Nozzle head, nozzle head holder, and droplet jet patterning device

First link members (56A and 56B), a pair of second link members (57A and 57B), and three head holders (51R, 51G, and 51B) are installed rotatably. Rotational pivots (50A and 50B) provided at intermediate portions of the second link members (57A and 57B) and a reference nozzle of the reference head holder (51R) are positioned on the same line in a main scanning direction. The reference head holder (51R) is rotated about the reference nozzle, and the other head holders (51G and 51B) are also rotated simultaneously. The head holders (51G and 51B) are formed to be movable parallel to a sub scanning direction, irrespective of the rotation angles thereof.

TECHNICAL FIELD

The present invention relates to a nozzle head holder and, in particular, to a nozzle head holder in which the nozzle pitch can be adjusted in a sub scanning direction and also the nozzle head position can be adjusted minutely in the sub scanning direction, and a droplet jet patterning device provided with the same.

BACKGROUND OF ART

Recently, as the use of inkjet printers of various configurations has spread widely, color inkjet printers that are capable of high-resolution color printing at substantially photographic quality have become popular. In an inkjet printer, a plurality of nozzle heads, each of which having a number (such as 128) of minute nozzles formed in one or a plurality of rows in the sub scanning direction, are mounted in a carriage. A dot pattern is formed on a discharge-target medium by discharging ink droplets from each nozzle, thus recording a desired image. Japanese Patent Application Laid-Open No. 11-334049 discloses a technique of varying the nozzle pitch by causing a movable link to move with respect to a fixed link, to rotate the nozzle heads partly.

In recent years, liquid-crystal displays have become common in personal computers, wordprocessors, copiers, fax machines, mobile phones, and various types of portable terminal. In addition, liquid-crystal displays that are capable of color display have recently been widely adopted. A color filter is used in the color display of a liquid-crystal display. A color filter is formed of a regular dot pattern of fine filter pixels in the three primary colors of light (red (R), green (G), and blue (B)) on a transparent film. The color filter can be formed by a droplet jet patterning device having a configuration similar to that of the above inkjet printer.

A droplet jet patterning device for manufacturing such a color filter is disclosed in Japanese Patent No. 3,121,226. This device is designed to discharge droplets of the three colors R, G, and B from a plurality of nozzles formed in a nozzle head, to record R, G, and B dot patterns on a glass substrate. The nozzle pitch can be adjusted to be suitably smaller than the actual nozzle pitch in the sub scanning direction by inclining the nozzle head with respect to the sub scanning direction. When the nozzle head is inclined, the discharge timing of each nozzle is made different to align the positions of the recording start edge on the glass substrate. Deviations of each nozzle from the center line of the nozzle array are corrected by controlling the discharge timing.

A droplet jet patterning device for manufacturing a color filter is disclosed in Japanese Patent Application Laid-Open No. 9-300664. In this case, the nozzle head is inclined and also the nozzle head is moved in the sub scanning direction. This device is provided with nozzle heads for the three colors R, G, and B that are formed in a plate. Each nozzle head is held in a state perpendicular to the discharge-target medium. The two ends of each nozzle head are supported in holders, with the holder at one end being connected rotatably to a head mount and the holder at the other end being connected rotatably to a slide member. Each nozzle head is urged toward the head mount side by a coil spring, so that the relative position of each nozzle head with respect to the head mount can be adjusted by using screws. If fine screws for slide members are used to move the slide members in the sub scanning direction, the inclination angle of the nozzle heads with respect to the sub scanning direction can be changed so that the dot pitch can be adjusted in the sub scanning direction.

Organic electroluminescent (EL) displays are gradually becoming practicable as the next generation of displays instead of liquid-crystal displays. An EL substrate for an organic EL display has an anode layer, a hole transport layer, a light-emitting layer, and a cathode layer formed on the surface of a glass substrate, by way of example. Various light-emitting organic compounds corresponding to light-emission colors are used in the light-emitting layer. An organic EL display has a simple configuration and can be made thinner, lighter, and less expensive, and it also has advantage such as little dependency on the angle of viewing and a lower power consumption.

The method of manufacturing an EL substrate for a color organic EL display will be briefly described here. Above an anode layer formed on a glass substrate, droplets for forming a hole transport layer are discharged and are then fixed by heating in a vacuum or an inert gas. Three different types of droplet corresponding to R, G, and B for an EL light-emitting layer are then discharged onto the hole-transport layer to form a regular dot pattern of three colors of light-emitting pixels. After the dot pattern has been heated in a vacuum, a cathode layer is formed over the EL light-emitting layer.

However, the above-described prior art has problems, as described below. First of all, since the inkjet printer of Japanese Patent Application Laid-Open No. 11-334049 has a configuration in which movable links are moved with respect to fixed links to incline the nozzle head itself, it is necessary to combine at least the fixed links, the movable links, and the nozzle head into a head mount to maintain the inclination angle. This configuration is complicated because the movable links move in an arc shape with respect to the fixed links. Therefore, it is difficult to manufacture a nozzle head unit with nozzle heads.

Japanese Patent No. 3,121,226 does not disclose any mechanism for supporting the nozzle head in an inclinable manner with respect to the sub scanning direction and the actuator for causing the rotation of the nozzle head. Japanese Patent No. 3,121,226 does not propose a technique for enabling removal of a plurality of nozzle heads as a nozzle head unit. The center of rotation during the inclination of the nozzle head is also not clear.

Since the droplet jet patterning device of Japanese Patent Application Laid-Open No. 9-300664 is provided with a plate-shaped nozzle head that stands vertically, there are large limitations on the shape of the nozzle head. During maintenance or replacement of the nozzle heads, each nozzle head must be removed from the holders. However, it would be difficult to set the vertical position of the nozzle head precisely when the two ends of the nozzle head can be inserted and removed from above with respect to the holders. If each nozzle head cannot be inserted and removed from above the holders, it is difficult to remove the nozzle head and thus maintainability cannot be ensured.

Moreover, since the center of rotation of each nozzle head is the rotational axis for supporting the holders, if the nozzle heads are partly rotated, all of the nozzles will change positions in both the main scanning direction and the sub scanning direction Y. For that reason, the data processing load is increased during the calculation of the recording drive data and a rotational angle for causing relative movement of the glass substrate with respect to the nozzle heads in the main scanning direction and the sub scanning direction, making it difficult to increase the precision of the pattern formation.

In addition, since the movement of the slide members is done by manually operating fine screws, the maximum inclination angle of the nozzle heads cannot be made so large. Accordingly, the width of variation of the dot pitch is small.

It often happens in the droplet jet patterning device that dots of a specific color (such as R dots) are displaced by a small distance from each of other dots (such as G or B dots) in the sub scanning direction, as shown inFIG. 29(c). In such a case, it is useful if each nozzle head is moved by just a predetermined distance in the sub scanning direction. However, the configuration of Japanese Patent Application Laid-Open No. 9-300664 enables fine movements of each nozzle head only in the lengthwise direction (nozzle array direction) of the nozzle head, making it impossible to move the nozzle head parallel to the sub scanning direction when the nozzle head is inclined with respect to the sub scanning direction. Since the calculation of the amount of fine movement in the sub scanning direction must be based on both the amount of movement due to the tangent screws and the inclination angle of the nozzle heads, the data processing load is increased during the obtaining of the recording drive data and the inclination rotational angle, making it difficult to increase the precision of pattern formation.

Furthermore, since the nozzle heads are returned in a parallel posture to the sub scanning direction and then the positions of the nozzle heads in the sub scanning direction must be minutely adjusted, the operation of the tangent screws is complicated. Since the positions of the tangent screws and the inclination state will vary with the inclination angle of the nozzle heads, a configuration in which the tangent screws are driven automatically would be totally impossible.

Thus an objective of the present invention is to provide a nozzle head holder in which the insertion and removal of nozzle heads is simple, and which enables the simple insertion to and removal from the device itself with the nozzle heads still installed.

Another objective of the present invention is to provide a nozzle head holder in which the rotatable angle of the nozzle heads is large and in which the nozzle heads can be moved parallel to the sub scanning direction, irrespective of the rotation angle of the nozzle heads.

A further objective of the present invention is to provide a droplet jet patterning device in which the above nozzle head holder is installed and a nozzle head that can be installed to such a nozzle head holder.

DISCLOSURE OF INVENTION

In order to solve the above-described problems, a nozzle head holder according to the present invention is characterized by holding a plurality of nozzle heads having a plurality of nozzles. Each nozzle head is disposed at a predetermined spacing in a main scanning direction. The nozzle head holder includes a four-bar linkage having a pair of first link members that extend parallel to the main scanning direction and a pair of second link members that connect the pair of first link members; and movement means for causing at least one nozzle head of the plurality of nozzle heads to move parallel to a sub scanning direction that is perpendicular to the main scanning direction. The two end portions of each of the nozzle heads are connected to the pair of first link members, respectively. The movement means causes the at least one of the nozzle heads to move parallel in the sub scanning direction (Y), relative to the pair of first link members.

Since this configuration ensures that at least one nozzle head of the plurality of nozzle heads can move parallel to the sub scanning direction with respect to the pair of first link members, the nozzle heads can be moved minutely in the sub scanning direction to finely adjust the positions of the nozzle heads in the sub scanning direction, irrespective of the rotation angle of the nozzle heads. The above structure makes it possible to perform accurate and efficient fine adjustments of the nozzle heads when it is necessary to finely adjust the positions in the sub scanning direction of the nozzle head for G and the nozzle head for B with respect to the nozzle head for R, in accordance with the disposition of pixels formed of three recording dots in R, G, and B, by way of example.

In addition, since a plurality of nozzle heads are provided, it is possible to form a pattern by discharging droplets of a plurality of types, when a color filter or color EL substrate is manufactured, by way of example.

Since this nozzle head holder is provided with the four-bar linkage, the pair of rotational pivots, and the nozzle heads having two end portions that are connected rotatably to the pair of first link members, respectively. The configuration of the nozzle head holder can be made simple. The configuration for removing and attaching the nozzle heads for repair or replacement can also be simplified, making it possible to ensure maintainability.

Since the four-bar linkage itself can be configured of high-precision components and the nozzle heads can be mounted highly precisely in this four-bar linkage, it is possible to manufacture a highly precise nozzle head holder that minimizes manufacturing errors.

It is preferable that concavities having guide surfaces are formed in the pair of first link members, respectively. The movement means are provided with a pair of roller members that are installed rotatably on the two end portions of the at least one of the nozzle heads, and pressure members that press the roller members against the guide surfaces. And the pressure members are moved parallel to the sub scanning direction along the guide surfaces, while the roller members are pressed against the guide surfaces.

This configuration makes it possible to move the nozzle heads finely parallel to the sub scanning direction, through the guide surfaces and the pair of roller members, even when the nozzle heads are in a rotational posture. In addition, since the pair of roller members are each positioned at fixed positions with respect to the pair of first link members, irrespective of the magnitude of the rotational angle of the nozzle heads, the movement mechanisms can be mounted at fixed positions of the first link members, and actuators for moving these movement mechanisms can be provided externally, so that fine adjustment of the nozzle heads in the sub scanning direction can be automated.

Preferably, the plurality of nozzle heads can be installed removably on the pair of first link members. This structure simplifies repair or replacement of the nozzle heads, improving maintainability.

The two end portions of each of the nozzle heads may be urged by a resilient member so as to be in surface-contact with upper surfaces of the first link members. If the two end portions of each nozzle head are in surface-contact with the first link members, errors in the heightwise positions of the nozzle heads in the vertical direction are minimized, and the height of the nozzle heads with respect to the discharge-target medium can be set precisely. Therefore, the performance of the discharge recording is increased.

Preferably, each of the nozzle heads is provided with a nozzle portion having a plurality of nozzles formed therein, and a head holder for supporting the nozzle portion. The two end portions of the head holder are connected to the pair of first link members, respectively.

A nozzle head according to the present invention is characterized in being used in the above-described nozzle head holder. In this nozzle head, a plurality of fine-diameter nozzles are formed in a row in the sub scanning direction, by way of example. Preferably, the pitch between these nozzles can be set to a dimension such as 75 dpi or 150 dpi. A pair of roller members can be provided for connecting the two ends of this nozzle head to the first link members in a rotatable manner, respectively. Since the roller members can rotate with respect to the nozzle head, smooth movement can be obtained by the rotation of the roller members during the rotation of the nozzle head as well as during the parallel movement of the nozzle head to the sub scanning direction in the inclined state.

A droplet jet patterning device according to the present invention includes: the above-described nozzle head holder; a head assembly attachment stand for installing the nozzle head holder in a removable manner; a medium holder means for holding a discharge-target medium; a relative movement generation means for causing the discharge-target medium to move in a main scanning direction and a sub scanning direction relative to the nozzle head; pivoting means for causing the four-bar linkage to pivot; and rotational pivots provided at intermediate portions of the pair of second link members. The pair of second link members are capable of rotating about the rotational pivots. The two end portions of the nozzle head are connected rotatably to the pair of first link members, respectively. The pivoting means causes the pair of second link members to rotate about the rotational pivots to cause the four-bar linkage to pivot

Since this droplet jet patterning device is provided with the nozzle head holder, the droplet jet patterning device has the similar effects to those of that nozzle head holder. Before pattern formation, when the pair of second link members is rotated about the rotational pivots at the intermediate portions thereof, the pair of second link members rotate, the pair of first link members move in the main scanning direction and also in opposite direction to each other. The two ends of each nozzle head connected to the pair of first link members are caused to move. The plurality of nozzle heads rotates with respect to the sub scanning direction. By rotating the nozzle heads with respect to the sub scanning direction, the discharge pitch in the sub scanning direction is adjusted finely, so that a desired discharge pitch is changed. And then, one pass of the discharge recording is done while the discharge-target medium is moved with respect to the nozzle head holder in the main scanning direction. After that, the next pass of discharge recording is done after a suitable relative movement of the discharge-target medium in the sub scanning direction. Thus, the discharge recording is done by repeating these operations sequentially.

Since the nozzle heads are rotated by causing the four-bar linkage to pivot, the rotation angle of the nozzle heads can be increased, so that it is possible to increase the width of variation of the discharge pitch in the sub scanning direction.

In this case, preferably, the droplet jet patterning device includes a movement drive means connected removably to the movement means for driving the movement means to cause at least one nozzle head to move parallel to the sub scanning direction. Accordingly, it is possible to use the movement drive means to cause the nozzle heads to move in the sub scanning direction through the movement mechanism, after the nozzle head holder is mounted into the head assembly attachment stand and the movement drive means is connected to the movement mechanism, thus enabling automation.

Furthermore, preferably, the droplet jet patterning device further includes rotational amount detection means for detecting the pivoting amount of the four-bar linkage, and rotational amount control means for controlling the pivoting means based on the detected amount of rotation. According to this configuration, it is possible to cause the four-bar linkage to pivot to any desired rotation angle, by detecting the rotation angle by the rotational amount control means, then using that rotational amount to control the pivoting means by the rotational amount control means.

Another nozzle head holder according to the present invention is a nozzle head holder for holding a nozzle head in which is formed a plurality of nozzles. The nozzle head holder includes; a four-bar linkage having a pair of first link members that extend parallel to a main scanning direction, and a pair of second link members that connect the pair of first link members: and rotational pivots provided at intermediate portions of the pair of second link members. The pair of second link members are capable of rotating about the rotational pivots. A tip end portion of the nozzle head is connected rotatably to one first link member, and a base end portion of the nozzle head is connected rotatably to the other first link member.

When the pair of second link members of the above configuration is rotated about the rotational pivots at intermediate portions thereof, the pair of second link members rotate, the pair of first link members move in the main scanning direction and in the opposite directions to each other. The two ends of each nozzle head connected to the pair of first link members to rotate the plurality of nozzle heads with respect to the sub scanning direction. Since the nozzle heads are rotated by pivoting the four-bar linkage, the rotational angle of the nozzle heads can be increased, and the width of variation of the discharge pitch in the sub scanning direction can be increased.

Since the above nozzle head holder is provided with the four-bar linkage, the pair of rotational pivots, and the nozzle heads having two end portions that are connected rotatably to the pair of first link members, the configuration of the nozzle head holder can be made simple. The configuration required for removing and attaching the nozzle heads for repair or replacement can also be simplified, thereby ensuring maintainability.

Since the four-bar linkage itself can be configured with high precision and the nozzle heads can be mounted precisely in this four-bar linkage, it is possible to provide a precise nozzle head holder that minimizes manufacturing errors.

The pair of rotational pivots is provided in intermediate portions of the pair of second link members and rotationally supported. Accordingly, the reference nozzle of the nozzle head (such as the No. 1 nozzle) can be positioned on the line linking the pair of rotational pivots. Since this configuration ensures that the position of the reference nozzle (the position in the main scanning direction and the sub scanning direction) does not change even if the nozzle heads rotate, data processing can be simplified to generate the drive data, for relative motion between the discharge-target medium and the nozzle head, thereby increasing the precision of the pattern formation.

A plurality of nozzle heads can be disposed at a predetermined spacing in the main scanning direction on the pair of first link members. According to the above configuration, it is possible to rotate the plurality of nozzle heads with respect to the sub scanning direction to form the pattern, which is applicable to manufacture color filters and EL substrates for organic color EL displays.

Preferably, the plurality of nozzle heads discharges droplets of each of a predetermined plurality of colors for forming EL light-emitting layers of the plurality of colors. This makes it possible to reduce the steps for forming the EL light-emitting layer, enabling an increase in throughput and making it possible to manufacture EL substrates for full-color use.

Preferably, the nozzle head discharges droplets for forming a hole transport layer for transporting holes within an EL light-emitting layer to cause the EL light-emitting layer to emit light. According to the above configuration, it is possible to form a hole transport layer.

Preferably, a plurality of nozzles is formed in each of the nozzle heads. A reference nozzle which is the closest to the base of the nozzle head among the plurality of nozzles formed in at least one nozzle head can be positioned on a line linking the pair of rotational pivots.

Since the above structure ensures that the position of the reference nozzle in the sub scanning direction (the position in the main scanning direction and the sub scanning direction) does not change even if the nozzle heads rotate, data processing can be simplified to generate the drive data for causing relative motion between the discharge-target medium and the nozzle head, while increasing the precision of the pattern formation. In addition, since the nozzle heads are rotated by causing the four-bar linkage to pivot, the rotation angle of the nozzle heads can be increased, thereby increasing the width of variation of the discharge pitch in the sub scanning direction.

Preferably, the plurality of nozzle heads is installed removably on the pair of first link members. This simplifies the repair and replacement of the nozzle heads, improving maintainability.

Another nozzle head according to the present invention is characterized by being used in the above described nozzle head holder. If connection pins are provided for connecting the two ends of the nozzle head to the first link members in a rotatable manner, for example, the nozzle heads can be installed to and removed from the nozzle head holder with a simple configuration.

Another droplet jet patterning device according to the present invention includes a head assembly attachment stand for installing the above-described nozzle head holder in a removable manner; a medium holder means for holding a discharge-target medium; pivoting means for causing a four-bar linkage to pivot; and relative movement means for causing the discharge-target medium, which is held in the medium holder means, to move in a main scanning direction and a sub scanning direction relative to the nozzle head.

Since this configuration ensures that the nozzle head holder is installed removably in the head assembly attachment stand, the nozzle head holder can be attached and removed easily and repair or replacement of the nozzle heads can be done easily. Since the pivoting means is provided that acts on the pair of rotational pivots of the four-bar linkage to cause the four-bar linkage to pivot, the four-bar linkage can be pivoted rapidly, automatically, and precisely when the discharge pitch in the sub scanning direction is adjusted by a small distance. In addition, the discharge-target medium is supported by the medium holder means and the pattern formation can be done while relative movement is implemented in both the main scanning direction and the sub scanning direction between the discharge-target medium and the nozzle heads.

Preferably, the nozzle head holder is further provided with rotation angle detection means for detecting the pivoting amount of the four-bar linkage, and rotational amount control means for controlling the pivoting means based on the detected pivoting amount. Since the rotation angle detection means and the rotational amount control means are provided in this configuration, it is possible to perform the rotation of the four-bar linkage, when the one or plurality of nozzle heads and the pair of second link members of the four-bar linkage is rotated are pivoting.

Preferably, the rotation means includes a rotational actuator connected to one second link member, where the rotational actuator causes the one second link member to rotate about one of the rotational pivots. According to this configuration, the rotational actuator is provided with to cause the second link member about either one of the pair of rotational pivots, the second link members, or the four-bar linkage can pivoting with a simple configuration. It is therefore possible to rotate the nozzle head by means of the four-bar linkage rapidly, automatically, and precisely when the discharge pitch in the sub scanning direction is to be adjusted by a small amount.

Another droplet jet patterning device according to the present invention is provided with a nozzle head having a plurality of nozzles formed along a sub scanning direction perpendicular to a main scanning direction, for discharging droplets from the plurality of nozzles to form a pattern on a discharge-target medium. The droplet jet patterning device includes a holder member for rotatably supporting the nozzle head; rotational drive means for causing the nozzle head supported on the holder member to rotate within a range of 0 to 60 degrees with respect to the sub scanning direction about an axis of the reference nozzle, or an axis in the vicinity thereof; and rotation control means for controlling the rotational angle of the nozzle head by the rotational drive means, based on a discharge resolution.

Since this configuration causes rotation of the nozzle head about the axis of the reference nozzle or an axis in the vicinity thereof when the nozzle head is rotated, and thus position of the reference nozzle in the sub scanning direction and the main scanning direction does not change or may change by a small amount, the data processing for creating the drive data for recording can be simplified, the control for discharge recording can be simplified, and the pattern formation can be done more precisely.

Since the nozzle heads can be rotated within the range of 0 to 60 degrees, if the nozzle pitch is P and the inclination rotational angle is θ, the discharge pitch in the sub scanning direction (P×cos θ) can be varied between P and 0.5P, making it possible to increase the width of variation of the discharge pitch in the sub spanning direction and set the resolution in the sub scanning direction continuously within the range of P to 0.5P. Moreover, the provision of the rotational mechanism, the rotational drive means, and the rotation control means cause the nozzle heads to rotate automatically, without any manual operation, thereby setting the rotational angle of the nozzle heads rapidly and precisely.

Preferably, the droplet jet patterning device further includes relative movement means for causing the discharge-target medium to move in the sub scanning direction relative to the nozzle head and feed amount control means for controlling the relative movement means on the basis of the discharge resolution so as to perform relative motion of the discharge-target medium in the sub scanning direction by an interlace method.

Since the droplet jet patterning device is provided with the relative movement means for causing the discharge-target medium to move in the sub scanning direction relative to the nozzle head and the feed amount control means for controlling the relative movement means on the basis of the discharge resolution so as to perform relative motion in the sub scanning direction by an interlace method, it is possible to set the feed amount in the sub scanning direction automatically and relatively move the discharge-target medium and the nozzle head automatically, to ensure that the discharge pitch in the sub scanning direction is set to a pitch suitable for the discharge resolution. In addition, since the discharge pitch in the sub scanning direction of the droplets discharged onto the discharge-target medium can be varied over an even wider range, the discharge pitch can be adjusted dependently on the discharge position on the discharge-target medium (the discharge pattern) completely reliably.

Preferably, the holder member includes a pair of first link members that extend parallel to the main scanning direction and a pair of second link members that connect together the pair of first link members. The two end portions of the nozzle head are connected rotatably to the pair of first link members.

According to the above configuration, it is possible to cause the nozzle head to rotate reliably within the range of 0 to 60 degrees. Moreover, this configuration ensure that the four-bar linkage itself is highly precise with few manufacturing errors. Additionally, the rotatable connections of the two ends of the nozzle head to the pair of first link members ensures that the precision of the nozzle head assembly and of the positioning during rotation can be maintained at high levels, thus making it possible to maintain high levels of precision in the pattern formation.

Preferably, the holder member further includes rotational pivots for supporting the pair of second link members at intermediate portions thereof, wherein the pair of second link members are supported to rotate about the rotational pivots.

According to this configuration, a reference nozzle which is the closest to the base of the nozzle head among the plurality of nozzles of the nozzle head is positioned on a line linking the pair of rotational pivots. Since such a configuration ensures that the position of the reference nozzle (the position in the main scanning direction and the position in the sub scanning direction) does not change even when the nozzle head is rotated, the data processing for calculating the rotational angle and the data processing for the recording drive data is simplified, thereby increasing the precision of the pattern formation.

Preferably, the nozzle heads are disposed at a predetermined spacing in the main scanning direction. According to this configuration, it is possible to provide a droplet jet patterning device that is provided with R, G, and B nozzle heads, by way of example. The droplet jet patterning device can produce color filters or EL substrates for color organic EL displays.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention is described below with reference to the accompanying drawings. Note that this embodiment relates to the application of the present invention to a droplet jet patterning device for manufacturing an EL substrate (a thin glass plate with light-emitting layers of three colors (R, G, and B) formed thereon) that is used in an organic EL (electro-luminescence) display.

As shown inFIG. 1, a droplet jet patterning device1is provided with a base frame2, a parallelepiped-shaped casing3, a medium holder moving device5, a Z-axis slide mechanism6, a nozzle head holder7, a liquid supply device12, and a feed loader H. The droplet jet patterning device1is further provided with an inspection/adjustment device9as shown inFIG. 2and a control device13as shown inFIG. 38. As shown inFIG. 6, the nozzle head holder7is provided with a head portion43, and a plurality of nozzle heads8for discharge recording is provided in the head portion43. The nozzle heads6discharge droplets of a plurality of colors to form a dot pattern on a glass substrate4that is a recording medium, thus forming EL light-emitting layers that emit light of a plurality of predetermined colors. The following description will be made for explaining the above elements in turn.

As shown inFIG. 1, the casing3is formed above the base frame2and the interior space of the casing3is partitioned by a horizontal partitioning plate14(partition member) at an intermediate position into a first-floor patterning room15and a second-floor maintenance room16. A pattern processing stage120is provided in the patterning room15and an inspection processing stage44is provided in the maintenance room16. An aperture portion14a(seeFIG. 6) is formed in the partitioning plate14to enable the passage of the nozzle head holder7. The above-mentioned discharge recording is done within the first-floor patterning room15. The air in the patterning room15is replaced with compressed nitrogen gas to achieve a state in which the moisture density and the oxygen density within the chamber are maintained below predetermined levels. In addition, inspection and adjustment of the nozzle heads8are done within the second-floor maintenance room16. Note that the partitioning plate14need not necessarily be disposed horizontally, provided it separates the patterning room15and the maintenance room16.

The patterning room15has dimensions such as 1500×1500×500 mm. A marble base stand17is disposed on an upper surface of the base frame2in the room5. A support pillar18rises from each corner of the base stand17.

As shown inFIGS. 1 and 2, a pair of box frames37that extend in the front-to-rear direction (a sub scanning direction Y) are supported on the support pillars18on the left and right sides above horizontal partitioning plate14of the maintenance room16. A support frame38is bridged between the box frames37.

The description now turns to the medium holder moving device5. At a wait position WP denoted by dot-dot-dash lines inFIG. 2, the medium holder moving device5receives the glass substrate4that is supported on and transported by the feed loader H from the rear of the droplet jet patterning device1, moves the substrate4to a predetermined automatic alignment start position, and then adjusts the alignment of the glass substrate4at an initial setting position. The medium holder moving device5also moves the glass substrate4in each of the X-axis and Y-axis directions (a main scanning direction X and a sub scanning direction Y) independently during discharge recording, and moves the glass substrate4to the wait position WP for transfer onto the feed loader H after the discharge recording.

As shown inFIG. 5, the medium holder moving device5is provided with a medium transfer mechanism24, a substrate receptacle21, a substrate lift mechanism23, and an angle adjustment device35. The medium transfer mechanism24is a mechanism for moving the glass substrate4in each of the main scanning direction X and the sub scanning direction Y, independently. The medium transfer mechanism24is provided with an X-axis slide mechanism20, a Y-axis slide mechanism19, an X-direction drive portion26, and a Y-direction drive portion29.

As shown inFIG. 6, the Y-axis slide mechanism19is provided with a Y-direction guide member19amounted on the base stand17and an output member19bwhich can move in the sub scanning direction Y along the Y-direction guide member19a. In addition, the X-axis slide mechanism20is provided with an X-direction guide member20amounted on the base stand17and an output member20bwhich can move in the main scanning direction X along the X-direction guide member20a. The substrate receptacle21is provided on top of this output member20b. The glass substrate4is mounted on the substrate receptacle21. The substrate receptacle21is made capable of rotating about a pin22shown inFIG. 5.

As shown inFIG. 5, the Y-direction drive portion29is provided with a Y-axis encoder30and a servomotor31, to cause the output member19bto move along the Y-direction guide member19a. Similarly, the X-direction drive portion26is provided with an X-axis encoder27and a servomotor28, to move the output member20balong the X-direction guide member20a. This configuration enables the glass substrate4mounted on the substrate receptacle21to move in each of the main scanning direction X and the sub scanning direction Y, independently. The actual discharge recording is done while the glass substrate4is moved relative to the nozzle heads8in the main scanning direction X and the sub scanning direction Y.

As shown inFIG. 38, the Y-axis slide mechanism19is further provided with a Y-axis linear scale198that is capable of detecting an amount of movement of the output member19bprecisely. The X-axis slide mechanism20is further provided with an X-axis linear scale189that is capable of detecting an amount of movement of the output member20bprecisely.

The substrate receptacle21is configured of a multiply perforated member of a synthetic resin or sintered metal. A negative pressure is applied through the multiply perforated member to the glass substrate4mounted on the substrate receptacle21in order to attract the substrate4to the substrate receptacle21. As shown inFIG. 5, the substrate receptacle21is formed to be wider than the glass substrate4in the left and right directions. A pair of trays21ais integral with the receptacle21on the left and right sides to accommodate flushing liquid, as will be described later. The substrate lift mechanism23is designed to lift the glass substrate4a predetermined small distance from the substrate receptacle21during transport in and out. The substrate lift mechanism23is provided with four lift bars23aand an air cylinder (not shown in the figures) for raising and lowering those lift bars23a.

The angle adjustment device35is provided with a cam piece33and an electric cylinder34. The cam piece33is frictionally engaged with the under surface of the substrate receptacle21. The electric cylinder34is designed to move the cam piece33in the main scanning direction X by a small distance to rotate the substrate receptacle21about the pin22. This configuration makes it possible to rotate the medium transfer mechanism24mounted on the substrate receptacle21by just a desired angle α, to correct the orientation of the medium transfer mechanism24.

The description now turns to an automatic alignment adjustment mechanism36. The automatic alignment adjustment mechanism36is designed to move the glass substrate4automatically at an initial setting position. As shown inFIGS. 33,35, and38, large and small alignment marks AM1, AM2, AM3, and AM4are printed in the left and right corners of the trailing-edge side of the glass substrate4. The automatic alignment adjustment mechanism36uses these alignment marks AM1to AM4to obtain amounts of deviation from the initial setting position of the glass substrate4, to ensure that the glass substrate4is placed at that initial setting position. The automatic alignment adjustment mechanism36is configured of the previously-described X-axis and Y-axis slide mechanisms20and19, the angle adjustment device35, the inspection/adjustment stage44shown inFIG. 1, and a control device13shown inFIG. 38. The X-axis and Y-axis slide mechanisms20and19and the angle adjustment device35have already been described so that further description thereof is omitted here, and the description now relates to the other components.

The inspection/adjustment stage44is provided in the maintenance room16and is provided with low-magnification CCD cameras32aand32b, high-magnification cameras32cand32d, an X-direction movement drive mechanism149, and a Y-direction movement drive mechanism150, as shown inFIG. 3. The low-magnification CCD camera32aand the high-magnification CCD camera32care attached to a common support plate145on the left side of the aperture portion14a. These CCD cameras32aand32care designed to image the alignment marks AM1and AM3, respectively, that are positioned below a glass window (not shown in the figure) provided in the partitioning plate14. The focus of the CCD cameras32aand32ccan be adjusted individually by manual operation. If the thickness of the glass substrate4changes, the vertical position of the CCD camera32aand the CCD camera32ccan be adjusted by an air cylinder146.

Similarly, the low-magnification CCD camera32band the high-magnification CCD camera32dare attached to a common support plate147on the right side of the aperture portion14a. These CCD cameras32band32dare designed to image the alignment marks AM2and AM4, respectively, that are positioned below a glass window (not shown in the figure) provided in the partitioning plate14. The focus of the CCD cameras32band32dcan be adjusted individually by manual operation. If the thickness of the glass substrate4changes, the heightwise position of the CCD camera32band the CCD camera32dcan be adjusted by an air cylinder148.

The X-direction movement drive mechanism149and the Y-direction movement drive mechanism150are designed to move the support plate147together with the CCD cameras32band32dby small amounts in each of the X and Y directions, individually. If the positional error of the glass substrate4is large or the size of the glass substrate4changes, the positions of the alignment marks AM2and AM4on the right side may change greatly in the X and Y directions. Even in such a case, the alignment marks AM2and AM4can be detected by moving the CCD cameras32band32dby an appropriate amount in the X and Y directions.

The method of adjusting the alignment of the glass substrate4on the substrate receptacle21to the initial setting position, using the automatic alignment adjustment mechanism36, will now be described in detail. First of all, the low-magnification CCD cameras32aand32bimage the larger alignment marks AM1and AM2to input the obtained image information to the control device13. The control device13processes and analyzes the input image information to analysis by a predetermined control program, to obtain displacement quantities ΔX and ΔY in the main scanning direction X and the sub scanning direction Y from the initial setting position of the glass substrate4, as well as an angular displacement quantity Δα about the pin22. The control device13then controls the X-axis and Y-axis slide mechanisms20and19and the angle adjustment device35in such a manner as to cancel the displacement quantities ΔX, ΔY, and Δα, to achieve rough positioning of the glass substrate4at the initial setting position.

The left and right high-magnification CCD cameras32cand32dthen image the smaller alignment marks. AM3and AM4to input the obtained image information to the control device13. In a similar manner to that described above, the image information is analyzed by the control device13to obtain displacement quantities ΔX, ΔY, and Δα from the initial setting position of the glass substrate4. The control device13then controls the X-axis and Y-axis slide mechanisms20and19and the angle adjustment device35to cancel the displacement quantities Δx, ΔY, and Δα. This achieves precise positioning of the glass substrate4at the initial setting position.

Since the plurality of CCD cameras32ato32dis provided in this manner, it is possible to detect the position of the glass substrate4held on the substrate receptacle21and then place the glass substrate4at the origin position accurately, based on the detection results.

The description now turns to the Z-axis slide mechanism6. The Z-axis slide mechanism6rises and lowers the nozzle head holder7so that the head portion43of the nozzle head holder7is positioned selectively among a discharge position (down position) DP, an inspection/adjustment position (up position) UP, and a home position HP that is slightly higher than the inspection/adjustment position UP, as shown inFIG. 6. Note that the discharge recording by the nozzle heads8is done at the discharge position DP. Inspection and adjustment for the head portion43, which will be described later, is done at the inspection/adjustment position UP. The home position HP is a standby position for the nozzle head holder7.

As shown inFIG. 4, the Z-axis slide mechanism6is configured of a slide case39, an output member40that can be guided into the slide case39, an electric cylinder41that raises and lowers the output member40, and a Z-axis encoder42for the electric cylinder41. The slide case39is fixed to the previously mentioned support frame38. A head assembly attachment stand25is fixed to the lower end of the output member40. The nozzle head holder7is attached in a removable manner to the head assembly attachment stand25. More specifically, as shown inFIG. 9, the head assembly attachment stand25has a support plate47. The support plate47is fixed to the lower end of the output member40by a plurality of bolts48. The nozzle head holder7is supported by this support plate47, details of which will be described later.

The description now turns to the nozzle head holder7. The nozzle head holder7is provided with a frame member46as shown inFIG. 14, a four-bar linkage49, a pair of rotational pivots50A and50B, three head holders51R,51G, and51B, two sets of guide mechanisms52A and52B shown inFIG. 19, and movement mechanisms53A and53B. As shown inFIGS. 27(a) and27(b), the four-bar linkage49is configured to be able to rotate about the centers of the rotational pivots50A and50B.

FIGS. 7 to 12show the state in which the nozzle head holder7is mounted on the support plate47.FIGS. 13 and 14ashow the state in which the nozzle head holder7has been removed from the support plate47.FIGS. 15 to 18show the state in which the nozzle head holder7has been removed from the support plate47and the frame member46is omitted.

The various members of the nozzle head holder7will now be described in sequence. The description first concerns the frame member46. As shown inFIG. 14, the frame member46has a main portion46athat extends in the lateral direction, a left arm portion46bthat extends forward from the left end of the main portion46a, and a right arm portion46cthat extends diagonally forward from the right end of the main portion46a. The rotational pivots50A and50B are supported an the left arm portion46band the arm portion46c, respectively.

A pair of attachment linkage mechanisms67having a similar configuration are provided on the left and right of a rearward portion of the frame member46. The attachment linkage mechanisms67attach the frame member46removably to the support plate47of the head assembly attachment stand25. The configuration of the attachment linkage mechanisms67will now be described with reference toFIGS. 12 and 13. As shown inFIG. 12, a through hole47band a through hole46dare formed in the support plate47and the frame member46, respectively. A ball retainer69a, a bearing bush69b, and a retainer removal prevention ring69care installed within the through hole47bso as to fit therein. A cylindrical bottomed metal fitting68is fixed by means of bolts to a lower end portion corresponding to the through hole47bof the support plate47. A ball retainer support spring68ais installed to urge the ball retainer69aupward. A ball retainer71a, a bearing bush71b, and a retainer removal prevention ring71care installed within the through hole46dso as to fit therein.

A pin assembly70is configured of a pin member70a, a cylindrical stopper member70bincluding a male thread, a nut plate70c, a knob70d, and a retainer screw70e. The stopper member70bis attached to the outer periphery of the upper half of the pin member70a. The stopper member70bis provided with a small-diameter portion701, a male thread portion702, and a flange-shaped removal prevention portion703, in that order from the top. The nut plate70cis engaged with the male thread portion. The knob70dis then mounted on the outside of the small-diameter portion, and is fixed thereto by the retainer screw70e. The nut plate70cis finally fixed to the frame member46.

When the nozzle head holder7is to be attached to the support plate47, the through hole46dof the frame member46has been brought into approximate alignment with the through hole47bof the support plate47. And, the knob70dof the pin assembly70is then rotated to insert the pin member70ainto the through hole47b. The nozzle head holder7is positioned accurately with respect to the support plate47. At this time, the ball retainer69amoves slightly downward against the resilient force of the ball retainer support spring68a. The nozzle head holder7is then fixed to the support plate47by a pair of bolts45. When the nozzle head holder7is to be removed from the support plate47, on the other hand, the pair of bolts45is removed, and then the knob70dis rotated to extract the pin member70afrom the through hole47b. Accordingly, the entire nozzle head holder7can be slid forward and detached from the support plate47, as shown inFIG. 13. At this time, the pin assembly70is prevented from separating from the frame member46by the ball retainer71amoving upward and the removal prevention portion703coming into contact with the nut plate70c.

The description now turns to the head holders51. As shown inFIG. 7, the head holders51R,51G, and51B are formed to have an elongated shape, and are provided in parallel at a predetermined spacing in the main scanning direction X. The two ends of each of the head holders51are supported so as to be able to rotate about a vertical axis by a pair of first link members56A and56B. As shown inFIG. 23, corresponding nozzle heads8(8R,8G, and8B) are fixed by screws99through spacers98to under surfaces of the head holders51. These head holders51, the corresponding nozzle heads8, and the spacers98together configure a head body500. In an initial setting state, the head holders51are disposed parallel to the sub scanning direction Y.

The nozzle heads8R,8G, and8B are formed of a solvent-resistant material such as a ceramic material to discharge discharge-liquids for red (R), green (G), and blue (B), respectively. In this embodiment, a solution of an organic substance such as an EL light-emitting organic substance that is dissolved in a solvent is used as the discharge liquid. As shown inFIG. 24, each of the nozzle heads8is provided with a number (such as64) of small-diameter nozzles55arrayed in a single row in the longitudinal direction at a predetermined nozzle pitch (such as at 75 dpi). The nozzles55of each nozzle head8are numbered 1, 2, . . .64in sequence from the furthermost end (a base end side). In this embodiment, the No. 1 nozzle55of each nozzle head8is assigned as a reference nozzle. The nozzle head BR is assigned as a reference head.

The head holder51R that acts as the reference head is provided so as to be unable to move in the sub scanning direction Y. The head holders51B and51G are each provided so as to be able to move in the sub scanning direction Y. The movement of the head holders51B and51G in the sub scanning direction Y is done by the guide mechanisms52A and52B and the movement mechanisms53A and53B, shown inFIG. 19. These guide mechanisms52A and52B and movement mechanisms53A and53B will be described later.

The description now turns to the four-bar linkage49. The four-bar linkage49is a rotational mechanism for rotating the head holders51, that is, the nozzle heads8, about the reference nozzle of the reference nozzle8, or a center in the vicinity thereof.

As shown inFIG. 14, the four-bar linkage49is provided with the pair of first link members56A and56B that extend in the main scanning direction X at the front and the rear at a predetermined spacing and a pair of second link members57A and57B that extend in the sub scanning direction Y. A protruding portion60is formed on the rear-side first link member56B to protrude a predetermined length beyond the right-side second link member57B. The first link members56A and56B and the second link members57A and57B are coupled together by four connective portions61, so that the second link members57A and57B can rotate about the connective portions61, vertical axes.

The description now turns to these connective portions61. Since all four of the connective portions61have the same configuration, the description relates to the connective portion61that connects the first link member56A and the second link member57A. As shown inFIGS. 10 and 17, a pin member62is provided to stand on the upper surface of the link member56A. A ball bearing bush63is provided vertically within a through hole formed in an end portion of the second link member57A. The pin member62penetrates through the interior of the ball bearing bush63and is prevented from falling out by a washer64, a coil spring65, and a hollow bolt66.

The description now turns to the pair of rotational pivots50A and50B. As shown inFIG. 7, the rotational pivots50A and50B are rotational pivots for rotating the four-bar linkage49. Each of the rotational pivots50A and50B is positioned at an intermediate part of the second link members57A and57B. In this embodiment, the rotational pivots50A and50B are provided at positions that are at approximately one-third of the length from the rear end of the second link members57A and57B, respectively.

The reference nozzle (No. 1 nozzle) of the nozzle head8R is positioned on a line8F that extends in the main scanning direction X through the centers of the pair of rotational pivots50A and50B, as shown inFIG. 28. This ensures that the reference nozzle of the reference nozzle head8R acts as the center of rotation of the reference nozzle8R. Note that the reference nozzles of the nozzle heads8G and8B may be disposed on the line BF, or that they may be displaced a very small distance in the sub scanning direction Y, if necessary.

The description first deals with the rotational pivot50A. As shown inFIG. 7, the left-side rotational pivot50A links the second link member57A to the left arm portion46bof the frame member46rotatably. As shown inFIG. 10, a vertical pin member75is fixed to stand on the upper surface of the second link member57A. A ball bearing bush76is installed vertically in a tip-end portion of the left arm portion46bof the frame member46. The pin member75penetrates through the ball bearing bush76in a tightly fitting state. A washer77, a coil spring78, and a hollow bolt79are installed on a protruding portion75aof the pin member75protruding from the ball bearing bush76to prevent the ball bearing bush76from falling out from the pin member75. When the four-bar linkage49is to be removed from the frame member46, the pin member75can be removed from the ball bearing bush76by removing the hollow bolt79, the coil spring78, and the washer77.

The rotational pivot50B has the similar configuration to that of the rotational pivot50A. The rotational pivot50B links the second link member57B to the arm portion46cof the frame member46. As shown inFIGS. 9 and 16, another vertical pin member75is fixed to stand on the second link member57B. Another ball bearing bush76is attached to stand upright on a leading end portion of the arm portion46c. The washer77, coil spring78, and hollow bolt79are installed on a protruding portion of the pin member75that penetrates the ball bearing bush76in a tightly fitting state.

The description now concerns a rotational drive mechanism60shown inFIG. 9. The rotational drive mechanism80is designed to exert a rotational moment on the rotational pivot50B to rotate the four-bar linkage49about the rotational pivots50A and SOB. The rotational drive mechanism80has a motor82with speed reducer, a lever member83, a rotational force input shaft84, and a motor support plate85. The motor82with speed reducer rotates about the same center as the rotational pivot50B (seeFIG. 7). The motor support plate85is fixed to the output member40of the Z-axis slide mechanism6. The motor82with speed reducer is attached to this motor support plate85in an upward-facing attitude.

As shown inFIG. 16, the rotational force input shaft84has a pin member87that is provided vertically in front of the rotational pivot50B on the second link member57B, a spacer88, a ball bearing bush89, and a hollow bolt90. As shown inFIG. 20, the lever member83has a main lever body83aand a resilient plate83bthat support the ball bearing bush89from the left and right sides. As shown inFIGS. 8 and 11, a rear position of the main lever body83ais fixed to an output shaft82aof the motor82with speed reducer by a bolt91. The resilient plate83bis fixed to the rear portion of the main lever body83aby a bolt92.

As shown inFIG. 20, when the output shaft82aof the motor82with speed reducer rotates, the lever member83rotates integrally with the rotational force input shaft84about the output shaft82a. In this case, since the rotational force input shaft84is fixed to the second link member578as described previously, the second link member57B rotates to an angle that is the same rotation angle of the output shaft82aabout the output shaft82a. As a result, the second link members57A and57B and the three head holders51rotate by just the same angle. In this embodiment, the second link members57A and57B can be rotated at any desired angle with respect to the sub scanning direction Y, within the range of 0 to 60 degrees.

The description now turns to an inclination angle detection encoder81shown inFIG. 7. The inclination angle detection encoder81is a high-resolution rotary encoder to detect the rotational angle θ with respect to the sub scanning direction Y of the four-bar linkage49rotated by the rotational drive mechanism80. As shown inFIG. 7, an input shaft81aof the encoder81is fixed in an upward-facing attitude on an extension portion47aof the support plate47. The axial center of the input shaft81ais positioned on the line BF that links the axial centers of the rotational pivots50A and50B. An arm95is fixed to the input shaft81a. A roller95ais pivoted about a leading end portion of the arm95. The arm95is pressed resiliently in the counterclockwise direction inFIG. 7by a resilient member93so that the roller95ais resiliently in contact with a right end surface of the protruding portion60of the first link member56B, as shown inFIG. 19. Note that a stopper groove96of the support plate47, denoted by a dot line inFIG. 7, is a stopper groove for holding the arm95at a suitable position when the nozzle head holder7is removed. The stopper groove96is configured to prevent the nozzle head holder7from interfering with the arm95when the nozzle head holder7is attached to the support plate47.

When the four-bar linkage49rotates in the clockwise direction ofFIG. 27(b) about the rotational pivots50A and50B, the first link member56B moves to the right. Therefore, the arm95that extends in the sub scanning direction Y shown inFIG. 27(a) in the initial setting state rotates in parallel to the second link members57A and57B, as shown inFIG. 27(b). This configuration makes it possible to precisely detect the rotational angle θ of the four-bar linkage49by using the encoder81.

Thus, if the motor82with speed reducer is controlled by the control device13while the detected rotational angle θ is fed back thereto, any desired rotational angle θ can be obtained. The desired rotational angle θ is determined on the basis of a predetermined resolution R for pattern formation, as will be described later.

The description now turns to the guide mechanisms52A and52B that guide the head holders51B and51G in the sub scanning direction Y. It should be noted that since the guide mechanisms52A and52B have the same configuration, the description deals only with the guide mechanism52A, with that of the guide mechanism52B being omitted. The guide mechanism52A is designed to support the head holder51B (nozzle head8B) to move it parallel to the sub scanning direction Y with respect to the first link members56A and56B. The guide mechanism52A has a front-end guide mechanism100and a rear-end guide mechanism101, as shown inFIG. 21.

The description first deals with the front-end guide mechanism100. As shown inFIG. 23, a roller member102A is attached to the lower surface of the head holder51so as to rotate about a vertical axis, a support shaft107A. As shown inFIGS. 16 and 21, a concavity103A is formed in an upper surface of the link member56A, with the roller member102A and a pressure member105A being accommodated therein. As shown inFIG. 21, a right-side surface of the concavity103A forms a guide surface104A. The pressure member105A is supported in the link member56A so that the pressure member105A is able to rotate about a rotational shaft105a. One end of the pressure member105A is urged by a pressure coil spring106A to rotate clockwise. The other end of the pressure member105A is in contact with the roller member102A, pressing the roller member102A against the guide surface104A.

The description now deals with the rear-end guide mechanism101. The rear-end guide mechanism101has a similar configuration to the front-end guide mechanism100. The rear-end guide mechanism101is configured of a roller member102B, a concavity103B formed in the first link member56B, a guide surface104B of the concavity103B, a pressure member105B, and a pressure coil spring106B, as shown inFIG. 21. The pressure member105B that is supported rotatably is urged by the pressure coil spring106B. This structure causes the roller member102B to be pressed rearwardly and rightwardly against the guide surface104B, thereby being in contact with the spindle108.

A pair of roller members102A and102B provided at each end of the head holder51R is engaged in guide holes of the first link members56A and56B, respectively, which prohibits the head holder51R from moving in the sub scanning direction Y.

The description now turns to the movement mechanisms53A and53B. The movement mechanisms53A and53B are movement mechanisms for moving the head holders51B and51G by small distances in the sub scanning direction Y. Since the movement mechanisms53A and53B have the same configuration, the description here relates to the movement mechanism53B alone. As shown inFIG. 15, a bracket112is fixed to a rear surface of the first link member56B. The movement mechanism53B is attached to the bracket112. As shown inFIG. 21, the movement mechanism53B is provided with a spindle108provided at a leading end portion thereof, an input portion114provided at a rear end portion thereof, and a rotation control portion115. The spindle108protrudes partially into the concavity103B. The leading end of the spindle108is in contact with a roller member102from the rear, as is previously described. The rotational force from a position adjustment drive mechanism113, which will be described later, is received to the input portion114so that the input portion114rotates.

When the input portion114rotates in a predetermined direction, the spindle108moves forward. In this case, the roller member102B moves forward against the pressure coil spring106B. Simultaneously, the roller member102A also moves forward in the concavity103A. Accordingly, the entire head holder51B moves forward. When the input portion114rotates in the opposite direction, on the other hand, the spindle108moves rearward so that the roller member102B is moved rearward to follow the leading end of the spindle108by the pressure coil springs106A and106B. Thus, the whole of head holder51B moves rearward. As described above, the spindle108can be moved forward and back by the small distance proportional to the rotational angle (φ) of the input portion114in a predetermined direction corresponding to the rotational direction, so that the position of the head holder51B can be adjusted in the sub scanning direction Y.

In addition, since the roller members102A and102B move forward and rearward along the corresponding guide surfaces104A and104B, the head holder51B can move parallel to the sub scanning direction Y regardless of the rotation of the four-bar linkage49, as shown inFIGS. 27(a) and27(b). Note that the rotation control portion115is controlled by friction on the input portion114, to ensure that the spindle108does not rotate freely during printing.

The description now turns to the configuration including the head holder51, with reference toFIGS. 7,16, and18. As shown inFIG. 7, pressing plates58A and58B are disposed on the upper surfaces of the three head holders51, and attached in a removable manner to the first link members56A and56B by a plurality of bolts97. As shown inFIG. 18, spacers59are disposed between the pressing plates58A and58B and the first link members56A and 5 GB and between neighboring head holders51. Each of the spacers59is fixed by a plurality of bolts97. Since the spacers59are formed to be approximately 5 μm thicker than the head holders51, a gap of approximately 5 μm is formed between the head holders51and the pressing plates58A and58B, as shown inFIG. 23. This gap allows the two end portions of each head holder51to rotate with respect to the pair of first link members56A and56B, thereby moving each head holder51in the sub scanning direction Y as described above.

In this case, as shown inFIG. 23, the support shafts107A and107B are formed to protrude upward from the upper surface of the head holders51. Concavities109A and109B are formed in the lower surfaces of the pressing plates58A and58B. Protruding portions107aof the support shafts107A and107B are accommodated in the concavities109A and109B. A pressure coil spring110and a spring receptacle cap111are installed in each protruding portion107a(seeFIG. 22). The head holders51is urged downward by the force of the pressure coil spring110. Accordingly, the lower surfaces of the head holders51are in contact with upper surfaces of the first link members56A and56B. On the other hand, the roller members102A and102B are in contact with the base surfaces of the concavities103A and103B, as shown inFIG. 16. Thus, the heightwise position of the head holders51is set with respect to the first link members56A and56B precisely. And the nozzles55are positioned in the vertical direction.

The description now turns to the position adjustment drive mechanism113that drives the movement mechanisms53A and53B. The position adjustment drive mechanism113is a mechanism for causing the head holders51B and51G to move in the sub scanning direction Y, as described previously. And, the position adjustment drive mechanism113is disposed on the rearward side of the aperture portion14awithin the second-floor maintenance room16, as shown inFIGS. 2 and 3.

As shown inFIG. 3, the position adjustment drive mechanism113is provided with a Y-direction drive mechanism116including an air cylinder, an X-direction drive mechanism117including an air cylinder, and a servomotor118. The Y-direction drive mechanism116is designed to drive the X-direction drive mechanism117to move in the sub scanning direction Y. The X-direction drive mechanism117is designed to drive the servomotor118to move in the X direction. The servomotor118has an output portion119that is disposed facing forward. The output portion119is designed to transfer the motor drive force to the input portion114of the movement mechanisms53A and53B. The parallel movement in the sub scanning direction Y of the head holders51B and51G by the position adjustment drive mechanism113is described below.

First of all, after the Z-axis slide mechanism6has been used to set the nozzle head holder7in the inspection/adjustment position UP, the servomotor118is made to move laterally to adjust the position of the output portion119to be concentric with the input portion114of the movement mechanisms53A or53B. The Y-direction drive mechanism116is then used to move the servomotor118forward to engage the output portion119with the input portion114. The input portion114is rotated by the transfer of motor drive force to the input portion114through the output portion119, to cause the head holders51B and51G to move in the sub scanning direction Y in the previously described manner.

Examples of the dispositions of R, G, and B dots that form one group of pixels in the EL light-emitting layer are shown inFIGS. 29(a) to29(c). In one example shown inFIG. 29(a), either one of the G dot or the B dot is shifted in the sub scanning direction Y with respect to the R dot. In other examples shown inFIGS. 29(b) and29(c), both of the G dot and the B dot are shifted in the sub scanning direction Y with respect to the R dot. These dot dispositions can be obtained by positional adjustment of the head holders51B and51G independently in the sub scanning direction Y, as described above.

The description now turns to the second-floor maintenance room16and the devices in the interior thereof. In the maintenance room16, the discharge state of the plurality of nozzles55of the nozzle heads8R,8G, and8B are inspected by a discharge inspection mechanism121. Maintenance of the nozzle head holder7itself is done.

The maintenance room16has dimensions such as 1500×1500×700 mm. In the maintenance room16, most of the Z-axis slide mechanism6, the position adjustment drive mechanism113, part of the automatic alignment adjustment mechanism36, and the inspection/adjustment device9are disposed. The inspection/adjustment device9is a device for inspecting and maintaining the nozzle heads8of the head holders51. The inspection/adjustment device9is provided with a head maintenance mechanism123and the discharge inspection mechanism121, as shown inFIG. 2.

The head maintenance mechanism123is provided slightly forward of the aperture portion14ain the maintenance room16.

The head maintenance mechanism123has an electric cylinder124, a blotting paper feed mechanism125, a paper feed drive mechanism126, a pressurized purge tray127, a rubber pad128for capping, and a movable table129, as shown inFIG. 34.

The blotting paper feed mechanism125, the tray127, and the rubber pad128are supported integrally on the movable table129. The electric cylinder124causes the movable table129to be driven to move in the sub scanning direction Y, thereby disposing the blotting paper feed mechanism125, the tray127, or the rubber pad128selectively under the nozzle heads8at the inspection/adjustment position UP.

The blotting paper feed mechanism125is designed to perform a wiping processing provided in printing, for blotting up droplets remaining on the nozzle surfaces of the nozzle heads8with blotting paper136to return the meniscuses of the nozzles55into a normal condition after a pressurized purge, which will be described later. The blotting paper feed mechanism125is provided with a drive roller130, a back-tension mechanism132, follower rollers133and134, and a support plate135. The drive roller130is a drive roller of a one-way clutch type that is driven by the paper feed drive mechanism126. The back-tension mechanism132is provided with a follower roller131aand a belt131b. The belt131bis mounted between the drive roller130and the follower roller131a. The blotting paper136is provided on the follower roller131a. The blotting paper136is wound around the drive roller130via the follower rollers133and134by rotating the drive roller130. At this time, a constant tension is applied to the blotting paper136in the direction opposite to the winding direction, by the back-tension mechanism132.

The paper feed drive mechanism126is provided with a servomotor137, an X-direction slide mechanism138, and an air cylinder139for slide driving. A rubber piece (not shown in the figure) having a high coefficient of friction is fixed around an output shaft137aof the servomotor137. The X-direction slide mechanism138supports the servomotor137in a freely sliding manner in the main scanning direction X. The air cylinder139for slide driving is designed to drive the output shaft137aof the servomotor137to move between a predetermined drive force transfer position and a non-transfer position.

The electric cylinder124drives the movable table129to a predetermined blotting paper winding position. Simultaneously, the air cylinder139for slide driving switches the output shaft137aof the servomotor137to the drive force transfer position. The rotational drive force of the servomotor137is transferred to the input shaft of the drive roller130to feed the blotting paper136in the direction indicated by the arrow inFIG. 34.

The pressurized purge tray127is provided with three concavities127B,127G, and127R. The nozzle heads8are moved with respect to the pressurized purge tray127to face these concavities127B,127G, and127R from above. The nozzles55are cleaned by supplying a flushing liquid11to each of the nozzle heads8B,8G, and8R and discharging the liquid from the nozzles to the concavities127B,127G, and127R. During discharge inspection, discharge from the nozzles55is done for each nozzle head8. This configuration makes it possible to recover the droplets that are discharged from the nozzle heads8into the concavities127B,127G, and127R without spattering of the surroundings, during the discharge inspection by the discharge inspection mechanism121.

The rubber pad128for capping has three rubber pads128B,128G, and128R. The nozzle heads8B,8G, and8R are capped by the corresponding rubber pads128B,128G, and128R, to prevent the nozzles55from drying out while the droplet jet patterning device1is suspended.

The description now turns to the discharge inspection mechanism121. As shown inFIG. 2, the discharge inspection mechanism121is disposed within the second-floor maintenance room16at symmetrical positions on the left and right sides of the aperture portion14ain the vicinity of the head maintenance mechanism123.

As shown inFIGS. 3 and 30, the discharge inspection mechanism121has imaging position switching mechanisms141aand141b, a CCD camera142for imaging the discharge state of the droplets, and a strobe floodlight143for lighting the CCD camera142.

The CCD camera142is disposed on the left side and the strobe floodlight143is disposed on the right side. The imaging position switching mechanism141ais provided with a Y-direction drive mechanism140afor moving the CCD camera142in the sub scanning direction Y and upper and lower two-stage air cylinders144for moving the CCD camera142in two stages in the main scanning direction X. The imaging position switching mechanism141bis provided with a Y-direction drive mechanism140bfor moving the strobe floodlight143in the sub scanning direction Y and upper and lower two-stage air cylinders144similar to the cylinders144described above.

The description now turns to details of the discharge inspection method. The inspection of the discharge status of the three nozzle heads8B,8G, and BR is done for each of the nozzle heads8. Since 64 nozzles55are formed in each of the nozzle heads8, the discharge inspection is done for each group of nozzles, such as one group having 16 nozzles, one group having as nozzles No. 1 to No. 16, another group having nozzles No. 17 to No. 32. In other words, the CCD camera142and the strobe floodlight143are set at initial positions in the sub scanning direction Y. And the discharge status of the first group of nozzles No. 1 to No. 16 is then examined. Subsequently, the CCD camera142and the strobe floodlight143are moved forward by the Y-direction drive mechanisms140aand140bby the distance of 16 nozzles, to inspect the discharge status of the second group of nozzles No. 17 to No. 32. The discharge of the third and fourth groups of nozzles is then tested in a similar manner.

To ensure that the discharge inspection of the nozzles55of the nozzle heads8R,8G, and8B is done under the same conditions during this time, the distance between the CCD camera142and the strobe floodlight143is always kept constant and also the droplets are discharged and imaged at an intermediate position between the CCD camera142and the strobe floodlight143. For that reason, the positions of the CCD camera142and the strobe floodlight143can be switched in three stages in the main scanning direction X dependently on the one of the three nozzle heads8R,8G, and8B that is being inspected. This position switching is described below.

That is to say, when the nozzle head BR is inspected, the two-stage air cylinders144of the left-side imaging position switching mechanism141aare extended to the maximum limit, and the two-stage air cylinders144of the right-side imaging position switching mechanism141bare at the most compressed. When the nozzle head8G is inspected, one of the two-stage air cylinders144of the left-side imaging position switching mechanism141ais contracted, and one of the two-stage air cylinders144of the right-side imaging position switching mechanism141bis extended. In addition, when the nozzle head BB is inspected, the two-stage air cylinders144of the left-side imaging position switching mechanism141aare most contracted, and the two-stage air cylinders144of the right-hand imaging position switching mechanism141bare extended to the maximum limit.

Since the Y-direction drive mechanisms140aand140band the imaging position switching mechanisms141aand141bare provided, and the CCD camera142and the strobe floodlight143can move in each of the main scanning direction X and the sub scanning direction Y in this manner, discharge from a plurality of the nozzles55of the plurality of nozzle heads8can be implemented sequentially and reliably. Since the imaging can be done in a state in which the relative positions of the CCD camera142and the strobe floodlight143with respect to the nozzle heads B to be inspected are always kept constant, the reliability of the discharge detection can be increased.

The description now turns to the discharge inspection technique that determines the quality of the discharge of the nozzles55. As shown inFIG. 31, 16 observation windows151corresponding to 16 nozzles55are set at a constant spacing in the sub scanning direction Y within a picture area PA (of approximately 6.5 mm×5 mm) of the CCD camera142. Each of the observation windows151is set to a position approximately 1.5 mm downward from the lower end of the corresponding nozzle55. The observation window151has a rectangular shape of 60 pixels long and 10 pixels wide, as shown inFIG. 32.

Droplets are discharged at a speed of approximately 7 m/s, by way of example, from each of the 16 nozzles55of the nozzle group being inspected, and the droplets are imaged through the observation windows151. Assume that the shutter speed of the CCD camera142is approximately 1/10,000 second. The strobe emission time is approximately 1 μsec. The captured image signals are supplied to the control device13and are then processed by a predetermined image processing program. In this image processing, the status is determined to be normal if most of the droplets from the nozzle heads8are within the observation windows151, and abnormal if not, by way of example. In the example shown inFIG. 31, the droplets from nozzles No. 1 to No. 7, No. 9, No. 10, and No. 12 to No. 16 are within the observation windows151. The droplets from nozzles No. 8 and No. 11, on the other hand, are outside the observation windows151. Factors such as abnormal discharge speed, failed discharge, or accumulation of foreign bodies (mainly temporary adhesion of EL polymers) are considered as causes of discharge abnormality.

In this manner, the droplets discharged from a plurality of the nozzles55are imaged by the CCD camera142, and the quality of discharged can be determined in a simple manner by processing and determining the image data. Since this determination can be done automatically by the control device13acting as an image processing means for inspection, the discharge inspection can be performed efficiently.

Since this discharge inspection can be done with the nozzle head holder7being raising it to the inspection/adjustment position UP, remaining installed on the output member40of the Z-axis slide mechanism6, the discharge inspection can be implemented during suspended period within the process of discharge recording on the glass substrate4. For that reason, the operating efficiency of the droplet jet patterning device1can be increased even further.

The description now turns to control over the discharge recording of the R, G, and B dot patterns on the glass substrate4at various recording resolutions. Note that this control is done by a host control unit173of the control device13(seeFIG. 38).

Since the nozzle pitch of the nozzle heads8is 75 dpi, as mentioned previously, the nozzle pitch (distance between nozzles) P is given by: P=(25.4/75) mm. If the three head holders51are rotated by the angle θ together with the second link members57A and57B, the nozzle pitch Pθ in the sub scanning direction Y is given by: Pθ=P×cos θ. If the angle θ is varied within the range of 0 to 60 degrees, it is possible to decrease the nozzle pitch continuously within the range of P×(1.0) to P×(0.5). Specific examples of resolution setting are described below.

a) For resolutions from 75 to 150 dpi (seeFIGS. 35 and 36):

The rotation angle θ of the nozzle heads8to an angle that gives the desired dpi in the sub scanning direction Y, within the range of 0 to 60 degrees is set. And the glass substrate4is moved backward (in the direction opposite to the sub scanning direction Y) by a distance of just {64×P×cos θ} for each pass of discharge recording in the main scanning direction X. For 75 dpi, θ is 0 degrees, and for 150 dpi, θ is 60 degrees, by way of example.

Discharge recording at a resolution of 150 dpi can be achieved by interlaced discharge recording by which the head holder51is displaced by just half the pitch after discharge recording at a resolution of 75 dpi, as shown by the broken lines in the figure. The rotation angle θ of the nozzle heads8is set to an angle that achieves a dpi that is half the desired dpi in the sub scanning direction Y, within the range of 0 to 60 degrees, in the same way as described above. After one pass of discharge recording in the main scanning direction X, the glass substrate4is moved minutely by 0.5×P×cos θ rearward and another one pass of discharge recording is done. And then the glass substrate4is moved rearward by just 63.5×P×cos θ. For 150 dpi, for example, θ=0°, and for 300 dpi, θ=60°.

c) For resolutions from 37.5 to 75 dpi:

The rotation angle θ of the nozzle heads8is set to an angle that gives a dpi that is twice the desired dpi in the sub scanning direction Y, within the range of 0 to 60 degrees. And the odd-numbered nozzles No. 1, No. 3, No. 5, . . . are used for one pass of discharge recording in the main scanning direction X, and then the substrate is stepped rearward by 64×P×cos θ. For 37.5 dpi, for example, θ=0°, and for 75 dpi, θ=60°.

In this manner, the rotation angle θ of the nozzle heads8is controlled within the range of 0 to 60 degrees by the rotational drive mechanism80, based on an arbitrary discharge resolution. Note that more detailed application of interlacing makes it possible to perform discharge recording at 225 to 450 dpi, or 300 to 600 dpi, or any other resolution.

The description now turns to correction control for correcting differences in nozzle pitch of the nozzle heads8by the rotation angle θ. This control is implemented by the host control unit173of the control device13. Correction control is done on the basis of the ranking of the nozzle heads8, so the description first concerns the ranks of the nozzle heads8.

As shown inFIG. 24, if the actual dimension between the nozzles at the front and rear ends of the nozzle heads8is L1and the theoretical dimension between nozzles is L0, the error therebetween ΔL is given by: ΔL=(L1−L0). Thus, if the number of nozzles is n, the nozzle pitch error ΔP is given by: ΔP=ΔL(n−1). In general, it is rare to have a plurality of nozzle heads8with nozzle pitch errors ΔP that are all the same. In the manufacturing process of the droplet jet patterning device1, the actual inter-nozzle dimension L1is measured for a large number of nozzle heads8that have been prepared previously, and five-stage rankings such as rank 1, 2, . . . 5 are assigned to the nozzle heads8on that basis of the measured dimension, as shown inFIG. 25. When the three nozzle heads8R,8G, and8B installed in one nozzle head holder7are configured of nozzle heads8of the same rank, the nozzle pitch errors ΔP in the plurality of nozzle heads8are approximated. In addition, assigning such rankings to the nozzle heads8also facilitates management of a large number of nozzle heads8.

The description now turns to specific details of the correction control for correcting the rotational angle θ in accordance with the ranking of the nozzle heads8. If the nozzle pitch between adjacent nozzles (set theoretical value) is P0and the number of nozzles is n, L0is expressed by: L0=P0×(n−1). The nozzle pitch (actual measured value) P1can be expressed as follows, using the actual inter-nozzle dimension L1, the theoretical inter-nozzle dimension L0, and the number n of nozzles:P1=⁢L1/(n-1)=(Δ⁢⁢L+L0)/(n-1)=⁢{Δ⁢⁢L+P0×(n-1)}/(n-1)=⁢Δ⁢⁢L/(n-1)+P0

If the resolution in the sub scanning direction Y of the recording pattern is R and the rotational angle θ is used, the apparent nozzle pitch PY as seen in the sub scanning direction Y is given by: PY=P1×cos θ. Thus following relationship holds:PY=⁢25.4/R=P1×cos⁢⁢θ=⁢[Δ⁢⁢L/(n-1)+P0]×cos⁢⁢θθ=⁢cos-1⁡(25.4/R)/[⁢Δ⁢⁢L/(n-1)+P0]

In other words, it is theoretically possible to calculate the rotational angle θ based on the resolution R. However, a desired resolution R cannot be obtained from the above equations because of the nozzle pitch error ΔP. In this case, an addition rotation by the angle Δθ corresponding to the nozzle pitch error ΔP makes it possible to substantially remove errors in the discharge recording caused by the nozzle pitch error ΔP, and increase the precision with which the pattern is formed. In other words, the nozzle pitch error ΔP can be corrected to achieve the desired resolution R by increasing the rotational angle θ if the nozzle pitch error ΔP has a positive value, or decreasing the rotational angle θ if the nozzle pitch error ΔP has a negative value.

Thus, if the resolution R and the nozzle pitch error ΔP are obtained, it is possible to calculate the actual rotational angle θ′ (θ+Δθ). The angle Δθ of this embodiment is obtained by using the central error (+10, +5, 0, −5, or −10 μm) for each rank, as shown inFIG. 25. Obtaining the central error from the angle Δθ generally enables accurate correction. Since nozzle heads8having the same ranking are used in this embodiment, it is possible to increase the correction precision of the rotational angle θ. Note that the central error is the value between the upper limit and the lower limit of the inter-nozzle dimension error ΔL for each rank. If the nozzle pitch errors ΔP of the plurality of nozzle heads8are all the same, the nozzle pitch errors ΔP itself can be used directly instead of the central value, in the method of calculating the angle Δθ.

Note that when the rotational angle θ is calculated, a correction processing program that uses the corresponding central error from the central errors for ranks 1 to 5 for correcting the rotational angle θ can be stored in the control device13beforehand. It should be noted that the nozzle pitch error between adjacent nozzles (in other words, the value of the inter-nozzle dimension error ΔL divided by the number of spaces between the nozzles) may be used instead of the inter-nozzle dimension error ΔL.

The above equations enable the nozzle pitch error ΔP to be cancelled by rotating the rotational angle θ, within a range that satisfies the condition 0≦θ≦60°, in other words, 0.5≦cos θ≦1. It should be noted, however, that the original θ=0° ought to be valid when P1×cos θ=25.4/R=P0. However, if the actual inter-nozzle dimension L1is shorter, P1≦P0and cos θ≧1, so that P1×cos θ=25.4/R=P0cannot be satisfied. In addition, the original θ=60° ought to be valid when 25.4/R=P0/2. However, if the actual inter-nozzle dimension L1is longer, P0≦P1and cos θ≦0.5, so that 25.4/R=P0/2=P1×cos θ cannot be satisfied. In such a case, the discharge recording can be done by returning the rotational angle θ to 0° and inserting an interlace stage (pass).

The description now turns to the liquid supply mechanism12. As shown inFIG. 2, the liquid supply mechanism12is provided on a side surface of the casing3. As shown inFIG. 26, the liquid supply mechanism12is provided with three liquid containers152R,152G, and152B, a waste liquid recovery container153, and a washing solvent container154. All of these are accommodated in a glove box172and can be replaced through a hatch (not shown in the figure).

Discharge liquids10in R, G, or B for forming EL light-emitting layers in three colors are accommodated in the liquid containers152R,152G, and152B, respectively. The discharge liquids10within the liquid containers152R,152G, and152B are supplied to each of the nozzle heads8R,8G, and8B through a valve unit155and is then discharged as droplets from the plurality of nozzles55. Note that the liquid containers152R,152G, and152B are raised and lowered in linkage with the raising and lowering of the Z-axis slide mechanism6, as will be described later.

A washing solvent (flushing liquid)11that is used for washing the nozzle heads8is accommodated in the washing solvent container154. When the nozzle heads8are washed, the flushing liquid11is supplied from the washing solvent container154through the valve unit155to the nozzle heads8R,8G, and8B, to perform a pressurized purge from the plurality of nozzles55. This pressurized purge is performed by the previously described head maintenance mechanism123. In other words, tubes (not shown in the figures) are connected to the concavities127B,127G, and127R of the pressurized purge tray127shown inFIG. 34, and waste liquid is sucked through the tubes by negative pressure. The thus-recovered waste liquid is recovered into the waste liquid recovery container153through the valve unit155shown inFIG. 26. Note that this negative pressure is generated by using a vacuum pump or ejector (not shown in the figures) and the exhaust thereof is released into an organic exhaust duct of the equipment.

A tube156is connected to the waste liquid recovery container153, and the waste liquid recovery container153is connected to a mist separation tank outside the figure through the tube156. The liquid containers152R,152G, and152B and the washing solvent container154are connected through tubes157,158,159, and160and the valve unit155to a compressed nitrogen gas line, respectively.

The description now turns to the mechanism by which the liquid containers152R,152G, and152B are raised and lowered in linkage with the raising and lowering of the Z-axis slide mechanism6. As shown inFIG. 26, the liquid supply mechanism12is further provided with a support frame161, a movable frame (support stand)162, a liquid container elevator mechanism163, and three liquid surface position maintenance mechanisms166. The movable frame162is attached to the support frame161in a vertically movable manner. The liquid container elevator mechanism163has an electric cylinder164with a metal bellows. A tip end of the rod164aof the electric cylinder164is connected to the movable frame162. The raising and lowering of the electric cylinder164is linked to the raising and lowering of the Z-axis slide mechanism6, with the movable frame162moving up and down along the support frame161. This keeps the height relationship between the movable frame162and the nozzle heads8R,8G, and8B constant.

The liquid surface position maintenance mechanisms166follow the consumption of liquid in the liquid containers152R,152G, and152B and are designed to ensure that the height of the liquid surface within each of the liquid containers152R,152G, and152B is kept at a reference height that is a predetermined distance (such as 50 mm) lower than the position of the nozzles55. As shown inFIG. 26, each of the liquid surface position maintenance mechanisms166is provided with a cylindrical casing168that is disposed vertically, a shaft-shaped member169, a compression coil spring170that acts as a resilient member, a sleeve171, and a holder165R,165G, and165B for holding the corresponding liquid container152R,152G, and152B.

A flange168ais formed at an upper end portion of the casing168, so that the flange168ais linked removably to the movable frame162. The shaft-shaped member169is attached integrally to the interior of the casing168and an upper end portion thereof is linked to the corresponding holder165. The sleeve171is formed of a ball-spline and is forced into the casing168. The compression coil spring170is inserted in an annular space surrounded by the casing168, the shaft-shaped member169, and the sleeve171to support the liquid container152and the holder165resiliently. According to this configuration, when the liquid level drops due to the liquid consumption, the weight of the liquid in the liquid container152falls by an equivalent amount, the corresponding liquid holder165and liquid container152are raised upward by the resilient force of the compression coil spring170by an amount corresponding to that lightening, and the liquid level is corrected to a constant heightwise position with respect to the nozzle heads8.

Configuring the liquid container elevator mechanism163in that manner stabilizes the liquid pressure in the nozzle heads8, even when the head portion43is raised or lowered. This configuration can reliably prevent leakage of liquid from the nozzle heads8and reverse-flow of the liquid within the nozzle heads8, and also stabilize the discharge of droplets. Furthermore, since it isn't necessary to provide liquid-level sensors, a simple construction can be simplified.

A locking mechanism167is also provided for each of the liquid surface position maintenance mechanisms166. The locking mechanism167is a mechanism for ensuring there is no vertical motion in the liquid container152and the holder165due to the resilience of the compression coil spring170during the vertical motion of the movable frame162. Each of the liquid surface position maintenance mechanisms166has a small air cylinder having a rod (not shown in the figures) and a locking pad fixed to the tip end portion of the rod, with the main body of the air cylinder being fixed laterally to a side wall in the upper half of the casing168. The tip end portion of the rod penetrates into the interior of the casing168so that the shaft-shaped member169can be pressed by the locking pad in order to be locked.

The description now turns to the control system that comprises the control device13of the droplet jet patterning device1, with reference toFIGS. 38 and 39. Note that the control device13is designed to control different devices and mechanisms provided for the droplet jet patterning device1.

The host control unit173of the control device13has a computer including a CPU, ROM, and RAM (not shown in the figures). Various control programs for controlling several motors, the imaging devices, the strobe floodlights, and other various components of the droplet jet patterning device1are stored in the ROM. An operating panel174, an external storage device175, and power supply176are connected to the host control unit173. Dot pattern image data to be formed on the glass substrate4, system constants for the droplet jet patterning device1, and production management information are stored in the external storage device175.

The host control unit173is further connected to a digital signal processor (DSP)178, a multi-shaft feed pulse generator circuit179, a multi-shaft feed pulse generator circuit180, an output register181, an input register182, an alignment roller183, a discharge inspection controller184, and a loader interface185, through an input-output line177. The DSP178is connected to the nozzle heads8R,8G, and8B by a signal output circuit186and a drive circuit187. The DSP178has a CPU, ROM, and RAM. A discharge recording control program for driving the nozzle heads8to perform discharge recording is stored in the ROM.

The drive circuit187has a pulse generation circuit which generates drive pulses for driving a large number of nozzle drive piezoelectric elements, and is connected to a waveform monitor188for displaying the drive pulses. The waveforms of the drive pulses can be set in common for the nozzle heads8R,8G, and8B, or they could be set independently for each of the nozzle heads8R,8G, and8B.

The DSP178is further connected to the multi-shaft feed pulse generator circuit179, the X-axis linear scale189, and a data storage device190. The X-axis linear scale189is designed to precisely detect the amount of movement of the X-axis slide mechanism20that is driven by the X-axis servomotor28. A detection signal of The X-axis linear scale189is supplied to the DSP178through an amplifier AMP.

The data storage device190is designed to store discharge recording data and phase data (data that sets the timing for discharge). The data storage device190stores data that has been supplied from the host control unit173, and outputs that data to the DSP178during the discharge recording.

Drive circuits191to195and197are connected to the multi-shaft feed pulse generator circuit179. The drive circuit191controls the driving of the X-axis servomotor28, based on detection signals from the encoder27incorporated in the X-axis servomotor28and detection signals from the X-axis linear scale189. The drive circuit192is connected to the Y-axis linear scale198for precisely detecting the amount of movement in the Y direction of the Y-axis slide mechanism19. The drive circuit192controls the driving of the Y-axis servomotor31, based on detection signals from the encoder30incorporated into the Y-axis servomotor31and detection signals from the Y-axis linear scale198. According to this configuration, the X-axis and Y-axis slide mechanism20and19are used to move the glass substrate4precisely in each of the main scanning direction X and the sub scanning direction Y, to control the position of the glass substrate4precisely in the main scanning direction X and the sub scanning direction Y.

The drive circuit193is designed to drive the rotation servomotor82, and is connected to an amplifier for amplifying detection signals of the encoder81that detects the rotational angle θ. The drive circuit194is designed to drive the position adjustment servomotor118that adjusts the position in the sub scanning direction Y of the head holders51G and51B. The drive circuit195is designed to drive a Z-axis slide servomotor410that causes the nozzle head holder7to rise and lower. The drive circuit197is designed to drive a Z1-axis slide servomotor196of the electric cylinder164that causes the movable frame162to rise and lower.

The multi-shaft feed pulse generator circuit180is connected to drive circuits200,202,204,206, and207. The drive circuit200is designed to control the driving of an alignment adjustment servomotor199to rotate the glass substrate4, thereby adjusting the alignment of the glass substrate4at the initial setting position. The drive circuits202and204are designed to control the driving of a servomotor201for moving the discharge inspection CCD camera and a servomotor203for moving the discharge inspection strobe, respectively. The drive circuit206is designed to control the driving of a servomotor205of the electric cylinder124for moving the maintenance mechanism. The drive circuit207is designed to control the driving of the servomotor137for the blotting paper winding of the head maintenance mechanism123.

As shown inFIG. 39, the output register181is connected to a relay circuit209. The relay circuit209controls a plurality of solenoid valves208that are provided in the valve unit155of the liquid supply mechanism12. The input register182is connected to a plurality of detection switches through an interface (I/F)210. The alignment controller183is connected to the four CCD cameras32ato32d, a keyboard, and a monitor211. The discharge inspection controller184is designed to control the driving of the CCD camera142and the strobe floodlight143for discharge inspection. The loader interface185is designed to transfer signals to and from the external loader H for transferring the substrate.

The description now turns to the control of the continuous recording to discharge droplets from the three nozzle heads8R,8G, and8B to discharge a dot pattern onto the glass substrate4, thereby creating a pattern such as light-emitting layers on an EL substrate, with reference toFIGS. 40 to 47. This control is executed by the host control unit173. In the figures, reference symbols Si (where i=1, 2, 3, . . . ) denote steps.

As shown inFIG. 40, the continuous recording control is started by operating a manual switch to turn on the main power source of the droplet jet patterning device1. First of all, the nozzle heads8are separated from the rubber pads (caps)128R,128G, and128B of the head maintenance mechanism123to expose the nozzle heads8(S1). The host control unit173then checks angle θ and the position of the Z axis of the nozzle head holder7, the position of the substrate receptacle21along the X and Y axes, and the rotational angle α about the pin22as the axis; causes the glass substrate4to move the nozzle heads8to θ=0°, the home position (HP) on the Z axis, and the wait position WP on the X and Y axes. A rotational angle α about the pin22is set to be 0° (S2).

In S3, the host control unit173determines whether or not the discharge recording for all the glass substrates4(total production) has been completed (S3). If it determines that it has been completed (YES at S3), inspection processing A′ is executed in S10, then the processing ends. This inspection processing A′ will be described later. If it is determined to not be completed (NO at S3), the host control unit173determines whether or not the workpiece is the same as the previous one (S4). In this context, “same workpiece” means that the type of the glass substrate4that is used is the same (all of the dimensions, shape, and alignment marks are the same) and also the dot pattern to be recorded thereon is the same.

If it is determined to be the same (YES at S4), the flow proceeds to S7. If it is determined to not be the same (NO at S4), the flow proceeds to S5, and all of the data relating to discharge recording (discharge-related data) that has been created in the host control unit173is set in the RAM, the data storage device190, and other registers of the host control unit173(S5). Adjustment processing is done in accordance with φG and φB that are included within the discharge-related data. In this case, φG and φB are rotational angles of the position adjustment drive mechanism113. This causes changes of position of the head holders51G and51B by extremely small distances in the sub scanning direction Y. In other words, if the position of the G dots and the B dots with respect to the R dots in the sub scanning direction Y are changed by a small amount, as shown inFIG. 29(c), the head holder51G or51B can be moved in the sub scanning direction Y. This movement in the sub scanning direction Y can be done by rotating the position adjustment drive mechanism113by just a predetermined angle. When the adjustment processing of S6ends, the flow proceeds to S7.

In S7, the recording preparation processing A and the inspection processing A′ start simultaneously. In this document, the description deals with the recording preparation processing A and the inspection processing A′ in sequence.

As shown inFIG. 41, when the recording preparation processing A starts, the feed loader H is used to mount the glass substrate4on the substrate receptacle21at the wait position WP. Then, the glass substrate4is attracted to the substrate receptacle21(S21). The substrate receptacle21with the glass substrate4mounted thereon is then moved to an automatic alignment start position by the X-axis and Y-axis slide mechanisms20and19(S22). Correction movement amounts ΔX, ΔY, and Δα are obtained by the Z-axis slide mechanism6, and position adjustment by those correction movement amounts is done to set the glass substrate4at the initial setting position (S23). The glass substrate4is moved by the X-axis and Y-axis slide mechanisms20and19so that the reference nozzle is positioned at the recording start point (S24), and processing ends.

When the inspection processing A′ starts, a flag is first turned off (S31) and the discharge inspection processing is done (S32). Details of this discharge inspection processing will be given later. History information for the previous glass substrate is added to the memory of the host control unit173(S33), and the host control unit173determines whether or not the discharge recording for all the glass substrates4(total production) has been completed (S34). If it determines that it has been completed (YES at834), the flow proceeds to S42. In S42, the nozzle heads8R,8G, and8B are brought into contact with the rubber pads128R,128G, and128B to be capped (S42), and the inspection processing A′ ends.

If it is determined that the discharge recording has not been completed for all the glass substrates4(NO at S34), the host control unit173determines whether or not the discharge status is normal, based on the previously executed discharge inspection (S35). If it is determined to be normal (YES at S35), the flag is set to on (S41) and the inspection processing A′ ends. If it is determined that it was not normal (NO at S35), the host control unit173determines whether or not purge processing has been executed a predetermined number of times (S36). If it is determined that the purge processing has not been executed the predetermined number of times (NO at S36), the purge processing and the wiping processing are executed (S37), discharge inspection processing similar to that of S32is then executed (S38), and the flow proceeds to S35.

If it is determined that the purge processing has been executed the predetermined number of times (YES at S36), it is determined that recording is not possible with the current nozzles55. And the host control unit173then determines whether or not discharge recording can be possible with substitute nozzles (S39). If it is determined to be possible (YES at S39), the flag is set to on (S41), and the inspection processing A′ is over. If it is determined to be not possible (NO at S39), continuous recording suspension processing is executed (S40), and the inspection processing A′ ends. In this case, the flag remains set to off.

As shown inFIG. 40, after S7, the host control unit173determines whether or not the recording preparation processing A and the inspection processing A′ have been completed (S8). If it is determined that one or both of the processes A and A′ has not ended (NO at S8), the host control unit173waits until both of them have ended. If both of them have ended (YES at S8), the host control unit173determines whether or not the flag is on (S9). If it determines that the flag is not on (NO at S9), the processing ends. If it determines that the flag is on, on the other hand (YES at S9), the flow proceeds to S51ofFIG. 43.

At S51, the Z-axis slide mechanism6is used to lower the head portion43to the discharge position DP (S51). The four-bar linkage49is then rotated aslant if necessary, based on the rotational angle θ that has been input and set (S52). If the results of the previous discharge inspection are normal (YES at S53), the regular recording, that is, the formation of a pattern while the glass substrate4is moved relative to the head portion43in the main scanning direction X and the sub scanning direction Y, is performed (S54) and the flow proceeds to S55.

If the results of the discharge inspection determine that the discharge is abnormal, on the other hand (NO at S53), skipped nozzle recording is performed (S56). This skipped nozzle recording is recording in a state in which some of the nozzles55are suspended. One example of the skipped nozzle recording is one stage of interlace recording in which only the odd-numbered nozzles operate in one pass of recording. Data for substitute nozzle recording is then created and stored in a page memory of the data storage device190or other types of registers (S57). The substitute nozzle recording is then executed (S58) and the flow proceeds to S55. The substitute nozzle recording is that, when No. 1 and No. 2 nozzles are not available, No. 3 and No. 4 nozzles are used again to record on the glass substrate4that has already been recorded upon, without using nozzles No. 1 and No. 2.

At S55, history information for that glass substrate4is stored in memory of the host control unit173(555), and the home position return processing and the wait position return processing start simultaneously (S59). As shown inFIG. 44, the home position return processing first returns the rotational angle θ of the four-bar linkage49to 0 degrees (S61), then raising the nozzle head holder7to the home position HP (S62), whereupon the processing ends. The wait position return processing causes the substrate receptacle21and the glass substrate4to move to the wait position WP (S63), then uses the substrate lift mechanism23to raise the glass substrate4by a predetermined small distance from the substrate receptacle21and transfer the raised substrate4to the feed loader H (S64). The values of ΔX, ΔY, and Δα that were adjusted in S23are returned to their original values (S65) and processing ends.

InFIG. 43, after S59, the host control unit173determines in S60whether or not the home position return processing and the wait position return processing have ended. If at least one of them has not ended (NO at S60), the host control unit173waits until the processing has ended. If both have ended (YES at S60), the flow returns to S3ofFIG. 40.

The description now turns to the discharge inspection processing executed in S32and S38, with reference to the flowchart ofFIG. 46. When this processing starts, the host control unit173first determines whether or not the nozzle head holder7is at the inspection/adjustment position UP (S70). If the nozzle head holder7is not at the inspection/adjustment position UP (NO at S70), the nozzle head holder7is moved by the Z-axis slide mechanism6to the inspection/adjustment position UP (S71), and the flow proceeds to S72. If the nozzle head holder7is at the inspection/adjustment position UP (YES at S70), the flow proceeds to S72without executing S71. At S72, the host control unit173determines whether or not the head maintenance mechanism123is at the inspection position (S72). If it is not at the inspection position, (NO at S72), the head maintenance mechanism123is moved to the inspection position. (S73) and the flow proceeds to S74. If the head maintenance mechanism123is at the inspection position (YES at S72), the flow proceeds directly to S74.

At S74, discharge inspection of the nozzle head8R is performed and in the subsequent S75and S76discharge inspection is performed for each of the nozzle heads8G and8B (S75and S76). The CCD camera142and the strobe floodlight143are then moved to their predetermined standby positions (S77), and the head maintenance mechanism123is moved to its predetermined standby position (S78). This completes the discharge inspection processing.

The description now turns to the discharge inspection of the nozzle head8R that is performed in S74. Note that the discharge inspection is the same for all of the nozzle heads8R,8G, and8B, therefore, only the discharge inspection of the nozzle head8B is described here, based on the flowchart ofFIG. 47, and description of the discharge inspection of the nozzle heads8G and8B performed in S75and S76is omitted.

InFIG. 47, when the processing starts, first a counter i is set to 1 (S80) and a position Ri is set in an imaging position register (S81). The CCD camera142is then moved to the position Ri and the strobe floodlight143is also moved to the position Ri (S82). A discharge instruction is then output to the i-th group of 16 nozzles55of the nozzle head8R (S83). Accordingly, 16 target nozzles15discharge a droplet, respectively. Note that the position Ri is the position corresponding to the i-th group of nozzles.

A timer T1and a timer T2are then started (S84). At S85, the host control unit173determines whether or not the timer T1has measured a predetermined time a; if the timer T1has not yet measured that time (NO at S85), the host control unit173waits until the timer T1measures the time α. If the timer T1has measured that time (YES at S85), the host control unit173instructs the shutter operation of the CCD camera142(S86). The host control unit173then determines whether or not the timer T2has measured a predetermined time β (S87). If timer T2has not yet measured that time (NO at S87), the host control unit173waits until the timer T2measures the time β. If the timer T2has measured that time (YES at S87), the host control unit173instructs the operation of the strobe floodlight143(S88). Thus the droplets that have been discharged from the 16 nozzles55are imaged. Note that the predetermined times α and β times are very short times that are substantially equal, so that the strobe lighting and the shutter operation are substantially simultaneous.

The host control unit173then executes image processing on image data of the image of the captured droplets, to determine whether the discharge is normal or abnormal, and posts the result on a display of the operating panel174(S89). At this time, each of the nozzles55is determined to be normal if the image of the droplets is within the observation window151of the CCD camera142. The nozzles55are determined abnormal if the image is outside of the windows (seeFIGS. 31 and 32). The host control unit173then increments the counter by 1 (S90) and determines whether or not the imaging of the fourth group of nozzles has been completed (S91). If it has not been completed (NO at S91), the flow returns to S82and the same processing is executed in sequence up until the fourth group. If the fourth group has been completed (YES at S91), the processing ends.

In this manner, since the inspection processing A′ can be executed by the discharge inspection mechanism121during the execution of the recording preparation processing A that moves the glass substrate4(S22) and performs automatic alignment (S23), it is possible to increase the operating efficiency of the droplet jet patterning device1and also reduce the occurrence of defective products (defective EL substrates) due to discharge errors.

As described above, the present invention relates to the nozzle head holder7which is provided with the four-bar linkage49, the pair of rotational pivots50A and50B, and the head holders51each having two ends that are connected in a rotatable manner to the pair of first link members56A and56B. Accordingly, the nozzle head holder7can be readily attached to and removed from the external head assembly attachment stand25that supports the nozzle head holder7. It is therefore possible to simplify the configuration for attaching and removing the nozzle heads8for repair and replacement, thus ensuring maintainability.

Since the rotational pivot50A is provided at an intermediate portion of the second link members57A and57B, the reference nozzles (such as the No. 1 nozzle) of the nozzle heads8can be positioned on the line BF that links the centers of the rotational pivots50A and50B. Even if the nozzle heads8are rotated, the position of the reference nozzle is not changed, or even if the positions of the nozzles are changed, the amount of the change is so small. Accordingly, it is possible not only to simplify the data processing for calculating the drive data and rotational angle for causing relative movements between the glass substrate4and the nozzle heads8, but also to increase the precision of the pattern formation.

In addition, since the plurality of nozzle heads8R,8G, and8B are disposed at a predetermined spacing in the main scanning direction X, these nozzle heads8R,8G, and8B can be inclined with respect to the sub scanning direction Y to set the discharge pitch in the sub scanning direction Y to a desired value for recording the pattern, so that the nozzle heads8R,8G, and8B are applicable to the manufacture of color filters or EL substrates for organic color EL displays. Moreover, since these nozzle heads8includes nozzle heads that discharge droplets of a plurality of different colors for forming an EL light-emitting layer, the throughput can be increased and it becomes possible to manufacture EL substrates for full-color use. In addition, use of the nozzle head holder7also makes it possible to discharge and record a hole transport layer from these nozzle heads8.

Note that if advances in technology make it possible to mix a hole transport component and an EL light-emitting component within a single droplet, and thus obtain light emission from a single layer, it is not necessary to form a hole transport layer.

The nozzle heads8G and8B move only in the sub scanning direction Y but do not move in the main scanning direction X, even when the nozzle heads8G and8B are rotated aslant with respect to the sub scanning direction Y. Accordingly, the nozzle heads8G and8B can be moved by small amounts in the sub scanning direction Y alone via the paired roller members102and guide surfaces104, making it possible to adjust the position of the nozzle heads8finely in the sub scanning direction Y accurately, efficiently, and automatically. In addition, since the pair of roller members102are each positioned at predetermined positions with respect to the pair of first link members56A and56B, irrespective of the rotation angle of the nozzle heads8. Accordingly, the movement mechanisms53A and53B can be mounted at predetermined positions of the first link members56A and56B. And actuators for moving these movement mechanisms53A and53B can be provided externally, so that fine adjustment of the nozzle heads8in the sub scanning direction Y can be automated.

The pattern processing stage120is disposed in the first-floor (lower side) patterning room15, the inspection/adjustment stage44is disposed in the second-floor (upper side) maintenance room16, and the head portion43can be raised and lowered between these two stages through the aperture portion14a. Accordingly, the head portion43can be moved to the inspection/adjustment position UP where discharge inspection can be performed on the nozzles55, during an idle period such as when the discharge formation processing is halted. After the discharge inspection, the head portion43can be moved immediately back to the discharge position DP and the discharge formation processing can be resumed. Since discharge inspection during a processing halt in the discharge formation processing step can be performed, it is possible to reduce the occurrence of defective products and improve the operating efficiency of the droplet jet patterning device1. Since the two stages are disposed in a vertical spatial arrangement, the usage efficiency of the space within the droplet jet patterning device1can be increased and the device can be made more compact, which is beneficial from the installation cost point of view. Moreover, since the horizontal partitioning plate14substantially separates the upper and lower parts of the device1, foreign bodies such as dust and debris do not fall onto the glass substrate4held on the substrate receptacle21, even when a movable member is moved higher than the horizontal partitioning plate14, making it possible to prevent the occurrence of defective products.

The pattern formation can be done by mounting and holding the glass substrate4on the substrate receptacle21and moving the glass substrate4relative to the nozzle heads8in both the main scanning direction X and the sub scanning direction Y.

In other words, since the medium transfer mechanism24is provided for moving the glass substrate4in each of the main scanning direction X and the sub scanning direction Y, it is not necessary to move the head portion43in either the main scanning direction X or the sub scanning direction Y to form the pattern. For that reason, the configuration for raising and lowering the head portion43by the Z-axis slide mechanism6be simplified. Accordingly, switching of the position of the head portion43by the Z-axis slide mechanism6can be performed between the space below the horizontal partitioning plate14and the space thereabove. It is possible to perform pattern formation and discharge inspection efficiently by providing the discharge inspection mechanism121for inspecting the discharge status of the plurality of nozzles55on the inspection/adjustment stage44and raising and lowering the head portion43by the Z-axis slide mechanism6.

The nozzle heads8are fixed to the head holder51. The two ends of the head holder51and the pair of first link members56A and56B are connected together in a rotatable and also removable manner by the roller members102acting as pins, and these roller members102extend in a direction perpendicular to the head surface of the nozzle heads8. According to the above configuration, the head body500can be simplified. Use of the rotatable roller members102as connecting pins is preferable, from the point of view of smoothing the rotation and the movement in the sub scanning direction Y of the head body500. However, the connecting pins need not be restricted to the roller members102.

The head body500provided with a plurality of nozzle heads8is attached rotatably and also removably to the first link members56A and56B of the four-bar linkage49. Accordingly, this four-bar linkage49is attached to the head assembly attachment stand25. Thus, the distance between the discharge-target medium and the head body500can be maintained extremely precisely. For that reason, the RGB light-emitting layers can be arrayed on the substrate to an extremely high precision. Since no play occurs in the movable portions between the head body500and the first link members56A and56B, it is possible to create an EL display in a simpler manner, in a shorter time, and at a lower cost than with a conventional screen-printing method.

The embodiment of the present invention is described above, however, various modifications and variations are included within the scope of the present invention. Thus the scope of the present invention must be comprehended by the claims herein, in addition to the above embodiment.

For example, the embodiment above was described as relating to a droplet jet patterning device that forms a dot pattern on a glass substrate for a color EL display. However, the present invention can also be applied to other applications. For instance, the present invention can be applied to the formation of a dot pattern during the manufacture of a color filter for a color LCD, or a large-scale inkjet printer, or a droplet jet patterning device for another application.

In addition, the output shaft of the motor82that causes the four-bar linkage49to pivot can be connected directly to the pin member75of the rotational pivot50B, to pivot the four-bar linkage49. Furthermore, means for moving and driving the front-side first link member56A precisely to the left or means for moving and driving the rear-side first link member56B to the right can be utilized as the means for pivoting the four-bar linkage49. An electric cylinder or a solenoid actuator can be used as the above means.

The means for detecting the rotational angle of the four-bar linkage49is not limited to the previously-described encoder81. For example, an encoder may be provided in a coaxial with and above the left-side rotational pivot50A to detect the rotational angle of the second link member57A. Similarly, a highly precise servomotor may be used as the motor82for rotation of the nozzle holder. Accordingly, the detection of the inclination rotational angle of the four-bar linkage49is based on signals from an encoder of that servomotor.

It is necessary to provide the pair of rotational pivots50A and50B of the four-bar linkage49at intermediate positions of the pair of second link members57A and57B (intermediate positions between the pair of first link members56A and56B). However, it is also possible to provide the pair of rotational pivots50A and50B at substantially central portions in the sub scanning direction Y of the pair of second link members57A and57B, and to position a predetermined numbered nozzle at substantially the central position of the nozzle array of the reference nozzle head8R on a surface that links the pair of rotational pivots50A and50B.

The pair of rotational pivots50A and50B of the four-bar linkage49are provided mainly on the pin members75that are fixed to the second link members57A and57B. However, a pair of pin members fixed to the frame member46side can be fitted in a freely sliding manner in a pair of holes formed in the second link members57A and578. In this case, the pair of holes formed the second link members57A and57B act as the pair of rotational pivots.

The relative movement generation means is not limited to the medium transfer mechanism24. Any suitable means of generating relative movement between the nozzle heads and the discharge-target medium in the X and Y directions (the main scanning direction X and the sub scanning direction Y) can be used as the relative movement generation means. For example, the nozzle heads8may be moved in the main scanning direction X, and the substrate receptacle21may be moved in the sub scanning direction Y.

Furthermore, the head holder51R may be supported to be freely movable in the sub scanning direction Y, in the same manner as the other head holders51G and51B.

The nozzle head holder7need not be removable. The nozzle head holder7can also be provided integrally with the droplet jet patterning device1.