Patent Publication Number: US-8523319-B2

Title: Method for arranging liquid droplet ejection heads, head unit, liquid droplet ejection apparatus, method for manufacturing electro-optical apparatus, electro-optical apparatus, and electronic device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a divisional application of U.S. Ser. No. 12/125,468 filed May 22, 2008 which claims priority to Japanese Patent Application No. 2007-147284 filed Jun. 1, 2007 all of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a method for arranging liquid droplet ejection heads to arrange and fix a plurality of liquid droplet ejection heads on a common carriage plate, and relates to a head unit and a liquid droplet ejection apparatus. The invention also relates to a method for manufacturing an electro-optical apparatus, and relates to an electro-optical apparatus and an electronic device. 
     2. Related Art 
     As a known method for arranging liquid droplet ejection heads of this kind, a plurality of liquid droplet ejection heads are arranged in groups step-wise in a main scan direction, and the liquid droplet ejection heads are arranged and fixed in two groups in a sub scan direction (see JP-A-2005-238821). In this method, while all the nozzle rows of the liquid droplet ejection heads form a single drawing line, the liquid droplet ejection heads can be arranged with good space efficiency. 
     Upon drawing processing with a head unit produced by such an arranging method, functional liquid droplets ejected from ejection nozzles at each outermost end of separate liquid droplet ejection heads may be landed close to each other. Specifically, functional liquid droplets ejected and landed from the ejection nozzle arranged at the outermost end of one liquid droplet ejection head are landed close to functional liquid droplets ejected and landed from the ejection nozzle arranged at the outermost end of another liquid droplet ejection head. Meanwhile, liquid droplet ejection heads arranged and fixed may particularly differ in the amount of droplet ejected from each ejection nozzle due to manufacturing error. Therefore, when a plurality of liquid droplet ejection heads are simply arranged by the above-mentioned method, a difference occurs in the amount of functional liquid droplets ejected from different liquid droplet ejection heads and landed close to each other, and there has been a problem that drawing processing of good quality cannot be performed due to unevenness of color, for example. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a method for arranging liquid droplet ejection heads in which drawing quality with a plurality of liquid droplet ejection heads can be improved while permitting different liquid droplet ejection properties for each liquid droplet ejection head; a head unit and a liquid droplet ejection apparatus; a method for manufacturing an electro-optical apparatus; an electro-optical apparatus; and an electronic device. 
     A method for arranging liquid droplet ejection heads according to one aspect of the invention includes arranging and fixing a plurality of inkjet liquid droplet ejection heads, ejecting a common functional liquid, on a common carriage plate, based on the amount of droplets ejected from a number of ejection nozzles in a nozzle row that each of the liquid droplet ejection heads has, with the heads shifted in a direction of the nozzle row. The liquid droplet ejection heads are so arranged and fixed that in the liquid droplet ejection heads closely aligned in the direction of the nozzle row, a difference between the amounts of droplets ejected from two ejection nozzles located at each innermost end of the liquid droplet ejection heads is within a predetermined range of tolerance, and the amounts of droplets ejected from two ejection nozzles located at the outermost ends in the direction of the nozzle row on the carriage plate are within a predetermined range of a reference amount. 
     With the configuration, by arranging and fixing each liquid droplet ejection head so that two ejection nozzles located at each innermost end of the liquid droplet ejection heads closely aligned in the direction of the nozzle row are within the predetermined range of tolerance, the difference between the amounts of adjacent functional liquid droplets ejected and landed from different liquid droplet ejection heads can be suppressed among the liquid droplet ejection heads arranged and fixed on the common carriage plate. Furthermore, by arranging and fixing each liquid droplet ejection head so that in two ejection nozzles located at the outermost ends in the direction of the nozzle row on the carriage plate, each amount of droplets ejected is within the predetermined range of the reference amount, the difference between the amounts of adjacent functional liquid droplets ejected and landed from different liquid droplet ejection heads can be suppressed among the liquid droplet ejection heads arranged and fixed on different carriage plates. Therefore, drawing quality with a plurality of liquid droplet ejection heads can be improved while permitting different liquid droplet ejection properties for each liquid droplet ejection head. 
     In this case, preferably, the liquid droplet ejection heads arranged on the carriage plate are selected from candidate liquid droplet ejection heads to be arranged whose number is greater than the number of the liquid droplet ejection heads arranged on the carriage plate. 
     With the configuration, preparation of the number of candidate liquid droplet ejection heads greater than the number of liquid droplet ejection heads arranged will increase a possibility that the above-mentioned conditions (range of tolerance and range of the reference amount) are satisfied, and provide more groups (patterns) that satisfy the conditions. Accordingly, arrangement and fixation that satisfy the above-mentioned conditions can be easily and certainly attained, thereby improving a manufacturing yield of the liquid droplet ejection heads. 
     In this case, preferably, the candidate liquid droplet ejection heads has a fluctuation in the amounts of droplets ejected from all the ejection nozzles within a predetermined range. 
     With the configuration, by excluding candidate liquid droplet ejection heads having a fluctuation in the amounts of droplets ejected from all the ejection nozzles out of the predetermined range, appropriate arrangement can be easily attained. 
     Preferably, the liquid droplet ejection heads are divided into two head groups in the direction of the nozzle row and arranged on the carriage plate, and the liquid droplet ejection heads belonging to one head group and the liquid droplet ejection heads belonging to the other head group face each other in the direction of the nozzle row. 
     With the configuration, the liquid droplet ejection heads can be efficiently arranged on the carriage plate, and drawing processing can be efficiently performed. 
     In this case, preferably, the functional liquid has either color of red, green, or blue, and the predetermined range of tolerance is determined based on the difference between the amounts of droplets ejected to avoid unevenness of color possibly generated when droplets ejected and landed from two ejection nozzles are adjacent to each other. 
     With the configuration, the adjacent droplets (functional liquid droplets) ejected and landed from the above-mentioned two ejection nozzles located at each innermost end can provide drawing processing of good quality without unevenness of color in any of the ejected and landed adjacent droplets. 
     In this case, preferably, the functional liquid has either color of red, green, or blue. Furthermore, preferably, the predetermined range of the reference amount is a range having a standardized amount of droplets ejected from a single ejection nozzle as a mean value, and determined based on a range of the amount of droplets ejected to avoid unevenness of color in any of the ejected and landed adjacent droplets. 
     With the configuration, by determining the predetermined range of the reference amount as a range having the standardized amount of droplets ejected from a single ejection nozzle as a mean value, the above-mentioned two ejection nozzles located at each outermost end eject the amounts of droplets of a value approximated to the standardized amount of droplets ejected, thereby suppressing a fluctuation in the amount of droplets ejected. Additionally, by determining the predetermined range of the reference amount based on the range of the amount of droplets ejected to avoid unevenness of color in any of the ejected and landed adjacent droplets, drawing processing of better quality without unevenness of color can be performed. 
     In this case, preferably, when two or more sets of alternatives exist within the predetermined range of the reference amount, an alternative is selected with which the sum of the square of the difference between the mean value in the range of the reference amount and the amount of droplets ejected from one of the above-mentioned two ejection nozzles in each set and the square of the difference between the mean value in the range of reference amount and the amount of droplets ejected from the other of the above-mentioned two ejection nozzles in each set is the minimum. 
     With the configuration, by selecting a set of ejection nozzles with which the sum of the square of the difference between the mean value in the range of the reference amount and the amount of droplets ejected from one of the two ejection nozzles and the square of the difference between the mean value in the range of the reference amount and the amount of droplets ejected from the other of the above-mentioned two ejection nozzles is the minimum, the difference between the amounts of droplets ejected from the two ejection nozzles can be further suppressed, and drawing processing of better quality can be performed. 
     In this case, preferably, on a premise that the average amount of droplets ejected in each nozzle row is the absolute target amount of droplets ejected, the amount of droplets ejected is compared using a numeric value normalized with the absolute target amount of droplets ejected defined as 1. 
     With the configuration, the amount of droplets ejected can be easily compared with the absolute target amount of droplets ejected. 
     In this case, preferably, the amount of droplets ejected from a number of ejection nozzles in each nozzle row is calculated from an approximate characteristic line based on measurement results. 
     With the configuration, by calculating the amount of droplets ejected from a number of ejection nozzles in each nozzle row from the approximate characteristic line based on the measurement results of several ejection nozzles, it is not necessary to measure the amount of droplets from all the ejection nozzles, and the amounts of droplets ejected from all the ejection nozzles can be efficiently calculated. 
     Preferably, the approximate characteristic line is derived from the results obtained by measuring the amount of droplets from all of a plurality of ejection nozzles located at both ends of a number of ejection nozzles in each nozzle row and by excluding the amount of droplets from a plurality of remaining ejection nozzles located in an intermediate part in each nozzle row. 
     With the configuration, a strict value can be obtained for the ejection nozzles located at both ends of a number of ejection nozzles. Therefore, comparison of the obtained value with the range of the reference amount or the range of tolerance can be performed with sufficient precision. 
     In this case, preferably, the amount of droplets ejected used when comparing whether to be in within the range of tolerance is the average value of the amounts of droplets ejected from the ejection nozzles located at the ends of a number of ejection nozzles. 
     In this case, preferably, the amount of droplets ejected used when comparing whether to be in within the range of the reference amount is the average value of the amounts of droplets ejected from the ejection nozzles located at the ends of a number of ejection nozzles. 
     With the configurations, a fluctuation in the amount of droplets ejected from one ejection nozzle can be reduced, and more accurate comparison can be made to determine whether the amount of droplets ejected from the ejection nozzle is within the range of tolerance (and range of the reference amount). 
     In this case, preferably, each liquid droplet ejection head has a plurality of ineffective ejection nozzles not used for drawing at both ends of a number of ejection nozzle in each nozzle row. 
     With the configuration, since the ejection nozzles at both ends eject the amount of droplets greater than the amount of droplets from the ejection nozzles located in the intermediate part, by setting the ejection nozzles at both ends as ineffective ejection nozzles not used for drawing, a fluctuation in the amount of droplets ejected in the nozzle row can be suppressed, thereby performing drawing processing of better quality. 
     In a head unit according to another aspect of the invention, a plurality of liquid droplet ejection heads are arranged and fixed on a carriage plate by using the above-mentioned method for arranging liquid droplet ejection heads. 
     With the configuration, by using the method for arranging liquid droplet ejection heads that permits different liquid droplet ejection properties for each liquid droplet ejection head and improves drawing quality obtained by using a plurality of liquid droplet ejection heads, a head unit that allows drawing processing of good quality can be provided. 
     A liquid droplet ejection apparatus according to still another aspect of the invention is provided with the above-mentioned head unit used to eject a functional liquid to a workpiece for drawing. 
     With the configuration, by using the above-mentioned head unit, drawing processing of good quality can be performed to a workpiece. 
     In a method for manufacturing an electro-optical apparatus according to yet another aspect of the invention, the above-mentioned liquid droplet ejection apparatus is used to form a film with functional liquid droplets on a workpiece. 
     An electro-optical apparatus according to yet another aspect of the invention has a film formed on a workpiece with functional liquid droplets by using the above-mentioned liquid droplet ejection apparatus. 
     With the configuration, electro-optical apparatuses of high quality can be efficiently manufactured. Functional materials include luminescent materials (electro-luminescence light-emitting layers and hole injection layers) for organic electroluminescence apparatuses; filter materials (filter elements) of a color filter used for liquid crystal displays; fluorescent materials (fluorescent bodies) for electron emission devices (field emission displays, FED); fluorescent materials (fluorescent bodies) for plasma display panel (PDP) apparatuses; and electrophoresis element materials (electrophoresis bodies) for electrophoretic displays. The functional materials are liquid materials that can be ejected by functional liquid droplet ejection heads (inkjet heads). The electro-optical apparatuses (flat panel displays, FPD) include organic electroluminescence apparatuses, liquid crystal displays, electron emission devices, PDP apparatuses, and electrophoretic displays. 
     An electronic device according to yet another aspect of the invention is provided with an electro-optical apparatus manufactured by the above-mentioned method for manufacturing an electro-optical apparatus, or provided with the above-mentioned electro-optical apparatus. 
     In this case, the electronic devices denote, for example, cellular phones carrying a so-called flat-panel display and personal computers as well as various kinds of electric products. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a plan view of a liquid droplet ejection apparatus according to a preferred embodiment. 
         FIG. 2  is a side view of the liquid droplet ejection apparatus. 
         FIG. 3  is a view showing an arrangement of functional liquid droplet ejection heads mounted on a head unit. 
         FIGS. 4A to 4C  are explanatory views for arrangement patterns of a color filter, showing a stripe arrangement, a mosaic arrangement, and a delta arrangement, respectively. 
         FIG. 5  is a perspective view of the functional liquid droplet ejection head. 
         FIG. 6  is a graph of an approximate characteristic line. 
         FIG. 7  is an explanatory view for an arrangement of the functional liquid droplet ejection heads on a carriage plate. 
         FIG. 8  is a flowchart illustrating manufacturing steps of a color filter. 
         FIGS. 9A-9E  are schematic sectional views in an order of manufacturing process for the color filter. 
         FIG. 10  is a sectional view of an essential part of a liquid crystal display using the color filter according to the invention. 
         FIG. 11  is a sectional view of an essential part of a liquid crystal display as the second example using the color filter according to the invention. 
         FIG. 12  is a sectional view of an essential part of a liquid crystal display as the third example using the color filter according to the invention. 
         FIG. 13  is a sectional view of an essential part of a display as an organic EL apparatus. 
         FIG. 14  is a flowchart illustrating manufacturing steps of the display as the organic EL apparatus. 
         FIG. 15  is a process chart illustrating formation of an inorganic bank layer. 
         FIG. 16  is a process chart illustrating formation of an organic bank layer. 
         FIG. 17  is a process chart illustrating processes of forming a positive-hole injection/transport layer. 
         FIG. 18  is a process chart illustrating a state where the positive-hole injection/transport layer has been formed. 
         FIG. 19  is a process chart illustrating processes for forming a light-emitting layer having a blue color component. 
         FIG. 20  is a process chart illustrating a state where the light-emitting layer having a blue color component has been formed. 
         FIG. 21  is a process chart illustrating a state where light-emitting layers having three color components have been formed. 
         FIG. 22  is a process chart illustrating processes for forming a cathode. 
         FIG. 23  is a perspective view illustrating an essential part of a plasma display apparatus (PDP apparatus). 
         FIG. 24  is a sectional view illustrating an essential part of an electron emission display apparatus (FED apparatus). 
         FIG. 25A  is a plan view illustrating an electron emission portion and the vicinity thereof of a display apparatus, and  FIG. 25B  is a plan view illustrating a method of forming the electron emission portion and the vicinity thereof. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, with reference to the accompanying drawings, a liquid droplet ejection apparatus to which a method for arranging liquid droplet ejection heads according to one embodiment of the invention is applied will be described. The liquid droplet ejection apparatus according to the present embodiment is incorporated into a production line of flat panel displays, and the liquid droplet ejection apparatus forms light emitting elements used as pixels in a color filter for liquid crystal displays or organic electroluminescence apparatuses, etc. by using functional liquid droplet ejection heads (liquid droplet ejection heads) having a functional liquid, i.e., a special ink or a luminescent resin liquid introduced therein. 
     As shown in  FIGS. 1 and 2 , a liquid droplet ejection apparatus  1  is arranged in an X-axis supporting base  2  supported by a stone surface plate. The liquid droplet ejection apparatus  1  includes an X axis table  11  that extends in an X axis direction as a main scan direction to move a workpiece W in the X axis direction (main scan direction); a Y axis table  12  that is arranged on one pair (two) of Y-axis supporting bases  3  extended over and across the X axis table  11  with two or more supports  4  therebetween, and that extends in a Y axis direction as a sub scan direction; and 10 pieces of carriage units  51  provided with a plurality of functional liquid droplet ejection heads  17 . The 10 pieces of the carriage units  51  are hung from the Y axis table  12 . When driving the functional liquid droplet ejection heads  17  to eject droplets in synchronization with drive of the X axis table  11  and the Y axis table  12 , functional liquid droplets of three colors of R, G, and B are ejected to draw a predetermined drawing pattern on the workpiece W. 
     The liquid droplet ejection apparatus  1  includes a maintenance device  5  having a flushing unit  14 , a suction unit  15 , a wiping unit  16 , and an ejecting performance inspection unit  18 . These units are used for maintenance of the functional liquid droplet ejection heads  17  to perform functional maintenance and functional recovery of the functional liquid droplet ejection heads  17 . Of the respective units that constitute the maintenance device  5 , the flushing unit  14  and the ejecting performance inspection unit  18  are mounted on the X axis table  11 , and the suction unit  15  and the wiping unit  16  are arranged on a mount  6  deposited off the X axis table  11  and in a position to which the carriage units  51  can be moved by the Y axis table  12  (strictly, the ejecting performance inspection unit  18  has a stage unit  77  mounted on the X axis table  11  and a camera unit  78  supported by the Y-axis supporting base  3  as will be described later). 
     The flushing unit  14  has a pair of pre-drawing flushing units  111 ,  111  and a periodic flushing unit  112 , and receives discharged droplets (flushing) from the functional liquid droplet ejection heads  17  discharged immediately before ejecting of the functional liquid droplet ejection heads  17  and when stopping drawing processing, for example, at the time of replacing the workpiece W. The suction unit  15  has a plurality of divided suction units  141  to forcibly suck a functional liquid from ejection nozzles  98  of each functional liquid droplet ejection head  17 . The wiping unit  16  has a wiping sheet  151  to wipe off a nozzle surface  97  of the functional liquid droplet ejection head  17  after suction. The ejecting performance inspection unit  18  has a stage unit  77  provided with a check sheet  83  thereon to receive functional liquid droplets ejected from the functional liquid droplet ejection head  17 , and a camera unit  78  to inspect the functional liquid droplets on the stage unit  77  according to image recognition. The ejecting performance inspection unit  18  inspects ejecting performance (ejection record, and flying course deviation of ejected droplets) of the functional liquid droplet ejection heads  17 . 
     Hereinafter, components of the liquid droplet ejection apparatus  1  will be described. As shown in  FIGS. 1 and 2 , the X axis table  11  includes a set table  21  to set the workpiece W on; a first X-axis slider  22  that supports the set table  21  slidably in the X axis direction; a second X-axis slider  23  that supports the flushing unit  14  and the ejecting performance inspection unit  18  slidably in the X axis direction; a pair of right and left X-axis linear motors (not shown) that extend in the X axis direction to move the set table  21  (workpiece W) in the X axis direction through the first X-axis slider  22  and to move the flushing unit  14  and the stage unit  77  in the X axis direction with the second X-axis slider  23  therebetween; and a pair (2 pieces) of X-axis common supporting bases  24  arranged in the X-axis linear motor side by side to guide movement of the first X-axis slider  22  and the second X-axis slider  23 . 
     The set table  21  has, for example, an adsorption table  31  to adsorb and set the workpiece W thereon, and a θ table  32  that supports the adsorption table  31  to correct a position of the workpiece W set on the adsorption table  31  in a θ axis direction. The pre-drawing flushing units  111  are attached on a pair of sides parallel with the Y axis direction of the set table  21 . 
     The Y axis table  12  includes 10 pieces of bridge plates  52  from which 10 pieces of the carriage units  51  are hung, 10 sets of Y-axis sliders (not shown) that support 10 pieces of the bridge plates  52  at both ends thereof, and a pair of Y-axis linear motors (not shown) deposited on the pair of the Y-axis supporting bases  3  to move the bridge plates  52  in the Y axis direction with the 10 sets of Y-axis sliders therebetween. The Y axis table  12  performs a sub scan of the functional liquid droplet ejection heads  17  through each carriage unit  51  at the time of drawing, and brings the functional liquid droplet ejection heads  17  into a position facing the maintenance device  5 . 
     Drive of the pair of Y-axis linear motors (in synchronization with each other) causes each of the Y-axis sliders to simultaneously move parallel with the Y axis direction using the pair of Y-axis supporting bases  3  as a guide. Accordingly, the bridge plates  52  move in the Y axis direction, and accordingly, the carriage units  51  move in the Y axis direction. In this case, by controlling drive of the Y-axis linear motors, each carriage unit  51  can be separated and individually moved, or the ten carriage units  51  can be moved together. 
     Each carriage unit  51  includes a head unit  13  having the plurality of functional liquid droplet ejection heads  17 , a rotating mechanism  61  that supports the head unit  13  to perform θ correction (θ rotation), and a hanging member  62  that supports the head unit  13  to the Y axis table  12  (each bridge plate  52 ) with the θ rotating mechanism  61  therebetween. 
     As shown in  FIG. 3 , the head unit  13  includes 12 pieces of the functional liquid droplet ejection heads  17 , and a carriage plate  53  on which 12 pieces of the functional liquid droplet ejection heads  17  are arranged and fixed. The 12 pieces of the functional liquid droplet ejection heads  17  are divided into two groups in the Y axis direction, and in each group, 6 pieces of the functional liquid droplet ejection heads  17  are arranged step-wise in the X axis direction to form a head group  54 . The 6 pieces of the functional liquid droplet ejection heads  17  belonging to one head group  54  and those belonging to the other head group are arranged opposing each other in the direction of a nozzle row  98   b  (see  FIG. 7 ), so that the functional liquid droplet ejection heads  17  can be efficiently arranged on the carriage plate  53  and efficient drawing processing can be performed. Furthermore, 2 pieces of the functional liquid droplet ejection heads  17  for each color in each head group  54  are aligned consecutively in the X axis direction to form a single drawing line. 
     The head unit  13  has 12×10 pieces of the functional liquid droplet ejection heads  17  that corresponds to either of three colors of R, G, and B of the functional liquids, and the sets of 4 pieces of the functional liquid droplet ejection heads  17  each for one color (in each head group  54 , 2 pieces of the functional liquid droplet ejection heads for each color) draw a drawing pattern on the workpiece W with the functional liquids of the three colors. In the present embodiment, by sub scanning all the functional liquid droplet ejection heads  17  (12×10 pieces) twice, drawing lines of three colors of R, G, and B continuing in the Y axis direction are formed. The length of the drawing lines is equivalent to the maximum width of the workpiece W that can be mounted on the set table  21 . The drawing pattern formed of the functional liquids of the three colors has three types of patterns as shown in  FIG. 4 , and in the present embodiment, drawing is performed in accordance with the drawing pattern (bitmap data) shown in  FIG. 4A . 
     As shown in  FIG. 5 , the functional liquid droplet ejection head  17  is a so-called twin type, and includes a functional liquid introductory part  91  having twin connection needles  92 , twin head substrates  93  connected to the functional liquid introductory part  91 , and a head body  94  connected to the lower part of the functional liquid introductory part  91  and having a head inner passage formed inside the head body  94  to be filled with the functional liquid. The connection needles  92  are connected to a functional fluid tank not shown to supply the functional liquid to the functional liquid introductory part  91 . The head body  94  includes a cavity  95  (piezoelectric element) and a nozzle plate  96  where a nozzle surface  97  has openings of a number of ejection nozzles  98 . When driving the functional liquid droplet ejection head  17  to eject droplets, (a voltage is applied to the piezoelectric element and) functional liquid droplets are ejected from the ejection nozzles  98  by means of a pumping action of the cavity  95 . 
     On the nozzle surface  97 , a first nozzle row  99   a  and a second nozzle row  99   b  each having a number of ejection nozzles  98  are formed parallel with each other. In addition, the position of the nozzle row  99   a  is shifted from the position of the nozzle row  99   b  by a pitch of a half of a nozzle. The two nozzle rows  99   a  and  99   b  each have 10 pieces of ineffective ejection nozzles not used for drawing processing at both ends of the nozzle rows. Accordingly, a fluctuation in the amount of droplets ejected from the nozzle rows  99   a  and  99   b  can be suppressed, and drawing processing of better quality can be performed. A “nozzle row” referred to as in claims denotes a combination of the first nozzle row  99   a  and the second nozzle row  99   b  according to the present embodiment. Therefore, hereinafter, the first nozzle row  99   a  and the second nozzle row  99   b  are collectively mentioned as a nozzle row  99 . 
     In drawing operations of the liquid droplet ejection apparatus  1 , first, the workpiece W is moved with the X axis table  11  in the X axis direction (to the upper side of  FIG. 1 ) to perform the first drawing operation (forward movement path). Then, the head unit  13  is moved by two heads in the Y axis direction (sub scan). Again, the workpiece W is moved in the X axis direction (to the lower side of  FIG. 1 ) to perform the second drawing operation (backward movement path). Then, an additional sub scan of the head unit  13  is performed by two heads. Once again, the workpiece W is moved in the X axis direction (to the upper side of  FIG. 1 ) to perform the third drawing operation (forward movement path). Thus, by repeating movement of the workpiece W and the drawing operation 3 times while changing the functional liquid droplet ejection heads  17  corresponding to positions on the workpiece W by a sub scan, drawing processing of the three colors of R, G, and B is performed efficiently. 
     Next, with reference to  FIG. 6  or  7 , a method for arranging the functional liquid droplet ejection heads  17  on the carriage plate  53  will be described in more detail. In arrangement of the functional liquid droplet ejection heads  17 , a plurality of functional liquid droplet ejection heads  17  that serve as candidates to be arranged (hereinafter, mentioned as candidate liquid droplet ejection heads) are prepared in advance, and based on the liquid droplet ejection properties of the candidate liquid droplet ejection heads, suitable functional liquid droplet ejection heads  17  are selected out of the candidate liquid droplet ejection heads to be arranged. To this end, selection of the candidate liquid droplet ejection heads and liquid droplet ejection property acquisition of the candidate liquid droplet ejection heads will be described first. Since the liquid droplet ejection properties of the candidate liquid droplet ejection heads are acquired by liquid droplet ejection property acquisition of pre-selected liquid droplet ejection heads performed when selecting the candidate liquid droplet ejection heads, the liquid droplet ejection property acquisition of the pre-selected liquid droplet ejection heads will be described here. The following description disregards the ineffective ejection nozzles not related to drawing or measurement. 
     For each of the pre-selected liquid droplet ejection heads that are a number of functional liquid droplet ejection heads  17  manufactured and pre-selected, the amount of ejecting, ejecting velocity, and poor ejecting of each ejection nozzle  98  are measured using test equipment not shown. Particularly, the amount of droplet ejected from a plurality of ejection nozzles  98  at both ends is all measured, whereas the amount of droplet ejected from remaining ejection nozzles  98  (a plurality of ejection nozzles  98  located in an intermediate part) is calculated using an approximate characteristic line (see  FIG. 6 ) based on measurement results of the ejection nozzles  98  at both ends. Thus, by calculating the amounts of droplets ejected from all the ejection nozzles  98  in each nozzle row  99  from the approximate characteristic line based on the measurement results of several ejection nozzles  98 , it is not necessary to measure the amount of droplets from all of the ejection nozzles  98 , and the amounts of droplets ejected from all the ejection nozzles  98  can be efficiently calculated. Additionally, by making the approximate characteristic line based on the measurement results of the ejection nozzles  98  at both ends, strict values can be obtained for the ejection nozzles  98  at both ends used to arrange and fix the functional liquid droplet ejection head  17 . Preferably, a 6th-order approximated curve is used as the approximate characteristic line. The above-mentioned poor ejecting of droplets includes non-ejecting, flying course deviation, unusual ejecting, etc. 
     Next, based on the measured liquid droplet ejection properties, the candidate liquid droplet ejection heads are selected from a number of pre-selected liquid droplet ejection heads. Specifically, when in a single pre-selected liquid droplet ejection head, a fluctuation in the amounts of droplets ejected from all the ejection nozzles  98  is determined to be within a predetermined range, and when the pre-selected liquid droplet ejection head is determined to have good quality based on judgment of ejecting velocity, flying course deviation, etc., the pre-selected liquid droplet ejection head is selected as a candidate liquid droplet ejection head. Thus, by setting a condition that a fluctuation in the amounts of droplets ejected from all the ejection nozzles  98  is within the predetermined range as a criterion, appropriate arrangement of the functional liquid droplet ejection heads  17  can be made with ease. The selected candidate liquid droplet ejection heads that are greater in number than the functional liquid droplet ejection heads  17  to be arranged are prepared. Accordingly, the possibility is raised that conditions used to arrange and fix the functional liquid droplet ejection heads  17  will be satisfied, and more groups (patterns) that satisfy the conditions can be provided. Therefore, the manufacturing yield of the functional liquid droplet ejection heads  17  is improved, and the functional liquid droplet ejection heads  17  can be easily and certainly arranged and fixed in accordance with the conditions. 
     As shown in  FIG. 7 , the functional liquid droplet ejection heads  17  are so arranged and fixed that two conditions, an innermost end nozzle condition and an outermost end nozzle condition, are satisfied. These conditions are taken into consideration for each color of the functional liquid. Therefore, red is used as an example here for description. 
     The innermost end nozzle condition is a condition that in 4 pieces (for each color) of the functional liquid droplet ejection heads  17  on the carriage plate  53 , for each set of two ejection nozzles  98  located at the innermost ends in the functional liquid droplet ejection heads  17  closely aligned in the direction of the nozzle row  99 , the difference between the amounts of droplets ejected from the two ejection nozzles  98  is within a predetermined range of tolerance. The range of tolerance is set based on the difference between the amounts of droplets ejected to avoid unevenness of color in any of ejected and landed droplets when the ejected and landed droplets (landed functional liquid droplets) are adjacent to each other. For example, in the present embodiment, the difference between the amounts of droplets ejected is up to a tolerance of 0.65% (0.65% of a standard value 1.011 pl). 
     The outermost end nozzle condition is a condition that in the functional liquid droplet ejection heads  17  located at both outermost ends in the direction of the nozzle row  99  on the carriage plate  53 , for two ejection nozzles  98  arranged at the outermost ends of the above-mentioned functional liquid droplet ejection heads  17 , that is, for the ejection nozzle  98  at the rightmost end of the functional liquid droplet ejection head  17  and the ejection nozzle  98  at the leftmost end of the functional liquid droplet ejection head  17 , each amount of droplet ejected from the two ejection nozzles  98  is within a predetermined range of a reference amount. The range of the reference amount is a range having the standardized amount of droplets ejected from a single ejection nozzle  98  as a mean value, and set based on the range of the amount of droplets ejected to avoid unevenness of color in any of the ejected and landed adjacent droplets. For example, in the present embodiment, the range of reference amount is 1.011 pl±0.45% (0.45% of the standard value 1.011 pl). 
     Thus, by arranging and fixing each functional liquid droplet ejection head  17  so that the two ejection nozzles  98  located at the innermost ends of the functional liquid droplet ejection heads  17  closely aligned in the direction of the nozzle row  99  have the amount of droplets ejected within the predetermined range of tolerance, the difference between the amounts of adjacent droplets ejected and landed from the different functional liquid droplet ejection heads  17  can be suppressed among the functional liquid droplet ejection heads  17  arranged and fixed on the common carriage plate  53 . Furthermore, by arranging and fixing each functional liquid droplet ejection head  17  so that in the two ejection nozzles located at the outermost ends in the direction of the nozzle row  99  on the carriage plate  53 , each amount of droplets ejected is within the predetermined range of the reference amount, the difference between the amounts of adjacent droplets (functional liquid droplets) ejected and landed from the different functional liquid droplet ejection heads  17  can be suppressed among the functional liquid droplet ejection heads  17  arranged and fixed on different carriage plates  53 . Therefore, while liquid droplet ejection properties different for each functional liquid droplet ejection head  17  are permitted, drawing quality obtained by using the plurality of functional liquid droplet ejection heads  17  can be improved. 
     Furthermore, on the innermost end nozzle condition, the range of tolerance is set based on the difference between the amounts of droplets ejected to avoid unevenness of color generated when the ejected and landed droplets are adjacent to each other. Accordingly, in the adjacent ejected and landed droplets ejected from the two ejection nozzles  98  located at the innermost ends, drawing processing of better quality without unevenness of color can be performed. 
     Furthermore, on the outermost end nozzle condition, the range of the reference amount is so determined that the standardized amount of droplets ejected from a single ejection nozzle is set as the mean value, and then, the range has a value approximated to the standardized amount of droplets ejected. Therefore, a fluctuation in the amount of droplets ejected can be suppressed. In addition, the range of the reference amount is determined based on the range of the amount of droplets ejected to avoid unevenness of color in any of the ejected and landed adjacent droplets, whereby drawing processing of better quality without unevenness of a color can be performed. 
     On the outermost end nozzle condition, when two or more sets of alternatives exist within the predetermined range of the reference amount, an alternative is selected wherein the sum of the square of the difference between the mean value (standard value) in the range of the reference amount in each set and the amount of droplets ejected from one ejection nozzle  98  at the outermost ends and the square of the difference between the mean value and the amount of droplets ejected from the other ejection nozzle  98  at the outermost ends is the minimum. Accordingly, the difference between the amounts of droplets ejected from the two ejection nozzles  98  can be further suppressed, and drawing processing of better quality can be performed. For example, when the mean value is 1.011 pl and there are 2 sets of alternatives, two ejection nozzles of one set eject amounts of droplets of 1.011+0.5 pl and 1.011−0.1 pl, and two ejection nozzles of the other set eject amounts of droplets of 1.011+0.3 pl and 1.011−0.2 pl, the sum of the square the difference between the mean value and one amount of droplets ejected and the square of the difference between the mean value and the other amount of droplets ejected in the one set is (1.011−(1.011+0.5)) 2 +(1.011−(1.011−0.1)) 2 =0.26; and the sum of the square of the difference between the mean value and one amount of droplets ejected and the square of the difference between the mean value and the other amount of droplets ejected in the other set is (1.011−(1.011+0.3)) 2 +(1.011−(1.011−0.2)) 2=0.13 . Therefore, in this case, the other set having the minimum of 0.13 is selected. 
     Preferably, on the premise that the average amount of droplets ejected from each nozzle row  99  is an absolute target amount of droplets ejected, the amount of droplets ejected used for these conditions is a numeric value normalized with the absolute target amount of droplets ejected defined as 1. Accordingly, the amount of droplets ejected with the absolute target amount of droplets ejected can be easily compared. 
     Preferably, the amount of droplets ejected used when comparing whether to be within the range of tolerance or the range of the reference amount is an average value of the amounts of droplets ejected from a plurality (10 pieces each) of ejection nozzles  98  located at the ends of the nozzle rows  99 . In other words, the average value is defined as an amount of droplets ejected from each ejection nozzle  98  used for the above-mentioned comparison. Accordingly, a fluctuation in the amount of droplets ejected from one ejection nozzle  98  reduces, allowing more accurate comparison of whether to be within the range of the reference amount. Preferably, when selecting an alternative under the above-mentioned outermost end nozzle condition, the sum of the square of the difference between 5 ejection nozzles located at one outermost end and the mean value and the square of the difference between another 5 ejection nozzles located at the other outermost end and the mean value is used as the value to be compared. 
     With the above-mentioned configuration, by arranging and fixing each functional liquid droplet ejection head  17  so that the two ejection nozzles  98  located at the innermost ends of the functional liquid droplet ejection heads  17  closely aligned in the direction of the nozzle row  99  have the amount of droplets ejected within the predetermined range of tolerance, the difference between the amounts of adjacent droplets ejected and landed from the different functional liquid droplet ejection heads  17  can be suppressed among the functional liquid droplet ejection heads  17  arranged and fixed on the common carriage plate  53 . Furthermore, by arranging and fixing each functional liquid droplet ejection head  17  so that in the two ejection nozzles located at the outermost ends in the direction of the nozzle row  99  on the carriage plate  53 , each amount of droplets ejected is within the predetermined range of the reference amount, the difference between the amounts of adjacent functional liquid droplets ejected and landed from the different functional liquid droplet ejection heads  17  can be suppressed among the functional liquid droplet ejection heads  17  arranged on and fixed to different carriage plates  53 . Therefore, while liquid droplet ejection properties different for each functional liquid droplet ejection head  17  are permitted, drawing quality obtained by using the plurality of functional liquid droplet ejection heads  17  can be improved. 
     Taking electro-optical apparatuses (flat panel display apparatuses) manufactured using the liquid droplet ejection apparatus  1  and active matrix substrates formed on the electro-optical apparatuses as display apparatuses as examples, configurations and manufacturing methods thereof will now be described. Examples of the electro-optical apparatuses include a color filter, a liquid crystal display apparatus, an organic EL apparatus, a plasma display apparatus (PDP (plasma display panel) apparatus), and an electron emission apparatus (FED (field emission display) apparatus and SED (surface-conduction electron emitter display) apparatus). Note that the active matrix substrate includes thin-film transistors, source lines and data lines which are electrically connected to the thin film transistors. 
     First, a manufacturing method of a color filter incorporated in a liquid crystal display apparatus or an organic EL apparatus will be described.  FIG. 8  shows a flowchart illustrating manufacturing steps of a color filter.  FIGS. 12A to 12E  are sectional views of the color filter  500  (a filter substrate  500 A) of this embodiment shown in an order of the manufacturing steps. 
     In a black matrix forming step (step S 101 ), as shown in  FIG. 9A , a black matrix  502  is formed on the substrate (W)  501 . The black matrix  502  is formed of a chromium metal, a laminated body of a chromium metal and a chromium oxide, or a resin black, for example. The black matrix  502  may be formed of a thin metal film by a sputtering method or a vapor deposition method. Alternatively, the black matrix  502  may be formed of a thin resin film by a gravure plotting method, a photoresist method, or a thermal transfer method. 
     In a bank forming step (step S 102 ), the bank  503  is formed so as to be superposed on the black matrix  502 . Specifically, as shown in  FIG. 9B , a resist layer  504  which is formed of a transparent negative photosensitive resin is formed so as to cover the substrate  501  and the black matrix  502 . An upper surface of the resist layer  504  is covered with a mask film  505  formed in a matrix pattern. In this state, exposure processing is performed. 
     Furthermore, as shown in  FIG. 9C , the resist layer  504  is patterned by performing etching processing on portions of the resist layer  504  which are not exposed, and the bank  503  is thus formed. Note that when the black matrix  502  is formed of a resin black, the black matrix  502  also serves as a bank. 
     The bank  503  and the black matrix  502  disposed beneath the bank  503  serve as a partition wall  507   b  for partitioning the pixel areas  507   a . The partition wall  507   b  defines receiving areas for receiving the functional liquid ejected when the functional liquid droplet ejection heads  17  form coloring layers (film portions)  508 R,  508 G, and  508 B in a subsequent coloring layer forming step. 
     The filter substrate  500 A is obtained through the black matrix forming step and the bank forming step. 
     Note that, in this embodiment, a resin material having a lyophobic (hydrophobic) film surface is used as a material of the bank  503 . Since a surface of the substrate (glass substrate)  501  is lyophilic (hydrophilic), variation of positions to which the liquid droplet is projected in the each of the pixel areas  507   a  surrounded by the bank  503  (partition wall  507   b ) can be automatically corrected in the subsequent coloring layer forming step. 
     In the coloring layer forming step (S 103 ), as shown in  FIG. 9D , the functional liquid droplet ejection heads  17  eject the functional liquid within the pixel areas  507   a  each of which are surrounded by the partition wall  507   b . In this case, the functional liquid droplet ejection heads  17  eject functional liquid droplets using functional liquids (filter materials) of colors R, G, and B. A color scheme pattern of the three colors R, G, and B may be the stripe arrangement, the mosaic arrangement, or the delta arrangement. 
     Then drying processing (such as heat treatment) is performed so that the three color functional liquids are fixed, and thus three coloring layers  508 R,  508 G, and  508 B are formed. Thereafter, a protective film forming step is reached (step S 104 ). As shown in  FIG. 12E , a protective film  509  is formed so as to cover surfaces of the substrate  501 , the partition wall  507   b , and the three coloring layers  508 R,  508 G, and  508 B. 
     That is, after liquid used for the protective film is ejected onto the entire surface of the substrate  501  on which the coloring layers  508 R,  508 G, and  508 B are formed and the drying process is performed, the protective film  509  is formed. 
     In the manufacturing method of the color filter  500 , after the protective film  509  is formed, a coating step is performed in which ITO (Indium Tin Oxide) serving as a transparent electrode in the subsequent step is coated. 
       FIG. 10  is a sectional view of an essential part of a passive matrix liquid crystal display apparatus (liquid crystal display apparatus  520 ) and schematically illustrates a configuration thereof as an example of a liquid crystal display apparatus employing the color filter  500 . A transmissive liquid crystal display apparatus as a final product can be obtained by disposing a liquid crystal driving IC (integrated circuit), a backlight, and additional components such as supporting members on the display apparatus  520 . Note that the color filter  500  is the same as that shown in  FIGS. 9A to 9E , and therefore, reference numerals the same as those used in  FIGS. 9A to 9E  to denote the same components, and descriptions thereof are omitted. 
     The display apparatus  520  includes the color filter  500 , a counter substrate  521  such as a glass substrate, and a liquid crystal layer  522  formed of STN (super twisted nematic) liquid crystal compositions sandwiched therebetween. The color filter  500  is disposed on the upper side of  FIG. 10  (on an observer side). 
     Although not shown, polarizing plates are disposed so as to face an outer surface of the counter substrate  521  and an outer surface of the color filter  500  (surfaces which are remote from the liquid crystal layer  522 ). A backlight is disposed so as to face an outer surface of the polarizing plate disposed near the counter substrate  521 . 
     A plurality of rectangular first electrodes  523  extending in a horizontal direction in  FIG. 10  are formed with predetermined intervals therebetween on a surface of the protective film  509  (near the liquid crystal layer  522 ) of the color filter  500 . A first alignment layer  524  is arranged so as to cover surfaces of the first electrodes  523  which are surfaces remote from the color filter  500 . 
     On the other hand, a plurality of rectangular second electrodes  526  extending in a direction perpendicular to the first electrodes  523  disposed on the color filter  500  are formed with predetermined intervals therebetween on a surface of the counter substrate  521  which faces the color filter  500 . A second alignment layer  527  is arranged so as to cover surfaces of the second electrodes  526  near the liquid crystal layer  522 . The first electrodes  523  and the second electrodes  526  are formed of a transparent conductive material such as an ITO. 
     A plurality of spacers  528  disposed in the liquid crystal layer  522  are used to maintain the thickness (cell gap) of the liquid crystal layer  522  constant. A seal member  529  is used to prevent the liquid crystal compositions in the liquid crystal layer  522  from leaking to the outside. Note that an end of each of the first electrodes  523  extends beyond the seal member  529  and serves as wiring  523   a.    
     Pixels are arranged at intersections of the first electrodes  523  and the second electrodes  526 . The coloring layers  508 R,  508 G, and  508 B are arranged on the color filter  500  so as to correspond to the pixels. 
     In normal manufacturing processing, the first electrodes  523  are patterned and the first alignment layer  524  is applied on the color filter  500  whereby a first half portion of the display apparatus  520  on the color filter  500  side is manufactured. Similarly, the second electrodes  526  are patterned and the second alignment layer  527  is applied on the counter substrate  521  whereby a second half portion of the display apparatus  520  on the counter substrate  521  side is manufactured. Thereafter, the spacers  528  and the seal member  529  are formed on the second half portion, and the first half portion is attached to the second half portion. Then, liquid crystal to be included in the liquid crystal layer  522  is injected from an inlet of the seal member  529 , and the inlet is sealed. Finally, the polarizing plates and the backlight are disposed. 
     The liquid droplet ejection apparatus  1  of this embodiment may apply a spacer material (functional liquid) constituting the cell gap, for example, and uniformly apply liquid crystal (functional liquid) to an area sealed by the seal member  529  before the first half portion is attached to the second half portion. Furthermore, the seal member  529  may be printed using the functional liquid droplet ejection heads  17 . Moreover, the first alignment layer  524  and the second alignment layer  527  may be applied using the functional liquid droplet ejection heads  17 . 
       FIG. 11  is a sectional view of an essential part of a display apparatus  530  and schematically illustrates a configuration thereof as a second example of a liquid crystal display apparatus employing the color filter  500  which is manufactured in this embodiment. 
     The display apparatus  530  is considerably different from the display apparatus  520  in that the color filter  500  is disposed on a lower side in  FIG. 11  (remote from the observer). 
     The display apparatus  530  is substantially configured such that a liquid crystal layer  532  constituted by STN liquid crystal is arranged between the color filter  500  and a counter substrate  531  such as a glass substrate. Although not shown, polarizing plates are disposed so as to face an outer surface of the counter substrate  531  and an outer surface of the color filter  500 . 
     A plurality of rectangular first electrodes  533  extending in a depth direction of  FIG. 11  are formed with predetermined intervals therebetween on a surface of the protective film  509  (near the liquid crystal layer  532 ) of the color filter  500 . A first alignment layer  534  is arranged so as to cover surfaces of the first electrodes  533  which are surfaces near the liquid crystal layer  532 . 
     On the other hand, a plurality of rectangular second electrodes  536  extending in a direction perpendicular to the first electrodes  533  disposed on the color filter  500  are formed with predetermined intervals therebetween on a surface of the counter substrate  531  which faces the color filter  500 . A second alignment layer  537  is arranged so as to cover surfaces of the second electrodes  536  near the liquid crystal layer  532 . 
     A plurality of spacers  538  disposed in the liquid crystal layer  532  are used to maintain the thickness (cell gap) of the liquid crystal layer  532  constant. A seal member  539  is used to prevent the liquid crystal compositions in the liquid crystal layer  532  from leaking to the outside. 
     As with the display apparatus  520 , pixels are arranged at intersections of the first electrodes  533  and the second electrodes  536 . The coloring layers  508 R,  508 G, and  508 B are arranged on the color filter  500  so as to correspond to the pixels. 
       FIG. 12  is an exploded perspective view of a transmissive TFT (thin film transistor) liquid crystal display device and schematically illustrates a configuration thereof as a third example of a liquid crystal display apparatus employing the color filter  500  to which the invention is applied. 
     A liquid crystal display apparatus  550  has the color filter  500  disposed on the upper side of  FIG. 12  (on the observer side). 
     The liquid crystal display apparatus  550  includes the color filter  500 , a counter substrate  551  disposed so as to face the color filter  500 , a liquid crystal layer (not shown) interposed therebetween, a polarizing plate  555  disposed so as to face an upper surface of the color filter  500  (on the observer side), and a polarizing plate (not shown) disposed so as to face a lower surface of the counter substrate  551 . 
     An electrode  556  used for driving the liquid crystal is formed on a surface of the protective film  509  (a surface near the counter substrate  551 ) of the color filter  500 . The electrode  556  is formed of a transparent conductive material such as an ITO and entirely covers an area in which pixel electrodes  560  are to be formed which will be described later. An alignment layer  557  is arranged so as to cover a surface of the electrode  556  remote from the pixel electrode  560 . 
     An insulating film  558  is formed on a surface of the counter substrate  551  which faces the color filter  500 . On the insulating film  558 , scanning lines  561  and signal lines  562  are arranged so as to intersect with each other. Pixel electrodes  560  are formed in areas surrounded by the scanning lines  561  and the signal lines  562 . Note that an alignment layer (not shown) is arranged on the pixel electrodes  560  in an actual liquid crystal display apparatus. 
     Thin-film transistors  563  each of which includes a source electrode, a drain electrode, a semiconductor layer, and a gate electrode are incorporated in areas surrounded by notch portions of the pixel electrodes  560 , the scanning lines  561 , and the signal lines  562 . When signals are supplied to the scanning lines  561  and the signal lines  562 , the thin-film transistors  563  are turned on or off so that power supply to the pixel electrodes  560  is controlled. 
     Note that although each of the display apparatuses  520 ,  530 , and  550  is configured as a transmissive liquid crystal display apparatus, each of the display apparatuses  520 ,  530 , and  550  may be configured as a reflective liquid crystal display apparatus having a reflective layer or a semi-transmissive liquid crystal display apparatus having a semi-transmissive reflective layer. 
       FIG. 16  is a sectional view illustrating an essential part of a display area of an organic EL apparatus (hereinafter simply referred to as a display apparatus  600 ). 
     In this display apparatus  600 , a circuit element portion  602 , a light-emitting element portion  603 , and a cathode  604  are laminated on a substrate (W)  601 . 
     In this display apparatus  600 , light is emitted from the light-emitting element portion  603  through the circuit element portion  602  toward the substrate  601  and eventually is emitted to an observer side. In addition, light emitted from the light-emitting element portion  603  toward an opposite side of the substrate  601  is reflected by the cathode  604 , and thereafter passes through the circuit element portion  602  and the substrate  601  to be emitted to the observer side. 
     An underlayer protective film  606  formed of a silicon oxide film is arranged between the circuit element portion  602  and the substrate  601 . Semiconductor films  607  formed of polysilicon oxide films are formed on the underlayer protective film  606  (near the light-emitting element portion  603 ) in an isolated manner. In each of the semiconductor films  607 , a source region  607   a  and a drain region  607   b  are formed on the left and right sides thereof, respectively, by high-concentration positive-ion implantation. The center portion of each of the semiconductor films  607  which is not subjected to high-concentration positive-ion implantation serves as a channel region  607   c.    
     In the circuit element portion  602 , the underlayer protective film  606  and a transparent gate insulating film  608  covering the semiconductor films  607  are formed. Gate electrodes  609  formed of, for example, Al, Mo, Ta, Ti, or W are disposed on the gate insulating film  608  so as to correspond to the channel regions  607   c  of the semiconductor films  607 . A first transparent interlayer insulating film  611   a  and a second transparent interlayer insulating film  611   b  are formed on the gate electrodes  609  and the gate insulating film  608 . Contact holes  612   a  and  612   b  are formed so as to penetrate the first interlayer insulating film  611   a  and the second interlayer insulating film  611   b  and to be connected to the source region  607   a  and the drain region  607   b  of the semiconductor films  607 . 
     Pixel electrodes  613  which are formed of ITOs, for example, and which are patterned to have a predetermined shape are formed on the second interlayer insulating film  611   b . The pixel electrode  613  is connected to the source region  607   a  through the contact holes  612   a.    
     Power source lines  614  are arranged on the first interlayer insulating film  611   a . The power source lines  614  are connected through the contact holes  612   b  to the drain region  607   b.    
     As shown in  FIG. 13 , the circuit element portion  602  includes thin-film transistors  615  connected to drive the respective pixel electrodes  613 . 
     The light-emitting element portion  603  includes functional layers  617  each formed on a corresponding one of pixel electrodes  613 , and bank portions  618  which are formed between the pixel electrodes  613  and the functional layers  617  and which are used to partition the functional layers  617  from one another. 
     The pixel electrodes  613 , the functional layers  617 , and the cathode  604  formed on the functional layers  617  constitute the light-emitting element. Note that the pixel electrodes  613  are formed into a substantially rectangular shape in plan view by patterning, and the bank portions  618  are formed so that each two of the pixel electrodes  613  sandwich a corresponding one of the bank portions  618 . 
     Each of the bank portions  618  includes an inorganic bank layer  618   a  (first bank layer) formed of an inorganic material such as SiO, SiO 2 , or TiO 2 , and an organic bank layer  618   b  (second bank layer) which is formed on the inorganic bank layer  618   a  and has a trapezoidal shape in a sectional view. The organic bank layer  618   b  is formed of a resist, such as an acrylic resin or a polyimide resin, which has an excellent heat resistance and an excellent lyophobic characteristic. Apart of each of the bank portions  618  overlaps peripheries of corresponding two of the pixel electrodes  613  which sandwich each of the bank portions  618 . 
     Openings  619  are formed between the bank portions  618  so as to gradually increase in size upwardly against the pixel electrodes  613 . 
     Each of the functional layers  617  includes a positive-hole injection/transport layer  617   a  formed so as to be laminated on the pixel electrodes  613  and a light-emitting layer  617   b  formed on the positive-hole injection/transport layer  617   a . Note that another functional layer having another function may be arranged so as to be arranged adjacent to the light-emitting layer  617   b . For example, an electronic transport layer may be formed. 
     The positive-hole injection/transport layer  617   a  transports positive holes from a corresponding one of the pixel electrodes  613  and injects the transported positive holes to the light-emitting layer  617   b . The positive-hole injection/transport layer  617   a  is formed by ejection of a first composition (functional liquid) including a positive-hole injection/transport layer forming material. The positive-hole injection/transport layer forming material may be a known material. 
     The light-emitting layer  617   b  is used for emission of light having colors red (R), green (G), or blue (B), and is formed by ejection of a second composition (functional liquid) including a material for forming the light-emitting layer  617   b  (light-emitting material). As a solvent of the second composition (nonpolar solvent), a known material which is insoluble to the positive-hole injection/transport layer  617   a  is preferably used. Since such a nonpolar solvent is used as the second composition of the light-emitting layer  617   b , the light-emitting layer  617   b  can be formed without dissolving the positive-hole injection/transport layer  617   a  again. 
     The light-emitting layer  617   b  is configured such that the positive holes injected from the positive-hole injection/transport layer  617   a  and electrons injected from the cathode  604  are recombined in the light-emitting layer  617   b  so as to emit light. 
     The cathode  604  is formed so as to cover an entire surface of the light-emitting element portion  603 , and in combination with the pixel electrodes  613 , supplies current to the functional layers  617 . Note that a sealing member (not shown) is arranged on the cathode  604 . 
     Steps of manufacturing the display apparatus  600  will now be described with reference to  FIGS. 14 to 22 . 
     As shown in  FIG. 14 , the display apparatus  600  is manufactured through a bank portion forming step (S 111 ), a surface processing step (S 112 ), a positive-hole injection/transport layer forming step (S 113 ), a light-emitting layer forming step (S 114 ), and a counter electrode forming step (S 115 ). Note that the manufacturing steps are not limited to these examples shown in  FIG. 17 , and one of these steps may be omitted or another step may be added according as desired. 
     In the bank portion forming step (S 111 ), as shown in  FIG. 15 , the inorganic bank layers  618   a  are formed on the second interlayer insulating film  611   b . The inorganic bank layers  618   a  are formed by forming an inorganic film at a desired position and by patterning the inorganic film by the photolithography technique. At this time, a part of each of the inorganic bank layers  618   a  overlaps peripheries of corresponding two of the pixel electrodes  613  which sandwich each of the inorganic bank layers  618   a.    
     After the inorganic bank layers  618   a  are formed, as shown in  FIG. 16 , the organic bank layers  618   b  are formed on the inorganic bank layers  618   a . As with the inorganic bank layers  618   a , the organic bank layers  618   b  are formed by patterning a formed organic film by the photolithography technique. 
     The bank portions  618  are thus formed. When the bank portions  618  are formed, the openings  619  opening upward relative to the pixel electrodes  613  are formed between the bank portions  618 . The openings  619  define pixel areas. 
     In the surface processing step (S 112 ), a hydrophilic treatment and a repellency treatment are performed. The hydrophilic treatment is performed on first lamination areas  618   aa  of the inorganic bank layers  618   a  and electrode surfaces  613   a  of the pixel electrodes  613 . The hydrophilic treatment is performed, for example, by plasma processing using oxide as a processing gas on surfaces of the first lamination areas  618   aa  and the electrode surfaces  613   a  to have hydrophilic properties. By performing the plasma processing, the ITO forming the pixel electrodes  613  is cleaned. 
     The repellency treatment is performed on walls  618   s  of the organic bank layers  618   b  and upper surfaces  618   t  of the organic bank layers  618   b . The repellency treatment is performed as a fluorination treatment, for example, by plasma processing using tetrafluoromethane as a processing gas on the walls  618   s  and the upper surfaces  618   t.    
     By performing this surface processing step, when the functional layers  617  is formed using the functional liquid droplet ejection heads  17 , the functional liquid droplets are ejected onto the pixel areas with high accuracy. Furthermore, the functional liquid droplets attached onto the pixel areas are prevented from flowing out of the openings  619 . 
     A display apparatus body  600 A is obtained through these steps. The display apparatus body  600 A is mounted on the set table  21  of the liquid droplet ejection apparatus  1  shown in  FIG. 1  and the positive-hole injection/transport layer forming step (S 113 ) and the light-emitting layer forming step (S 114 ) are performed thereon. 
     As shown in  FIG. 17 , in the positive-hole injection/transport layer forming step (S 113 ), the first compositions including the material for forming a positive-hole injection/transport layer are ejected from the functional liquid droplet ejection heads  17  into the openings  619  included in the pixel areas. Thereafter, as shown in  FIG. 21 , drying processing and a thermal treatment are performed to evaporate polar solution included in the first composition whereby the positive-hole injection/transport layers  617   a  are formed on the pixel electrodes  613  (electrode surface  613   a ). 
     The light-emitting layer forming step (S 114 ) will now be described. In the light-emitting layer forming step, as described above, a nonpolar solvent which is insoluble to the positive-hole injection/transport layers  617   a  is used as the solvent of the second composition used at the time of forming the light-emitting layer in order to prevent the positive-hole injection/transport layers  617   a  from being dissolved again. 
     On the other hand, since each of the positive-hole injection/transport layers  617   a  has low affinity to a nonpolar solvent, even when the second composition including the nonpolar solvent is ejected onto the positive-hole injection/transport layers  617   a , the positive-hole injection/transport layers  617   a  may not be brought into tight contact with the light-emitting layers  617   b  or the light-emitting layers  617   b  may not be uniformly applied. 
     Accordingly, before the light-emitting layers  617   b  are formed, surface processing (surface improvement processing) is preferably performed so that each of the positive-hole injection/transport layers  617   a  has high affinity to the nonpolar solvent and to the material for forming the light-emitting layers. The surface processing is performed by applying a solvent the same as or similar to the nonpolar solvent of the second composition used at the time of forming the light-emitting layers on the positive-hole injection/transport layers  617   a  and by drying the applied solvent. 
     Employment of this surface processing allows the surface of the positive-hole injection/transport layers  617   a  to have high affinity to the nonpolar solvent, and therefore, the second composition including the material for forming the light-emitting layers can be uniformly applied to the positive-hole injection/transport layers  617   a  in the subsequent step. 
     As shown in  FIG. 19 , a predetermined amount of second composition including the material for forming the light-emission layers of one of the three colors (blue color (B) in an example of  FIG. 19 ) is ejected into the pixel areas (openings  619 ) as functional liquid. The second composition ejected into the pixel areas spreads over the positive-hole injection/transport layer  617   a  and fills the openings  619 . Note that, even if the second composition is ejected and attached to the upper surfaces  618   t  of the bank portions  618  which are outside of the pixel area, since the repellency treatment has been performed on the upper surfaces  618   t  as described above, the second component easily drops into the openings  619 . 
     Thereafter, the drying processing is performed so that the ejected second composition is dried and the nonpolar solvent included in the second composition is evaporated whereby the light-emitting layers  617   b  are formed on the positive-hole injection/transport layers  617   a  as shown in  FIG. 20 . In  FIG. 20 , one of the light-emitting layers  617   b  corresponding to the blue color (B) is formed. 
     Similarly, as shown in  FIG. 21 , a step similar to the above-described step of forming the light-emitting layers  617   b  corresponding to the blue color (B) is repeatedly performed by using functional liquid droplet ejection heads  17  so that the light-emitting layers  617   b  corresponding to other colors (red (R) and green (G)) are formed. Note that the order of formation of the light-emitting layers  617   b  is not limited to the order described above as an example, and any other orders may be applicable. For example, an order of forming the light-emitting layers  617   b  may be determined in accordance with a light-emitting layer forming material. Furthermore, the color scheme pattern of the three colors R, G, and B may be the tripe arrangement, the mosaic arrangement, or the delta arrangement. 
     As described above, the functional layers  617 , that is, the positive-hole injection/transport layers  617   a  and the light-emitting layers  617   b  are formed on the pixel electrodes  613 . Then, the process proceeds to the counter electrode forming step (S 115 ). 
     In the counter electrode forming step (S 115 ), as shown in  FIG. 22 , the cathode (counter electrode)  604  is formed on entire surfaces of the light-emitting layers  617   b  and the organic bank layers  618   b  by an evaporation method, sputtering, or a CVD (chemical vapor deposition) method, for example. The cathode  604  is formed by laminating a calcium layer and an aluminum layer, for example, in this embodiment. 
     An Al film and a Ag film as electrodes and a protective layer formed of SiO 2  or SiN for preventing the Al film and the Ag film from being oxidized are formed on the cathode  604 . 
     After the cathode  604  is thus formed, other processes such as sealing processing of sealing a top surface of the cathode  604  with a sealing member and wiring processing are performed whereby the display apparatus  600  is obtained. 
       FIG. 23  is an exploded perspective view of an essential part of a plasma display apparatus (PDP apparatus: hereinafter simply referred to as a display apparatus  700 ). Note that, in  FIG. 26 , the display apparatus  700  is partly cut away. 
     The display apparatus  700  includes a first substrate  701 , a second substrate  702  which faces the first substrate  701 , and a discharge display portion  703  interposed therebetween. The discharge display portion  703  includes a plurality of discharge chambers  705 . The discharge chambers  705  include red discharge chambers  705 R, green discharge chambers  705 G, and blue discharge chambers  705 B, and are arranged so that one of the red discharge chambers  705 R, one of the green discharge chambers  705 G, and one of the blue discharge chambers  705 B constitute one pixel as a group. 
     Address electrodes  706  are arranged on the first substrate  701  with predetermined intervals therebetween in a stripe pattern, and a dielectric layer  707  is formed so as to cover top surfaces of the address electrodes  706  and the first substrate  701 . Partition walls  708  are arranged on the dielectric layer  707  so as to be arranged along with the address electrodes  706  in a standing manner between the adjacent address electrodes  706 . Some of the partition walls  708  extend in a width direction of the address electrodes  706  as shown in  FIG. 26 , and the others (not shown) extend perpendicular to the address electrodes  706 . 
     Regions partitioned by the partition walls  708  serve as the discharge chambers  705 . 
     The discharge chambers  705  include respective fluorescent substances  709 . Each of the fluorescent substances  709  emits light having one of the colors of red (R), green (G) and blue (B). The red discharge chamber  705 R has a red fluorescent substance  709 R on its bottom surface, the green discharge chamber  705 G has a green fluorescent substance  709 G on its bottom surface, and the blue discharge chamber  705 B has a blue fluorescent substance  709 B on its bottom surface. 
     On a lower surface of the second substrate  72  in  FIG. 23 , a plurality of display electrodes  711  are formed with predetermined intervals therebetween in a stripe manner in a direction perpendicular to the address electrodes  706 . A dielectric layer  712  and a protective film  713  formed of MgO, for example, are formed so as to cover the display electrodes  711 . 
     The first substrate  701  and the second substrate  702  are attached so that the address electrodes  706  are arranged perpendicular to the display electrodes  711 . Note that the address electrodes  706  and the display electrodes  711  are connected to an alternate power source (not shown). 
     When the address electrodes  706  and the display electrodes  711  are brought into conduction states, the fluorescent substances  709  are excited and emit light whereby display with colors is achieved. 
     In this embodiment, the address electrodes  706 , the display electrodes  711 , and the fluorescent substances  709  may be formed using the liquid droplet ejection apparatus  1  shown in  FIG. 1 . Steps of forming the address electrodes  706  on the first substrate  701  are described hereinafter. 
     The steps are performed in a state where the first substrate  701  is mounted on the set table  21  on the liquid droplet ejection apparatus  1 . 
     The functional liquid droplet ejection heads  17  eject a liquid material (functional liquid) including a material for forming a conducting film wiring as functional liquid droplets to be attached onto regions for forming the address electrodes  706 . The material for forming a conducting film wiring included in the liquid material is formed by dispersing conductive fine particles such as those of a metal into dispersed media. Examples of the conductive fine particles include a metal fine particle including gold, silver, copper, palladium, or nickel, and a conductive polymer. 
     When ejection of the liquid material onto all the desired regions for forming the address electrodes  706  is completed, the ejected liquid material is dried, and the disperse media included in the liquid material is evaporated whereby the address electrodes  706  are formed. 
     Although the steps of forming the address electrodes  706  are described as an example above, the display electrodes  711  and the fluorescent substances  709  may be formed by the steps described above. 
     In a case where the display electrodes  711  are formed, as with the address electrodes  706 , a liquid material (functional liquid) including a material for forming a conducting film wiring is ejected from the functional liquid droplet ejection heads  17  as liquid droplets to be attached to the areas for forming the display electrodes. 
     In a case where the fluorescent substances  709  are formed, a liquid material including fluorescent materials corresponding to three colors (R, G, and B) is ejected as liquid droplets from the functional liquid droplet ejection heads  17  so that liquid droplets having the three colors (R, G, and B) are attached within the discharge chambers  705 . 
       FIG. 24  shows a sectional view of an essential part of an electron emission apparatus (also referred to as a FED apparatus or a SED apparatus: hereinafter simply referred to as a display apparatus  800 ). In  FIG. 24 , a part of the display apparatus  800  is shown in the sectional view. 
     The display apparatus  800  includes a first substrate  801 , a second substrate  802  which faces the first substrate  801 , and a field-emission display portion  803  interposed therebetween. The field-emission display portion  803  includes a plurality of electron emission portions  805  arranged in a matrix. 
     First element electrodes  806   a  and second element electrodes  806   b , and conductive films  807  are arranged on the first substrate  801 . The first element electrodes  806   a  and the second element electrodes  806   b  intersect with each other. Cathode electrodes  806  are formed on the first substrate  801 , and each of the cathode electrodes  806  is constituted by one of the first element electrodes  806   a  and one of the second element electrodes  806   b . In each of the cathode electrodes  806 , one of the conductive films  807  having a gap  808  is formed in a portion formed by the first element electrode  806   a  and the second element electrode  806   b . That is, the first element electrodes  806   a , the second element electrodes  806   b , and the conductive films  807  constitute the plurality of electron emission portions  805 . Each of the conductive films  807  is constituted by palladium oxide (PdO). In each of the cathode electrodes  806 , the gap  808  is formed by forming processing after the corresponding one of the conductive films  807  is formed. 
     An anode electrode  809  is formed on a lower surface of the second substrate  802  so as to face the cathode electrodes  806 . A bank portion  811  is formed on a lower surface of the anode electrode  809  in a lattice. Fluorescent materials  813  are arranged in opening portions  812  which opens downward and which are surrounded by the bank portion  811 . The fluorescent materials  813  correspond to the electron emission portions  805 . Each of the fluorescent materials  813  emits fluorescent light having one of the three colors, red (R), green (G), and blue (B). Red fluorescent materials  813 R, green fluorescent materials  813 G, and blue fluorescent materials  813 B are arranged in the opening portions  812  in a predetermined arrangement pattern described above. 
     The first substrate  801  and the second substrate  802  thus configured are attached with each other with a small gap therebetween. In this display apparatus  800 , electrons emitted from the first element electrodes  806   a  or the second element electrodes  806   b  included in the cathode electrodes  806  hit the fluorescent materials  813  formed on the anode electrode  809  so that the fluorescent materials  813  are excited and emit light whereby display with colors is achieved. 
     As with the other embodiments, in this case also, the first element electrodes  806   a , the second element electrodes  806   b , the conductive films  807 , and the anode electrode  809  may be formed using the liquid droplet ejection apparatus  1 . In addition, the red fluorescent materials  813 R, the green fluorescent materials  813 G, and the blue fluorescent materials  813 B may be formed using the liquid droplet ejection apparatus  1 . 
     Each of the first element electrodes  806   a , each of the second element electrodes  806   b , and each of the conductive films  807  have shapes as shown in  FIG. 25A . When the first element electrodes  806   a , the second element electrodes  806   b , and the conductive films  807  are formed, portions for forming the first element electrodes  806   a , the second element electrodes  806   b , and the conductive films  807  are left as they are on the first substrate  801  and only bank portions BB are formed (by a photolithography method) as shown in  FIG. 25B . Then, the first element electrodes  806   a  and the second element electrodes  806   b  are formed by an inkjet method using a solvent ejected from the liquid droplet ejection apparatus  1  in grooves defined by the bank portions BB and are formed by drying the solvent. Thereafter, the conductive films  807  are formed by the inkjet method using the liquid droplet ejection apparatus  1 . After forming the conductive films  807 , the bank portions BB are removed by ashing processing and the forming processing is performed. Note that, as with the case of the organic EL device, the hydrophilic treatment is preferably performed on the first substrate  801  and the second substrate  802  and the repellency treatment is preferably performed on the bank portion  811  and the bank portions BB. 
     Examples of other electro-optical apparatuses include an apparatus for forming metal wiring, an apparatus for forming a lens, an apparatus for forming a resist, and an apparatus for forming an optical diffusion body. Use of the liquid droplet ejection apparatus  1  makes it possible to efficiently manufacture various electro-optical apparatuses.