Spacer forming method and spacer fabricating device

[0056] The following describes specific implementation forms of the present invention with reference to the drawings. Furthermore, the present invention is not limited to the following embodiments but can be modified in various ways based on the technical idea of ​​the present invention.

[0057] (First implementation form)

[0058] The liquid crystal panel is constructed by enclosing liquid crystal in a gap of approximately several μm formed between a pair of substrates. One of the pair of substrates is composed of a polarizer, a color filter, a counter electrode, an alignment film, etc. formed on a glass substrate. On the other side, polarizers, pixel electrodes, driving transistors, and alignment films are formed on the glass plate.

[0059] The two substrates are laminated with the alignment films facing each other backwards. The sealing material used for bonding two substrates into one body is coated on one substrate and the spacer is formed on the other substrate on which the sealing material is not applied.

[0060] The spacer is usually formed on the color filter side substrate with the color filter. This color filter is like figure 1 The black matrix shown has a grid shape and red pixels R, green pixels G, and blue pixels B respectively formed in the grid holes. The black matrix 5 surrounds the periphery of each of the R, G, and B pixels with black edges, regardless of the on/off of the voltage applied to the liquid crystal cell, and often shields the non-pixel area of ​​the background light.

[0061] The spacers are usually contained in ink, and the ink 7 containing such spacers is dropped onto many intersections (spacers forming positions) of the grid-shaped black matrix 5 by an inkjet method. The ink 7 containing the spacer is not dropped directly onto the black matrix 5, but is dropped onto the position (overlapping position) corresponding to the intersection of the black matrix 5 in the opposite part (orientation film) of the substrate 1 forming the spacer and the other substrate. on.

[0062] The ink 7 containing the spacer includes a solvent such as water or an alcohol-based solvent, and a spacer dispersed in such a solvent. The spacer is a spherical plastic, glass, quartz, etc. having a diameter corresponding to the distance between the two substrates (the distance between the liquid crystal sealing gap, for example, about 4 to 5 μm). The viscosity, fluidity, volatility, and the dispersion density of the spacer in the solvent of the ink 7 containing the spacer must be adjusted to suit the dripping operation of the inkjet method.

[0063] Ink 7 with spacers such as figure 2 As shown, a nozzle having a plurality of (9 in this example) nozzles n1 to n9 is used to drop onto a plurality of spacer formation positions on the substrate 1. in figure 2 In the example of, for example, the ink 7 containing the spacers can be simultaneously dropped onto 9 spacer forming positions to form spacers.

[0064] When the ink 7 containing the spacer is dropped into the spacer forming position, the solvent will naturally evaporate or the evaporation surface will be heated to leave the spacer on the spacer forming position. At this time, the peripheral portion of the droplet dropped to the spacer formation position gradually evaporates the solvent, and as the center of the droplet becomes smaller, the spacer is also concentrated in the center, so that the spacer is arranged near the center.

[0065] In the present embodiment, at each spacer formation position, the ink 7 of the necessary number for forming the desired number of spacers is not collected together and dropped, but is divided into multiple drops. That is, the ink 7 is dripped multiple times for each spacer formation position. Compared with the prior art, this can reduce the amount of dripping per drop, thereby suppressing the degree of diffusion of the dripped ink 7 and reliably storing the spacer within a predetermined range (region of the black matrix 5). As a result, it is possible to prevent the spacers from being formed in the respective pixels of the R, G, and B transmitting portions of light contributing to the display, and suppress the degradation of the display image quality.

[0066] In the case where multiple drops of ink 7 are dropped at one spacer formation position, due to the volatility of ink 7 and the dropping time interval of each drop and the surrounding environment, etc., the droplets of ink 7 dropped earlier are sometimes dried (solvent evaporation) The next drop is dropped before, and sometimes it is dropped after the previously dropped drop has dried.

[0067] In addition, the ink 7 may be dropped to linear portions other than the intersection of the black matrix 5. However, generally speaking, compared with the width of the linear portion of the black matrix 5, the intersections of the grids of the black matrix 5 are sometimes formed as TFTs (thin film transistors) for operating the liquid crystal shutter, and the plane size is generally larger. However, even in the area of ​​the black matrix 5, if the ink 7 containing the spacer is dropped to a wide intersection, it is difficult for the spacer to diffuse into the pixels.

[0068] If it is possible to maintain a uniform interval between the substrates with respect to the direction of the substrate plate surface, it is not necessary to form spacers in all the intersections of the black matrix 5. In addition, the number of spacers required on the entire substrate also varies depending on the size of the substrate plane.

[0069] In addition, in this embodiment, for example, the amount of ink 7 dropped per one drop (amount of one drop) is 5.5 pl on average, and each drop (one drop) includes 1.3 spacers on average. In order to accommodate the ink 7 and the spacer in the area of ​​the black matrix 5 without spreading to the pixels, the amount of dripping per one drop (amount of one drop) is preferably 10 pl or less. However, if the amount of one drop is too small, one of the spacers may not be included in this one drop. Therefore, the amount of one drop (one drop) is preferably 5 pl or more.

[0070] The graph of FIG. 4 is a graph showing the probability of forming n spacers when ink 7 containing spacers is dropped at the same place once (1 drop), 2 times (2 drops), 3 times (3 drops) . Specifically, the vertical axis represents the probability (percentage) that the number of spacers shown on the horizontal axis is contained in the ink 7 after dripping. It is assumed that the dripping amount per one time (1 drop) is approximately 5.5 pl.

[0071] According to this graph, when the number of spacers is 0 in one drop, that is, there is no spacer in the droplet after the drop, it occurs with a probability of about 29%. However, in the case of 2 drops, the probability of the spacer being 0 cases ≤ 10%, and in the case of 3 drops, the probability of the spacer being 0 cases ≤ 2%.

[0072] When using the same ink 7 as in the past, in this embodiment, in order to suppress the spread after dripping, the amount of one drop is smaller than in the past, although one spacer is not included in one drip (one drop). The possibility is high, but from the results of Figure 4, it can be seen that even if the amount of dripping is small at one time, dripping to the same spacer formation position two to three times can significantly reduce the droplets after dripping. With the probability of the spacers, the spacers can be reliably formed at the formation positions of the spacers.

[0073] (Second implementation form)

[0074] The second embodiment of the present invention will be described below, wherein the same components as those of the first embodiment described above are denoted by the same reference numerals and detailed descriptions thereof will be omitted.

[0075] In the inkjet method, in order to make the ink 7 containing the spacer drop at a very narrow area, the nozzle diameter is very small, and it is easy to block the ink and cause clogging. The blocked nozzle cannot drip ink 7 containing spacers. Therefore, at a certain spacer formation position, whether it is the first time, the second time, ... or even the nth time, it receives from the same nozzle every time In the structure where the ink 7 is dropped, if the nozzle corresponding to the spacer formation position is closed, a drop of the ink 7 will not be dropped to the spacer formation position, so no spacer will be formed at the spacer formation position.

[0076] For this reason, in order not to drop the ink 7 from the same nozzle multiple times to one spacer formation position, the present embodiment is changed to be as follows in each drop image 3 As shown, the positional relationship between the nozzles n1 to n9 in the shower head 3 and the positions where the spacers are formed on the substrate 1 is changed.

[0077] Specifically, first, nozzles n7, n8, and n9 are positioned corresponding to the spacer formation position in the first column, the spacer formation position in the second column, and the spacer formation position in the third column, respectively, along the row direction of the spacer formation position ( In the horizontal direction in the figure), the inkjet head 3 at the start position (first position) is moved in the inkjet head scanning direction indicated by the arrow. In this way, the ink 7 containing the spacer is dropped from the nozzle n7 to the spacer forming position of the first row, and the ink 7 containing the spacer is dropped from the nozzle n8 to the spacer forming position of the second row, and the ink 7 containing the spacer is dropped from the nozzle n9. The ink 7 of the element drops to the spacer formation position in the third row.

[0078] The number of nozzles, the number of rows and columns where the spacers are formed are not limited image 3 The number shown in the example. In addition, the inkjet head 3 and the substrate 1 may have a structure capable of relative movement, or the inkjet head 3 may not move in the arrow direction but the substrate 1 may move in the reverse direction indicated by the arrow.

[0079] Next, the inkjet head 3 is shifted by 3 nozzles in the row direction (the right direction in the figure) from the starting position, and the nozzles n4, n5, n6, n7, n8, and n9 are respectively set to correspond to the spacers in the first column. Position, second row spacer formation position, third row spacer formation position, fourth row spacer formation position, fifth row spacer formation position, and sixth row spacer formation position are positioned at the second position, so The inkjet head 3 moves in the inkjet scanning direction indicated by the arrow. In this way, ink 7 with spacers is dropped from nozzle n4 to the spacer forming position in the first row, ink 7 with spacers is dropped from nozzle n5 to the spacer forming position in the second row, and spacers with spacers are dropped from nozzle n6. Ink 7 is dropped to the spacer formation position in the third row, ink 7 with spacers is dropped from nozzle n7 to the spacer formation position in the fourth column, and ink 7 with spacers is dropped from nozzle n8 to the spacer formation in the fifth column In the position, the ink 7 containing the spacer is dropped from the nozzle n9 to the spacer formation position in the sixth row. Although the spacer formation positions in the first to third rows receive the second drop of ink, they each receive ink dropped from a nozzle different from the nozzle that received the drop before.

[0080] Then move the inkjet head from the second position, for example, in the row direction (the right direction in the figure) by 3 nozzles. The nozzles n1, n2, n3, n4, n5, n6, n7, n8, and n9 are respectively set to correspond to the first position. 1 row of spacer formation position, 2nd row of spacer formation position, 3rd row of spacer formation position, 4th row of spacer formation position, 5th row of spacer formation position, 6th row of spacers The formation position, the spacer formation position of the 7th column, the spacer formation position of the 8th column, and the third position of the spacer formation position of the 9th column are positioned so that the inkjet head 3 jets ink along the arrow The head scan direction moves. In this way, the spacer-containing ink 7 is dropped from the nozzle n1 to the spacer forming position in the first row, the spacer-containing ink 7 is dropped from the nozzle n2 to the spacer forming position in the second row, and the spacer-containing ink 7 is dropped from the nozzle n3. Ink 7 is dropped to the spacer formation position in the third row, ink 7 with spacers is dropped from nozzle n4 to the spacer formation position in the fourth column, and ink 7 with spacers is dropped from nozzle n5 to the spacer formation in the fifth column Position, drop ink 7 with spacers from nozzle n6 to the spacer formation position in the sixth row, drop ink 7 with spacers from nozzle n7 to the spacer formation position in the seventh column, and drop the spacers with spacer from nozzle n8 The ink 7 is dropped to the spacer forming position in the eighth row, and the ink 7 including the spacer is dropped from the nozzle n9 to the spacer forming position in the ninth row. Although the spacer formation positions in the first to third rows receive the third drop of ink, they receive ink dropped from nozzles different from the nozzles that receive the first and second drops. Next, the same number of ink drops are performed on all spacer positions on the substrate 1 in the same manner.

[0081]According to the above, it is possible to drip (multiple drops) of ink from different nozzles with respect to one spacer formation position. Even if a certain nozzle is blocked, there will be no spacer formation where even a single drop of ink 7 is not dripped. position. Therefore, it is possible to reduce the possibility of generating a spacer formation position where none of the spacers are formed.

[0082] In addition, the method of changing the corresponding positional relationship between each nozzle n1 to n9 and each spacer formation position is not limited to the above, and the inkjet head 3 may be arranged in the column direction of the spacer formation position and scan in the row direction. The nozzles can be moved along the column direction for each drop. Or it is also possible to scan and drop in the column direction and then change the direction of the inkjet head 3 by 90° to scan and drop in the row direction.

[0083] (Third implementation form)

[0084] Next, the third embodiment of the present invention will be described. Here, the parts having the same structure as the first embodiment described above are given the same reference numerals, and detailed descriptions thereof are omitted.

[0085] Ink 7 with spacer figure 2 As shown, a line inkjet head type inkjet head 3 having a plurality of nozzles n1 to n9 arranged in a row is dropped onto a plurality of spacer formation positions on the substrate 1. The spacer-containing ink 7 can be simultaneously dropped to a plurality of spacer formation positions along the arrangement direction of the nozzles n1 to n9 to form spacers.

[0086] In this embodiment, the ejection head 3 and the substrate 1 move relatively in a direction orthogonal to the direction in which the nozzles are arranged, and at the same time, the ink 7 including the spacer is dropped from each of the nozzles n1 to n9. For example, relative to the stationary inkjet head 3, the substrate 1 is moved in a direction orthogonal to the direction in which the nozzles are aligned. Alternatively, the inkjet head 3 may be moved relative to the stationary substrate 1, or both may be moved.

[0087] The specific steps of forming the spacer will now be described.

[0088] Before ejecting the spacer-containing ink with respect to the substrate to be the product, first, test ejection is performed on the dummy substrate to confirm whether the ink ejection from each nozzle is abnormal. At this time, the ejection observation device observes the ink ejection of each nozzle.

[0089] The jet observation device is composed of a laser optical system, a camera, and an image processing device. The ejection observation device is installed in the inkjet head supporting position, and the ink droplets ejected when the inkjet head moves to the ejection observation position flash with a laser at a predetermined time interval, and the ink flying trajectory is obtained by imaging as a still image. This image is processed by the image processing device, the ejection speed and ejection angle of the ink are calculated, and the ejection abnormality is determined based on these values. The ejection observation device may be moved to the observation position of the installed ejection head without moving to a predetermined position. Observe the ink ejected from the nozzle and splashed onto the dummy substrate to determine whether it is an abnormal ejection. In the case where the nozzle is completely blocked and there is no ejection at all, an image of the flying trajectory of the ink cannot be obtained. Naturally, this situation is an abnormal injection. It is also possible to take the form of the ink ejected from the nozzle as a moving image, and calculate the ejection speed and ejection angle based on the moving image data.

[0090] When judging an abnormal ejection, for example, if the threshold value of the ejection velocity Vd of the nozzle ink is 5.0m/sec±5%, and the threshold value of the ejection angle θ is ±0.5°, the results of Table 1 can be used to determine the nozzle N0.8 and 17 are abnormal nozzles. No. 17 nozzles do not eject ink at all, and the ejection speed and ejection angle cannot be observed. In addition, the above-mentioned ejection angle θ corresponds to the inclination angle of the connecting line between the center of the nozzle and the center of the spacer formation position corresponding to the nozzle (the vertical line from the nozzle down to the substrate) with respect to the ink flying trajectory.

[0091] Nozzle No.

[0092] The ejection abnormality can also be determined based on the amount of deviation of the ink splashing position from the reference position (splashing to the position directly below the nozzle).

[0093] For example, when photographing each row of nozzles with a camera from a direction parallel to the relative movement direction of the inkjet head and the substrate, the amount of deviation of the splash position in the direction orthogonal to the relative movement direction is represented by D×tanθ. Where D is the shortest distance along the vertical direction between the nozzle and the substrate (the length of the straight line connecting the center of the nozzle and the center of the spacer formation position corresponding to this nozzle), for example, 0.5mm, and θ is from the center of the nozzle to the corresponding nozzle The spacers form the inclination angle of the line connecting the center of the position relative to the flying trajectory of the ink.

[0094] When the flying ink is captured by the camera from a direction orthogonal to the relative movement direction of the inkjet head and the substrate, the amount of deviation of the splash position in the direction along the relative movement direction is represented by Vs×D/Vd. Vs is the moving speed of the substrate relative to the stationary inkjet head, for example, 200 mm/sec, and D and Vd are as described above.

[0095] The injection abnormality can also be determined based on the value of D×tanθ+Vs×D/Vd.

[0096] When there is a nozzle with an abnormal ejection, the ejection from the abnormal nozzle is not performed, and only the normal nozzle is ejected to the substrate (the substrate that should actually become the product). If it is not directed to the ink pressure chamber corresponding to the abnormal nozzle The piezoelectric element whose pressure fluctuates applies voltage and cannot eject ink from the abnormal nozzle. Or in the case of a heated inkjet head, it is necessary to supply heat to the ink storage chamber.

[0097] For example in Figure 5 In the case where the two nozzles No. 8 and No. 17 out of the 32 nozzles are abnormal nozzles, first, the nozzles No. 8 and No. 17 are not ejected, and only the other normal nozzles (No. 1 to No. 1 to No. 7, 9-16, 18-32) Ink is ejected to the substrate. In this example, the substrate is moved in the arrow direction (the direction orthogonal to the direction in which the nozzles are arranged) relative to the stationary inkjet head 3, and ink is ejected from each nozzle and dropped onto the spacer formation position on the substrate 1. This first ejection end stage is in a state where there is no ink at the spacer formation positions in the 8th and 17th rows corresponding to the abnormal nozzles and the spacers contained in the ink are dripping.

[0098] Then put the inkjet head 3 in Figure 5 Move the size of 1 nozzle from the center to the right. The position where the spacers are formed in the 8th column corresponds to the normal nozzle of No.7, and the position where the spacers are formed in the 17th column corresponds to the normal nozzle of No.16. The nozzle and the substrate 1 can be relatively displaced along the direction in which the nozzles are aligned, or one of the inkjet head 3 and the substrate 1 can be moved.

[0099] In the above-mentioned state where the nozzles and the spacers form a positional correspondence relationship, the ink is ejected to the substrate 1 for the second time as in the first time. At this time, only No. 7 and No. 16 nozzles are ejected, and the other nozzles are not ejected.

[0100] As a result, the ink drop was performed once (1 drop) for all the spacer formation positions. in Figure 5 Among them, the nozzle ● indicates a nozzle that ejects ink, and ○ indicates a nozzle that does not eject ink. The ● on the substrate 1 indicates the spacer formation position. As described above, each spacer formation position receives one drop of ink. This prevents the part where the spacer is not formed from forming a line corresponding to the abnormal nozzle position. It is possible to stably maintain the desired liquid crystal sealing gap pitch.

[0101] (Fourth implementation form)

[0102] Reference below Figure 6 The fourth embodiment of the present invention will be described, in which the parts having the same structure as the above-mentioned first embodiment are assigned the same reference numerals, and detailed description thereof will be omitted. Figure 6 In the middle, ● indicates a normal nozzle, and ○ indicates an abnormal nozzle. The numbers on the substrate 1 indicate that several times (a few drops) of ink have been dropped at the formation positions of each substrate.

[0103] Figure 6 When the nozzles No. 8 and No. 17 out of the 32 nozzles are abnormal nozzles, the nozzles No. 8 and No. 17 are not sprayed first, and only No. 6-7, 9-16 , 18 to 32 normal nozzles eject ink to the substrate 1. In this example, the substrate 1 is moved relative to the stationary inkjet head 3 in the direction of the arrow shown in the figure (the direction orthogonal to the direction in which the nozzles are aligned), and at the same time from the normal nozzles such as No. 6 to 7, 9 to 16, 18 to 32 The ink is dropped into the spacer formation position on the substrate 1. At the end of this first ejection, the ink and the ink containing the spacers are in a state where they do not drip to the spacer formation positions of the third and twelfth rows positioned corresponding to the abnormal nozzles.

[0104] Then put the inkjet head 3 in Figure 6 Shift the size corresponding to 5 nozzles in the middle to the right, and shift the formation position of the spacer corresponding to the abnormal nozzle from the first one. In such a state of the corresponding relationship between the nozzle and the spacer formation position, the second ink jet is performed on the substrate 1 in the same manner as the first time described above. At this time, only the normal nozzles of No. 1-7, 9-16, and 18-27 do not eject ink from other nozzles.

[0105] As a result, in the first and second inkjets, two ink drops were performed at the spacer formation positions corresponding to the normal nozzles (two ink drops were performed), and in the first and second ink drops One ink drop can be performed at the spacer formation position corresponding to the abnormal nozzle in one of the two times. Since there is no spacer formation position that corresponds to the abnormal nozzle for the first time and the second time, the part where the spacer is not formed is prevented from forming a line corresponding to the abnormal nozzle position, and the desired liquid crystal sealing gap can be maintained stably Pitch.

[0106] For the spacer formation position where there are two drops of ink, it is not that the amount of ink necessary to form the desired number of spacers is collected together (to become one drop), but is divided into two drops, so each one The dropping amount of the drop is small, so that the spread of the dropped ink can be suppressed, and the spacer can be reliably accommodated in the predetermined range (the area of ​​the black matrix 5). As a result, it is possible to prevent the spacers from being formed in the R.G.B. pixels that contribute to the light transmission portion, and suppress the degradation of the display image quality.

[0107] It is preferable to form about 3 to 7 spacers within a certain range of each spacer formation position. The number of spacers per drop will vary with the concentration of the spacers in the ink, the size of the droplet, etc. However, when only one drop is dropped, there are sometimes no spacers at all or the desired number of spacers. From the viewpoint of preventing this situation, it is preferable to drop a plurality of ink drops on each spacer formation position.

[0108] (Fifth implementation form)

[0109] Reference below Figure 7 The fifth embodiment will be described, and the parts having the same structure as the above-mentioned embodiments are given the same reference numerals, and detailed descriptions thereof will be omitted. Figure 7 Medium ● means normal nozzle, ○ means abnormal nozzle. The numbers on the substrate 1 indicate how many times (how many drops) of ink droplets are performed at each spacer formation position.

[0110] Figure 7 In the case of 32 nozzles with two nozzles No. 8 and 17, the nozzles of No. 8 and No. 17 are not ejected at first, but only nozzles No. 7, 9-16, and 18-32. The normal nozzle sprays the substrate 1.

[0111] Then put the inkjet head 3 in Figure 7 Move 3 nozzles from the center to the right to shift the formation position of the spacer corresponding to the abnormal nozzle from the first phase. In such a state of the corresponding relationship between the nozzle and the spacer formation position, the substrate is ejected for the second time in the same manner as the first time described above. At this time, only nozzles Nos. 4-7, 9-16, 18-29 The normal nozzles eject, but not from other nozzles.

[0112] After this second time, put the inkjet head 3 in Figure 7 Move 3 nozzle parts from the center to the right, so that the spacer formation position corresponding to the abnormal nozzle is shifted from the first and second time. In such a state where the nozzles and the spacers form a positional correspondence relationship, the third inkjet is performed on the substrate in the same manner as the first and second times described above. At this time, only the normal nozzles of No. 1 to 7, 9 to 16, and 18 to 26 eject ink, and no ink is ejected from other nozzles.

[0113] According to the above results, in the first to third shots, three ink drops were performed at the spacer formation position corresponding to the normal nozzle (three drops of ink were dropped), and any one of the first to third shots The ink dripping was performed twice at the spacer formation position corresponding to the abnormal nozzle (two ink dripping was performed). In this embodiment, since the corresponding positions of the abnormal nozzle and the spacer formation position are also shifted for multiple times, it is possible to prevent the part where the spacer is not formed from forming a line corresponding to the abnormal nozzle position, and the position can be stably maintained. The pitch of the desired liquid crystal packing gap remains unchanged.

[0114] Furthermore, since all the spacer formation positions receive multiple drops of ink, the diffusion of ink can be suppressed, and the spacer can be reliably stored in the predetermined range (the area of ​​the black matrix 5). In addition, the probability of the number of spacers being 0 or not reaching the desired number can be reduced.

[0115] (Sixth implementation form)

[0116] Reference now Figure 8 The sixth embodiment of the present invention will be described, in which the parts having the same structure as the previous embodiments are assigned the same reference numerals, and detailed descriptions thereof will be omitted. Figure 8 In the position of the first jet head and the second jet head position ● indicates a normal nozzle, ○ indicates an abnormal nozzle, and in the third jet head position ● indicates a normal nozzle that ejects ink, and ○ indicates a nozzle that does not eject ( Including abnormal nozzles). The numbers on the substrate 1 indicate how many times (how many drops) of ink droplets are performed at each spacer formation position.

[0117] Figure 8 Among the 32 nozzles, No. 8 and 17 are the two nozzles with abnormal ejection. At this time, the nozzles of No. 8 and 17 are not ejected first, but only No. 7, 9-16, and 18-32 are normal. The nozzle ejects ink to the substrate 1.

[0118] Next, put the inkjet head 3 in Figure 8 Move 3 nozzles from the center to the right to shift the spacer formation position corresponding to the abnormal nozzle from the first time. In such a state where the nozzle and the spacer form a positional correspondence relationship, the substrate 1 is ejected for the second time in the same manner as the first time described above. At this time, only the normal nozzles of No. 4 to 7, 9 to 16, and 18 to 29 are ejected, and the other nozzles are not ejected.

[0119] After the second time, the inkjet head 3 is Figure 8 Move 3 nozzles from the center to the right to shift the position of the spacer corresponding to the abnormal spray from the first and second phases. In such a state where the nozzles and the spacers form a positional correspondence relationship, the substrate 1 is ejected for the third time in the same manner as the first and second times described above. At this time, only No. 2, 5, 11, 14 and other normal nozzles are ejected, and no other nozzles are ejected.

[0120] According to this, the number of ink drops can be uniformly 2 for all spacer formation positions, and fluctuations in the distribution of the number of spacers in the substrate surface can be suppressed. This can ensure a more stable liquid crystal sealing gap pitch.

[0121] In this embodiment, all the spacer formation positions can receive multiple drops of ink. Therefore, the diffusion of the dripped ink can be suppressed, and the spacer can be reliably stored in the predetermined range (the area of ​​the black matrix 5). It can also reduce the probability of the number of spacers being 0 or not reaching the desired number.

[0122] (7th implementation form)

[0123] The seventh embodiment of the present invention will be described below, in which the parts having the same structure as the above-mentioned embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0124] Picture 9 It is a block diagram showing the structure of the spacer forming device of this embodiment. This spacer forming device includes an inkjet head 3 having a plurality of nozzles arranged in a row (refer to figure 2 ), the inkjet head moving device 17, the substrate moving device 18, the jet observation device 19, the cleaning device 20, the storage device 14, the display device 15 and the processing device 10 to which they are connected.

[0125] The inkjet head moving device 17 uses, for example, a stepping motor or a piezoelectric motor as a driving source, and moves the inkjet head 3 in a direction parallel to the direction in which the nozzles are arranged. The substrate moving device 18 moves the stage supporting the substrate 1 in a direction (scanning direction) orthogonal to the nozzle parallel direction. The ejection observation device 19 is a laser optical system, a camera, an image processing device, etc., which observe the ejection form of the nozzle as described above. The storage device 14 stores abnormal nozzle positions such as semiconductor memory, magnetic disks, and the like. The processing device 10 has a control unit 11 and a calculation unit (ejection pattern forming unit 12 and ejection abnormality determination unit 13).

[0126] Furthermore, in each of the above-mentioned embodiments, an X-Y stage that can move in two orthogonal directions (X-Y directions) can be used as the substrate moving device 18. Alternatively, the substrate may be fixed, and an X-Y stage movable in two orthogonal directions (X-Y directions) may be used as the inkjet head moving device 17.

[0127] See below Picture 10 The flowchart illustrates the spacer forming method of this embodiment.

[0128] First, the flow is started in step S1, and then the test injection is performed in step S2. This test injection is observed by the injection observation device 19 (step S3). The observation data (injection speed and injection angle) are sent to the processing device 10, and the injection abnormality determination unit 13 of the processing device 10 determines the injection abnormality based on the observation data.

[0129] When the result of this determination is that there are no nozzles with abnormal ejection at all, step S4 becomes "No", and ejection of all nozzles corresponding to the spacer formation positions in each row is performed (step S13), and the flow is ended (step S17). One drop or multiple drops can be sprayed at each spacer formation position.

[0130] When there are nozzles with abnormal ejection, it becomes "YES" in step S4, and it is determined in the next step S5 whether the number of abnormal nozzles is less than the allowable value. When the number of abnormal nozzles is too large, it becomes "NO" in step S5, and the display device 15 displays an error (step 14), automatically or manually selects the cleaning mode (step 15), and the cleaning device 20 performs nozzle cleaning (step S16) .

[0131] When the number of abnormal nozzles is below the allowable value, it becomes "YES" in step S5, and the position of the abnormal nozzle is stored in the storage device 14 (step S6). For example, in the above embodiments, the two nozzles No. 8 and No. 17 are stored as abnormal nozzles.

[0132] Based on this abnormal nozzle position and various set values ​​(the number of scans, the target number of ejection revolutions, the minimum number of ejections, and the minimum ejection line pitch), the ejection pattern forming unit 12 forms an ejection pattern (step S7). Examples of spray patterns are shown in Figure 11-16. The number of scans is the number of times the inkjet head and the substrate are moved relative to each other in a direction orthogonal to the nozzle alignment direction. The target number of ejection is the target number of ink drops (several drops) at a spacer formation position. The minimum number of ejections indicates that due to the existence of abnormal nozzles, it is relative to the number of ink drops that cannot accept the target number of ejection. Form the position, plan to ensure the lowest number of ink drops of this number. The minimum ejection line spacing indicates the degree to which the spacing between the columns (rows) of the spacer formation position of the drop receiving the number of times less than the ejection target number is ensured as much as possible, and in the case of adjacent, this line spacing is 0. On the other hand, the number of columns (rows) of the spacer formation position where the number of receptions does not reach the target number of injections may be set as a set value.

[0133] Figure 11-16 Among them, ○ represents a normal nozzle that does not eject ink, ◎ represents a normal nozzle that ejects ink, and ● represents an abnormal nozzle that does not eject ink. In addition, in each figure, the spacer formation position on the substrate is shown in a row along the nozzle parallel direction, and the number of ink drops is also shown.

[0134] Regarding the injection pattern formed in step S7, it is determined by steps S8 to S11 whether it satisfies the above-mentioned set value condition. When the conditions of each set value are not satisfied in steps S8 to S10, the injection pattern is corrected in step S7. In addition, when the setting condition of the number of scans is not satisfied, the increase of the number of scans is not conducive to productivity, and becomes "NO" in step S11, and the error display is performed on the display device 15 (step S14), and the cleaning is automatically or manually selected. Mode (step S15), nozzle cleaning is performed by the cleaning device 20 (step S16).

[0135] When the ejection pattern formed in step S7 completely satisfies the conditions of steps S8 to S11, based on the ejection pattern, the control unit 11 controls the operation of the inkjet head 3 and the substrate, and controls which nozzle to eject ink and drop the ink onto the substrate The spacer formation position on the upper side (step S12), and the flow ends (step S17).

[0136] Picture 11 The spray pattern example of is an example of a spray pattern in which only one drop is dropped to minimize the number of rows and maximize the interval between rows.

[0137] Picture 12 The ejection pattern example of is an example of the ejection pattern in which only one drop is dropped to widen the row interval and the number of rows is reduced in priority.

[0138] in Figure 13 In the example of the ejection pattern, the formation position of the spacer in the 11th row relative to the substrate 1 is one drop (one drop) that does not reach the set value "2" of the minimum number of ejections, which becomes an error. At this time, the jet pattern is corrected in step 7 above. Figure 13 If the ejection pattern example is changed to the movement amount of the inkjet head after the second time (the movement amount of the nozzle position) and the nozzle selection is changed Figure 14 In the example of spray pattern, the set value can be met without error.

[0139] in Figure 15 In the example of the injection pattern, errors often occur when the columns (rows) with the lowest number of injections "2" are adjacent to each other, and the set value of the interval between the lowest injection rows cannot be satisfied at "1" or more. At this time, the jet pattern is corrected by step 7 above. If will Figure 15 The ejection pattern example is changed to the change of the movement amount of the inkjet head (the movement amount of the nozzle position) after the second time and the change of the nozzle selection Figure 16 In the example of spray pattern, the set value can be met without error.