1, wherein fuzzy control is applied to the determination of printing density by the first control means. 4. The printing apparatus according to claim 2, wherein fuzzy control is applied to the determination of printing density by the second control means.