JP2006061795A - Droplet discharge method and droplet discharge apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharge method capable of controlling a total discharge amount for each nozzle with high accuracy even when a combination of nozzles for simultaneously discharging ink is changed.
In step S1, for each channel of an inkjet head 10, a discharge amount measured by discharging ink in only one channel is set as discharge amount data. In step S2, a discharge change amount that is a difference between the discharge amount measured by discharging ink simultaneously and the discharge amount of the corresponding channel in the discharge amount data is obtained. In step S3, the obtained discharge change amount is set as discharge amount correction data associated with the position of the channel to be discharged simultaneously. In step S4, the discharge amount of the channel selected from the discharge amount data is corrected based on the discharge amount correction data, and the number of dots, which is the discharge condition of the selected channel, is corrected using the corrected discharge amount. Ask. In step S5, the determined ejection condition, that is, the determined number of dots of ink is ejected, and the process ends.
[Selection] Figure 4

Description

  The present invention relates to a droplet discharge method and a droplet discharge device for discharging a droplet to attach a droplet on a substrate.

  A display device such as a liquid crystal display or an organic EL (Electro-Luminescence) is manufactured by depositing ink on a substrate using an inkjet head. For example, when manufacturing a color filter used in a liquid crystal display, by using an ink jet head, ink of three colors of red, blue, and green is ejected in parallel while moving the ink jet head in one direction. It can land on and adhere to. In the method using the inkjet head, the color filter pattern can be formed by ejecting three colors of ink in one scan as described above, and the landing position of the ejected liquid droplet is controlled in units of 1 μm. High accuracy that can be achieved is achieved, and color filters and the like can be manufactured by taking advantage of these advantages.

  As the ink jet head, there is a thermal jet type ink jet head that discharges ink by heat generated by a heater. This thermal jet type ink-jet head has the disadvantages that the ink is discharged by the heat generated by the heater, so that the energy efficiency is low and the power consumption is large, and the ink solvent that can be used is limited. .

  Other ink jet heads use shear mode ink jets that eject liquid droplets by changing the fluid pressure in the channels using shear strain generated by applying an electric field to the piezoelectric material that forms the partition walls between the channels. There is a head. This shear mode type ink jet head is more energy efficient than the thermal jet type ink jet head and has a high degree of freedom in selecting an ink solvent (see, for example, Patent Document 1).

  FIG. 5 is a diagram showing an example of the structure of a shear mode type inkjet head 10 used in the embodiment of the present invention. FIG. 5A is a cross-sectional view of the inkjet head 10. The inkjet head 10 includes a cover plate 11, a piezoelectric material 12, an electrode 13, a noise plate 16, a manifold 17, a conductive resin 18, and an external electrode 19. Consists of.

  A plurality of grooves for storing ink are formed in the piezoelectric material 12, and these grooves are hereinafter referred to as ink chambers or channels. Each ink chamber is surrounded by a cover plate 11 at the top, a piezoelectric material 12 at the left and right and the bottom, and a nozzle plate 16 having a nozzle 14 at the front, and a common ink chamber 15 for supplying ink at the rear upper part of the ink chamber. Communicating with The common ink chamber 15 communicates with a manifold 17 located behind the inkjet head 10, and ink is supplied from the manifold 17 to the common ink chamber 15. The electrode 13 is an electrode formed on the side surface of the partition wall that separates the ink chamber adjacent to the ink chamber, and is electrically connected to the external electrode 19 through the conductive resin 18.

  FIG. 5B is a diagram showing a part of the inkjet head 10 viewed from the noise plate 16 side, with the noise plate 16 removed. The ink chamber or channel is surrounded by the cover plate 11 at the top and the piezoelectric material 12 at the left and right and the bottom. Electrodes 13 are formed on both side surfaces of the partition wall of the piezoelectric material 12 that separates the respective channels, for example, the channel ChA, the channel ChB, and the channel ChC. The upper half and the lower half of the piezoelectric material 12 of the partition walls between the channels are polarized in opposite directions, and the partition walls are deformed by applying a potential difference to the electrodes 13 formed on both side surfaces of the partition walls. The liquid pressure in the channel is changed by the deformation, and the ink droplet 20 can be ejected from the nozzle 14.

  FIG. 6 is a diagram illustrating a voltage waveform applied to the electrode 13 in order to eject ink. FIG. 6A shows a voltage waveform V1 applied to the electrodes 13 formed on both side surfaces of the channel for ejecting ink. When a voltage is applied for time T1, the volume of the channel increases, so the amount of ink in the channel increases. FIG. 6B shows a voltage waveform V2 applied to the electrode 13 formed on the side surface of the channel side that ejects ink among the side surfaces of the channel adjacent to the channel that ejects ink. When the voltage is applied for the time T2, the volume of the channel through which the ink is ejected decreases, so that the fluid pressure in the channel increases and the ink is ejected from the nozzle 14. FIG. 6C is a voltage waveform V1-V2 showing a potential difference between the electrodes 13 formed on both side surfaces of both partition walls of the channel for ejecting ink. The period of the voltage waveform V1 and the voltage waveform V2 is a time obtained by adding the time T1, the time T2, and the time T3.

  FIG. 7 is a diagram for explaining the relationship between the voltage waveform shown in FIG. 6 and the deformation of the partition walls between the channels. FIG. 7A is a diagram showing a state where the partition walls of the channel are not deformed, and none of the partition walls is deformed. In FIG. 7B, the first drive pulse shown in FIG. 6A, that is, the voltage of the voltage waveform V1 is applied to the electrode 131 and the electrode 132 formed on the side surface of the channel ChB, which is a channel for ejecting ink. It is a figure which shows the state of a deformation | transformation of the partition of the channel at the time. Since the channel ChB expands, that is, the volume of the channel ChB increases, ink is supplied from the common ink chamber 15 to the channel ChB.

  FIG. 7C shows a second drive pulse, that is, a voltage waveform, on the electrode 133 and the electrode 134 formed on the side surface on the channel ChB side among the side surfaces of the channel ChA and the channel ChC adjacent to the channel ChB that is a channel for ejecting ink. It is a figure which shows the state of a deformation | transformation of the partition of a channel when the voltage of V2 is applied. Since the channel ChB contracts, that is, the volume of the channel ChB decreases, the fluid pressure in the channel increases and ink is ejected from the nozzles 14.

  FIG. 8 is a diagram showing a modification of the partition walls of the grouped channels. In the case of a structure in which the partition wall of the channel is shared with the adjacent channel, the shear mode type inkjet head cannot deform the partition wall so as to increase or decrease the volume of both of the adjacent channels. Ink cannot be ejected simultaneously from these channels. Therefore, a method is used in which the channels are divided into three or more groups so that the channels of the same group are not adjacent to each other, and each group is driven sequentially, that is, a voltage is sequentially applied to each group to eject ink.

  For example, the channels are divided into three groups, A group, B group, and C group, in which every second channel is selected. The A group includes channels 1A, 2A, and 3A, the B group includes channels 1B, 2B, and 3B, and the C group includes channels 1C, 2C, and 3C. A case where ink is ejected from a channel selected from the channels of the B group, for example, the channel 2B and the channel 3B will be described.

  FIG. 8A is a diagram showing a state where the partition walls of the channel are not deformed, and none of the partition walls is deformed. FIG. 8B shows deformation of the partition when the first drive pulse is applied to the electrodes on both side surfaces of the channel 2B and the channel 3B. The both partitions of the channel 2B and the channel 3B are shown in FIG. The volume of the channel 2B and the channel 3B is deformed so as to increase.

  FIG. 8C shows the second drive pulse applied to the electrodes on both sides of each of the electrodes other than the channels 2B and 3B, that is, the B group channels other than the channel 2B and 3B, and the A group and C group channels. The deformation | transformation of the partition when applying is shown. Both the partition walls of the channel 2B and the channel 3B are deformed so as to reduce the volume of the channel 2B and the channel 3B and to discharge ink from the respective channels.

  The potential difference of the voltage waveform shown in FIG. 6C is given to the channels for discharging ink, in this example, the electrodes on both sides of the partition walls of the channels 2B and 3B. Due to this potential difference, these channels are inflated, that is, in the state of negative pressure in the channel, maintained in the expanded state, contracted, that is, in the state of positive pressure in the channel, maintained in the contracted state, and without deformation, and eject ink. To do.

  The expansion maintaining time AP is a time for maintaining the expanded state, that is, a time for maintaining the expanded state, and is determined by the pulse width T1 of the first drive pulse. The pressure wave propagation time AL corresponds to the length of the ink chamber in the longitudinal direction of the ink chamber, that is, the direction perpendicular to the paper surface of each channel shown in FIG. It is time to propagate. As shown in FIG. 5A, the pressure wave propagation time AL is obtained by dividing the length LI of the ink chamber by the speed of sound a in the ink, where LI is the length of the ink chamber and a is the speed of sound in the ink. And can be expressed as AL = LI / a.

  When the expansion maintenance time AP is 1 to 2 times the pressure wave propagation time AL, the pressure fluctuation can be increased most effectively, and the discharge efficiency can be increased. In other words, a high discharge speed can be obtained at this time. Therefore, a preferable expansion maintenance time AP can be expressed as AP = k · AL. This coefficient k depends on the behavior of the meniscus in the vicinity of the hole of the nozzle 14, that is, the fluctuation of the position of the curved surface formed by the ink surface, and is usually a value of about 1-2. For example, when the length LI of the ink chamber is 1 mm and the coefficient k is 2, the expansion maintenance time AP is obtained from AP = 2AL and is about 2 μsec. The second drive pulse is a pulse given to cancel the pressure wave in the ink chamber, and its pulse width T2 is optimally twice the pulse width T1 of the first drive pulse.

  The time required for ejecting one ink droplet, that is, one droplet ejection cycle is a time obtained by adding the time T1, the time T2, and the time T3 as described above. Therefore, since the time T1 is the expansion maintaining time AP and the time T2 is twice the time T1, if the time T3 is half the time T1, one droplet discharge cycle is AP × (1 + 2 + 0.5) = 3. .5AP. For example, when the length LI of the ink chamber is 1 mm, as described above, the expansion maintaining time AP is about 2 μsec, and one droplet ejection cycle is about 7 μsec.

  In the above description, the example of ejecting ink from the channel 2B and the channel 3B selected from the channels of the B group, that is, the example of the B group as the drive group for ejecting ink is shown. However, the drive group is one group. There is no need to limit. For example, when the channel is divided into three groups of A group, B group, and C group, all the driving groups are switched to A group, B group, and C group every one droplet discharge period, so that all By using the channel of the group, ink can be ejected continuously for each droplet ejection cycle.

  The film thickness of the pattern formed on the substrate using the inkjet head depends on the total ejection amount of the ink ejected from the nozzle of the inkjet head to the ink receiving portion that forms the unit region to which the ink is to be adhered. Therefore, if the total ejection amount of ink ejected from each nozzle changes due to channel variation or the like, it becomes a film thickness unevenness and greatly affects the quality. In order to eliminate the film thickness unevenness, the discharge amount must be controlled with high accuracy.

  As a first conventional technique for controlling the discharge amount of a droplet, there is a filter manufacturing method in which the discharge amount of an ink droplet can be set for each drive timing of discharging an ink droplet that is a droplet. By changing the drive waveform of the ink droplet discharge amount for each nozzle, that is, the drive voltage, an attempt is made to eliminate the difference in the discharge amount due to the variation of each nozzle (see, for example, Patent Document 2).

  As a second conventional technique for controlling the discharge amount of droplets, there is a method for manufacturing a color filter that performs head shading correction for correcting density unevenness by adjusting the discharge density of ink for each nozzle. An attempt is made to make the ink ejection density constant by changing the number of ink ejections for each nozzle (see, for example, Patent Document 3).

  As a third conventional technique for controlling the discharge amount of droplets, there is a discharge method in which ink is discharged using nozzles other than the nozzles at both ends in the arrangement direction in which the discharge amount is 10% or more higher than the average value. By excluding channels whose discharge amount is far from the average value, a layer with uniform characteristics can be formed (see, for example, Patent Document 4).

  In the fourth conventional technique for controlling the discharge amount of droplets, when the discharge amount of ink varies depending on the combination of nozzles used, the discharge amount of the nozzles used in the combination is measured, and according to the measured discharge amount. There is a method of manufacturing a color filter that performs correction. By correcting the ejection amount based on the actually measured value, a color filter having uniformly colored pixels can be manufactured (see, for example, Patent Document 5).

  The head structure of the shear mode type ink jet head described above is a structure in which crosstalk occurs between the channels, and among the plurality of parallel channels, the channels near both ends are different from the channels other than the channels near both ends. Has discharge characteristics. Specifically, among the plurality of parallel channels, the channels near both ends have a faster discharge speed and a larger discharge amount than the channels other than the channels near both ends.

  FIG. 9 is a diagram showing an arrangement of nozzles of the inkjet head 10 shown in FIG. The inkjet head 10 includes a plurality of nozzles 1A, 1B, 1C, 2A, 2B, 2C,..., And these nozzles are divided into three groups, an A group, a B group, and a C group. The A group includes nozzles 1A, 2A, 3A,..., The B group includes nozzles 1B, 2B, 3B,..., And the C group includes nozzles 1C, 2C, 3C,. Since the nozzle and the channel correspond one-to-one, hereinafter, the nozzle is also referred to as a channel.

  FIG. 10 is a diagram illustrating an ejection change amount for each channel of the B group illustrated in FIG. 9. For the channel of the B group, the discharge change amount, which is the change amount of the discharge amount when ink is discharged only for one channel and when ink is discharged simultaneously with other channels, is shown. The horizontal axis represents the channel number, and the vertical axis represents the discharge change amount (pl: picoliter). The channel 1B has a discharge change amount of −0.19 pl, the channel 2B has a −0.32 pl, the channel 3B has a −0.37 pl, and the channels 4B to 7B have a discharge change amount of −0.38 pl.

  For example, when the B group is composed of 20 channels from channel 1B to channel 20B, the ejection amount when ink is ejected simultaneously from these channels is greater than the ejection amount when ink is ejected from one channel. Less. The discharge change amounts of the channels near both ends, that is, the discharge change amounts of the channels 1B to 3B and the channels 18B to 20B are smaller than the discharge change amounts of the channels 4B to 17B. That is, the discharge amounts of the channels 1B to 3B and the channels 18B to 20B tend to be larger than the discharge amounts of the channels 4B to 17B. Therefore, when ink is ejected onto the substrate, the thickness of the ink ejected from channel 1B to channel 3B and channel 18B to channel 20B tends to be thicker than the thickness of channel 4B to channel 17B.

  When ink is simultaneously ejected using a channel selected from the B group channels, for example, channel 1B to channel 15B, channel 1B to channel 3B and channel 13B to channel 15B become channels near both ends. The discharge amount of the channels near both ends tends to be larger than the discharge amounts of the channels 4B to 12B.

  As described above, the discharge change amount of the channels near the both ends among the channels selected to discharge ink at the same time is different from the discharge change amount of the channels other than the channels near the both ends, and thus the pattern formed on the substrate. The film thickness unevenness occurs in the film thickness, and the quality of the pattern is greatly deteriorated.

Japanese Patent Publication No. 6-61936 JP 2003-21714 A JP 2001-296420 A JP 2003-159787 A JP 2000-89019 A

  However, the first and second prior arts do not show a method of correcting the ink ejection amount of the selected channel when the channel selected for ejecting ink at the same time fluctuates. There is a problem that occurs.

  The third prior art uses channels other than the channels near the both ends where the discharge amount is 10% or more higher than the average value among the channels selected to simultaneously discharge ink, so the channels near the both ends are used. There is a problem in that the channels near both ends cannot be used.

  The fourth conventional technique measures the discharge amount of the nozzle of the combination to be used, and corrects the discharge amount for each nozzle according to the measured discharge amount. Therefore, it is used whenever the combination of nozzles to be used is changed. Therefore, there is a problem that it is necessary to measure the discharge amount of the nozzle to be performed, which requires a large amount of labor and time.

  An object of the present invention is to provide a droplet discharge method and a droplet discharge device that can easily control the total discharge amount for each nozzle with high accuracy even if the combination of nozzles that simultaneously discharge ink fluctuates. It is.

The present invention relates to a method for ejecting liquid droplets using a liquid droplet ejecting section capable of ejecting liquid droplets from a plurality of nozzles in order to attach the liquid droplets on a substrate.
Liquid droplets when liquid droplets are discharged from only one nozzle for each of the plurality of selected nozzles are set as discharge conditions for simultaneously discharging liquid droplets from the plurality of nozzles selected from the plurality of nozzles. The droplet discharge method is characterized in that the amount is calculated based on the liquid amount of the droplet corrected by predetermined discharge amount correction data, and the droplet is discharged under the determined discharge condition.

  According to the present invention, when a droplet is ejected using a droplet ejection unit capable of ejecting a droplet from a plurality of nozzles in order to deposit the droplet on the substrate, The discharge conditions for simultaneously discharging droplets from a plurality of nozzles selected from the above are set to a predetermined discharge amount for each of the selected plurality of nozzles when a droplet is discharged from only one nozzle. The liquid droplets are obtained based on the liquid amount of the liquid droplets corrected by the correction data, and the liquid droplets are discharged under the determined discharge conditions.

  In this way, the discharge conditions of the nozzles selected as the nozzles that simultaneously discharge the droplets are obtained based on the discharge amount that is the liquid amount of the droplets corrected with the predetermined discharge amount correction data. Even if the combination of nozzles to be discharged varies, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  In the invention, it is preferable that the ejection condition is the number of droplets ejected to a unit region having a predetermined unit area of the substrate.

  According to the present invention, for a nozzle selected as a nozzle that simultaneously ejects droplets, the number of droplets ejected to a unit region having a predetermined unit area of the substrate is corrected with predetermined discharge amount correction data. Since it is obtained on the basis of the discharge amount that is the liquid amount of the liquid droplets, the total discharge amount for each nozzle can be easily controlled with high accuracy even if the combination of nozzles that simultaneously discharge liquid droplets varies.

Further, according to the present invention, the discharge amount correction data includes the amount of liquid discharged when a droplet is discharged from only one of the plurality of nozzles and the droplet discharged simultaneously from the plurality of nozzles. The discharge change amount, which is the difference between the liquid amount of the liquid droplets discharged from the corresponding nozzle at the time, is correlated with the relative position from the outermost nozzle among the plurality of nozzles that simultaneously discharge the liquid droplets. Data,
The liquid amount of the droplets of the plurality of selected nozzles is corrected by the amount of change in ejection at the relative position corresponding to the nozzle.

  According to the present invention, the discharge change amount associated with the relative position from the outermost nozzle among the nozzles that simultaneously discharge droplets is used as the discharge amount correction data, so that it is selected as a nozzle that simultaneously discharges droplets. It is possible to correct the discharge amount of the nozzle with the change amount of discharge at the corresponding nozzle position in the discharge amount correction data to obtain highly accurate discharge conditions or the number of droplets, and at the same time, the nozzles that discharge droplets Even if the combination varies, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  Further, according to the present invention, the volume of the ink chamber for storing the droplet to be ejected can be changed by applying a voltage pulse, and the volume of the droplet ejection section can be decreased after increasing the volume of the ink chamber. A droplet is ejected by applying a voltage pulse.

  According to the present invention, when the droplet discharge unit is a shear mode type inkjet head, even if the combination of nozzles that simultaneously discharge droplets varies, the total discharge amount for each nozzle can be easily controlled with high accuracy. Can do.

The present invention also provides a droplet discharge means capable of discharging droplets from a plurality of nozzles in order to attach droplets on a substrate,
Storage means for storing discharge amount data indicating a liquid amount of a droplet when the droplet is discharged from only one nozzle and predetermined discharge amount correction data for correcting the liquid amount;
The amount of liquid droplets in the discharge amount data stored in the storage means for each of the selected plurality of nozzles is set as a discharge condition for simultaneously discharging droplets from the plurality of nozzles selected from the plurality of nozzles. And a control means for controlling the droplet discharge means so as to discharge the droplets under the determined discharge conditions based on the liquid amount of the droplet corrected by the discharge amount correction data stored in the storage means. This is a droplet discharge device.

  According to the present invention, the droplet discharge means can discharge droplets from a plurality of nozzles in order to deposit the droplets on the substrate, and the storage means discharges droplets from only one nozzle. Discharge amount data indicating the liquid amount of the liquid droplets and predetermined discharge amount correction data for correcting the liquid amount are stored, and from the plurality of nozzles selected from the plurality of nozzles by the control means The discharge conditions for simultaneously discharging the droplets are corrected by the discharge amount correction data stored in the storage unit for the selected plurality of nozzles for the liquid amount of the discharge amount data stored in the storage unit. The liquid droplet discharge means is controlled so as to discharge the liquid droplets under the determined discharge conditions.

  In this way, the discharge conditions of the nozzles selected as the nozzles that simultaneously discharge the droplets are obtained based on the discharge amount that is the liquid amount of the droplets corrected with the predetermined discharge amount correction data. Even if the combination of nozzles to be discharged varies, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  In the invention, it is preferable that the ejection condition is the number of droplets ejected to a unit region having a predetermined unit area of the substrate.

  According to the present invention, for a nozzle selected as a nozzle that simultaneously ejects droplets, the number of droplets ejected to a unit region having a predetermined unit area of the substrate is corrected with predetermined discharge amount correction data. Since it is obtained on the basis of the discharge amount that is the liquid amount of the liquid droplets, the total discharge amount for each nozzle can be easily controlled with high accuracy even if the combination of nozzles that simultaneously discharge liquid droplets varies.

Further, according to the present invention, the discharge amount correction data is discharged from the liquid amount of the liquid droplet of the discharge amount data stored in the storage unit and the corresponding nozzle when the liquid droplets are discharged simultaneously from the plurality of nozzles. The amount of change in discharge, which is the difference between the amount of liquid droplets, is data that correlates to the relative position from the outermost nozzle among the plurality of nozzles that simultaneously discharge droplets,
The control means corrects the liquid amount of the liquid droplets of the selected plurality of nozzles by an ejection change amount at a relative position corresponding to the nozzle.

  According to the present invention, the discharge change amount associated with the relative position from the outermost nozzle among the nozzles that simultaneously discharge droplets is used as the discharge amount correction data, so that it is selected as a nozzle that simultaneously discharges droplets. It is possible to correct the discharge amount of the nozzle with the change amount of discharge at the corresponding nozzle position in the discharge amount correction data to obtain highly accurate discharge conditions or the number of droplets, and at the same time, the nozzles that discharge droplets Even if the combination varies, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  Further, according to the present invention, the droplet discharge means can change the volume of the ink chamber for storing the droplet to be discharged by applying a voltage pulse, and decreases the volume after increasing the volume of the ink chamber. A droplet is ejected by applying a voltage pulse.

  According to the present invention, when the ink jet head as the droplet discharge means is a shear mode type ink jet head, even if the combination of nozzles that simultaneously discharge droplets fluctuates, the total discharge amount for each nozzle can be easily set. It can be controlled with high accuracy.

  According to the present invention, the discharge conditions of the nozzles selected as the nozzles that simultaneously discharge droplets are obtained based on the discharge amount that is the liquid amount of the droplets corrected with the predetermined discharge amount correction data. Even if the combination of nozzles for discharging droplets varies, the total discharge amount for each nozzle can be easily controlled with high accuracy, and a pattern with a desired film thickness can be easily and quickly formed on a substrate.

  Further, according to the present invention, for a nozzle selected as a nozzle that simultaneously ejects droplets, the number of droplets ejected to a unit region having a predetermined unit area of the substrate can be calculated using predetermined ejection amount correction data. Since it is calculated based on the discharge amount, which is the liquid amount of the corrected droplet, the total discharge amount for each nozzle can be easily controlled with high accuracy even if the combination of nozzles that simultaneously discharge droplets varies. .

  Further, according to the present invention, the discharge change amount associated with the relative position from the outermost nozzle among the nozzles that simultaneously discharge droplets is used as the discharge amount correction data, so that it is selected as a nozzle that simultaneously discharges droplets. A nozzle that discharges liquid droplets at the same time by correcting the discharge amount of the nozzles that have been corrected with the discharge change amount at the corresponding nozzle position in the discharge amount correction data to obtain highly accurate discharge conditions or the number of droplets Even if this combination fluctuates, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  Further, according to the present invention, when the droplet discharge unit is a shear mode type inkjet head, even if the combination of nozzles that simultaneously discharge droplets fluctuates, the total discharge amount for each nozzle can be easily controlled with high accuracy. be able to.

  Further, according to the present invention, the discharge conditions of the nozzles selected as the nozzles that simultaneously discharge droplets are obtained based on the discharge amount that is the liquid amount of the droplets corrected with the predetermined discharge amount correction data. Even if the combination of nozzles for discharging droplets changes, the total discharge amount for each nozzle can be easily controlled with high accuracy, and a pattern with a desired film thickness can be easily and quickly formed on a substrate. .

  Further, according to the present invention, for a nozzle selected as a nozzle that simultaneously ejects droplets, the number of droplets ejected to a unit region having a predetermined unit area of the substrate can be calculated using predetermined ejection amount correction data. Since it is calculated based on the discharge amount, which is the liquid amount of the corrected droplet, the total discharge amount for each nozzle can be easily controlled with high accuracy even if the combination of nozzles that simultaneously discharge droplets varies. .

  Further, according to the present invention, the discharge change amount associated with the relative position from the outermost nozzle among the nozzles that simultaneously discharge droplets is used as the discharge amount correction data, so that it is selected as a nozzle that simultaneously discharges droplets. A nozzle that discharges liquid droplets at the same time by correcting the discharge amount of the nozzles that have been corrected with the discharge change amount at the corresponding nozzle position in the discharge amount correction data to obtain highly accurate discharge conditions or the number of droplets Even if this combination fluctuates, the total discharge amount for each nozzle can be easily controlled with high accuracy.

  Further, according to the present invention, when the ink jet head as the droplet discharge means is a shear mode type ink jet head, even if the combination of nozzles that simultaneously discharge droplets fluctuates, the total discharge amount for each nozzle can be easily Can be controlled with high accuracy.

  FIG. 1 is an overview of a drawing apparatus 1 according to an embodiment of the present invention. The drawing apparatus 1 that is a droplet discharge device includes an inkjet head 10 and a stage 30 that are droplet discharge units. The inkjet head 10 is, for example, a shear mode type inkjet head shown in FIG. Hereinafter, the movement of the inkjet head 10 relative to the substrate 31 mounted on the stage 30 while discharging droplets is referred to as scanning.

  The inkjet head 10 ejects droplets to the ink receiving portion 32 that forms a unit region to which droplets are to be attached. Ink, which is a droplet ejected from a nozzle, is a solution in which a solute for forming a pattern on a substrate is dissolved. For example, when manufacturing a color filter, a pigment or dye such as red, blue, or green is dissolved. It is a solution.

  When one scan is completed, the inkjet head 10 moves in a direction orthogonal to the scan direction, and then scans to eject ink to the next stage ink receiving portion. Thereafter, the above-described operation is repeated until the ejection of ink to all ink receiving portions in a predetermined region on the substrate 31 is completed. At the time of scanning, not only the inkjet head 10 is moved, but the inkjet head 10 may be fixed and the stage 30, that is, the substrate 31 may be moved, or both may be moved. Furthermore, ink may be ejected only in one direction of the scanning direction, or ink may be ejected in both directions of the scanning direction.

  FIG. 2 is a detailed view of the ink receiving portion 32 shown in FIG. The ink receiving portion 32 forms a unit region in which ink ejected from the nozzles 14 of the inkjet head 10 is adhered and stored, and has a length L and a width M. Since the ink receiving portion 32 has hydrophilicity, the ink ejected to the ink receiving portion 32 spreads over the entire ink receiving portion 32. When the ink jet head 10 moves in the scanning direction, ink of the number of ink droplets described later is ejected to the ink receiving portion 32, and when the solvent evaporates, a pattern having a desired film thickness is formed on the ink receiving portion 32. .

  The ink receiving portion adjacent to the ink receiving portion 32 is separated by a barrier 33 which is a water-repellent member, and ink does not leak to the adjacent ink receiving portion beyond the barrier 33. The minimum resolution, which is the minimum ink discharge interval, is indicated by a dotted line, but is drawn more coarsely than the actual interval for easy understanding.

  FIG. 3 is a block diagram showing a configuration of the drawing apparatus 1 shown in FIG. The drawing apparatus 1 includes a control unit 41, a droplet discharge unit 42, a storage unit 43, and an input / output unit 44.

The control unit 41 is a part that controls the drawing apparatus 1 as a whole.
Processing Unit), a memory for storing a program, and a memory for temporarily storing information necessary for processing, and a predetermined program is executed by executing the program stored in the memory. Perform processing.

  The droplet discharge unit 42 is a shear mode type inkjet head that discharges ink by changing the fluid pressure in the channel using shear deformation generated by applying an electric field to the piezoelectric material forming the channel wall. Yes, for example, the inkjet head 10 shown in FIG. The droplet discharge unit 42 scans the substrate, and the ink receiving unit 32, which is a unit region to which ink is attached, for example, indicates the number of droplets instructed under the discharge conditions specified by the control unit 41, that is, the number of ink droplets Is ejected to form a pattern having a desired film thickness on the ink receiving portion 32 on the substrate.

  The storage unit 43 is a part for storing data such as discharge amount data and discharge amount correction data, and may be a readable / writable memory constituted by a semiconductor memory or a storage device such as a magnetic disk device. Well, the form doesn't matter. The ejection amount data is ejection amount data that is the amount of ink droplets measured by ejecting ink from only one channel for each channel to be selected by the droplet ejection unit 42. The discharge amount correction data is a discharge change amount that is a difference between the discharge amount for each channel of the discharge amount data and the discharge amount for each channel when ink is simultaneously discharged from all the channels to be selected by the droplet discharge unit 42. Is associated with the relative position from the endmost channel among the plurality of parallel channels. The discharge amount data is, for example, data shown in Table 1, and the discharge amount correction data is, for example, data shown in Table 2.

  The input / output unit 44 includes an input unit having an operation button for a user to input an instruction to the drawing apparatus 1 and an output unit such as a liquid crystal display for displaying information from the drawing apparatus 1 to the user or a printer for outputting to paper. It is comprised including. The input / output unit 44 transfers information input from the input unit to the control unit 41, and outputs information from the control unit 41 to the user to the output unit.

  When the channel for simultaneously discharging ink is selected as the selected channel, the control unit 41 causes the droplet discharge unit 42 to inject ink into the ink receiving unit 32 from the discharge amount data and discharge amount correction data stored in the storage unit 43. For each selected channel, for example, the number of ink droplets, that is, the number of dots. Specifically, the discharge amount of the selected channel is obtained from the discharge amount data stored in the storage unit 43, and the obtained discharge amount is determined by the discharge change amount at the corresponding channel position of the discharge amount correction data stored in the storage unit 43. to correct. The corrected ejection amount is substituted into equation (1) described later, and the number of dots is obtained for each selected channel. When the control unit 41 instructs the droplet ejection unit 42 to determine the calculated number of dots, the droplet ejection unit 42 ejects ink of the instructed dot number for each selected channel.

  FIG. 4 is a flowchart showing a droplet discharge method according to another embodiment of the present invention. A channel that simultaneously ejects ink is selected from the channels of the inkjet head 10 that is a droplet ejection unit, and the number of ink droplets of ink to be ejected is obtained for each channel based on data for correcting the ejection amount that has been obtained in advance. This process is executed when ink is ejected.

  In step S <b> 1, the control unit 41 uses the discharge amount, which is the amount of ink droplets measured by discharging ink for only one channel, for each channel to be selected of the inkjet head 10 as discharge amount data. Is stored in the storage unit 43 which is a storage medium. For example, Table 1 shows the discharge amounts measured for the channels 1B to 20B of the B group shown in FIG. The discharge amount of these channels is in the range of 4.58 pl to 4.77 pl.

  In step S <b> 2, the control unit 41 first discharges ink from the channels to be selected simultaneously from all the channels to be selected of the inkjet head 10 and discharges of channels corresponding to the discharge amount data stored in the storage unit. The difference from the amount is obtained as the discharge change amount. For example, the discharge change amount obtained for the channels 1B to 7B of the B group shown in FIG. 9 is the discharge change amount shown in FIG.

  In step S <b> 3, the control unit 41 associates the obtained ejection change amount with the relative position from the endmost channel among the channels that simultaneously eject ink, and stores the storage unit of the drawing apparatus 1 as ejection amount correction data. 43. The amount of ink ejection change for each channel when ink is ejected at the same time varies depending on the position from the end of the channel to be ejected simultaneously due to the influence of crosstalk between channels. For example, in the example shown in FIG. 10, the discharge change amount is −0.19 pl for channel 1B, −0.32 pl for channel 2B, −0.37 pl for channel 3B, and −0.38 pl for channels 4B to 7B. . The data indicating the relationship between the position of the channel to be discharged simultaneously and the discharge change amount is discharge amount correction data. Table 2 shows the discharge amount correction data in the example shown in FIG.

  As described above, the channel position and the ejection change amount are such that the decrease amount of the first channel from the end among the plurality of channels that eject ink simultaneously is as small as 0.19 pl, the second is 0.32 pl, and the third is There is a relationship that the amount of decrease is 0.37 pl, the fourth is 0.38 pl, and the amount of decrease in the fourth and subsequent channels is 0.38 pl, which is the same as the fourth amount of decrease, that is, constant. The amount of change in ejection is constant depending on the position in the selected channel even if the channel selected to eject ink at the same time fluctuates, that is, in the channel selected as the channel for ejecting ink at the same time. If the position is known, the discharge change amount can be specified.

  The amount of change in ejection depending on the channel position depends on the physical properties of the ink, the head structure of the inkjet head, and the like. In the head structure shown in FIG. 5, the discharge amount of the channels near the both ends among the channels that simultaneously discharge ink is larger than the discharge amount of the other channels, but may be reduced depending on the head structure.

  In step S4, the control unit 41 determines the ejection conditions of the selected channel selected from the selection target channels based on the ejection amount data and the ejection amount correction data stored in the storage unit 43 in order to eject ink simultaneously. Ask. Specifically, first, the discharge amount data and the discharge amount correction data stored in the storage unit 43 are read, the discharge amount of the selected channel is obtained from the discharge amount data, and the obtained discharge amount is determined as the discharge amount correction data, that is, the selected channel. The amount of change in discharge corresponding to the relative position is corrected. Next, using the corrected ejection amount, the ejection condition for each selected channel, for example, the number of ink dots to be ejected to the ink receiving unit 32, that is, the number of ink droplets, is obtained and instructed to the droplet ejection unit.

The number of dots N of ink discharged to the ink receiving portion 32 is L for the length of the ink receiving portion 32, M for the width, h for the film thickness of the pattern to be formed on the ink receiving portion 32, and discharge per ink droplet, that is, per dot. If the amount is V ₀ , the total amount of ink discharged to the ink receiving portion 32 is V _sum , and the solute concentration of the ink is P, it can be obtained by equation (1).

For example, if the length L of the ink receiving portion 32 is 600 μm, the width M is 200 μm, the film thickness h is 2 μm, the discharge amount V ₀ per dot is 5 pl, and the solute concentration P of the ink is 10%, the ink receiving portion 32 The number N of dots of ink to be ejected is 480 dots. The film thickness formed with one dot ink is approximately 0.004 μm when the film thickness h = 2 μm is divided by the number of dots N = 480, and the film thickness is formed with an accuracy of 0.01 μm. For this, it is necessary to control the number N of dots of ink ejected to the ink receiving unit 32 in units of dots. For this purpose, it is necessary to obtain the discharge amount of each channel with high accuracy.

  For example, when the channels 1B to 15B are selected from the channels 1B to 20B of the B group shown in FIG. 9 and ink is simultaneously ejected, ejection corrected for each of these selected channels. Table 3 shows the amount and the number of dots obtained from the corrected ejection amount.

The discharge amount shown in Table 3 was obtained by subtracting the discharge change amount at the corresponding position of the discharge amount correction data shown in Table 2 from the discharge amount of the channels 1B to 15B of the discharge amount data shown in Table 1. Is. For example, since the channel 1B and the channel 15B are the first channels from the ends, the discharge change amount of 0.19 pl is subtracted from the respective discharge amounts, and the channels 2B and the channels 14B are the second channels from the ends. Since the discharge change amount 0.32 pl is subtracted from each discharge amount, and the channel 3B and the channel 13B are the third channels from the end, the discharge change amount 0.37 pl is subtracted from each discharge amount, and the channels 4B to 4B. Since the channel 12B is the fourth and subsequent channels from the end, the value is obtained by subtracting the discharge change amount of 0.38 pl from each discharge amount. The number of dots shown in Table 3 is a value obtained by substituting the discharge amount shown in Table 3 into the discharge amount V ₀ of Equation (1) and rounding off the decimals. For example, the number of dots in channel 1B is 547, the number of dots in channel 2B is 559, and the number of dots in channel 3B is 563.

  In step S5, the droplet ejector 42 applies, for example, the number of dots obtained for each selected channel, specifically, the number of dots shown in Table 3 for each selected channel under the ejection conditions specified by the controller 41. To discharge.

  In the above-described embodiment, the number of dots ejected to the ink receiving unit 32 is calculated using the volume that is the ejection amount per dot. However, the number representing the physical amount of the ejection amount, such as density, transmittance, and ejection weight. It may be calculated using. For example, when calculating using the discharge weight per dot, the number of dots satisfying the weight of the film formed on the ink receiving portion 32 is obtained. In this way, by using the physical quantity, the total discharge amount for each channel can be obtained by calculation, and the number of dots necessary for realizing a desired film thickness can be obtained accurately.

  Instead of the storage unit 43 included in the drawing device 1, the discharge amount data and the discharge amount correction data are stored in a storage medium outside the drawing device 1, and the discharge amount data and the discharge amount correction data read from the storage medium are used. At the same time, the number of dots may be obtained by correcting the ejection amount for each channel that ejects ink. Since the discharge amount data and the discharge amount correction data are stored in the storage medium, no matter what the pattern on the substrate is, for example, when the shape of the ink receiving portion 32 is different or the pattern to be formed Even when the film thickness is different, the number of dots can be determined based on the stored discharge amount data and discharge amount correction data. The total discharge amount for each can be controlled with high accuracy, and a pattern with a desired film thickness can be easily and quickly formed on the substrate.

  The droplet discharge method and the droplet discharge apparatus according to the above-described embodiments can be applied to the manufacture of a color filter. For example, if ink of different colors is distributed to a plurality of inkjet heads or groups of nozzles and the above-described droplet discharge method is applied to each inkjet head or each group of nozzles, an accurate discharge amount The color filter can be manufactured quickly and inexpensively. Furthermore, it can be applied to an organic EL manufacturing apparatus for applying an organic EL light emitting material, a PDP manufacturing apparatus for applying a PDP (Plasma Display Panel) fluorescent material, or a wiring drawing apparatus for forming electrical wiring on a substrate. The applicable range is not limited to the above-described apparatus.

  The substrate on which ink is ejected according to the above-described embodiment is not limited to a substrate for a color filter, an organic EL, a PDP, or an electrical wiring, and it is necessary to control the ejection amount with high accuracy. Paper or a seal may be used, and the material to which the droplet is attached is not limited.

1 is an overview diagram of a drawing apparatus 1 according to an embodiment of the present invention. It is the figure which showed the ink receiving part 32 shown in FIG. 1 in detail. It is a block diagram which shows the structure of the drawing apparatus 1 shown in FIG. It is a flowchart which shows the droplet discharge method which is the other form of implementation of this invention. 1 is a diagram illustrating an example of a structure of a shear mode type inkjet head 10 used in an embodiment of the present invention. It is a figure which shows the voltage waveform applied to the electrode 13 in order to discharge an ink. It is a figure for demonstrating the relationship between the voltage waveform shown in FIG. 6, and the deformation | transformation of the partition between channels. It is a figure which shows the deformation | transformation of the partition of the channel divided into groups. It is the figure which showed the arrangement | sequence of the nozzle of the inkjet head 10 shown in FIG. It is a figure which shows the discharge variation | change_quantity for every channel of B group shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drawing apparatus 10 Inkjet head 11 Cover plate 12 Piezoelectric material 13 Electrode 14 Nozzle 15 Common ink chamber 16 Nozzle plate 17 Manifold 18 Conductive resin 19 External electrode 20 Droplet 30 Stage 31 Substrate 32 Ink receiving part 33 Barrier 41 Control part 42 Liquid Droplet discharge unit 43 Storage unit 44 Input / output unit

Claims (8)

In a method for ejecting droplets using a droplet ejection unit that can eject droplets from a plurality of nozzles in order to attach the droplets on a substrate,
Liquid droplets when liquid droplets are discharged from only one nozzle for each of the plurality of selected nozzles are set as discharge conditions for simultaneously discharging liquid droplets from the plurality of nozzles selected from the plurality of nozzles. A droplet discharge method characterized in that an amount is obtained based on a liquid amount of a droplet corrected by predetermined discharge amount correction data, and a droplet is discharged under the determined discharge condition.   The droplet discharge method according to claim 1, wherein the discharge condition is the number of droplets discharged to a unit region having a predetermined unit area of the substrate. The ejection amount correction data corresponds to the amount of liquid droplets ejected when droplets are ejected from only one of the plurality of nozzles and when droplets are ejected simultaneously from the plurality of nozzles. The amount of change in discharge, which is the difference between the amount of liquid droplets discharged from the nozzle, is data that associates the relative position from the outermost nozzle among the plurality of nozzles that simultaneously discharge droplets,
The droplet discharge method according to claim 1 or 2, wherein the liquid amount of the droplets of the selected plurality of nozzles is corrected by an amount of change in discharge at a corresponding relative position of the nozzles.   The droplet discharge unit can change the volume of the ink chamber storing the droplets to be discharged by applying a voltage pulse, and applies a voltage pulse that decreases after increasing the volume of the ink chamber. The droplet discharge method according to claim 1, wherein the droplet is discharged by this. A droplet discharge means capable of discharging droplets from a plurality of nozzles in order to deposit the droplets on the substrate;
Storage means for storing discharge amount data indicating a liquid amount of a droplet when the droplet is discharged from only one nozzle and predetermined discharge amount correction data for correcting the liquid amount;
The amount of liquid droplets in the discharge amount data stored in the storage means for each of the selected plurality of nozzles is set as a discharge condition for simultaneously discharging droplets from the plurality of nozzles selected from the plurality of nozzles. And a control means for controlling the droplet discharge means so as to discharge the droplets under the determined discharge conditions based on the liquid amount of the droplet corrected by the discharge amount correction data stored in the storage means. A droplet discharge apparatus characterized by the above.   6. The droplet discharge device according to claim 5, wherein the discharge condition is the number of droplets discharged to a unit region having a predetermined unit area of the substrate. The discharge amount correction data includes the liquid amount of the liquid droplet of the discharge amount data stored in the storage unit and the liquid amount of the liquid droplet discharged from the corresponding nozzle when the liquid droplets are simultaneously discharged from the plurality of nozzles. The discharge change amount that is the difference between the two and the nozzles that simultaneously discharge droplets is associated with the relative position from the outermost nozzle among the plurality of nozzles,
7. The droplet discharge device according to claim 5, wherein the control unit corrects the liquid amount of the droplets of the selected plurality of nozzles by a discharge change amount at a corresponding relative position of the nozzle. .   The droplet discharge means can change the volume of the ink chamber for storing the droplet to be discharged by applying a voltage pulse, and applies the voltage pulse that decreases after increasing the volume of the ink chamber. The liquid droplet ejection apparatus according to claim 5, wherein the liquid droplets are ejected by the operation.

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