JPH11115172A - Ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet printer which is capable of preventing an ink from bleeding at the time of lamination. SOLUTION: The entire area of an image formation face on a paper is divided into 8×8 dots of reference area for decision based on entered image data and assigned positions for these areas are initialized (S1, S2). Then the image data for the reference area is extracted from the sets of the entered image data with regard to the reference area for decision (S3). Further, the number of dots to which an ink is actually discharged based on the image data worth the reference area for decision of the extracted 64 dots, is detected and thereby, the gross amount of the ink is detected (S4). It is interpreted whether the detected gross amount of the ink is less than a specified amount (S5). When the decision results of this step S5 are negative, a corrective processing by which the amount of the ink for dots reaches a desired amount level is performed until the decision results are affirmative (S6). Thereafter, an image is formed and a lamination process is performed (S9, S10).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer which forms a desired image on a recording medium such as paper by discharging ink from nozzles of a recording head, and more particularly to an ink jet printer for laminating an image forming surface. Regarding what prevents bleeding.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer that heats and melts a solid ink and discharges the melted ink from a recording head onto a recording medium such as paper to form a desired image has been known.
As shown in FIG. 10, the discharged ink 1 is the recording medium 2
When the ink 1 adheres, the temperature of the ink 1 immediately drops,
Solidifies before the dot diameter of the recording medium expands to a predetermined size. If the surface of the recording medium is rubbed with a nail or the like in this state, the solidified ink 1 is scraped, and image quality is impaired. Disadvantages occur.

Therefore, as shown in FIG. 11, the recording medium 2 on which the ink 1 has adhered and solidified is reheated to re-melt the adhered ink 1 or the solidified ink 1 is pressurized. It is common practice to smooth the ink 1 on the recording medium 2 and enlarge the dot diameter to a predetermined size, and then fix the attached ink 1. Various methods of reheating at this time have been proposed.For example, when ejecting ink, a platen arranged in contact with the back side of the recording medium is preheated, or a heat platen for fixing is disposed downstream of the recording head. There is a method of disposing a heater.

On the other hand, in the case of a recording medium having an image for a display installed outdoors, it is necessary to ensure weather resistance. Therefore, as shown in FIG. The laminating material 3 is laminated on the image forming surface. Since such lamination is usually performed by heating and pressing the laminating material 3, it has been conventionally proposed to simultaneously fix the above-described ink 1 at the lamination stage.

[0005]

However, when the laminating of the laminating material 3 and the fixing of the ink 1 are performed at the same time, the printing duty, that is, the total number of dots in the reference area having the size of m dots.times.n dots is reduced. Because heating and pressurization are performed regardless of the ratio of the number of print dots,
Ink 1 in the large print duty area and the small print duty area
In particular, since the total amount of ink in the region where the print duty is large is large, the spread of the ink 1 exceeds the expectation when heating and pressurization are performed uniformly. Bleeding may occur, leading to a reduction in image quality.

Conversely, it is conceivable to reduce the heat and pressure applied during lamination so that the ink 1 does not spread more than expected. However, in such a case, the lamination may be defective and sufficient weather resistance may not be obtained. Therefore, the heat and pressure applied during lamination cannot be reduced more than necessary.

An object of the present invention is to prevent bleeding of ink at the time of lamination.

[0008]

According to the first aspect of the present invention, there is provided an ink jet printer which discharges ink from nozzles of a recording head to form a desired image on a recording medium such as paper. In particular, an image forming surface dividing unit that divides an image forming surface of the recording medium into regions each having a predetermined size, and each of the regions divided by the image forming surface dividing unit is ejected to the region. An ink total amount detecting means for detecting the total amount of the ink, a specified amount storing means for storing a specified amount of ink to be ejected when the image forming surface is laminated, and the total amount detected by the ink total amount detecting means The total ink amount determining means for determining whether or not is less than the specified amount stored in the specified amount storage means, and the total ink amount determining means,
When the total amount is determined to be not less than the prescribed amount, an ink total amount correcting unit for correcting the total amount to a desired amount is provided.

According to this configuration, when laminating the image forming surfaces, the total amount of ink ejected to the area divided by the image forming surface dividing means is not less than the specified amount stored in the specified amount storage means. In this case, the total amount is corrected to a desired amount by the total ink amount correction unit.

Therefore, even if lamination is performed without lowering the heat and pressure applied during lamination, lamination can be performed without causing bleeding of ink as in the related art, and lamination and fixing of ink can be performed simultaneously.

In the ink jet printer according to the present invention, the specified amount and the desired amount are substantially the same.

According to such a configuration, the total amount of ink ejected to the area divided by the image forming surface dividing means is corrected to an amount substantially equal to the specified amount stored in the specified amount storage means.

According to a third aspect of the present invention, in the ink jet printer, the desired amount is set to about 70 to 100 of the total amount.
%.

According to such a configuration, it is possible to perform lamination in a substantially optimum state without bleeding of ink.

According to a fourth aspect of the present invention, in the ink jet printer, the total ink amount correcting means stops the discharge of the ink corresponding to some of the recording dots in the area. It is characterized by having stopping means.

According to such a configuration, of the recording dots in the area divided by the image forming surface dividing means,
The ejection of ink of some of the recording dots is stopped by the ink ejection stopping means, and the total amount of ink is corrected.

Further, the ink jet printer according to the present invention is characterized in that the total ink amount correcting means includes a dot ink amount correcting means for correcting the ink amount per recording dot.

According to such a configuration, the ink amount per recording dot is corrected by the dot ink amount correcting means for all the recording dots in the area divided by the image forming surface dividing means.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 is a schematic diagram showing the entire configuration of the ink jet printer, FIG. 2 is a block diagram of a control system, FIG. 3 is a partial functional block diagram of FIG. 2, FIG. 4 and FIG. 8 are operation explanatory diagrams.

As shown in FIG. 1, a paper 11 as a recording medium is wound around a supply roll 10 in a roll shape, and the paper 11 fed out of the roll 10 is placed around an outer periphery of a main roller 12 called a platen. The ink is ejected from the nozzles of the recording head 14 onto the paper 11 that is wound around substantially half the circumference and wound around the main roller 12. At this time, one dot corresponding to one pixel constituting an image is formed by ink ejected from the nozzles of the recording head 14 on the paper 11, and based on such data for each pixel of the image to be recorded, the head The controller 15 controls the ejection and non-ejection of ink from the recording head 14 so that a desired image is formed on the paper 11.

A laminate film 18 is wound around the film roll 17 in a roll form, and the laminated film 18 unwound from the film roll 17 is guided by a heat roller 19 and laminated while being guided by the heat roll 19. The film 18 is heated to a predetermined temperature, and the sheet 11 guided by the guide roller 20 and the laminated film 18 superposed on the image forming surface of the sheet 11 are sandwiched by a pair of laminating rollers 21 to form an image of the sheet 11. The heated laminate film 18 is laminated on the forming surface.

Next, the configuration of the control system will be described.
As shown in FIG. 2, image data input from a personal computer or the like is temporarily transferred to an image memory 2 via an image data input interface (hereinafter, referred to as an input IF) 25.
The image data is read from the image memory 26 by the CPU 27 at the time of printing, and is read by the CPU 27 to the recording head 14 via an image data output interface (hereinafter referred to as an output IF) 28. Image data is output.

Further, under the control of the CPU 27, the actuator driver 30 is controlled to drive various motors such as a timing belt driving motor for moving the recording head 14, and the recording head 14 is moved in the recording direction based on image data. Then, ink is ejected from the nozzles of the recording head 14 in accordance with the image data, and a desired image is formed on the paper 11.

The ROM 31 stores, in addition to a main program relating to printing, various control programs such as a total ink amount control program for controlling the total amount of ink, and a RAM 32 stores output dot data corresponding to image data. An image data buffer to be stored, a specified amount buffer as a specified amount storage means for storing a specified amount of ink in a determination reference region which does not cause ink bleeding when the image forming surface of the paper 11 is laminated, and a control of the total amount of ink And a buffer for storing the result of the operation by the CPU 27 in. Incidentally, 33 is an internal bus.

Now, the functional configuration of the CPU 27 will be described. As shown in FIG. 3, an image forming surface dividing section 35 divides the image forming surface of the paper 11 into a predetermined number of, for example, 8 × 8 dot determination reference regions. And an ink total amount detection unit 36 for detecting the total amount of ink ejected to the judgment reference region for each judgment reference region divided by the image forming surface division unit 35, and an ink total amount detected by the ink total amount detection unit 36. Total ink amount determination unit 3 that determines whether the amount is equal to or less than a specified amount stored in a specified amount buffer of RAM 32.
And an ink discharge stop function for stopping the discharge of ink corresponding to some of the 8 × 8 dots in the determination reference area when the total ink amount determination unit 37 determines that the total ink amount is not less than the specified amount. And an ink total amount correction unit 38 for correcting the total amount of ink to a desired amount.

At this time, the amount of ink correction by the total ink amount correction section 38 differs between a paper-based medium and a film-based medium as shown in Tables 1 and 2, for example. It is set in advance by parameters such as the feeding speed, the pressing force of both laminating rollers 21, and the surface temperature of the recording medium after ink ejection. In the case of paper, as shown in Table 1, 0 to 2 depending on the surface temperature of the paper-based recording medium.
The total ink amount is corrected with a correction amount of 5%, and in the case of a film system, as shown in Table 1, the total ink amount is corrected with a correction amount of 0 to 30% depending on the surface temperature of a film-based recording medium. Is corrected, and the total ink amount after the correction is controlled to be 100 to 70% before the correction.

[0027]

[Table 1]

[0028]

[Table 2]

However, in both Tables 1 and 2, the feeding speed of the recording medium is 1 to 3 m / min.
Pressure of 0.2 to 0.5 megapascal (= 10 ⁶
In the case of N / m ² ), the ink correction amount for each surface temperature of the recording medium after ink ejection, that is, the amount of ink to be thinned out from the total ink amount in a steady state is expressed as a percentage.

The specified amount stored in the specified amount buffer of the RAM 32 is set to, for example, an ink amount equivalent to 75% of a reference area of 8 × 8 dots (= 64 dots). Further, in the present embodiment, the desired amount of the total ink amount corrected by the total ink amount correction unit 38 is set to 75%, which is the same as the specified amount.

Then, the image forming surface dividing unit 3 of the CPU 27
In the case where the total amount of ink ejected to each area is determined for each of the determination reference areas divided by 5, the number of dots where ink is ejected is detected by the total ink amount detection unit 36, and the total amount of ink is detected by the total ink amount determination unit 37. The total amount of ink in the criterion area depends on whether or not the number of dots is 48 dots (= 64 dots × 0.75) or less.
A determination is made as to whether the value is equal to or less than the specified amount stored in the specified amount buffer 33.

Next, the operation of the above-described ink jet printer will be described with reference to the flowcharts of FIGS.

FIG. 4 shows a main routine of the printer. As shown in FIG. 4, when image data is first input from a personal computer or the like (step S1).
The entire area of the image forming surface of the sheet 11 is divided by the image forming surface dividing unit 35 into the 8 × 8 dot (= 64 dots) determination reference area. That is, as shown in FIG. 6, one end of the image forming surface of the X dots × Y dots of the paper 11 is set as the first allocation position (step S).
2) The necessity of the correction of the ink amount is determined for the determination reference area at the set first allocation position as described in detail below, and thereafter, the second determination is sequentially performed in the arrow direction in FIG. , The third,..., Nth allocation positions are set, and the necessity of correcting the ink amount is determined.

Then, for the judgment reference area (= 64 dots) of the first allocation position, image data of the judgment reference area is extracted from the input image data (step S3), and the extracted 64 dots are obtained. The number of dots where ink is actually ejected is detected by the ink total amount detection unit 36 based on the image data for the determination reference area (step S4), and the detected total amount of ink is stored in the specified amount buffer of the RAM 32. It is determined whether the amount is equal to or less than the amount (step S5). This determination is made based on whether or not the number of ejected dots of ink detected by the total ink amount detection unit 36 is equal to or less than 48 dots, as described above.

If the decision result in the step S5 is NO, a correction process of the ejection ink amount described later is performed (step S6), and if the decision result in the step S5 is YES,
After the process of step S6, the process proceeds to step S7, and it is determined whether the setting of the allocation position of the determination reference region for the entire area of the image forming surface and the determination of the necessity of correcting the ink amount have been completed ( Step S7) If this determination result is NO, it is determined that the processing for the entire area of the image forming surface has not been completed, and the allocation position of the next determination reference area is calculated (Step S8), and then Step S3 is performed.
Return to

On the other hand, if the decision result in the step S7 is YES, it is determined that the processing for the entire area of the image forming surface is completed, and the ink is ejected from the recording head 14 to form an image on the paper 11 based on the image data. (Step S
9), a laminate film 18 on the image forming surface of the paper 11
Are laminated (step S10), and the operation ends.

Next, a description will be given of the correction processing of the discharge ink amount. As shown in FIG. 5, a filter processing using a predetermined filter is performed (step S20). The calculation of the total amount of ink, that is, the calculation of the number of dots for ejecting ink is performed (step S21), and the corrected total amount of ink is stored in the specified amount buffer of the RAM 32 according to whether the calculated number of discharge dots of ink is 48 dots or less. It is determined whether or not the stored amount has become equal to or less than the specified amount (step S22). If the determination result is NO, the process returns to step S20 again, and a filtering process using a filter different from the previous one is performed. If the determination result is YES, the operation ends, assuming that the total amount of ink in the determination reference area has been corrected to the specified amount or less.

By the way, the above-described filter processing in step S20 means that, for example, as shown in FIG. 7, in the judgment reference area of 8.times.8 dots (= 64 dots), the hatched dots in FIG. (4 dots), the thinning correction of the dots to be ejected based on the image data corresponding to the determination reference area is performed using the first filter set to stop the ejection of the ink for 4 dots. The total amount of ink in the criterion area after thinning out is calculated by the process of step S21 in FIG.

If the total amount of ink does not fall below the specified amount even in the thinning correction using the filter shown in FIG. 7, for example, a second filter set to stop the ejection of ink for six dots is used. The thinning correction of the dots to eject ink based on the original image data corresponding to the determination reference area is performed, and the total amount of ink in the determination reference area after thinning out the six dots is calculated by the process of step S21 in FIG. It is done.

Further, when the total amount of ink does not become less than the specified amount even in the thinning correction using such a filter, a filter for performing thinning correction for 8 dots and 10 dots is used. 1 as shown in 8
A filter for performing thinning correction for six dots (dots hatched in FIG. 8) is used.

Therefore, according to the first embodiment described above, when the image forming surface of the paper 11 is laminated, the ink is discharged to the 8 × 8 dot determination reference area divided by the image forming surface dividing unit 35. If the total amount of ink is not less than the specified amount stored in the specified amount buffer of the RAM 32, the total amount is corrected to a specified amount (= desired amount) by the total ink amount correction unit 38, so that the heat and pressure applied during lamination are not reduced. Even in the case of lamination, lamination can be performed without causing ink bleeding as in the related art, and lamination and fixing of the ink can be performed simultaneously.

In the first embodiment, when the desired amount of ink to be corrected is equal to the prescribed amount (75%), that is, ink in the 8 × 8 dot determination reference area should be ejected. The maximum number of dots is 48 dots (= 64 dots x
0.75) has been described, but the desired amount of ink to be corrected is determined in the RAM 3
The specified amount may not be the same as the specified amount stored in the second specified amount buffer.

Further, the thinning pattern of the filter used for the correction is not limited to the patterns shown in FIGS. 7 and 8, and a process using a different filter with the same thinning dot number may be performed. Of course.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIG. Note that the overall configuration of the ink jet printer and the block configuration of the control system in the present embodiment are the same as those in the first embodiment described above, and therefore, FIG. 1 to FIG. 3 will be referred to in the following description.

The present embodiment differs from the first embodiment in that the total ink amount is determined by the total ink amount determining unit 37 of the CPU 27 so that the total amount of ink is equal to the specified amount (= 75).
%) When it is determined that the value is not less than or equal to 8 ×
A dot ink amount correction function for correcting the amount of ink per dot to be ejected out of the eight dots is provided, whereby the total amount of ink is reduced to a desired amount which is the same as the specified amount stored in the specified amount buffer of the RAM 32. This is to make corrections.

At this time, for example, when each dot is output at four gradations (each gradation value = 3, 2, 1, 0) according to the ink amount, the dot ink amount at the gradation value "3" is 12c.
c, assume that the dot ink amount at the tone value "2" is 8 cc, the dot ink amount at the tone value "1" is 4 cc, and the dot ink amount at the tone value "0" is 0 cc. , 75%, the relationship between the original gradation value and the corrected gradation value is as shown in Table 3.

[0047]

[Table 3]

The CPU 2 having such a function
7 (step S6 in FIG. 4)
To be more specific, as shown in FIG. 9, the ink amount of each dot that actually ejects ink in the target determination reference area is decremented by, for example, several% so that the ink amount of each dot becomes the gradation value shown in Table 3, for example. (Step S3
0), the calculation of the total ink amount in the determination reference area after the decrement processing is performed (step S31), and whether the calculated total ink amount after correction has become equal to or less than the specified amount stored in the specified amount buffer of the RAM 32; A determination is made (step S32). If the determination result is NO, the flow returns to step S30 again to perform the decrement processing. If the determination result in step S32 becomes YES, the total amount of ink in the determination reference area is defined. The operation ends assuming that the correction has been made to be equal to or less than the amount (= desired amount).

Therefore, according to the above-described second embodiment, the same effect as that of the first embodiment can be obtained.

In the above-described second embodiment, a case has been described in which the correction is performed such that the desired amount of ink to be corrected is equal to the specified amount. It does not have to be the same as the specified amount stored in the amount buffer.

Further, in both the above embodiments, the case where the recording medium is a paper-based recording medium has been described, but it is a matter of course that a film-based recording medium other than the paper may be used.

In the above-described embodiments, the specified amount of ink, which is used as a reference for determining whether correction is necessary, is 75%.
However, it goes without saying that it is not particularly limited to 75%.

The present invention is not limited to the above-described embodiment, and can be arbitrarily changed without departing from the spirit of the present invention.

[0054]

As described above, according to the first aspect of the present invention, when laminating the image forming surface, the total amount of ink ejected to the divided area of the image forming surface is not less than the specified amount. Sometimes, the total amount of ink in that area is corrected to a desired amount, so even if lamination is performed without lowering the heat and pressure applied during lamination, lamination can be performed without causing ink bleeding as in the conventional case. And fixing can be performed simultaneously.

According to the second aspect of the present invention, the total amount of ink ejected to the area divided by the image forming surface dividing means is a desired amount substantially equal to the specified amount stored in the specified amount storage means. The amount can be corrected.

According to the third aspect of the present invention, it is possible to perform lamination in an almost optimum state without bleeding of ink.

According to the fourth aspect of the present invention, it is possible to correct the total amount of ink by reducing the number of recording dots in the area divided by the image forming surface dividing means.

According to the fifth aspect of the present invention, the total amount of ink is reduced by reducing the amount of ink per recording dot without changing the number of recording dots in the area divided by the image forming surface dividing means. Correction becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first embodiment.

FIG. 2 is a block diagram of the first embodiment.

FIG. 3 is a partial block diagram of the first embodiment.

FIG. 4 is a flowchart for explaining the operation of the first embodiment.

FIG. 5 is a flowchart for explaining the operation of the first embodiment.

FIG. 6 is an operation explanatory diagram of the first embodiment.

FIG. 7 is an operation explanatory diagram of the first embodiment.

FIG. 8 is an operation explanatory diagram of the first embodiment.

FIG. 9 is a flowchart for explaining the operation of the second embodiment.

FIG. 10 is a cross-sectional view showing a state in a part of a conventional example.

FIG. 11 is a cross-sectional view of a conventional example in a partially different state.

FIG. 12 is a partial cross-sectional view of another conventional example.

[Explanation of symbols]

 Reference Signs List 11 paper (recording medium) 14 recording head 18 laminate film 27 CPU 32 RAM (prescribed amount storage means) 35 image forming surface dividing section (image forming surface dividing means) 36 total ink amount detecting section (total ink amount detecting means) 37 total ink amount Judgment unit (total ink amount judgment unit) 38 Ink total amount correction unit (total ink amount correction unit)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hirohiro Kondo 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Inside Brother Industries, Ltd. (72) Inventor Akira Ago 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-city (72) Inventor Yukihiro Wakasugi 15-1 Naeshiro-cho, Mizuho-ku, Nagoya Inside Brother Industries, Ltd.

Claims (5)

[Claims] 1. An ink jet printer which forms a desired image on a recording medium such as paper by discharging ink from nozzles of a recording head, wherein an image forming surface of the recording medium is placed in an area having a predetermined size. Laminating the image forming surface dividing unit, for each of the regions divided by the image forming surface dividing unit, an ink total amount detecting unit for detecting a total amount of the ink ejected to the region, and the image forming surface In the case, a prescribed amount storage means for storing a prescribed amount of ink to be ejected, and whether or not the total amount detected by the total ink amount detection means is equal to or less than the prescribed amount stored in the prescribed amount storage means If the total ink amount determining means determines that the total amount is not less than the specified amount, the total amount is determined to be a desired amount. Inkjet printer is characterized in that a total amount of ink correcting means for correcting. 2. The ink jet printer according to claim 1, wherein the prescribed amount and the desired amount are substantially the same. 3. The method according to claim 1, wherein the desired amount is about 70 to 1 of the total amount.
3. The ink jet printer according to claim 1, wherein the amount is less than 00%. 4. The apparatus according to claim 1, wherein the total ink amount correcting means includes an ink discharge stopping means for stopping the discharge of the ink corresponding to some of the recording dots in the area. The inkjet printer according to claim 1. 5. An ink jet printer according to claim 1, wherein said total ink amount correcting means includes a dot ink amount correcting means for correcting said ink amount per said recording dot.