JP2002059559A - Color ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color ink jet printer capable of reducing a quantity of ink ejected by priming in such a manner that ejection nozzles for a non-used color is capped even during the operation of printing. SOLUTION: A paper sheet 34 is inserted from a lower section to be conveyed in the left side by being attracted to a conveyance belt 35 and is reversed by a following roller 33. After that, the paper sheet 34 is printed by passing through a platen 31 to be discharged to the outside. In the case of monochrome printing, a color print head unit 22 is moved to a maintenance position at the left side by a sliding mechanism 29 and is covered with a cap member 26 for the color print head unit 22 to be stopped and then a black color print head unit 21 is positioned opposite the platen 31 to form a black color image on the paper sheet 34. During the printing, the priming of the color print head unit 22 is not executed. In the case of color printing, the black color print head 21 and the color print head unit 22 are supported by head unit holders 23, 24 to be positioned opposite the platen 31 and then a full-color image is formed on the paper sheet 34 by inks of yellow, cyan, magenta and black colors ejected from the print heads.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color ink jet printer in which priming ejection ink is reduced by capping unused ejection nozzles even when other ejection nozzles are printing.

[0002]

2. Description of the Related Art Conventionally, an ink jet printer has been used. The printing method in this ink jet printer is to print (print) characters, images, and the like by discharging ink droplets from discharge nozzles of a print head and absorbing the ink droplets to a recording material such as paper or cloth. It is. This printing method is a printing method that generates little noise, does not require a special fixing process, can perform high-speed printing, and can perform full-color printing.

[0003] In the case of full-color printing, three colors of the subtractive primary colors, yellow (yellow), magenta (red dye name) and cyan (greenish blue), are usually used.
Printing is performed using four colors of ink to which black (black) used for black portions of characters and images is added. That is, a nozzle row dedicated to each color is arranged in one print head, and four color inks of yellow, magenta, cyan, and black are discharged from these nozzle rows while controlling the discharge amount of each color, For example, full-color printing is performed by mixing and absorbing each ink in one pixel of the recording material.

In a print head of an ink-jet printer that discharges ink droplets from the above-mentioned discharge nozzles, pressure due to mechanical deformation is generated in a finely formed ink pressurizing chamber by using an electromechanical transducer such as a piezo element. A print head of a piezo-type ink-jet printer that discharges ink droplets from minute discharge nozzles by this instantaneous pressure, and a resistive heating element in a fine ink pressurizing chamber There is a print head of a thermal type ink jet printer that heats and foams ink by using the growth power of the bubble.

FIG. 11 (a) is a plan view showing an ink ejection surface of a roof shooter type print head in such a thermal type, and FIG. 11 (b) is a rear view thereof. FIG. 3C is an enlarged view showing the inside of the top plate, which is enclosed by a dashed line a in FIG.
FIG. 3 is a sectional view taken along the line AA ′ of FIG.

The print head 1 shown in FIG. 1A is a print head having four nozzle rows 2 on one chip substrate. Each of the four nozzle rows 2 includes a large number of discharge nozzles 3, and from these discharge nozzles 3, yellow ink (Y), magenta ink (M), cyan ink (C), It is configured to eject ink drops of black ink (K).

As shown in FIGS. 1A to 1D, in the print head 1, a drive circuit 5 is formed on the upper surface of a chip substrate 4 by an LSI forming technique, and an ink supply groove 6 is formed by, for example, sandblasting. An ink supply hole 7 penetrating from the bottom surface of the ink supply groove 6 to the back surface of the chip substrate 4 is formed.

The heating portion of the heating resistor is provided between the driving circuit 5 and the ink supply groove 6 by a thin film forming technique such as sputtering, a mask pattern forming technique such as photolithography, and a patterning technique such as etching. A heating element is formed by the common electrode 9 and the individual wiring electrodes 11 connected to both ends of the heat generating portion 8. For example, 64 heating elements, 128 heating elements may be used depending on the design policy.
Many such as 256 pieces are formed. Further, the circuit electrode terminals 5-1 of the drive circuit 5 are connected to these individual wiring electrodes 11, and external connection electrode terminals 12 are formed at upper and lower ends of the upper surface of the chip substrate 4.

[0009] On these, a partition 13 (13-1, 1-1) is formed on the entire surface except for the connection electrode terminals 12 described above.
3-2, 13-3) are stacked. The partition wall 13 forms a seal partition wall 13-1 on the left side of the ink supply groove 6 for blocking the ink from the outside, and on the other hand, the individual wiring electrode 1.
A seal partition 13-2 for blocking the ink from the outside is formed on the first and drive circuits 5, and further extends between the heat generating portions 8 from the seal partition 13-2 of the individual wiring electrode 11 portion. A partition wall 13-3 is formed.

If the individual partition electrode 13 of the partition 13 and the seal partition 13-2 on the drive circuit 5 are formed as a comb body, the partition 13-3 extends between the heat generating portions 8 from here.
The part has a shape corresponding to the teeth of a comb. A fine ink pressurizing chamber 14 having a U-shaped cross section (see FIG. 3 (c)) in which the heat generating portion 8 is disposed at the base between the teeth of the comb.
Are formed by the number of heat generating portions 8. An ink flow path 15 is formed between the ink pressurizing chamber 14 and the ink supply groove 6.

Further, a top plate 16 is laminated on these components, and a large number of the above-described discharge nozzles 3 are drilled at positions of the top plate 16 facing the heat-generating portions 8 as shown in FIG. )
The four nozzle rows 2 shown in FIG. With such a shape, the print heads 1 are completed on a number of chip substrates 4 formed on a silicon wafer (not shown).
Finally, the silicon wafer is cut using a dicing saw or the like, separated into individual chip substrates 4, die-bonded to a mounting substrate, and connected to terminals to complete a print head module in practical units.

In the print head 1, ink supplied from an external ink cartridge or the like to the ink supply hole 7 is supplied to the ink pressurizing chamber 14 via the ink supply groove 6 and the ink flow path 15. The heating section 8 is selectively energized according to print information and generates heat instantaneously, causing a film boiling phenomenon at the interface between the heating section 8 and the ink, and corresponding to the heating section 8 by the growth pressure of the film bubble. Ink droplets are ejected from the ejection nozzle 3. The ink droplet becomes a print dot having a size approximately twice as large as that of the ink droplet and lands on a paper surface (not shown). As a result, an image is formed on the sheet surface.

By the way, in the above-mentioned print head manufacturing technology, it is difficult to make a long print head having a long nozzle array because of various limitations in the processing technology (mainly the processing device). The head 1 has conventionally been used exclusively for a serial printer.

In a serial type printer, a head unit on which a print head 1 is mounted is mounted on a carriage together with an ink cartridge and a printing main scanning direction (FIGS. 11A and 11B).
(Left-right direction of the carriage), and prints (prints) by ejecting ink from the ejection nozzles 3 to the sheet intermittently conveyed in a direction orthogonal to the reciprocating direction of the carriage. Since it is relatively compact and easy to use, it is widely used as a personal printer.

[0015] However, although such a small and light,
The serial printer has a problem that printing cannot be performed at high speed because the width that can be printed at a time is narrow. Also, even if a print head with a long nozzle array is moved, the load when the print head moves increases, and various troublesome problems such as deterioration of print quality due to vibration, strengthening of the frame, and enlargement of the apparatus occur. Not practical.

Generally, printers are roughly classified into line printers in addition to the serial printers described above. The line type printer uses a print head having a longer length by arranging printing elements to fill the entire printing area in the main scanning direction, and fixing the print head to the printer main body side to transport only the paper. Since the operation is only for conveying the paper, the load on the drive system is small, the power consumption is small and the operation is economical.

Further, the line type printer is a printer which itself is compatible with high speed. Therefore, in order to respond to the desire to increase the speed of the printing process as in recent years, in order to respond to the request of a serial type printer,
Line-type printers will be the center of future development.

FIG. 12 is a diagram schematically showing the configuration of a color print head of such a line type printer. As shown in the figure, the color print head 17 extends in the main printing
11 (similar to the print head 1 in FIG. 11) are alternately arranged on the parent substrate 19 in a staggered pattern (staggered arrangement) to form a print area of length C in the main scanning direction.

In the above-described ink-jet print head, since the printer body is not in use or the ink is not ejected for a long time depending on the ejection nozzle even during use, the ink jet print head is used for printing. There is a possibility that the water content of the ink in the ejection nozzles that has not been evaporated evaporates to increase the viscosity of the ink, and that some of the ejection nozzles may be clogged to cause ejection failure.

Therefore, in order to eliminate the clogging that may occur, that is, to recover the ejection function, wiping, which is a wiping process of the ink ejection surface by the wiping member, or ink ejection by all ejection nozzles is performed. Priming, which is idle discharge processing (discharge of ink without printing), is periodically performed.

When the print head is not used,
A drying prevention mechanism such as capping of the print head is provided so that the above-described clogging due to drying of the ink discharge nozzle does not occur.

[0022]

In general, a printer is not exclusively used for color printing just because it is a color printer. Sometimes used for printing. In particular, when a printer is used for business purposes, the ratio of output in black printing increases. In such black printing, the nozzle row of black ink (K) of the print head 1 shown in FIG. 11A is used, and cyan ink (C), magenta ink (M), and yellow ink for color printing are used. The nozzle row of the color ink such as (Y) is at rest.

However, since the nozzle rows of color ink for color printing are exposed to the outside air together with the nozzle rows of black ink even though they are at rest, they are dried in the same manner as the nozzle rows of black ink. Priming must be performed to prevent this. That is, there is a disadvantage that the color ink is consumed without being used for printing every time of priming. This is yellow without using black ink,
The same applies to the case of color printing using only magenta and cyan inks, in which case the black ink is consumed without being used for printing every priming.

In particular, in the case of a line type printer as shown in FIG. 12, since the number of ejection nozzles per color is large, the amount of ejection due to the priming of the ink of an unused color increases, which is a serious problem. Become. SUMMARY OF THE INVENTION An object of the present invention is to provide a color inkjet printer that can significantly reduce the amount of ink consumed for recovery ejection and is advantageous in running cost in view of the above-mentioned conventional circumstances.

[0025]

SUMMARY OF THE INVENTION A color ink jet printer according to the present invention comprises a black print head for discharging black ink, and a cap member for the black print head detachably mounted on the ink discharge surface of the black print head. A color print head that discharges at least yellow, magenta, and cyan color inks, and a color print head cap member that is detachably mounted on the ink discharge surface of the color print head, The print head or the color print head performs printing in a state in which the cap member corresponding to the print head is detached at the time of each print execution, and when the respective prints are not executed, the print head or the color print head is self-regardless of whether or not the other is performing the print. It is configured to cover the corresponding cap member.

The black print head and the color print head are line type print heads each having a discharge nozzle array corresponding to the entire print area width. Further, for example, the cap member for the black print head and the cap member for the color print head are fixedly provided at a maintenance position where a maintenance process is performed, and the black print head and the color print head are respectively provided. The head is movably disposed between a printing position where printing is performed facing the paper and the maintenance position where the cap member corresponding to the head is mounted.

Further, for example, the cap member for the black print head and the cap member for the color print head are movably disposed between a maintenance position where a maintenance process is performed and a retract position during printing. The black print head and the color print head are provided
The maintenance position may be movably disposed between a printing position where printing is performed on the paper and a maintenance position.

Further, for example, the black print head is fixed to a print position where printing is performed facing the paper, and the color print head is provided between a print position and a maintenance position where maintenance processing is performed. The cap member for the black print head is movably disposed between a head removal / retreat position during printing and a fixed position for mounting on the fixed black print head during non-printing. The cap member for the color print head may be movably disposed between a head removal / retreat position during printing and a position where the color print head is mounted at a maintenance position during non-printing.

The maintenance processing may include, for example, any or all of capping, wiping, and priming as processing for maintaining proper ejection performance. Is preferred.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view schematically illustrating a configuration of a line-type inkjet printer (hereinafter, simply referred to as a line printer) as a first embodiment. As shown in FIG. 1, the line printer 20 includes a black print head unit 21, a color print head unit 22, a black head unit holder 23 for holding the black print head unit 21, a color print head unit 22.
, A color print unit cap member 25 disposed at the maintenance position, and a color print head cap member 26 also disposed at the maintenance position.

The line printer 20 further moves the two head unit holders 23 and 24, that is, the black print head unit 21 and the color print head unit 22, to the above-mentioned maintenance position and the print position with the double-headed arrow E in the figure.
The slide mechanism 29 includes a guide shaft 27 that slides and a drive belt 28 as shown in FIG.

Although the black head unit holder 23 is engaged with the slide mechanism 29, the color head unit holder 24 is not engaged with the slide mechanism 29 but is engaged with the black head unit holder 23. . That is, the black head unit holder 23 is actively disposed with respect to the color head unit holder 24, and the color print head unit 22 is passively disposed with respect to the black head unit holder 23.

Further, the line printer 20 further includes a platen 31 disposed opposite to the black print head unit 21 and the color print head unit 22 held by the two head unit holders 23 and 24 at the print positions shown in FIG. , A driving roller 32 and a driven roller 33 disposed on both sides of the platen 31,
A paper transport belt 35 is provided between the driven member 2 and the driven member 33 to electrostatically attract and transport the paper 34.

FIG. 2 shows the black print head unit 21.
It is an exploded perspective view of. The color print head unit 2
2 has the same configuration. As shown in the figure, the black print head unit 21 (or the color print head unit 2)
2) F has an opening arranged in a zigzag pattern and a number of wiring connection pads arranged at both ends of the opening.
PC (flexible substrate) 36, FPC reinforcing and positioning / fixing plate 37 having notches arranged in a staggered manner at positions corresponding to the openings of FPC 36, and notches of plate 37 And a plurality of (17 in the example in the figure) element chips 38 which are precisely positioned and fixed with the ink ejection surface facing downward, and correspond to ink supply holes 39 opened on the back surface of these element chips 38. A contact pad 42 having a communication hole 41 at a position,
Through the communication hole 41 of the contact pad 42, the element chip 3
And an ink flow path member 43 having a plurality (three in this example) of ink flow paths for supplying ink to the eight ink supply holes 39.
And an ink tank 44 for supplying ink to the ink flow path member 43.

The inside of the ink tank 44 is partitioned into three ink storage chambers 45a, 45b and 45c. In the case of the black print head unit 21, the ink storage chamber 45
Black ink is stored in each of a, 45b, and 45c. In the case of the color print head unit 22, for example, yellow, magenta, and cyan inks are stored in the ink storage chambers 45a, 45b, and 45c, respectively.

FIG. 3A is a diagram showing the ink ejection surface of the element chip 38, and FIG. 3B is a diagram showing the back surface thereof. As shown in FIG. 3A, the element chip 38 has three nozzle rows 47 on the ink ejection surface 46. The nozzle row 47 has, for example, 300 ejection nozzles 4 for each row.
8 are formed. These discharge nozzles 48 have a diameter of 20 μm and an arrangement pitch of 600 nozzles per 25.4 mm.

In the case of the element chip 38 of the black print head unit 21, black ink is ejected from all three nozzle rows 47 and the color print head unit 22.
In the case of the element chip 38, yellow, magenta and cyan inks are respectively discharged.

On the back surface of the element chip 38,
As shown in (b), a total of three ink supply holes 39 are provided for each nozzle row 47. This element chip 38 has the printing shown in FIGS. 11 (a) to 11 (d) except that the number of the nozzle rows 47 is three and the number of the ink supply holes 39 on the back side is three. It has the same internal structure as the head 1.

The connection terminals 49 at both ends of the element chip 38 shown in FIG. 3A are connected to the positioning and fixing plate 37 shown in FIG.
When disposed so as to be exposed downward from the opening of the FPC 36, the FPC 36 is connected to the wiring connection pad.

FIGS. 4A, 4B, and 4C are diagrams schematically showing the operation state of the line printer 20 of this embodiment. The figure
(a), (b), and (c) show only the components necessary for explanation in FIG.
The same components as those shown in FIG.
The other components are not shown.

First, the sheet 34 shown in FIG.
As shown by an arrow F, the printer body is inserted from the lower right side in the figure, is attracted to the conveyor belt 35, is conveyed to the left side in the figure, makes a U-turn by the driven roller 33, and
1 while being printed and discharged in the direction indicated by arrow G.

In monochrome printing using only black ink (hereinafter simply referred to as monochrome printing), as shown in FIG. 4A, the color print head unit 22 covers the color print head cap member 26 at the maintenance position. The black print head unit 21 is placed opposite to the platen 31. Then, black ink is ejected according to a control signal from a control device (not shown) to form a black-only print image on the paper 34 (see FIG. 1). During this time, since the color print head unit 22 is covered with the color print head cap member 26 and is sealed from the outside air, the priming operation is not performed.

As described above, the black print head unit 21
Even during printing, the ejection nozzles of the unused color print head unit 22 are capped, so that the unused colors of yellow, magenta, and cyan ink are not primed during this time. The amount of ink consumed in priming can be reduced.

In color printing, as shown in FIG. 4B, a black print head unit 21 and a color print head unit 22 are held by head unit holders 23 and 24 shown in FIG. In response to a control signal from the control device, a yellow, cyan, magenta, and black ink is ejected to form a full-color image on paper.

When the line printer 20 is not printing, the black print head unit 21 and the color print head unit 22 move integrally to the maintenance position, and the black print head unit 21 is provided with a cap member 25 for the black print head. The color print head unit 22
Is provided with a cap member 26 for a color print head.

In the monochrome printing by the black print head unit 21, the element chips 38 of the black print head unit 21 have three nozzle rows 47 as shown in FIG. When printing control is performed such that ink droplets ejected from each ejection nozzle of each of the three nozzle rows individually form print dots, the printing speed is three times as large as the printing speed performed by the conventional one nozzle row. Printing can be performed at a high printing speed.

When printing is controlled so that the landing positions of the ink droplets ejected from each of the three nozzle arrays overlap, the printing speed drops to the same speed as when printing is performed by the conventional single nozzle array. The ink density and the diameter of the print dot can be controlled in three ways as much as the ink landing position overlaps, so that when a print image with a high gradation is output, the high gradation of the original image is faithful. High quality monochrome images can be printed.

Further, since the black print head unit 21 and the color print head unit 22 have the same configuration as described above, there is no need to separately manufacture them, and as a result,
Productivity can be improved and manufacturing costs can be reduced. FIGS. 5A to 5D are diagrams showing modified examples of the line printer 20. FIG. 5 (a) to 5 (d) also show only the components necessary for the description, the same components as those in FIG. 1 are assigned the same reference numerals as in FIG. 1, and the other components are not shown. Omitted. In the example shown in FIGS. 5 (a) to 5 (d), first, the paper is inserted upward from the lower left side of the printer main body as indicated by an arrow J in FIG.
The sheet is inverted by 0 degrees, passes through the print position, is further inverted by 90 degrees at the drive roller 32, and is discharged to the lower right side of the printer main body as indicated by the arrow K in the figure.

There are two maintenance positions, left and right. A cap member 26 for a color print head is disposed at the left maintenance position, and a cap member 25 for the black print head is disposed at the right maintenance position. . In the case of FIG. 1, the color head unit holder 24 is used.
Are passively arranged with respect to the black head unit holder 23, and printing is not performed only by the color print head unit 22 as shown in FIGS. 4 (a) and 4 (b). Although not particularly shown, the black head unit holder 23 and the color head unit holder 24 are respectively engaged with the slide mechanism 29 independently.

Therefore, as shown in FIG. 5 (a), color printing by only the color print head unit 22 is different from that in FIG.
(b) monochrome printing using only the black print head unit 21 as shown in (b), and black print head unit 21 and color print head unit 22 as shown in FIG.
The three types of printing methods of color printing performed using both can be selectively adopted.

As in the above-described embodiment, the head unit not used during printing (black print head unit 21 in FIG. 5A, color print head unit 22 in FIG. 5B). Since the ejection nozzles are capped, the priming of the ink of the unused color is not performed, so that the ejection ink amount due to the priming can be reduced in this case as well.

In the above-described embodiment, the configuration of the element chips 38 of the black print head unit 21 and the color print head unit 22 is the same, including the modifications, but in the line printer of the present invention, the black print head High-resolution monochrome printing can be performed by only slightly changing the configuration of the element chips 38 of the unit 21, that is, the arrangement of the nozzle rows.

FIG. 6 is a view showing a modification of the element chip 38 of the black print head unit 21. As shown in FIG. As shown in the figure, in all three nozzle rows 47-1, 47-2, and 47-3 formed on the element chip 38 ', the discharge nozzles 48 are arranged at an arrangement pitch P.

In this modified example, the arrangement of these three nozzle rows 47 (47-1, 47-2, 47-3) is made P · 1/1 more than the arrangement of the adjacent nozzle rows. It is shifted by three. That is, the nozzle row 47-1
The nozzle row 47-2 adjacent to the upper part of the
The nozzle row 47-3 adjacent to the nozzle row 47-2 is shifted to the right of the drawing by 1/3 pitch and further shifted to the right of the drawing by PＰ pitch. I have.

When printing is controlled by using the element chip 38 'so that the printing dots of the three nozzle rows 47 are on the same line, for example, each nozzle row 47 has 2 nozzles.
Assuming that they are arranged at an arrangement pitch of 600 dots per 5.4 mm, the printed resolution is 1 per 25.4 mm.
800 dots, which makes it possible to print at a resolution as high as three times the arrangement of the ejection dots 48.

FIG. 7 is a side sectional view schematically showing the configuration of a line printer according to the second embodiment. As shown in the figure, a line printer 50 of this example has a color print head unit 51 and a black print head unit 52 arranged in the center of the main body. The color print head unit 51 is a print head unit having a configuration that is long in the width direction of the paper (in the drawing, the direction perpendicular to the paper surface), is used at the time of color printing, and is fixed in position by a pressing force of a spring 53. The black print head unit 52 is also a print head unit that is long in the width direction of the paper, is used at the time of color printing and monochrome printing, and is fixed to a main body frame (not shown).

At the top of the printer body 50, ink tanks 54 (54-1, 54-2, 54-3) for yellow (Y), magenta (M) and cyan (C) colors are provided.
And an ink tank 54 (54-4) for black ink. These ink tanks 54 are configured to be detachable from the upper surface of the printer main body 50. When the ink tanks 54 are attached to the printer main body 50 as shown in the figure, one ends of the ink supply tubes 55 corresponding to the respective ink tanks 54 are automatically connected. Is done. The other end of the ink supply tube 55 is connected to a print head corresponding to the color of the ink stored in the ink tank 54 to which one end is connected.

Immediately below the color print head unit 51, two moving platens 56 (56-1, 56-2) are provided.
A plurality of moving platens 56 (56-3) are provided.
The downstream side of the moving platen 56-1 in the sheet conveying direction (left side in the drawing), the moving platen 56-2 and the moving platen 5
Between 6-3 and on the upstream side (right side in the drawing) of the moving platen 56-3 in the sheet conveyance direction, platen storage portions 57 (57-1, 57-2, 57-3) which also serve as sheet guides are arranged. The paper transport path is formed by the moving platen 56 and the platen storage unit 57.

A transport roller pair 58, a paper feed roller 59, and a paper feed tray 61 are disposed upstream of the paper transport path, and a paper discharge roller pair 62 is disposed downstream of the paper transport path. And a discharge port 63 and a discharge tray 64 downstream thereof.
Is formed. In addition, moving platens 56-1 and 5-5
Immediately below 6-2, a color cap unit 65 corresponding to the color print head unit 51 is provided. The color cap unit 65 includes a color cap member 66, a holding member 67 for holding the color cap member 66, and a waste ink tube 68 having one end connected to the color cap member 66. It is arranged so that it can engage and move up and down. The collar cap member 66 is made of an elastic material and a gas-impermeable rubber material, and the holding member 67 is made of a rigid material.

Further, immediately below the moving platen 56-3,
A black cap unit 69 corresponding to the black print head unit 52 is provided. Black cap unit 6
9 is a black cap member 71, and the black cap member 71
, And a waste ink tube 73 having one end connected to the black cap member 71, which is also arranged to be able to move up and down by engaging with a drive mechanism (not shown). These constituent materials are used in the color print head unit 5.
The same as in the case of 1.

In the color cap unit 65, the moving platens 56-1 and 56-2 immediately above the platen housing 5
A hole is opened in the paper transport path accommodated in 7-1 and 57-2, and a hoistway is opened to a color cap unit 65 below the color print head unit 51, and then the color cap member is raised. Reference numeral 66 abuts on the four edges of the ink ejection surface of the color print head unit 51 to seal the ink ejection surface from the outside.

Similarly, after the moving platen 56-3 immediately above the black cap unit 69 is accommodated in the platen accommodating portion 57-3, the lift path of the black cap unit 69 below the black print head unit 52 is opened. As a result, the black cap member 71 comes into contact with the four edges of the ink ejection surface of the black print head unit 52 to seal the ink ejection surface from the outside.

One end of each of the waste ink tubes 68 and 73 connected to the color cap member 66 and the black cap member 71 is connected to a waste ink processing mechanism 74 at the other end. The waste ink processing mechanism 74 includes:
Although not shown, a pump mechanism and a waste ink absorbing member are provided therein.

Further, wiper members 75 and 76 are provided below the above-mentioned paper transport path. Wiper member 75
And 76 are slidably supported on slide shafts 77 and 78, respectively. When the movable platens 56-1 and 56-2 are housed in the platen housing sections 57-1 and 57-2 for wiping and the space below the color print head unit 51 is opened, the wiper member 75 performs the color printing. The space between the head unit 51 and the color cap member 66 is slid in the direction perpendicular to the plane of the drawing to wipe the ink ejection surface of the color print head unit 51 and wipe off the adhered ink to clean it.

Similarly, the wiper member 76 is moved by the movable platen 56-3 for wiping.
7-3, when the space below the black print head unit 52 is opened, the black print head unit slides between the black print head unit 52 and the black cap member 71 in the direction perpendicular to the plane of the drawing. The wiping of the ink ejection surface of 52 is performed to wipe off the adhered ink and clean.

FIG. 8A is a perspective view showing the structure of the color cap unit 65 in more detail, and FIG.
Is a cross-sectional view taken along the line MM ′ in FIG.
(a) is an NN 'sectional arrow view. The color cap unit 65 is configured to be moved up and down by a drive system including a mechanism such as a rack and a pinion (not shown).

As shown in FIGS. 9A, 9B and 9C, the color cap member 66 of the color cap unit 65 is
The bottom surface has a funnel shape inclined downward toward the center, and a waste ink collecting hole 79 is provided at the center. The waste ink collecting hole 79 is connected to an end of the waste ink passage 81 through a waste ink passage 81 provided at an upper portion of the holding member 67.
8 is connected.

As described above, the color cap unit 65 rises, the color cap member 66 seals the ink discharge surface of the color print head unit 51 from the outside, and the color print head unit 51 performs priming. At this time, the color ink primed in the color cap member 66 is collected by the waste ink processing mechanism 74 shown in FIG. 7 via the waste ink collecting hole 79, the waste ink conducting path 81, and the waste ink tube 68. A paper passage 82 is formed in the holding member 67 of the color cap unit 65. The function of the paper passage 82 will be described later.

Since the black cap unit 69 has substantially the same configuration as the color cap unit 65, a detailed view is not shown and described.
That is, the holding member 72 of the black cap unit 69 does not have the paper passage 82 as in the color cap unit 65. Of course, black cap unit 6
9, a paper passage may be formed, but this will also be described later in detail.

FIGS. 9A, 9B and 9C are diagrams showing the operation state of the line printer 50 having the above-described configuration. 7 shows only the main parts necessary for the explanation of the operation, and the same components as those shown in FIG. 7 and FIG.
8 and the same numbers as in FIG.

First, FIG. 9A shows an operation state during printing in full color. Color cap unit 65
The black cap unit 69 and the black cap unit 69 are both lowered to the retreat position below, and all the movable platens 56 (56-1, 5-6)
6-2, 56-3) are closed and the platen storage 57
(57-1, 57-2, 57-3) together form a paper transport path. Above the paper transport path, there is a black print head unit 52 located at a fixed position.
The color print head unit 51 descending to the printing position is arranged close to the paper transport path.

The paper (not shown) is transported on the paper transport path, and the color print head unit 51 is moved toward the paper surface.
Then, the color ink and the black ink are ejected from the black print head unit 52 to form a full-color image including black on the paper surface. Next, FIG. 9B shows an operation state during monochrome printing by only the black print head unit 52. Only the black cap unit 69 is lowered to the retracted position below, the black print head unit 52 is in the printing position, and the color print head unit 51 is raised to the capping position. Then, the color cap unit 65 raised to the capping position from below.
Has been capped and is in a dormant state.

Prior to this, the moving platens 56-1 and 56-2 immediately below the color print head unit 51 are housed in the platen housing sections 57-1 and 57-2, and a hole is opened in the paper transport path. The rising path of the color cap unit 65 is open. Then, the holding member 67 of the color cap unit 65 raised in the hole of the paper conveyance path.
The paper passage 82 described above is formed. When the color cap unit 65 is raised to the capping position as shown in FIG. Then, a paper guide portion is formed there.

As a result, the paper passes through the platen storage section 57-3, the moving platen 56-3, and the platen storage section 57-2 from the upstream side of the transport path, and enters the paper path 82.
From there, the paper is conveyed along the same conveyance path that does not change in the direction of the path, which exits onto the platen storage section 57-1. Black ink is ejected from the black print head unit 52 toward the paper surface, and An image is formed on the paper surface.

During this time, since the color print head unit 51 is capped by the color cap unit 65, there is no need for priming, and the consumption of color ink due to priming is suppressed. FIG. 9C shows a state where the line printer 50 has paused printing. The color print head unit 51 is capped by the color cap unit 65 raised to the capping position and set to a rest state, as in the case of monochrome image printing shown in FIG. Then, the black print head unit 52 at the fixed position is also capped by the black cap unit 69 raised from below and set in a rest state. The ascending path of the black cap unit 69 is the moving platen 56-
3 is accommodated in the platen accommodating portion 57-3 and is opened.

FIG. 10 is a diagram showing a configuration and an operation state of a modification of the line printer 50. 9 differs from the case of FIG. 9 in that the black print head unit 52 moves up and down to the print position and the capping position similarly to the color print head unit 51, and the black cap unit 69 '. Is provided with the same paper passage 83 as the color cap unit 65.

FIG. 10A shows an operation state during printing in full color. The color cap unit 65 and the black cap unit 69 'are both lowered to the lower retracted position, and the color print head unit 51 and the black print head unit 52 are both in the print position close to the paper transport path from the upper capping position. To a full-color printing position. The printing operation is the same as in the case of FIG.

FIG. 10B shows an operation state during monochrome printing. Only the black cap unit 69 'is lowered to the retracted position below and the black print head unit 5
2 is in the printing position, the color print head unit 51 is raised to the capping position, is capped by the color cap unit 65, and is in a rest state.
The operation of other parts before this and the printing operation after this,
This is the same as the case of FIG.

Next, FIG. 10C shows a state of a printing operation unique to this modification. The status of this printing operation is
This shows a state in which color printing is performed by the color print head unit 51 without black ink using only three color inks of yellow (Y), magenta (M) and cyan (C).

That is, the black print head unit 52
Rises to the capping position, the ascending path of the black cap unit 69 'in the paper transport path immediately below is opened, and the black cap unit 69' rises to the capping position to cap the black print head unit 52,
The sheet passing path 83 complements the hole of the sheet conveying path opened as the above-mentioned ascending path to form a sheet guide.

As a result, the paper is transferred from the upstream side of the transport path to the platen storage section 57-3, the paper passage path 83, the platen storage section 57-2, the moving platens 56-2 and 56-1 and the platen storage section 57-1. Transported via This allows
Also in this case, the sheet is conveyed along the same conveyance path as that in which the direction of the path does not change, and a color image without black is formed on the paper surface.

During this time, since the black print head unit 52 is capped by the black cap unit 69 ', priming is not required, and consumption of black ink due to priming is suppressed. Note that FIG.
(d) shows a state in which the line printer has paused printing.

In the first and second embodiments, the capping operation is performed by moving the print head unit or the capping unit in the horizontal direction or the vertical direction. The direction of the ink ejection surface may be changed, and the capping operation by the capping unit may be performed at that position.

In the second embodiment, the ink primed in the cap member is processed as waste ink, but may be recovered and reused.

[0085]

As described above in detail, according to the present invention, even when printing is being performed, the discharge nozzles of the head unit of the unused color are capped, so that the ink consumption due to the priming of the unused color ink is achieved. Can be greatly reduced.

Further, as in the first embodiment of the present invention, the number of nozzle rows of the black print head unit is made three in the same configuration as that of the color print head unit, so
High-speed printing can be performed at three times the printing speed compared to the printing speed performed by the nozzle row, and ink density is controlled in three ways by overlapping ink landing positions Then, a monochrome image with high gradation can be printed.

Further, since the black print head unit and the color print head unit have the same configuration, the productivity is good and the manufacturing cost can be reduced. Further, as in the second embodiment of the present invention, by providing a paper passage in the capping member, the head unit of the unused color ink during the printing operation is operated only by the vertical movement of the head unit and the capping member. Capping operation can be performed, thereby making it easier to retract the capping, and providing a line printer advantageous for miniaturization.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically illustrating a configuration of a line printer according to a first embodiment.

FIG. 2 is an exploded perspective view of a black print head unit or a color print head unit having the same configuration used in the line printer according to the first embodiment.

3A is a diagram illustrating an ink ejection surface of an element chip used in a black print head unit or a color print head unit, and FIG. 3B is a diagram illustrating a back surface thereof.

FIGS. 4A, 4B, and 4C are diagrams schematically showing an operation state of the line printer according to the first embodiment.

FIGS. 5A to 5D are diagrams showing modified examples of the line printer according to the first embodiment.

FIG. 6 is a diagram illustrating a modification of the element chips of the black print head unit of the line printer according to the first embodiment.

FIG. 7 is a side sectional view schematically illustrating a configuration of a line printer according to a second embodiment.

8A is a perspective view showing the configuration of a color cap unit according to a second embodiment in more detail, and FIG. 8B is a perspective view of FIG.
(C) is an NN 'cross-sectional view of (a).

FIGS. 9A, 9B, and 9C are diagrams illustrating an operation state of the line printer according to the second embodiment.

FIG. 10 is a diagram illustrating a configuration and an operation state of a modification of the line printer according to the second embodiment.

11A is a plan view showing an ink ejection surface of a conventional print head, FIG. 11B is a rear view thereof, and FIG. 11C is a perspective view of a top plate of a portion surrounded by a broken line a in FIG. Enlarged view showing the inside, (d)
FIG. 3C is a sectional view taken along the line AA ′ of FIG.

FIG. 12 is a diagram schematically showing a configuration of a color print head of a conventional line type ink jet printer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Print head 2 Nozzle row 3 Discharge nozzle 4 Chip board 5 Drive circuit 5-1 Circuit electrode terminal 6 Ink supply groove 7 Ink supply hole 8 Heat generation part 9 Common electrode 11 Individual wiring electrode 12 Connection electrode terminal 13 Partition 13-1, 13-2 Seal partition 13-3 Partition partition 14 Ink pressurizing chamber 15 Ink flow path 16 Top plate 17 Color print head 18 Element chip 19 Parent board 20 Line printer 21 Black print head unit 22 Color print head unit 23 Head unit for black Holder 24 Head unit holder for color 25 Cap member for black print head 26 Cap member for color print head 27 Guide shaft 28 Drive belt 29 Slide mechanism 31 Platen plate 32 Drive roller 33 Follower roller 34 Paper 35 Paper transport belt 36 FPC ( Flexible board) 37 Positioning and fixing plate 38, 38 'Element chip 39 Ink supply hole 41 Communication hole 42 Adhesive pad 43 Ink flow path member 44 Ink tank 45a, 45b, 45c Ink storage chamber 46 Ink ejection surface 47 (47-1, 47) -2, 47-3) Nozzle row 48 Discharge nozzle 49 Connection terminal 50 Line printer 51 Color print head unit 52 Black print head unit 53 Spring 54 (54-1, 54-2, 54-3, 54-4) Ink tank 55 Ink supply tube 56 (56-1, 56-2, 56-3) Moving platen 57 (57-1, 57-2, 57-3) Platen storage section 58 Transport roller pair 59 Paper feed roller 61 Paper feed tray 62 Paper discharge roller pair 63 Paper discharge port 64 Paper discharge tray 65 Color cap unit 6 Color cap member 67 Holding member 68 Waste ink tube 69 Black cap unit 71 Black cap member 72 Holding member 73 Waste ink tube 74 Waste ink processing mechanism 75, 76 Wiper member 77, 78 Slide shaft 79 Waste ink collection hole 81 Waste ink path 82, 83 Paper path

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Naohiro Osugi 3-2-1 Sakaemachi, Hamura-shi, Tokyo Casio Computer Co., Ltd. Hamura Technical Center F-term (reference) 2C056 EA11 EA17 EA25 EA27 EC22 EE09 FA13 JA04 JA13 JC20

Claims (6)

[Claims] 1. A black print head that discharges black ink, a cap member for a black print head detachably mounted on an ink discharge surface of the black print head, and at least yellow, magenta, and cyan color inks. A color print head that discharges, and a cap member for a color print head that is detachably mounted on an ink discharge surface of the color print head, wherein the black print head or the color print head prints the respective prints. At the time of execution, printing is performed in a state where the cap member corresponding to the self is detached, and at the time of non-printing of each, the cap member corresponding to the self is covered regardless of whether the other is performing printing. Color inkjet printer. 2. The color print head according to claim 1, wherein the black print head and the color print head are both print heads for line-type printing having ejection nozzle arrays corresponding to the entire print area width. Inkjet printer. 3. The cap member for the black print head and the cap member for the color print head are respectively fixed at a maintenance position for performing a maintenance process, and the black print head and the color print head are respectively provided on paper. The collar according to claim 1 or 2, wherein the collar is movably disposed between a printing position where printing is performed facing the printing surface and the maintenance position where the cap member corresponding to the printing position is mounted. Inkjet printer. 4. The black print head cap member and the color print head cap member are movably disposed at a maintenance position for performing a maintenance process and a retracted position at the time of printing. The color ink jet printer according to claim 1, wherein the color print head is movably disposed between a print position where printing is performed facing the paper and the maintenance position. 4. 5. The printing head according to claim 1, wherein the black print head is fixed to a printing position where printing is performed facing the paper, and the color printing head is movably disposed between a printing position and a maintenance position where maintenance processing is performed. A cap member for the black print head is movably disposed between a head removal / retreat position during printing and a fixed position for mounting on the black print head which is fixed during non-printing, and the cap member for the color print head. 2. The color inkjet printer according to claim 1, wherein the printer is movably disposed between a head removal / retreat position during printing and a position where the color print head is mounted at a maintenance position during non-printing. 6. The maintenance process according to claim 3, wherein the maintenance process includes a process of performing any or all of capping, wiping, and priming as a process for maintaining proper ejection performance. Color inkjet printer.