JP2014040024A - Recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording method in which deterioration in recording quality is suppressed even if recording is performed using a liquid discharge head that has been affected by telecentricity of an exposure device.SOLUTION: A liquid discharge head includes a recording element substrate in which a plurality of discharge ports for discharging ink is arranged side by side to form a discharge port array. The discharge port array has an inclined discharge portion including some of the discharge ports each having an angle in a thickness direction of the recording element substrate. Processing for reducing the density of a portion where an image is formed by the discharge port included in the inclined discharge portion from image data is performed, and ink is discharged from the discharge port based on the processed image data.

Description

  The present invention relates to a recording method using a liquid discharge head that discharges liquid.

  An example of using a liquid discharge head that discharges a liquid is an ink jet recording apparatus that performs recording by discharging liquid ink onto a recording medium. As a method for producing a liquid discharge head used in an ink jet recording apparatus, Patent Document 1 introduces a method using a projection type i-line exposure apparatus. The liquid discharge head described in Patent Document 1 generates a discharge port forming member provided with a discharge port and a flow path for supplying liquid to the discharge port, and discharge energy used for discharging ink from the discharge port. And a substrate having an energy generating element.

  And the manufacturing method of the discharge port of the liquid discharge head of this patent document 1 is as follows. First, a positive photosensitive resin layer is formed on a substrate. Then, the formed positive photosensitive resin layer is exposed to form a liquid flow path pattern. Next, a negative photosensitive resin layer to be a discharge port forming member is formed on the formed pattern. Then, the formed negative photosensitive resin layer is subjected to i-line exposure, patterned, and developed to form discharge ports.

  By this method, an extremely good circular discharge port can be easily obtained with good reproducibility.

  Further, in order to process an ejection port array (rows of a plurality of ejection ports) of a liquid ejection head having an angle of view larger than that of the exposure apparatus by an exposure apparatus using a projection type i-line, the ejection port array is set to 2 in the longitudinal direction. It is common to divide and expose, that is, to divide into two exposures. By doing in this way, a liquid discharge head provided with the discharge port row | line more than an angle of view can be manufactured.

JP 2009-166492 A

  However, when exposure is performed in a divided manner, a boundary portion (hereinafter also referred to as a “joint portion”) between a portion exposed first time and a portion exposed second time in the formed ejection opening array is referred to as an exposure apparatus. If exposure is performed at the outer peripheral portion of the angle of view, a problem arises. Specifically, the ejection port array is formed under the influence of telecentricity caused by the optical system of the exposure apparatus.

  The exposure of the i-line exposure apparatus is a projection exposure in which the laser light that has passed through the position of the discharge port pattern formed on the mask of the exposure apparatus is a projection exposure that is reduced by the lens unit and exposed to a wafer composed of a plurality of substrates. The exit is affected by telecentricity. Therefore, the cross section of the discharge port array of the liquid discharge head has a shape as shown in FIG. It should be noted that the shape is exaggerated for ease of imagery.

  When recording is performed by a recording apparatus having a liquid ejection head manufactured by the above method, the ejection ports 25 located at both ends of the ejection port array 29 are formed on the recording element substrate 21 as shown in FIG. Since the ink droplets are parallel to the vertical direction, the ejected ink droplets land vertically on the recording medium 43. Therefore, there is no deviation between the position of the ejection port 25 and the position of the dot 44 formed on the recording medium 43. However, as the ejection port 25 is gradually affected by the telecentricity as it approaches the connecting portion 42 that is the boundary between the first exposed portion and the second exposed portion, the thickness direction of the recording element substrate 21 is increased. With an angle to Along with this, the ejected ink droplets also land on the recording medium 43 so as to gradually approach the joint portion 42, and therefore shift toward the joint portion 42 with the dots 44. Therefore, the dots 44 are concentrated on the recording medium 43 at a position facing the connecting portion 42, and black streaks are generated in the recorded image.

  Further, the distance between the recording medium 43 formed by the ink droplets ejected from the ejection port 25 near the connecting portion 42 and the dots 24 is the distance between the sheets (the distance between the liquid ejection head 21 and the recording medium 43). Changes if fluctuates. In other words, if the distance between the papers is small, the flying distance, which is the distance from when the ink droplets are ejected from the ejection ports 25 until they land on the recording medium 43, is also small. . However, if the inter-paper distance is large, the flying distance of the ink droplet is large, and the deviation between the position of the ejection port 25 and the position of the dot 44 is large.

  In general, the discharge port 25 (nozzle) inclined in the direction of the connecting portion 42 is formed in the vicinity of the connecting portion 42, and the inclination becomes larger as the connecting portion 42 is approached. Therefore, in order to solve this problem, for example, there is a method of moving the positions of the ejection ports 25 in the vicinity of the connecting portion 42 in a direction away from each other so that the dots 44 do not overlap. However, if the position of the ejection port 25 is determined in accordance with, for example, the maximum distance between sheets (the distance between the liquid ejection head and the recording medium is the largest), the connecting portion 42 is obtained when the distance between the sheets is reduced. The distance between the dots 24 by the ink ejected from the nearby ejection ports 25 increases. As a result, white streaks occur in the recorded image.

  In a recording apparatus that takes various paper-to-paper distances depending on the type of recording medium, image quality without black or white stripes is required at any paper-to-paper distance.

  The present invention has been made in view of the above problems, and provides a recording method in which reduction in recording quality is suppressed even when recording is performed using a liquid discharge head affected by the telecentricity of an exposure apparatus. The purpose is to do.

  The liquid ejection head includes a recording element substrate in which a plurality of ejection ports for ejecting ink are arranged to form an ejection port array, and the ejection port array has an angle with respect to the thickness direction of the recording element substrate. And an inclined discharge part composed of the discharge outlet of the part. From the image data, a process of reducing the density of the portion where the image is formed by the discharge port forming the inclined discharge portion is performed. Then, based on the processed image data, ink is ejected from the ejection port.

  According to the present invention, even when recording is performed using a liquid discharge head affected by the telecentricity of the exposure apparatus at the time of manufacture, it is possible to suppress a reduction in recording quality.

It is a schematic diagram of one Embodiment of a liquid discharge head. It is a schematic diagram which shows the image of exposure with the stepper of i line | wire. It is a schematic diagram which shows the method of dividing | segmenting and exposing using an i line | wire stepper. It is the schematic of the AA cross section of FIG. It is a figure for demonstrating the image processing method. It is a schematic diagram for showing the difference in flight distance. It is a schematic diagram explaining the discharge outlet row | line | column of a 2nd Example. It is a schematic diagram explaining the discharge outlet row | line | column of a 3rd Example. It is a schematic diagram explaining the discharge outlet row | line | column of the modification of a 3rd Example. FIG. 6 is a schematic diagram illustrating a cross section of an ejection port array and a landing position of an ink droplet.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In addition, the same number is attached | subjected to the structure which has the same function in an accompanying drawing, and the description may be abbreviate | omitted.

(First embodiment)
FIG. 1 is a schematic diagram of an embodiment of a liquid discharge head. The liquid ejection head 51 is formed by a recording element substrate 1 formed of a silicon (Si) substrate and an ejection port forming member 4 made of a resin material laminated on the recording element substrate 1. The recording element substrate 1 and the discharge port forming member 4 may be integrally formed to form one recording element substrate. On the recording element substrate 1, the ejection energy generating elements 2 are arranged in two rows at a predetermined pitch, and the supply port 3 formed by anisotropic etching of the Si substrate is further provided with the ejection energy generating elements 2. Are opened so as to be sandwiched between the two rows. The discharge port forming member 4 is formed with a plurality of discharge ports (nozzles) 5 provided at positions facing the respective energy generating elements 2. The plurality of discharge ports 5 is hereinafter referred to as “discharge port array 9”. The discharge port forming member 4 also functions as a flow channel member that forms an individual flow channel 6 that communicates from the supply port 3 to the discharge port 5. In the description of the present embodiment, not only the opening on the surface of the discharge port forming member 4 but also a part of the flow path 6 connected to the opening is expressed as the discharge port 5.

  Each energy generating element 2 generates heat in response to a drive control signal from a control unit (not shown) of the recording apparatus main body. Therefore, in the liquid ejection head 51, energy (for example, heat energy) generated by the energy generating element 2 is added to, for example, ink filled in the flow path 6 through the supply port 3. Then, the ink droplets are ejected from the ejection port 5 by the foaming pressure due to heating and adhere to the recording medium, so that recording can be performed.

  The recording apparatus of the present invention includes a liquid ejection head 51, a carriage that mounts the liquid ejection head 51, and that scans a recording medium that is transported at a position facing the liquid ejection head 51, a control unit, a recording medium, and a liquid ejection head. And at least a sensor for detecting the distance between the two. For recording on the recording medium, scanning of the carriage in the width direction of the recording medium, ink ejection from the liquid ejection head 51, and conveyance of the recording medium are performed alternately.

  A method for forming the discharge port 5 of the liquid discharge head 51 will be described. First, a positive photosensitive resin layer is formed on the recording element substrate 1, and then the positive photosensitive resin is patterned by a photolithography process to form an ink flow path pattern.

  Next, a layer of a negative photosensitive resin that forms the discharge port forming member 4 is formed on the recording element substrate 1 on which the flow path pattern is formed. Next, in the i-line exposure apparatus, the negative photosensitive resin layer is subjected to pattern exposure using i-line that is ultraviolet light through a mask, and development processing is performed to form the discharge ports 5. Examples of the i-line exposure apparatus that exposes the discharge port 5 include an i-line stepper.

  Next, a method for forming the discharge port 5 will be described more specifically. FIG. 2 is a schematic diagram showing an image of exposure with an i-line stepper. The wafer 11 on which a plurality of recording element substrates 1 are arranged is later cut out by a dicer or the like to become individual recording element substrates 1. The mask 10 has an ejection port pattern 12, and laser light 14 (i-line light) that has passed through the pattern is projected through the lens unit 13 and exposed onto the wafer 11.

  In order to form an ejection port array having an angle of view larger than that of the i-line stepper, for example, a method of performing exposure in two steps is generally used. FIG. 3 is a schematic diagram showing a method of dividing and exposing using an i-line stepper.

  As shown in FIG. 3A, exposure is performed through a mask 10 on which a 1st shot pattern 15 and a 2nd shot pattern 16 which are ejection port patterns are formed. First, with the shutter 21 covering the 2nd shot pattern 16, the first exposure is performed using the 1st shot pattern 15 (see FIG. 3B). Note that the i-line of the stepper is applied to substantially the entire mask 10.

  Next, the second exposure is performed using the 2nd shot pattern 16 in a state where the first shot pattern 15 is covered with the light-shielding shutter 21. At this time, the position of the wafer 11 (recording element substrate 1) exposed by the first exposure through the position of the A portion 17 of the 1st shot pattern 15 and the B ′ portion 20 of the 2nd shot pattern 16 are in the longitudinal direction. Then, exposure is performed so as to be adjacent or overlap with each other (see FIG. 3C). In addition, the part irradiated by the 1st exposure is shown with the broken line of FIG.3 (c).

  By performing the exposure in two steps in this way, it is possible to form a discharge port array pattern having a size larger than the angle of view of the stepper. Then, by performing development processing, the ejection port array 9 is formed (see FIG. 3D).

  The telecentricity is poor at the positions of the A portion 17 and the B ′ portion 20 located near the outer periphery of the angle of view (the outer periphery of the mask 10), and the A ′ portion 18 and the B portion 19 located near the center of the mask 10 are telecentric. Good sex. When exposure is performed to form the discharge port array 9, the portion A portion 17 having poor telecentricity in the 1st shot pattern 15 and the portion B 'portion 20 having poor telecentricity in the 2nd shot pattern 16 are connected to form the discharge port array 9. It formed (refer FIG.3 (d)). That is, the portion A ′ portion 18 with good telecentricity in the 1st shot pattern 15 and the portion B portion 19 with good telecentricity in the 2nd shot pattern 16 are arranged at both ends in the longitudinal direction of the ejection port array 9.

  As shown in FIG. 4 showing the AA cross section of FIG. 1, a plurality of discharge ports 5 are formed in the discharge port forming member 4. Then, in the thickness direction of the discharge forming member 4 in the vicinity of the joint portion 22, which is a boundary portion between the portion exposed first time and the portion exposed second time in the discharge port row 9 of the discharge port row 9. On the other hand, the inclined discharge part 52 which consists of the discharge port 5 which has an angle with respect to is formed. In other words, the ink from the ejection port 5 that forms the inclined ejection unit 52 is ejected obliquely with respect to the surface of the recording medium 23, more specifically, near the position of the recording medium 23 that faces the connecting part 22. Is done. In FIG. 4, the recording element substrate 1 is omitted.

  In the recording method of the present invention, even if a liquid ejection head having an ejection port affected by the telecentricity of the exposure apparatus is used, it is possible to suppress the degradation of the recording quality.

  First, a recording procedure by the recording apparatus of the present invention will be briefly described. A computer is connected to the recording apparatus via, for example, a USB (Universal Serial Bus) interface. In the computer, a printer driver is stored as software. The printer driver transmits image data such as a document or a photograph desired by the user to the recording device in response to a print command from the user.

  Based on the image data transmitted from the computer to the recording apparatus, the control unit drives various motors such as a carriage motor that drives the carriage on which the liquid discharge head 51 is mounted and a conveyance motor that conveys the recording medium. The control unit also sends a drive control signal to the energy generating element 2 of the liquid ejection head 1 to eject ink based on the image data, thereby forming a recorded image on the recording medium 23.

  Black streaks occur in the recorded image because the dots 24 by the ink ejected from the ejection ports 5 forming the inclined ejection section 52 are concentrated on the position of the recording medium 23 facing the connecting section 22 and the ink ejection. This is because this is performed while the carriage is moving in the width direction of the recording medium.

  Therefore, in the present embodiment, in consideration of the angle of the discharge port 5 of the inclined discharge unit 52 and the distance between the sheets, the density at a position corresponding to a portion where a streak can be formed on the recorded image is reduced if no processing is performed. The image data is processed by the control unit. That is, the image data is processed so that the density of the position where recording is performed by the ejection port 5 forming the inclined ejection section 52 is reduced in the input image data. Then, a recorded image is formed based on the processed image data.

  When the image data is not processed by the control unit, the ink ejected from the ejection port 5 of the inclined ejection unit 52 causes black streaks as in the prior art. However, as shown in FIG. 5, when the image data is processed as described above by the control unit, the density of the portion where the dots overlap in the recorded image causes a black streak is reduced. Does not appear. That is, it is possible to prevent black streaks from occurring in the vicinity of the position facing the connecting portion 22 in the recorded image.

  Note that as the processing of the image data, conversion processing such as brightness, contrast, and color tone may be performed. In the above description, the case of reducing the density has been described. However, the process for increasing the density of the image data may be performed as necessary.

  As shown in FIG. 4, in the longitudinal direction of the ejection port array 9, the smaller the inter-paper distance at the start of recording, the closer the ink ejected from the ejection port 5 that forms the inclined ejection part 52 on the recording medium 23. The distance between the dots 24 increases. Therefore, when the distance between the sheets is small, the degree of performing the process of reducing the density on the image data is reduced in the process in the control unit. In the longitudinal direction of the ejection port array 9, the distance between adjacent dots 24 on the recording medium 23 of the ink ejected from the ejection ports 5 forming the inclined ejection part 52 increases as the inter-paper distance decreases. If such a processing method is not used, white streaks may occur.

  As described above, it is possible to prevent black streaks and white streaks from occurring in a recorded image by performing processing for changing the density of image data input from a computer or the like in advance by the control unit. .

  Further, the ejection port 5 serving as the inclined ejection unit 52 has an angle with respect to the thickness direction of the recording element substrate 1. For this reason, the flying distance L2 until the ink ejected from the ejection port 5a serving as the inclined ejection unit 52 lands on the recording medium 23 is the ink ejected from the ejection port 5b parallel to the thickness direction of the recording element substrate 1. It is greater than the flight distance L1 until landing on the recording medium 23 (see FIG. 6). Accordingly, the time required for the ink ejected from the ejection port 5a having an angle with respect to the thickness direction of the recording element substrate 1 to land on the recording medium 23 is also increased. As a result, when ink is simultaneously ejected from the ejection ports 5a and 5b, the ink ejected from the ejection ports 5a lands on the recording medium 23 later than the ink ejected from the ejection ports 5b. The liquid discharge head 51 is mounted on a carriage (not shown) of the recording apparatus, and discharges ink while scanning the recording medium. Therefore, the ejected ink has a speed in the scanning direction of the carriage due to the scanning of the carriage, and if the time from the ejection of the ink to the landing becomes longer, the landing position is shifted accordingly. . Therefore, the landing position of the ink discharged from the discharge port 5a is shifted in the carriage movement direction. However, by making the timing of ink ejection from the ejection port 5a earlier than that of the ejection port 5b, it is possible to prevent landing position deviation in the scanning direction of the carriage when the ink lands on the recording medium 23.

(Second embodiment)
In the present embodiment, the thickness of the recording element substrate 1 in the vicinity of the joint portion of the discharge port array 9, which is the boundary between the first exposed portion and the second exposed portion of the formed discharge port array. The ink discharge amount from the inclined discharge portion where the discharge port 5 having an angle with respect to the direction exists is adjusted. That is, the amount of ink discharged from the discharge ports near the connecting portion 22 and having an angle with respect to the thickness direction of the recording element substrate 1 is set to be larger than the amount of ink discharged from the discharge ports located at both ends of the discharge port array. Reduce.

  FIG. 7 is a schematic view of an AA cross section of the discharge port forming member 4 of FIG. Note that the recording element substrate 1 is omitted. In the present embodiment, as shown in FIG. 7, the diameter of the discharge port 5 of the inclined discharge unit 52 that includes the inclined discharge port 5 and in which the connecting portion 22 exists is set to the discharge port 5 positioned at the end of the discharge port array. Make it smaller than the caliber. By adopting such a configuration, the amount of ink ejected from the ejection ports 5 in the vicinity of the connecting portion 22 that causes black streaks in the recorded image is reduced. Therefore, one dot 24 becomes small and the interval between the dots 24 becomes large. Accordingly, the dots 24 ejected from the ejection port 5 near the joint portion 22 and formed on the recording medium 23 are less likely to overlap each other, and the dots are less likely to concentrate on the recording medium 23 at a position facing the joint portion 22. Therefore, overlapping of the dots 24 can be suppressed, and black streaks can be prevented from occurring in the recorded image.

  The connecting portion 22 is located at the center of the inclined discharge portion 52 in the longitudinal direction of the discharge port array 9. For this reason, the diameter of only the discharge port 5 positioned so as to sandwich the connecting portion 22 may be reduced.

  Further, when the distance between the sheets is the maximum, the dots 24 formed by the ink ejected from the ejection ports 5 that are positioned so as to sandwich the connecting portion 22 and have the most angle from the thickness direction of the recording element substrate 1 overlap each other. In this case, the dots do not overlap each other until the inter-paper distance is maximized. Even if dots overlap each other when the inter-paper distance is maximum, one dot 24 is small, so even if the dots 24 overlap each other, a large dot is not formed. Therefore, it is possible to prevent black stripes and white stripes from occurring even if the distance between the sheets changes.

  Further, since the diameter of the discharge port 5 may be adjusted by adjusting the size of the mask 10 at a position corresponding to the discharge port 5 at the position where it is desired to reduce the diameter, the liquid discharge head 51 of the present invention can be easily manufactured. Can do.

(Third embodiment)
In this embodiment, as shown in FIG. 8 (the recording element substrate 1 is not shown), the inclined discharge portion 52 is positioned at the most angle with respect to the thickness direction of the recording element substrate 1 that is located with the connecting portion 22 interposed therebetween. Ink is not ejected from one of the ejection ports 5 provided. That is, the discharge ports 5 are thinned out in the discharge port array 9 in which the plurality of discharge ports 5 are arranged at equal intervals, and the interval between the discharge ports 5 is increased. For example, one of the discharge ports 5 (and the energy generating element 2) positioned with the connecting portion 22 interposed therebetween may not be formed in advance or may be closed.

  At this time, the diameters of all the discharge ports 5 may be the same. However, when white stripes are conspicuous, as shown in FIG. 9 (printing element substrate 1 is not shown), the diameter of the other discharge port 5 is increased to reduce the number of non-printed portions. A configuration that aims to reduce may be adopted.

  By adopting such a configuration, it is possible to reduce the dots 24 concentrated on the recording medium 23 at a position facing the connecting portion 22. For this reason, it is possible to prevent black streaks from occurring in the recorded image.

DESCRIPTION OF SYMBOLS 1 Recording element board | substrate 3 Supply port 5 Discharge port 9 Discharge port row | line | column 15 1st shot pattern 16 2nd shot pattern 22 Connection part 51 Liquid discharge head 52 Inclined discharge part

Claims (6)

A plurality of ejection openings for ejecting ink and a recording element substrate having an ejection opening array formed thereon, the ejection opening array having a portion of an ejection angle with respect to the thickness direction of the recording element substrate; A recording method for recording on a recording medium using a liquid discharge head having an inclined discharge portion comprising an outlet,
The image data is subjected to a process of reducing the density of a portion where an image is formed by the discharge port forming the inclined discharge portion,
A recording method, wherein the ink is ejected from the ejection port based on the processed image data.   The recording method according to claim 1, wherein an amount of reducing the density is adjusted according to a distance between the liquid ejection head and the recording medium when recording is started.   The recording method according to claim 2, wherein the amount by which the density is reduced is reduced as the distance between the liquid ejection head and the recording medium when starting recording is smaller. A plurality of ejection openings for ejecting ink and a recording element substrate having an ejection opening array formed thereon, the ejection opening array having a portion of an ejection angle with respect to the thickness direction of the recording element substrate; A recording apparatus having a liquid discharge head having an inclined discharge portion comprising an outlet, and a control portion,
The control unit is a recording apparatus that performs a process of reducing a density of a portion where an image is formed by the discharge port forming the inclined discharge unit, on input image data.   The recording apparatus according to claim 4, wherein the control unit adjusts an amount of reducing the density according to a distance between the liquid discharge head and a recording medium when recording is started.   The recording apparatus according to claim 5, wherein the control unit decreases the amount of decreasing the density as the distance between the liquid ejection head and the recording medium when starting recording is smaller.