JP3942272B2 - Color inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an ink tank for each color. Each color ink on each nozzle head Can supply and drive the selected nozzle head Inkjet nozzle To print media Color ink The present invention relates to a color ink jet printer capable of printing while discharging ink.
[0002]
[Prior art]
Each color nozzle head with the ink cassette mounted is reciprocated over the entire length in the row direction, and printing is performed during each forward movement to perform one line (or 1 / N line), and one line (or 1 / N rows) After printing, the printing medium (plain paper, OHP paper, etc.) is fed one row in the column direction, and these are repeated. Has been proposed by the present applicant (for example, Japanese Patent Application No. 8-296959), which is capable of continuous printing operation over a long period of time and can be significantly reduced in size as compared with an electrophotographic so-called laser printer. Yes.
[0003]
In FIG. 7, a printing medium (for example, paper P) sent from the paper feeding unit is fed to the drum 41 side by the feeding unit at a predetermined timing and is wound around the outer peripheral surface of the drum 41. The drum 41 is rotated about the axis Z and in the rotation (R) direction, for example, at 120 RPM.
[0004]
Then, the nozzle head for each color which has a large number of inkjet nozzles and is integrated (or integrated with a plurality of nozzle head elements arranged in the row direction) over the entire length in the row direction (printing direction... Perpendicular to the paper surface). Each color ink (cyan C, yellow Y, magenta M, black B) is ejected from 42C, 42Y, 42M, 42B.
[0005]
The nozzle unit 42 (42C, 42Y, 42M, 42B) is moved back and forth in the printing direction by a predetermined distance (for example, the pitch between the ink jet nozzles) by the reciprocating means, and is rotated onto the rotating drum 41, that is, the printing medium (printing surface). In addition to the row direction printing, the column direction printing can be performed using the rotation of the drum 41 during the forward movement in the printing direction. That is, since the row direction printing and the column direction printing can proceed simultaneously, it is possible to greatly increase the printing speed (for example, 20 PPM).
[0006]
The printed print medium is peeled from the drum 41 and discharged along the discharge path by the discharge means. The nozzle unit 42 is supplied with ink from the ink supply means.
[0007]
In addition, since the nozzle heads for each color and the ink tanks for each color can be arranged at a distance, the nozzle heads for each color can be lightened, and the speed of reciprocating movement in the row direction can be greatly increased. In addition, the capacity of the ink tanks for each color can be greatly increased, so that, for example, 500 or more continuous printing operations can be performed.
[0008]
[Problems to be solved by the invention]
By the way, in a color inkjet printer that can continuously print a large number of sheets at a high speed, for example, there are many jobs that print 15 copies of 20 documents at A4, for example. However, if the ink runs out during printing, printing must be stopped.
[0009]
Therefore, for example, as in the case of a printer using toner, the discharge amount of each color ink is switched to a so-called save mode, which is smaller than that in the normal mode, and the discharge amount per unit time of each color ink is made uniform. It is desirable to extend the printable time while narrowing down.
[0010]
However, the idea of the conventional save mode is based on extending the printing time because printing may be lighter than in the normal mode. However, in the case of a color ink jet printer, if the conventional save mode is introduced as it is, there is a strong possibility that the printing color will change. For example, when the magenta color ink and the yellow color ink are respectively halved in the normal mode, the yellow color is hardly noticeable. In other words, as long as it is color printing, it is pointed out that even if it is unavoidable to make it thin, it is not allowed to change the printing color.
[0011]
Furthermore, in actual operation, when monochrome printing of only black (black) color is frequently used, the black ink tends to decrease compared to other color inks, or in the case of full color printing, the black color is more than other colors. There is also a request to make only the black color thinner because it is too conspicuous. On the other hand, even if the black color ink disappears, if there is another color ink, color printing including black color can be performed, so there is a request that only color ink other than black color ink be printed in the save mode. is there.
[0012]
An object of the present invention is to provide a color inkjet printer that can promote the extension of the printing operation without changing the printing color. Also, the black color ink and other color inks can be switched to the save mode separately and independently. Color inkjet printer I will provide a.
[0016]
[Means for Solving the Problems]
In order to solve the above-described problem, a color inkjet printer according to the present invention drives a selected nozzle head capable of supplying each color ink from each color ink tank to each nozzle head. In a color inkjet printer formed so that printing can be performed while discharging color ink from a inkjet nozzle to a print medium,
Each of the ink tanks for each color is formed so that it can be detected that the amount of ink has decreased to a predetermined amount or less, and each ink nozzle discharge amount is set to be higher than that in the normal mode and the normal mode. Reduced print mode can be selectively switched, and the ink in one of the ink tanks for each of the colors other than the black ink tank has decreased below the predetermined amount. Is detected Nozzle head for each color other than black nozzle head Save mode all at once And also When it is detected that the ink in the black ink tank has decreased below the predetermined amount, only the black nozzle head is placed in the save mode. ,Respectively Selectable switchable The black ink and other color inks other than the black ink can be selected and switched to the save mode separately and independently by the mode selection switching control means. Is.
[0017]
In this invention, the discharge amount of each color ink in the normal mode of each color nozzle head is set for each. Also, the discharge amount of each color ink in the save mode Each normal mode Set each to a smaller value than in the case of. For example, the value is determined while predicting or confirming the print result so that the discharge amount is smaller for the magenta color which is conspicuous than for the yellow color which is not conspicuous.
[0018]
Thus, when the save mode is selected for inks other than black, the black ink tank is excluded during color printing without using full color or black ink in normal mode. Ink tank for other colors And ink in one of the ink tanks Each predetermined amount When the following decrease is detected, each color nozzle head except for black ejects each amount of ink switched to the save mode simultaneously. That means Ink for each color Is not uniform (for example, 30% reduction), but is reduced to the amount set for each color. Therefore, extension of the color printing operation can be promoted without changing the printing color.
[0019]
In addition, when the save mode is selected only for the black ink, the full color printing operation in the normal mode is in progress. Or black ink During black-and-white printing operation using only Predetermined amount When the following decrease is detected, the black nozzle head ejects the amount of ink switched to the save mode.
[0020]
Therefore, black (black) Color ink And other color inks can be independently switched to the save mode, and the extension of the color printing operation or the monochrome printing operation in which the black color is made light without changing the printing color can be promoted.
[0021]
further, Claim 2 According to the invention, there is provided an ink drying means for drying the ink on the print medium after printing, the drying degree of the ink drying means is formed so as to be switchable between strengths, and the ink is dried when the selection is switched to the save mode. This is a color ink jet printer formed so that the degree of drying of the means can be switched to a weaker drying as compared with that in the normal mode.
[0022]
In such an invention, when the selection is switched to the save mode, the degree of drying of the ink drying means is switched to weaker drying than in the normal mode. Therefore, Claim 1 In addition to being able to achieve the same operational effects as in the case of the present invention, it is possible to dry the ink appropriately and without excess or deficiency in accordance with the amount of ink printed on the print medium. Can prevent overheating and save energy.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 to 3, the color ink jet printer 20 is formed so as to be able to detect that the ink in the ink tanks 52 for each color has decreased below the predetermined amount, and for each color nozzle head 42C, 42Y. , 42M, 42B are formed to be selectively switchable between a normal mode and a save mode in which the ink discharge amount of each color is reduced as compared with the normal mode. Each of the color nozzle heads 42C, 42Y, 42M, and 42B can be selected and switched to the save mode all at once when it is detected that the ink has decreased below the predetermined amount.
[0024]
In addition, the save mode for other colors (cyan C, yellow Y, magenta M) excluding black (black B) color and the save mode for only black (black B) color can be selected and switched separately. Is formed.
[0025]
Here, as shown in FIGS. 2 and 3, the color ink jet printer 20 has the same basic structure as that of the previously proposed case (FIG. 7), and each nozzle head 42C, 42Y, 42M having a plurality of ink jet nozzles. , 42B are supplied to each color ink and ejected from a selected inkjet nozzle so as to be printed on a print medium (for example, paper P). For example, A4 paper can be printed in full color at a high speed of 20 PPM.
[0026]
That is, in FIG. 1, the color inkjet printer 20 is formed of an image processing unit 30 and an engine unit 40, and is created based on a print command generated in the own device (30) and in the own device (30). Print the print data. Note that an ink jet printing system that prints print data transmitted from an external computer 100 via a data communication line (network..., LAN, for example) 18 according to the print command may be constructed.
[0027]
The image processing unit 30 includes an input / output port (I / O) to which a CPU 31, a ROM 32, a RAM 33, an operation panel (PNL) 34, a display unit (IND) 35, an interface (I / F) 36, and an ink reduction detecting means 60 are connected. 37) and a timer (TMR) 39, which controls the drive of the entire printer in a timely manner by converting the print data into bitmap data depending on the model and outputting it to the engine unit 40 in a timely manner.
[0028]
In FIG. 1, the head drivers 42DC, 42DY, 42DM, and 42DB of the nozzle unit 42 (42C, 42Y, 42M, and 42B), the rotation mechanism 43 driver (DRVR) 43D, and other mechanism 45 drivers (DRVR) 45D. Is expressed as being disposed in the image processing unit 30 for convenience.
[0029]
In addition to the nozzle unit 42 described above, the engine unit 40 includes a drum 41 that can wind and hold the print medium (P) on the outer peripheral surface and can be rotated at a set rotation speed (for example, 120 RPM) by the rotation mechanism 43, and FIG. Other mechanisms 45 including an ink supply means 56, a paper feed means, a feed means, a transport means, a discharge means, and the like having an ink tank 52, etc. are provided, and are configured to be capable of color printing and monochrome printing.
[0030]
Specifically, in FIG. 2, the printing medium (P) sent out from the paper feeding means below the main body case 1 (opening / closing cover 2) is fed to the drum 41 rotating in the R direction at a predetermined timing by the feeding means. The drum 41 is fed and held on the outer peripheral surface of the drum 41 using, for example, static electricity.
[0031]
The ink chambers 42BX (see FIG. 3 showing only the yellow color) of the nozzle heads 42C, 42Y, 42M, and 42B forming the nozzle unit 42 are provided with piping, pumps, and valves from the ink tank 52 shown in FIG. For example, the ink is constantly replenished via the ink supply means 56 including the above. Then, ink is ejected from the inkjet nozzle 42NL connected to the ink chamber 42BX to the printing medium (P). Reference numeral 57 denotes ink return means.
[0032]
The ink tank 52 is formed so that an ink bottle (cassette) 51 for ink replenishment can be attached and detached, and an ink reduction detecting means 60 comprising a float 61 and a sensor 62 is attached.
[0033]
Here, the ink discharge amounts (consumption amounts) of the nozzle heads 42C, 42Y, 42M, and 42B can be set and changed, and the normal mode (each ink discharge amount... Yellow = high ink discharge amount) shown in ST41 of FIG. In contrast to the case of 1, cyan = 1, magenta = 1, black = 1), the ink discharge amount (consumption amount) in the save mode shown in FIG. 4 (FIG. 5) is reduced. Note that ST41 includes monochrome printing.
[0034]
Further, in this embodiment, the ink discharge amount in the save mode is configured to be changeable in three stages. That is, when each color (C, Y, M, B) ink shown in ST14 in FIG. 4 (ST28 in FIG. 5) is selected (yellow = ly, cyan = lc, magenta = lm, black = lb), ST18 ( When each color (C, Y, M) ink excluding black (black) ink shown in ST33) is selected (yellow = ly, cyan = lc, magenta = lm), and black (black B) shown in ST22 (ST38). ) When only color ink is selected (black = lb).
[0035]
Note that the discharge amount of each color ink in the save mode (yellow = ly, cyan = lc, magenta = lm, black = lb) is the normal mode discharge amount (yellow = ly, cyan = lc, magenta = lm, black = For example, 40% (ly = 1 × 0.4, lc = 1 × 0.4, lm = 1 × 0.4, lb = 1 × 0.4) with respect to lb). Instead of setting the values unilaterally, it is possible to select and set values that can improve the printing result when the printing operation is performed in the save mode.
[0036]
For example, lb = 1 × 0.2 is set for black that is most prominent, and ly = 1 × 0.5, lc = 1 × 0.4, and lm = 1 × 0.3 for color. be able to. This setting is performed by adjusting the ejection amount of each head driver 42DC, 42DY, 42DM, 42DB for each nozzle head 42C, 42Y, 42M, 42B shown in FIG.
[0037]
Then, the print medium (P) after the printing is peeled off from the drum 41 and discharged in the H direction along the discharge path as shown in FIG. In this discharge path, an ink drying means (drying heater) 70 for drying the ink on the printing medium after printing is provided.
[0038]
The ink drying means 70 can switch the degree of dryness, and when the mode is selected and switched to the save mode, the drying degree is reduced by the dry switching control means (31, 32) as compared with the normal mode. The selection is switched.
[0039]
Furthermore, in this embodiment, the drying degree is not just two stages of the drying degree in the normal mode (Hn%... 100%, for example) and the drying degree in the save mode shown in ST42 in FIG. The mode can be switched to three stages with different numbers of selected color inks.
[0040]
That is, in the save mode, the drying degree (His%) at the time of full color printing operation shown in ST15 of FIG. 4, the drying degree (His%) at the time of color (or full color) printing operation shown in ST19, and the monochrome (STC 23). (Or full color) is the dryness (Hisb) at the time of printing operation, and the dryness is based on ON-OFF (DUTY switching) control of the heater.
[0041]
Next, the selection switching from the normal mode to the save mode can be performed automatically and manually, and in either case, the ink type (number) can be designated and executed.
[0042]
That is, the “type” of ink to be pre-saved is set for all color (C, M, Y, B) inks that can be printed in full color by key operation on the operation panel 34, or in black (black B) that can be color printed. Either a color (C, M, Y) ink other than the color or only a black (black B) color ink that can be printed in monochrome can be selected (ST12, 16, 20 in FIG. 4). , ST25, 30, 35 in FIG. Of course, it is also possible to select the save mode only for the black ink during the full color or color printing operation.
[0043]
Further, “ink save” can be selected (YES in ST10 of FIG. 4) and “execute now” can be commanded (YES in ST11). Manual selection switching.
[0044]
In the case of automatic selection switching, “ink save” is selected (YES in ST10), “execute immediately” is not commanded (NO in ST11), and “execute with ink near empty (ink reduction)” is selected. By selecting (YES in ST24 of FIG. 5).
[0045]
Then, when any one of the ink reduction detection means 60 detects that the ink in each ink tank 52 has decreased below the predetermined amount (ink near empty) (YES in ST26, ST31, and ST36 in FIG. 5). Then, the selected color ink is switched to the save mode by the mode selection switching control means (CPU 31, ROM 32).
[0046]
That is, when the ink colors to be saved are C, M, Y, and B (YES in ST25), detection is made for any one of the ink tanks 52 for the respective colors (C, M, Y, B) (ST26). If YES, selection switching is executed (ST27, ST28). If the ink color to be saved is C, M, or Y (YES in ST30), any one of the ink tanks 52 for each color (C, M, Y) ink is detected (YES in ST26). Selection switching is executed (ST32, ST33). Further, when the ink color to be saved is only black (B) (YES in ST35), selection switching is executed when the ink tank 52 for black (B) color ink is detected (YES in ST36). (ST37, ST38).
[0047]
In the embodiment having such a configuration, the ejection amounts (yellow = ly, cyan = lc) of each color (C, M, Y, B) ink in the normal mode of each color nozzle head 42C, 42Y, 42M, 42B shown in ST40 of FIG. , Magenta = lm, black = lb). Further, the discharge amount of each color ink in the save mode shown in ST14, 18, 22 in FIG. 4 and ST28, 33, 38 in FIG. 5 is smaller than that in each normal mode (for example, ly = 1 × 0). .5, lc = 1 × 0.4, lm = 1 × 0.3, lb = 1 × 0.2). Note that the values of ST14, 18, 22 in FIG. 4 and ST28, 33, 38 in FIG. 5 may be the same.
[0048]
In any case, for example, the value is determined by checking the printing result so that the discharge amount is less for the inconspicuous magenta (M) color than in the inconspicuous yellow (Y) color. Further, the drying degree (strength) of the ink drying means 70 is the drying degree (Hn%..., 100%, for example) shown in ST42 of FIG. 6, and the drying degree shown in ST15 of FIG. 4 in the save mode. (Hisa%), the degree of drying (Hisc%) shown in ST19 and the degree of drying (Hisb) shown in ST23 are set respectively.
[0049]
For example, in the case of full-color printing (ST15), the drying degree (100%) in the normal mode is set to Hisa% (for example, 30%), and in the case of color printing (or full-color printing) (ST19) The normal mode [100% (100%)] is set to Hisc [for example, 30% (40%)], and in the case of monochrome printing (or full color printing), the normal mode [100% (100%) ] Is set to Hisb [for example, 20% (40%)].
[0050]
In ST12, ST16, and ST20, a simplified expression is used. In ST12, whether or not YES is included including determination of full-color printing, and ST16 includes determination of whether color printing or full-color printing is performed. Whether or not it is YES and whether or not it is YES including determination of whether monochrome printing or full-color printing is possible in ST20 can be automatically determined.
[0051]
The same applies to ST25, ST30 and ST35 in FIG.
[0052]
Thus, during, for example, full-color printing operation in the normal mode (ST40 in FIG. 6), the ink in the ink tank 52 in any one of the ink tanks 52 for each color (C, M, Y, B) is used by the ink reduction detection means 60. Is detected to be less than the predetermined amount (YES in ST26 in FIG. 5).
[0053]
Then, the mode selection switching control means (31, 32) selects and switches the color nozzle heads 42C, 42Y, 42M, 42B simultaneously to the save mode (ST27, ST28). By switching signals to the head drivers 42DC, 42DY, 42DM, and 42DB.
[0054]
Further, the drying switching control means (31, 32) selectively switches the drying degree (DUTY) of the ink drying means (drying heater) 70 to the drying degree (Hisa%) during the full color printing operation (ST29). Therefore, it is possible to promote the extension of the full-color printing operation without changing the printing color, and it is possible to appropriately dry the ink without excess or deficiency according to the amount of ink printed on the printing medium (P). While securing, it is possible to prevent overheating of the print medium and to save energy.
[0055]
The same applies to color printing in ST30 to ST34.
[0056]
Further, during the full color printing operation in the normal mode (ST40 to ST42 in FIG. 6) or the monochrome printing operation using only the black ink (ST40 to ST42 in FIG. 6), the ink reduction detection unit 60 performs the black ink tank. When it is detected that the ink in 52 has decreased below the predetermined amount (YES in ST36 in FIG. 5), the mode selection switching control means (31, 32) switches only the black nozzle head 42B to the save mode (ST37). , ST38).
[0057]
Further, the drying switching control means (31, 32) switches the drying degree (DUTY) of the ink drying means (drying heater) 70 to the drying degree (Hisb%) when black ink is selected (ST39).
[0058]
Therefore, since the black (B) color ink and the other color (C, M, Y) ink can be switched to the save mode independently, the color printing operation in which the black color is lightened without changing the print color. Alternatively, the extension of the monochrome printing operation can be promoted.
[0059]
Thus, for example, when the magenta (M) color ink and the yellow (Y) color ink are respectively set to 40% (= 0.4) of the normal mode (“1”), the yellow color becomes almost inconspicuous and the print color Can be eliminated.
[0060]
Further, since the printing operation in which only black is thinned can be performed, it is possible to prevent black from being noticeably conspicuous than other colors in the case of full color printing. Further, even when monochrome printing using only black (black B) color ink is frequently used, it is possible to eliminate the difficulty that the black ink is reduced as compared with other color inks.
[0061]
Furthermore, on the contrary, even if the black ink runs out, color printing including black is possible if there is another color ink, so the actual operation of printing in save mode only for color ink other than black ink It can respond to the request about.
[0063]
【The invention's effect】
According to the first aspect of the present invention, the nozzle head for each color is detected when it is detected that the ink in any one of the other color ink tanks excluding the black ink tank has decreased to a predetermined amount or less. Can be selected and switched to save mode all at once, and only the black nozzle head can be selected and switched to save mode when it is detected that the amount of ink in the black ink tank has decreased below a predetermined amount. The black ink and the ink for each color other than the black ink can be selected and switched to the save mode separately and independently by the mode selection switching control means. Because it is a color inkjet printer, Exclude this black ink It is possible to switch to the save mode independently from other color inks, and it is possible to promote the extension of the color printing operation or the monochrome printing operation in which black is lightened without changing the printing color.
[0064]
further, Claim 2 According to the invention, when the selection is switched to the save mode, the degree of drying of the ink drying means is formed so that it can be switched to weak drying compared to the case of the normal mode. Invention of Claim 1 In addition to being able to achieve the same effect as the above, in addition, since the ink can be appropriately dried without excess or deficiency according to the amount of ink deposited on the print medium, the print medium is overheated while ensuring the print quality. Can be prevented and energy can be saved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a side view for mainly explaining the positional relationship between a drum, a nozzle head, and ink drying means.
FIG. 3 is a system diagram for explaining an ink tank and an ink supply unit.
FIG. 4 is a flowchart (1) for explaining the operation in the same manner.
FIG. 5 is also a flowchart (2) for explaining the operation.
FIG. 6 is a flowchart (3) for explaining the operation in the same manner.
FIG. 7 is a side view for explaining the previously proposed ink jet printer.
[Explanation of symbols]
1 Body case
20 color inkjet printer
30 Image processing unit
31 CPU (mode selection switching control means, drying switching control means)
32 ROM (mode selection switching control means, drying switching control means)
33 RAM
35 Operation panel
36 Display
40 Engine part
41 drums
42 Nozzle unit
42C, 42Y, 42M, 42B Nozzle head
42DC, 42DY, 42DM, 42DB Head driver
52 Ink tank
56 Ink supply means
60 Ink reduction detection means
70 Ink drying means
100 computers
P paper (printing media)

Claims (2)

In a color inkjet printer that is capable of supplying each color ink from each color ink tank to each nozzle head and driving the selected nozzle head to discharge the color ink from the inkjet nozzles to the print medium, and capable of printing,
Each of the ink tanks for each color is formed so that it can be detected that the amount of ink has decreased to a predetermined amount or less, and each ink nozzle discharge amount is set to be higher than that in the normal mode and the normal mode. Reduced print mode can be selectively switched, and the ink in one of the ink tanks for each of the colors other than the black ink tank has decreased below the predetermined amount. When all the color nozzle heads except for the black nozzle head are simultaneously put into the save mode , and when it is detected that the ink in the black ink tank has decreased below the predetermined amount, only use the nozzle head to the save mode, each selectively switchable to form, mode and other color inks except the black ink and the black ink Color inkjet printer, wherein separate and independently be selected switchably configured to save mode by択切exchange control means.   An ink drying means for drying the ink on the printing medium after printing is provided, and the drying degree of the ink drying means is formed so as to be switchable between strengths and when the selection is switched to the save mode, the drying degree of the ink drying means is set. The color ink jet printer according to claim 1, wherein the color ink jet printer is formed so as to be switchable to dryness lower than in the normal mode.

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