JP2000289233A - Print head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make inconspicuous the unevenness of shade caused by positional shift between adjacent print chips. SOLUTION: Totally twenty two print chips 31 of a color print head 30 are arranged in zigzag in the longitudinal direction of a master substrate 32 and four nozzle arrays 33 each comprising N print dots 34 are provided. In each nozzle array 33 of each print chip 31, start point dots 34a (34a1,..., 34a4) and end point dots 34b (34b1,..., 34b4) of the print dots 34 are arranged while being shifted by L dots (5 dots) in the longitudinal direction. According to the arrangement, even if the interval m between the print dots 34 (end point dot and start point dot) at the end of upper and lower print chips 31 of adjacent zigzag arrangements is not exactly identical to the arrangement density n between the print dots 34 of the print chips 31 itself (m≠n) but shifted slight therefrom, print of the shifted dots is not overlapped at a same position for respective colors and unevenness of shade due to positional shift can be made inconspicuous.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head having a staggered dot array, performing full-color printing, and inconspicuous printing deviation at a seam of the dot array.

[0002]

2. Description of the Related Art Heretofore, a heat transfer printer which drives a heating element of a print head to thermally transfer ink on an ink ribbon to a paper surface by sublimation or melting to perform printing, and ejects ink from an ink bottle to the paper surface. There is an ink-jet printer that performs printing by using an ink jet printer. Each of these printers forms an arbitrary print pattern on a sheet according to print information by a print head having a large number of print elements formed at a fine resolution of 300 dpi (dots / inch) or more. This records (prints and prints) characters and color images.

In particular, in a recording method using an ink jet printer, ink droplets (print dots) are ejected from a large number of fine holes (nozzles) arranged on an ink ejection surface of a print head, and the ink droplets (print dots) are printed on paper, cloth, or the like. It discharges and lands on the recording material and absorbs it, thereby recording characters, images, etc., generating less noise, requiring no special fixing process, and making full-color recording relatively easy. It is a recording method.

[0004] Full-color recording usually uses three color inks of three subtractive primary colors, yellow (yellow), magenta (red dye name) and cyan (greenish blue), or black characters or images. Recording (printing) is performed by using four color inks added with black (black) used for parts and the like.

As a method of discharging ink droplets,
A piezo-jet method that generates pressure due to mechanical deformation in the ink chamber using an electromechanical transducer such as a piezoresistive element (piezoelectric element), thereby discharging droplets from minute nozzles, or a heating element in a fine ink chamber There is a thermal jet method in which an electric pulse is applied to this, a bubble is generated at the interface between the ink and the heating element at a high speed, and a droplet is similarly ejected from a fine nozzle using the growth force of the bubble. .

[0006] The thermal jet method described above includes:
There are two configurations depending on the ejection direction of the ink droplet. One is a side shooter type that discharges ink in a direction parallel to the heat generating surface of the heat generating element, and the other is a roof shooter type that discharges ink in a direction perpendicular to the heat generating surface of the heat generating element.

As a method of manufacturing such a roof shooter type thermal ink jet head, a plurality of heating elements, a driving circuit for individually driving these elements, an ink supply path, and ink ejection are utilized by utilizing a silicon LSI forming processing technique and a thin film forming technique. There is a method of forming a nozzle (orifice) monolithically on one silicon chip substrate.

According to this method, for example, 10 mm × 15
resolution of 360 dpi on a silicon chip substrate
When a (dot / inch) print head is to be produced, 128 heating elements, drive circuits, and orifices (ink ejection holes) can be formed.

FIG. 4A is a plan view showing an ink ejection surface of such a roof shooter type thermal ink jet head (hereinafter simply referred to as a print chip), and FIG.
Is a rear view thereof. Also, FIG. 3C is an enlarged view showing the inside of the same view by removing the orifice plate in a portion surrounded by a dashed line a in FIG. 3A, and FIG. It is an AA 'sectional arrow view.

The print chip 1 shown in FIG. 1A is a print head having four nozzle rows 2 on one silicon chip substrate. These four nozzle rows 2 are configured to discharge ink of yellow ink (Y), magenta ink (M), cyan ink (C) or black ink (Bk), respectively.

As shown in FIGS. 1A to 1D, in a print chip 1, a drive circuit 4 is formed on an upper surface of a chip substrate 3 by an LSI forming technique, and a common ink supply path 5 is formed by, for example, wet etching. The common ink supply path 5
Ink supply holes 6 communicating with the
Penetrates the chip substrate 3.

Between the driving circuit 4 and the common ink supply path 5, 64 heat-generating portions (heat-generating elements) 7 of heat-generating resistors are formed by a thin film forming technique such as a photolithography technique. 7, a common electrode 8 and an individual wiring electrode 9 are connected as wiring electrodes, the electrode terminal 4-1 of the drive circuit 4 is connected to the individual wiring electrode 9, and the upper and lower ends of the surface of the chip substrate 3 are connected to the outside. A connection electrode terminal 10 is formed.

A partition 11 is laminated on the entire surface except for the connection terminal 10.
The partition wall 11 forms an ink seal wall on the one hand on the left side of the common ink supply path 5 for blocking ink from the outside, and on the other hand the ink seal wall on the individual wiring electrode 9 and the drive circuit 4 also blocks ink from the outside. Are formed, and the partition 11 in the portion of the individual wiring electrode 9 is formed with each heating element 7 and the heating element 7.
And a protruding portion 11-1 extending between them. Partition wall 1
If the portion on the individual wiring electrode 9 and the drive circuit 4 is a comb body, the protruding portion 11-1 extending between the heating elements 7 has a shape corresponding to the teeth of the comb.

As a result, the fine ink reservoirs 12 in which the heating elements 7 are located at the roots between the teeth are defined and formed by the number of the heating elements 7 using the teeth of the comb as partition walls.

Further, an orifice plate 13 is laminated thereon, and a large number of orifices 14 are formed at positions of the orifice plate 13 facing the heating elements 7 to form the above-described four nozzle rows 2. are doing. 4 nozzle rows 2
Are formed in parallel with each other, and the orifices 14 at the ends are formed to be flush with each other. That is, the four nozzle rows 2 are formed so as not to be displaced vertically.

With such a shape, the print chips 1 are completed on a number of chip substrates 3 on a silicon wafer (not shown). Then, finally, cutting is performed using a dicing saw or the like, the chip substrate is divided into individual chip substrate units, die-bonded to a mounting substrate, and terminals are connected to complete a print head in a practical unit.

In the printing chip 1, ink supplied from the outside to the ink supply holes 6 is supplied to the ink reservoir 12 through the common ink supply path 5, and the heating element 7 is used for printing.
Is selectively energized in accordance with the print information, and heat is generated instantaneously to cause a film boiling phenomenon in the ink. The pressure of the nuclear bubble causes ink droplets to be ejected from the orifice 14 corresponding to the heating element 7. In such a print chip 1, the ink droplets are ejected in a substantially spherical shape having a size corresponding to the hole diameter of the orifice 14, and are printed on the paper with a diameter approximately twice as large.

The configuration of such a print head can be classified into a serial type and a line type. Conventionally, in the serial type, the above-described print chip 1 was often used alone. However, in recent years, a print head having a longer length by arranging a plurality of print chips 1 in the sub-scanning direction of printing has been commercialized. is there.

In this serial type printer, the printing speed of the printer depends on whether the number of print chips 1 is large or small. Of course, the larger the number of print chips 1 arranged in the longitudinal direction, the wider the width (vertical width) in the sub-scanning direction for printing in one main scan, so that the printing process becomes faster.

On the other hand, a line-type printer uses a long print head in which print chips 1 are arranged to fill a print area in the main scanning direction, and the print head is fixed to the printer main body and only the paper is conveyed. This method itself corresponds to high speed.

In any case, the arrangement density of the print chips 1 conforms to the resolution of an image formed by the printer. The resolution is very common nowadays, 300dp
i (dot / inch), 600dp for high resolution
i is normal. 600m in millimeters is 1m
Approximately 24 printing elements per m (heating elements and orifices)
Are arranged in a line, and the pitch is about 42 μm. According to the current technology, a print chip having such a print element can be easily formed monolithically on a silicon wafer or a glass substrate as described above.

However, since the processing technology (mainly the processing device) has various limitations, the size of the unit chip (printing chip) is, for example, about 10 × 15 mm in the case of a printing chip for an ink jet printer head. You can only make things up to that point.

Therefore, in order to respond to the demand for higher printing speed as in recent years, a serial type printer performs printing with a vertical width as long as possible in one main scanning line. Therefore, it is necessary to connect the print chips in the sub-scanning direction to form a print head that is long in the sub-scanning direction. In a line type printer, forming a print head by connecting print chips in the main scanning direction has been an essential operation from the beginning.

FIG. 5A is a diagram schematically showing the configuration of a color print head of such a line type printer, and FIG. 5B is a diagram showing the adjacent print chip 1 (1-1, 1). −
It is a figure which takes out and enlarges two 2). Figure (a)
The color print head 15 shown in FIG. 4 extends in the main scanning direction indicated by a double-headed arrow x in the figure, and a total of 22 print chips 1 shown in FIG. They are arranged (staggered arrangement) to form a print area of length B in the main scanning direction.

In FIG. 1B, a large number (20 are shown) of printing elements (orifice 1) are arranged in one nozzle row 2.
4 and the heating element 7 shown in FIGS. 4 (c) and 4 (d), which is hidden below, hereinafter referred to as a print dot 14-1).

These printing dots 14-1 have a resolution of about 4 if the resolution is 600 dpi as described above.
They are arranged at a pitch of 2 μm. At both ends of the printing chip 1, although not shown, there are provided edges 17 on which the connection electrode terminals 10 shown in FIG.

As shown in FIG. 5 (a), the positions of the printing chips 1 arranged in two rows in the sub-scanning direction in the main scanning direction are alternately shifted and arranged in a staggered arrangement.
7B. On the other hand, as shown in FIG. 3B, the rightmost print dot 14-a of the lower print chip 1-1 in the zigzag arrangement and the upper print chip in the zigzag arrangement are arranged in the x direction. 1-2, the distance K in the x direction between the leftmost print dots 14-b.
Must be the same as the array density k between the print dots 14 of the print chip 1 (1-1, 1-2) itself.

If the print chips 1 and 1-2 are connected in a line by cutting off the edge 17 of the print chip 1 by force instead of the staggered arrangement as shown in FIG. In order to connect the two print chips 1-1 and 1-2 so as to maintain the above-mentioned pitch of 42 μm, a distance of 21 μm from the center of the print dot 14-a at the right end of one of the print chips 1-1. It is necessary to precisely cut the edge 17 at the position, and also to cut the edge 17 accurately at a position 21 μm away from the center of the print dot 14-b at the left end of the other print chip 1-2. is there.

In some cases, such an accurate cut is possible, but as a result, the end print dots 14
-A and 14-b are likely to be destroyed. Therefore, it can be said that the best connection is to stagger the positions in the x direction and connect them in a staggered arrangement as shown in FIG.

FIG. 6A is a diagram showing another example of the configuration of a color print head, and FIG. 6B is an enlarged view showing two adjacent print chips taken out. The color print head 18 shown in FIG. 5A has a print chip 21 having only one nozzle row 19 extending in the main scanning direction indicated by a double-headed arrow x on the sub-parent board in the same manner as described above. A total of 22 sub-print heads 22 are formed. The sub-print heads 22 are arranged in four rows in the sub-scanning direction on the parent board 24 to form a printing area of length C in the main scanning direction. I have. Each sub print head 22 includes a yellow ink (Y),
Magenta ink (M), cyan ink (C), and black ink (Bk) are respectively ejected.

Also in this case, the x of the rightmost print dot 23-a of the print chip 21-1 below the staggered array and the leftmost print dot 23-b of the print chip 21-2 above the staggered array are arranged in the x direction. The distance K ′ in the direction is the print chip 21 (21
-1, 21-2) must be the same as the array density k 'between the print dots 23 themselves.

[0032]

The above-mentioned x
Print chips 1-1 (or 2) below the zigzag arrangement
1-1) Right-side print dot 14-a (or 23-a)
And the print chip 1-2 (or 21-2) above the staggered arrangement
The distance K (or K ′) in the x direction between the print dots 14-b (or 23-b) at the left end of the print chip 1 (1-1, 1-
2) Or, in a staggered arrangement so that the arrangement density k (or k ') between the print dots 14 (or 23) of the print chip 21 (21-1, 21-2) itself becomes the same, extremely high accuracy is required. Requires a chip connection device.

If this precision is poor, the spacing K or K 'between adjacent printing chips may be coarser or denser than the spacing k or k' between the printing dots of the printing chip itself. If such a coarse or dense shift occurs in the interval between the print chips, the image formed on the paper by the ink droplets ejected from the orifice 14 at the joint between the print chips has the above-mentioned coarse or dense deviation. Light and dark spots occur depending on the color.

In particular, when the printing chips having the four nozzle rows shown in FIG. 5B are arranged in a staggered manner, the places where the shading of all the colors occur are overlapped at the same place, so that a single color is inconspicuous. Regarding minute shading, all of the colors of yellow, cyan, magenta, and black similarly cause shading at the same place and become very conspicuous. That is, in this case, since a nozzle array of four colors is formed on one print chip, no color misregistration or uneven shading appears in only one color. At the same time, color shift and shading are generated.

However, it is desirable that the positional deviation of each print chip on the print head should be 1/4 or less of the resolution of the printer. If the resolution of the printer is 600 dpi, for example, one print is required. Since the interval between the dots is 42.3 μm, the allowable deviation amount between the adjacent print chips is required to be about 10 μm or less, which requires extremely high precision technology.

Even in the case of a print head actually made with high precision, adjacent print dots (orifices) of adjacent print chips are affected by the influence of the warpage of the mother board when the print head is attached to the printer body. Often changes. Therefore, it is difficult to completely eliminate the unevenness of light and shade which appears as a streak along the paper transport direction in the printing portion between the adjacent print chips, and it is difficult to completely eliminate such unevenness. Was thought to be inevitable.

The object of the present invention is to solve the above-mentioned conventional situation,
An object of the present invention is to provide a print head in which unevenness in density due to a positional shift between adjacent print chips is less noticeable.

[0038]

The construction of the print head according to the present invention will be described below. First, in the print head according to the first aspect of the present invention, a dot array having a predetermined number of print dots in a first direction is arranged in a predetermined direction in a second direction, and printing of a different color for each predetermined line is performed. A print chip that performs staggered arrangement so as to extend in the first direction and enables printing exceeding the predetermined number of print dots in the first direction. The dot array of the predetermined row is configured such that the start dot and the end dot of the print dot are different in position in the first direction for each of the dot array.

Next, according to a second aspect of the present invention, a print head having a single dot array having a predetermined number of print dots in a first direction is staggered so as to extend in the first direction. The sub print heads arranged so as to be capable of printing exceeding the predetermined number of print dots in the first direction are arranged in a predetermined row in the second direction, and printing of different colors is performed for each of the predetermined rows. A first dot and a trailing dot in the staggered arrangement of the print chips in the sub print head are arranged so as to have different positions in the first direction for each of the sub print heads. You.

In any of the print heads, when the number of print dots in the dot array is N and the number of rows in the predetermined row is T, the first print head may be a first print head.
When the distance between the starting dot of the printing dot of the dot row array and the starting dot of the printing dot of the second dot row array is L, the distance L is configured to satisfy 1 ≦ L ≦ N / T. . In addition, for example, as set forth in claim 4, the first
Is the main scanning direction of printing, and the second direction is the sub-scanning direction of printing. Further, for example, the first direction is a sub-scanning direction of printing, and the second direction is a main scanning direction of printing.

[0041]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a diagram schematically showing a configuration of a color print head of a line type printer according to an embodiment, and FIG. 1B is an enlarged view showing two adjacent print chips. FIG. A color print head 30 shown in FIG. 1A is a color print head of a line type printer which can print, for example, a maximum of A4 size paper while conveying it vertically, and a total of 22 print chips 31 are used. Are arranged in a zigzag pattern on the parent board 32 (in a zigzag arrangement) so as to extend in the main scanning direction indicated by the double-headed arrow X in the figure.

As shown in FIG. 4B, each of the print chips 31-1 and 31-2 has four nozzle rows 33 (dot row array), and each nozzle row 33 has a predetermined number of N rows. (A printing element (see FIGS. 4 (a) to 4 (d)) composed of an orifice and a heating element therebelow) in the main scanning direction. The number N of the printing dots 33 is set variously according to the specifications of the printer of the apparatus main body, for example, 64, 128, 256, etc. (showing 20 in FIG. 4B).

In the above example, the four nozzle rows 33 formed on the print chip 31 are configured to perform printing in different colors of yellow, magenta, cyan, and black, respectively. In addition, since a total of 22 print chips 31 extending in the main scanning direction are arranged in a staggered manner, the print head 30 has a print area exceeding the range of the N print dots in the main scan direction. It is configured to be able to print D.

Each of the four nozzle rows 33 in each print chip 31 has a starting dot 34a (3
4a1, 34a2, 34a3, 34a4) and end point dot 34b (34b1, 34b2, 34b3, 34b4)
Are formed in such a manner that the positions in the main scanning direction are different from each other by L print dots (five in FIG. 4B) for each nozzle row 33 (the positions are shifted).

Accordingly, the interval m between the print dots 34 (end point dot and start point dot) at the end of each of the upper and lower print chips 31 in the adjacent staggered arrangement is equal to the array density n between the print dots 34 of the print chip 31 itself. It is desirable that the interval is the same as the above, but even if they are not exactly the same, that is, even if “m ≠ n”, there is no noticeable shading of the printed image.

That is, the print chip 31 shown in FIG.
-1 black (Bk) nozzle row 34-1-4 end point dot 34b4 and print chip 31-2 black (B
Even if the distance m between the nozzle dot 33a-4 of k) and the starting dot 34a4 is different from the array density n between the print dots 34 of the print chip 31 (31-1, 31-2) itself, (m
≠ n), the image in the sub-scanning direction by another color of this portion is
The printing dots of the cyan (C) nozzle array 33-1-3 of the printing chip 31-1 at regular intervals, and the magenta (M), respectively.
Is printed by the regular interval print dots of the nozzle row 33-1-2 and the regular interval print dots of the yellow (Y) nozzle row 33-1-1. do not do. In other words, the shading of the shade appears as a misregistration of only black (Bk), and the misalignment of another color does not overlap the same portion, so that the shading of the shading of only black does not stand out.

Similarly, the misalignment of “m ≠ n” is caused by the cyan (C) nozzle row 33-3 of the print chip 31-1.
1-3, the end point dot 34b3, and the start point dot 34 of the cyan (C) nozzle row 33-2-3 of the print chip 31-2.
a3, the image in the sub-scanning direction by another color in this portion is printed by the print chip 31 respectively.
-1, magenta (M) nozzle row 33-1-2, regularly spaced print dots, yellow (Y) nozzle row 33-1-1
Since the printing is performed by the printing dot of the regular interval of 1 and the printing dot of the regular interval of the black (Bk) nozzle row 33-2-4 of the print chip 31-2, there is no positional deviation, and the unevenness of shading by these colors is obtained. Does not occur. That is, also in this case, the shading of the shade appears as a displacement of only cyan (C), and the misalignment of other colors does not overlap the same portion. Therefore, the shading of the shading of only cyan (C) does not stand out.

Similarly, the misalignment of “m」 n ”is caused by the magenta (M) nozzle row 33-1-1 of the print chip 31-1.
2 end point dot 34b2 and the start point dot 34a of the magenta (M) nozzle row 33-2-2 of the print chip 31-2.
2, the end dot 34b1 of the yellow (Y) nozzle row 33-1-1 of the print chip 31-1, and the yellow (Y) nozzle row 33-2-1 of the print chip 31-2.
May also occur between the start point dot 34a1 and the image in the sub-scanning direction with other colors of those portions.
As described above, printing is performed with printing dots of other colors at regular intervals,
The shading of the other colors does not overlap at the same location, and therefore is not noticeable because it is shading of only one color.

As described above, the positions of the end dots between the nozzle arrays of the print chips 31 in the main scanning direction and the positions of the end dots in the main scanning direction are shifted by L dots, so that they are staggered. Even if there is a slight shift in the pitch between the end point dot and the start point dot between the print chips 31, the shading due to the position shift occurs for only one color at each position, that is, the shading of each color. Are not dispersed and overlapped at the same place.
Therefore, the shading becomes less noticeable as a whole.

The above-described nozzle row 3 between the print chips 31
It is preferable that the shift amount of No. 3 is suppressed to about １ ／ or less of the number of print dots 34 in the nozzle row 33. This “１ ／” means that the number of print dots 34 in the nozzle row 33 is divided by the number of rows (4) of the nozzle row 33 in the above example. Therefore, in general, the number of print dots 34 per color (one nozzle row 33) in the print chip 31 is N (number), and the number of colors (number of nozzle rows 33) is T (color or row). Assuming that the pitch of adjacent print dots is 1 (dot), the shift amount L (for each nozzle) of the nozzle row 33 for each color
Is preferably defined by the following inequality: 1 ≦ L ≦ N / T (L is an integer).

In this case, “L” print dots of the magenta (M) nozzle row 33-1-2 of the print chip 31-1 located on the left outside of the print area D shown in FIG. The “L × 2” print dots of the nozzle row 33-1-3 in (C) and the “L × 3” print dots of the black (Bk) nozzle row 33-1-4 are each actually printed. , And “L × 3” print dots of the yellow (Y) nozzle row 33-2-1 of the print chip 31-2 located on the right outside of the print area D, magenta “L × 2” print dots of the nozzle row 33-2-2 of (M) and “L” print dots of the nozzle row 33-2-3 of cyan (C) are also used for actual printing. It is a play dot that does not participate.

Referring to the print chip 31, the print dots 34 are formed at both ends of the color print head 30, respectively.
This length is wasted by “L × 3”, which is negligible in comparison with the advantage that the unevenness of density becomes inconspicuous even when the alignment is performed with low accuracy.

In the above embodiment, the nozzle row 3 for each color is used.
3 is shifted by the same shift amount L. However, since yellow is a color that is less noticeable than other magenta, cyan, or black, the nozzle arrays of magenta, cyan, and black are shifted by the same shift amount, respectively. Only the yellow nozzle array is arranged so as to be shifted from the other one of the nozzle arrays by a shift amount different from the above, and is arranged so as to fall within the range of the magenta, cyan and black nozzle arrays. You may.

FIG. 2A is a view schematically showing the configuration of a color print head in which only the yellow nozzle row is arranged with a different shift amount from the nozzle rows of the other colors.
(b) is a diagram showing two adjacent print chips taken out and enlarged. The color print head 35 shown in FIG.
A color print head of a line type printer capable of printing while transporting, for example, A4 size paper in a vertical direction as in the case of FIG. FIG. 1A also shows that a total of 22 print chips 36 extending in the main scanning direction indicated by the double-headed arrow X in the figure are arranged in a staggered pattern (staggered arrangement) on the parent substrate 37. Same as in the case.

As shown in FIG. 5B, four nozzle arrays 38 (formed in yellow, magenta, cyan, and black) formed on these print chips 36 (36-1, 36-2). 38-2-1 to 38-2-4) each include N print dots 39 in the main scanning direction. Of the four nozzle rows 38, the black (Bk) nozzle row 38-2-4 and the cyan (C) nozzle row 38-
The amount of deviation between 2-3 and the cyan (C) nozzle row 3
The amount of deviation between the nozzle row 8-2-3 and the magenta (M) nozzle array 38-2-2 is the distance corresponding to Q print dots 39 on the right side of the figure, whereas the shift amount is magenta (M). Nozzle row 38-2-2 and yellow (Y) nozzle row 38-2-2
The shift amount between the print dots 39 is shifted in the opposite direction (to the left in the figure) by P print dots 39. Where Q and P
Is “P <Q”.

In the above case, the yellow (Y) nozzle array 38-2-1 is replaced by the magenta (M) nozzle array 38-2.
-2 and the cyan (C) nozzle row 38-2-3, but the yellow (Y) nozzle row 38-2.
-1 is further shifted to the left so that the cyan (C) nozzle row 3
8-2-3 and black (Bk) nozzle array 38-2-4
May be set within the range.

In this case, the space between the seam of yellow and the seam of the other color is narrower than the space between seams of the other colors, but as described above, the unevenness of the shade of the yellow color itself is less noticeable. There is no problem because it is a color, and since there is no difference in dispersing the place where the shading of each color occurs, the shading becomes less noticeable as a whole also in this case.

In this case, the color print head 3
The length of play at the print dots of the print chip 36 at both end portions of No. 5 is a portion that cannot be printed in four colors, that is, “Q × 2” print dots. Here, assuming that Q = L, the length of the play of FIG. 2A is shorter than that of FIG. 1A by L (= Q) compared to the structure of FIG. I understand.

The configuration of the color print head 30 or the color print head 35 shown in FIG. 1 and FIG. 2 described above has a staggered arrangement of print chips having four nozzle rows. The configuration of the print head of the present invention in which the nozzle rows for each color are displaced in the main scanning direction is not limited to this.

FIG. 3 (a) is a diagram schematically showing the configuration of a print head according to another embodiment, and FIG. 3 (b) shows only the print chip at the end of the sub print head. FIG. As shown in FIG. 1A, the print head 40 has four sub print heads 41.
(41-1, 41-2, 41-3, 41-4) are arranged on the main board 42 side by side in the sub-scanning direction. In each sub print head 41, a total of thirteen print chips 43 each having only one nozzle row extend in the main scanning direction and are staggered. The sub print head 41-1 prints yellow (Y), the sub print head 41-2 prints magenta (M), the sub print head 41-3 prints cyan (C), and The print head 41-4 prints black (Bk).

The print chip 4 of these sub print heads 41
3 includes a single nozzle row 45 composed of N print dots 44, as shown in FIG. 3B, and is disposed at an end (for example, the right end in the figure) of an adjacent sub print head 41. Between the print chips 43 (between the print chips 43y and 43m, between the print chips 43m and 43c, between the print chips 43c and 43bk
The amount of deviation in the main scanning direction between
Are set to the distance of L pieces.

In this case, similarly to the case of FIGS. 1 and 2 described above, when the print chips 43 are arranged in the staggered arrangement on the sub print head 41, the print dots 44 and 44 at the ends of the adjacent print chips 43 are arranged. It is not necessary to use a high-precision device to adjust the pitch between the positions. In this case, even if there is a slight displacement, the places where the density unevenness occurs for each color due to the displacement are dispersed. In this case, the density unevenness is not conspicuous.

In the above-described embodiment, the print head elongated in the main scanning direction has been described as an example.
The present invention is not limited to this, but can be applied to the case where the print head is elongated in the sub-scanning direction.

[0064]

As described above in detail, according to the present invention, in a long print head in which print chips are formed in a staggered arrangement, a print dot connection portion between adjacent print chips is formed for each color. By shifting in the lengthening direction so that the printing of the connection part does not overlap the same position for each color,
Even if there is some misalignment in the pitch of the print dot connection part between adjacent print chips, the misregistration for each color occurs in a single color at a different location without overlapping the same location. It is not noticeable even if the print dots at the connection part have a slight misalignment, so it is possible to print an image of good image quality. Therefore, it is not necessary to use the above device, and therefore, it is possible to provide a print head with high productivity and high yield.

[Brief description of the drawings]

FIG. 1A is a diagram schematically showing a configuration of a color print head of a line type printer according to an embodiment, and FIG. 1B is a diagram showing two adjacent print chips taken out and enlarged. .

FIG. 2A is a diagram schematically showing a configuration of a color print head in which only a yellow nozzle array is arranged at a different shift amount from nozzle arrays of other colors, and FIG. It is a figure which takes out two pieces and expands them.

FIG. 3A is a diagram schematically showing a configuration of a print head according to another embodiment, and FIG. 3B is a diagram showing a positional relationship by extracting only a print chip at an end of the sub print head. is there.

4 (a) is a plan view showing an ink ejection surface of a conventional roof shooter type thermal inkjet head, FIG. 4 (b) is a rear view thereof, and FIG. 4 (c) is an orifice of a portion surrounded by a dashed line a in FIG. 4 (a). FIG. 3D is an enlarged view showing the inside with the plate removed, and FIG. 4D is a sectional view taken along the line AA ′ of FIG.

5A is a diagram schematically showing the configuration of a color print head of a conventional line printer, and FIG. 5B is a diagram showing two adjacent print chips taken out and enlarged.

FIG. 6A is a diagram showing another example of the configuration of a conventional color print head, and FIG. 6B is an enlarged view showing two adjacent print chips taken out therefrom.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 1-1, 1-2 Print chip 2 Nozzle row 3 Chip board 4 Drive circuit 4-1 Electrode terminal 5 Common ink supply path 6 Ink supply hole 7 Heating element 8 Common electrode 9 Individual wiring electrode 10 Connection electrode terminal 11 Partition wall 11-1 Projecting portion 12 Ink reservoir 13 Orifice plate 14 Orifice 14 Print dot 14-a Right end print dot 14-b Left end print dot 15, 18 Color print head 16 Parent substrate 17 Edge 18 Color print head 19 nozzle Row 21 (21-1, 21-2) Print chip 22 Sub print head 23-a Right end print dot 23-b Left end print dot 24 Parent board 30 Color print head 31 (31-1, 31-2) Print chip 32 parent board 33 (33-1-1 to 33-1-4, 33-2-1 to 3-2-3)
3-2-4) Nozzle row 34 Print dot 34a (34a1, 34a2, 34a3, 34a4)
Start point dot 34b (34b1, 34b2, 34b3, 34b4)
End point dot 35 Color print head 36 (36-1, 36-2) Print chip 37 Parent board 38 (38-2-1 to 38-2-4) Nozzle array 39 Print dot 40 Print head 41 (41-1, 41) -2, 41-3, 41-4) Sub print head 42 Parent board 43 (43y, 43m, 43c, 43bk) Print chip 44 Print dot 45 Nozzle array

Claims (5)

[Claims] 1. A printing chip for printing a different color for each row of a predetermined row by arranging a dot row array having a predetermined number of printing dots in a first direction in a second direction. A print head configured to be staggered so as to extend in one direction and to allow printing exceeding the predetermined number of print dots in the first direction, wherein each of the dots in the predetermined row in the print chip is provided. The print head according to claim 1, wherein the start point dot and the end point dot of the print dot are different in position in the first direction for each of the dot row arrays. 2. A printing chip having a one-dot array having a predetermined number of printing dots in a first direction is provided in the first direction.
Sub-print heads arranged in a staggered manner so as to extend in the direction of the first row and capable of printing exceeding the predetermined number of print dots in the first direction are arranged in a predetermined row in a second direction, and A print head that performs printing of a different color for each column, wherein a leading dot and a trailing end dot in the sub print heads of the staggered print chips are respectively provided for each of the sub print heads in the first direction. A print head characterized by different positions. 3. When the number of print dots in the dot row array is N and the number of rows in the predetermined row is T, the start dot of the print dots in the first dot row array and the second dot row array 3. The print head according to claim 1, wherein the distance L is 1 ≦ L ≦ N / T, where L is the distance between the print dot and the starting dot. 4. The print head according to claim 1, wherein the first direction is a main scanning direction of printing, and the second direction is a sub-scanning direction of printing. 5. The print head according to claim 1, wherein the first direction is a sub-scanning direction of printing, and the second direction is a main scanning direction of printing.