JP2003288839A - Liquid application device and liquid application method as well as imaging device and imaging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to measure ink discharge volume each time from a nozzle of a liquid application device. <P>SOLUTION: The device is provided with a liquid discharge nozzle 1501 discharging an application matter of a liquid state, a concentration measuring part 1504 for measuring optical concentration of an image formed by the application matter applied on an applied matter 1 by the liquid discharge nozzle with a color material or an optical function matter added, and a control part 1507 controlling a discharge volume of the application matter from the liquid discharge nozzle based on the measurement results by the concentration measurement part. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for applying a liquid coating material, for example, an electron-emitting device and an electron source substrate using the device, an electron source, a display panel, etc. using an inkjet drawing apparatus. Regarding manufacturing technology.

[0002]

2. Description of the Related Art A surface conduction electron-emitting device used for an electron source substrate, an electron source, a display panel, etc., has a thin film formed on the substrate and is made to flow a current in parallel with the film surface. It utilizes the phenomenon of electron emission. FIG. 6 shows an example of the structure of the surface conduction electron-emitting device.

FIG. 6 is a schematic view showing an example of an electron-emitting device,
FIG. 7 is a diagram showing an example of a surface conduction electron-emitting device that can be manufactured by using an inkjet ejection device.

In FIGS. 6 and 7, 1 is a substrate, 2 and 3
Is an element electrode, 4 is a conductive thin film, 5 is an electron emitting portion, 7 is a droplet applying device, 24 is a droplet, and 25 is a conductive thin film before energization forming.

In this example, first, the device electrodes 2 and 3 are formed on the substrate 1 at a distance L1 (see FIG. 7).
(A)). Next, a droplet 24 made of a solution containing a metal element is discharged from a droplet applying device (inkjet recording device) 7 (FIG. 7B), and a conductive thin film 4 is formed so as to contact the element electrodes 2 and 3. (FIG. 7C). next,
For example, a forming process described later causes a crack in the conductive thin film to form the electron emitting portion 5.

By using such a droplet application method, minute droplets of the contained solution can be selectively formed only at a desired position, so that the material forming the element portion is wasted. Absent. In addition, a vacuum process that requires an expensive device and patterning by photolithography including many steps are not required, so that the production cost can be reduced.

To give a specific example of the droplet applying device 7,
Any device may be used as long as it can form an arbitrary droplet, but in particular, it is possible to control in the range of about ten ng to several tens ng and a minute amount of about 10 ng to several tens ng. It is preferable to use an inkjet type device that can easily form the droplets.

A method for producing a surface conduction electron-emitting device using an ink jet ejecting apparatus is disclosed in JP-A-11-3540.
No. 15 publication.

The conductive thin film 4 is particularly preferably a fine particle film composed of fine particles in order to obtain good electron emission characteristics. The thickness of the conductive thin film 4 depends on the step coverage to the device electrodes 2 and 3, and between the device electrodes 2 and 3. The resistance is appropriately set depending on the resistance value and the energization forming conditions described later, but is preferably several Å to several thousand Å, particularly preferably 10 Å to 500 Å. The sheet resistance value is 103 to 107 Ω / □.

The materials forming the conductive thin film 4 are Pd and P.
t, Ru, Ag, Au, Ti, In, Cu, Cr, F
e, Zn, Sn, Ta, W, Pb and other metals, PdO, S
Oxides such as nO ₂ , In ₂ O ₃ , PbO and Sb ₂ O ₃ , Hf
Borides of B ₂ , ZrB ₂ , LaB ₆ , CeB ₆ , YB ₄ , GdB _4, etc., TiC, ZrC, HfC, TaC, SiC, W
Carbides such as C, nitrides such as TiN, ZrN and HfN, S
Examples thereof include semiconductors such as i and Ge, carbon, and the like.

The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure is not only in a state in which fine particles are individually dispersed and arranged, but also in a state in which fine particles are adjacent to each other or overlap each other (also in an island shape). Including)), the particle size of the fine particles is several Å to several thousand Å, preferably 10
It is Å-200Å.

The solution which forms the droplets 24 may be a solution of the above-mentioned constituent material of the conductive thin film in water, a solvent, or an organic metal solution.

As the substrate 1, quartz glass, glass containing a small amount of impurities such as Na, soda lime glass, a glass substrate having SiO ₂ formed on its surface, and a ceramic substrate such as alumina are used.

As the material of the device electrodes 2 and 3, a general conductive material is used, and for example, Ni, Cr, Au,
Metals or alloys such as Mo, W, Pt, Ti, Al, Cu, Pd, and Pd, Ag, Au, RuO ₂ , Pd-.
It is appropriately selected from a printed conductor composed of a metal such as Ag or a metal oxide and glass, a transparent conductor such as In ₂ O ₃ —SnO ₂ and a semiconductor material such as polysilicon.

The electron emitting portion 5 is a high resistance crack formed in a part of the conductive thin film 4, and is formed by energization forming or the like. In addition, the cracks may have conductive fine particles having a particle diameter of several Å to several hundred Å. The conductive fine particles contain at least a part of the elements forming the conductive thin film 4. Further, the electron emitting portion 5 and the conductive thin film 4 in the vicinity thereof may contain carbon and a carbon compound.

The electron-emitting portion 5 is formed by conducting an energization process called energization forming of the element having the conductive thin film 4 and the element electrodes 2 and 3 formed thereon. In the energization forming, as described in Japanese Patent Application Laid-Open No. 2-56822, energization is performed between the device electrodes 2 and 3 from a power source (not shown) to locally break, deform or deteriorate the conductive thin film 4. This is to form a site with a changed structure. The site where the structure is locally changed is called an electron emitting portion 5. The voltage waveform of the energization forming is particularly preferably a pulse shape, and there are a case where a voltage pulse having a constant pulse peak value is continuously applied and a case where the voltage pulse is applied while increasing the pulse peak value.

When the voltage pulse is applied while increasing the pulse wave height value, the pulse wave height value (peak voltage during energization forming) is increased by, for example, about 0.1 V step and applied in an appropriate vacuum atmosphere.

In the energization forming process in this case, the element current is measured at a voltage that does not locally break or deform the conductive thin film 4, for example, a voltage of about 0.1 V, and the resistance value is obtained, for example, 1 MΩ or more. When the resistance of is indicated, the energization forming is completed.

Next, it is desirable to perform a process called an activation process on the element for which the energization forming has been completed. The activation process is, for example, a process of repeatedly applying a voltage pulse with a constant pulse peak value at a vacuum degree of about 10 ⁻⁴ to 10 ⁻⁵ Torr, similar to the energization forming. This is a process of depositing carbon and a carbon compound derived from a substance on a conductive thin film to remarkably change the device current If and the emission current Ie. The activation process is completed, for example, when the emission current Ie is saturated while measuring the device current If and the emission current Ie.

Here, the carbon and the carbon compound are as follows.
Graphite (refers to both single crystal and polycrystal) and amorphous carbon (refers to a mixture of amorphous carbon and polycrystal graphite), and its film thickness is preferably 500Å or less, more preferably 300Å or less. .

The thus manufactured electron-emitting device is preferably operated and driven in an atmosphere having a higher vacuum degree than the vacuum degree in the energization forming step and the activation step. Also, in an atmosphere with a higher degree of vacuum, 80 ° C to 150 ° C
It is desirable to drive after heating.

The degree of vacuum higher than the degree of vacuum treated in the energization forming step and activation step is, for example, about 10 ^−6.
The degree of vacuum is equal to or higher than Torr, more preferably an ultrahigh vacuum system, and the degree of vacuum is such that new carbon and carbon compounds are hardly deposited on the conductive thin film. By doing so, the device current If and the emission current Ie can be stabilized.

The flat surface conduction electron-emitting device can be manufactured as described above.

FIG. 1 shows an external view of an ink jet ejecting apparatus for producing a surface conduction electron-emitting device.

In FIG. 1, 101 is a housing for housing the control device, 102 is a monitor of a personal computer housed in the housing,
Reference numeral 103 is a personal computer keyboard or operation panel, 104 is a stage on which a substrate is mounted, 105 is an inkjet head for ejecting a liquid, 106 is a substrate on which a surface conduction electron-emitting device is formed, 107 is any substrate on the substrate 106. An XY stage that moves freely in both vertical and horizontal directions so that droplets can be applied to the position, 108 is a surface plate that holds the entire inkjet ejection device, and 109 is an alignment camera for aligning the droplet application position on the substrate 106. is there.

FIG. 11 is a schematic block diagram showing various embodiments of the electron-emitting device manufacturing apparatus usable in this example.
FIG. 12 is a flowchart showing the steps of one embodiment of the method for manufacturing the electron-emitting device of this example.

In FIG. 11, 7 is an ink jet ejecting device (droplet applying device), 8 is a light emitting means, 9 is a light receiving means,
Reference numeral 10 represents a stage, and 11 represents a controller. In the light emitting means and the light receiving means here, the object to be generated and received is not limited to light, and any object that can be recognized as a signal may be used. There are diodes and infrared lasers. Further, the light receiving means may be any one capable of receiving a signal in accordance with the light emitting means. Further, the light emitting means and the light receiving means may be of a configuration that generates or receives a signal transmitted or reflected by the insulating substrate.

Items relating to the state of liquid droplets detected in the method and apparatus for manufacturing the electron-emitting device of this example are as follows.
It is the amount of droplets applied in the gap, which is the recess between the pair of device electrodes, the position of the droplet, the presence or absence of the droplet itself, and the like.
Based on the acquired information regarding such items, the controller controls the number of ejections, the ejection position, and the ejection parameters of the inkjet ejection device including the driving conditions in the inkjet ejection device using the piezoelectric element.

Further, as means for performing the above detection,
It is preferable to include a droplet information detection unit that detects the presence or absence and the amount of the droplet discharged from the nozzle by the inkjet method in the inter-electrode gap, and a landing position detection unit that detects the position where the droplet has landed.

In this case, as the landing position detecting means, an electrode pattern or an alignment mark provided for exclusive use is optically detected before ejection, or the modulation of the transmittance by the droplet after ejection is optically detected. The position of the droplet after landing is detected. The position of the droplet is detected by detecting the transmittances at a plurality of points in the gap and in the vicinity of the gap and taking the correlation between them.

As shown in FIG. 12, in the manufacturing method of this example, the liquid application position is determined by detecting the light passing between the electrodes or the light reflected by the light emitting means and the light receiving means by utilizing the electrode interval. The head of the inkjet ejecting apparatus is moved to a position where it can be detected and droplets can be applied between the electrodes (positioning step). Next, a droplet is applied between the electrodes by an inkjet ejecting device (droplet applying step), and whether or not the droplet is applied between the electrodes is determined by a signal that passes or reflects between the electrodes as in the alignment step. Or (the above-mentioned information regarding the presence or absence of the droplet itself) is detected (droplet detection step). If the droplet is applied to the desired region at the desired position in the droplet detection step, the process proceeds to the next alignment step between the electrodes, and if the droplet is not applied, the droplet is applied again.

Further, dummy droplets for information detection are preliminarily ejected to a place other than between the element electrodes, and ejection conditions are set to proper ones based on the detection result, and then the droplets are ejected between the element electrodes. There is also a way to do.

As a control method of the ejection conditions, parameters such as drive pulse height, pulse width, pulse timing, and pulse number are used so that the detection value is held at an optimum value using the detection signal difference component of the droplet information as a correction signal. At least one of
There is a method of performing feedback control of one of the parameters in real time, a method of correcting at least one of the parameters according to an algorithm predetermined according to the amount of deviation of the detected value from the optimum value, and the like.

The position detecting means optically detects the electrode pattern or an alignment mark provided for exclusive use before the ejection, or optically detects the modulation of the transmittance due to the droplet after the ejection to drop the droplet after landing. Detect the position of. In that case, the position of the droplet is detected by detecting the transmittances at a plurality of points in the region in the gap and in the vicinity of the gap and taking the correlation between them.

After applying the thin film by the above method, heat treatment is performed to evaporate the solvent to form a conductive thin film. The subsequent forming and the like are performed in the same manner as described above.

The above substrate alignment method, conductive thin film forming method, and forming method are disclosed in JP-A-11-3540.
15 publication. Furthermore, a method for producing a display panel using the surface conduction electron-emitting device produced by the above method is also described in Kaihei 11-354015.

[0037]

When a display panel is manufactured by arranging the surface conduction electron-emitting devices described above on a plane, variations in the size of the electron source cause variations in the brightness of each pixel of the display panel. There are variations, which greatly affect the image quality of the display panel. Therefore, it is desirable that all the droplets of the element film forming liquid applied by the liquid applying device have the same size. Otherwise, variations in the size of the liquid droplets for forming the element film cause variations in the electron source element film, resulting in uneven brightness of the display panel.

In particular, it is effective to use a liquid coating apparatus having a plurality of nozzles in order to improve the production efficiency of element film formation, but if the discharge amount of each nozzle varies, the electron source element film also varies. The display panel has uneven brightness.

Therefore, it is necessary to accurately measure the liquid amount of the discharged droplet. In particular, it is necessary to accurately measure the amount of ejected liquid droplets for each nozzle. For that, first
There is a method for measuring the amount of liquid used, and secondly, there is a method for measuring the absorbance of coating liquid drops.

The first liquid usage measuring method is to continuously discharge droplets under the same conditions as for coating on a substrate, collect all discharged liquids, and measure the weight or volume of the discharged liquids. Is the way to do it. With this method, it takes time to collect the minimum amount of liquid necessary for measuring the weight or volume of the liquid, and the measurement accuracy is low. This way again,
The average amount of a plurality of droplets can be measured, but the discharge amount variation of each discharge cannot be measured. Therefore, it is necessary and important to measure the discharge amount variation of each discharge once in order to evaluate the coating stability of the liquid coating device and ensure the quality of the display panel.

The second optical measuring method of the applied droplets is to read the droplets landed on the substrate with a camera, and read the read image by image processing to determine the weight or volume of the droplets from the absorbance of the droplets landed. This method is a method of measurement, and this method is disclosed in JP-A-9-4
8111, JP-A-2000-193814, JP-A-2001-147317, etc., describe a discharge amount measuring method in a color filter manufacturing apparatus.
The method will be described.

A fixed size frame (hereinafter referred to as a window) as shown in FIG. 3 is applied to the image of the dot to be measured captured by the measuring camera. Originally, in order to measure the density of the dot itself, it is desirable to integrate the density levels of all the smallest pixels within the dot range.
When the dots are actually observed with a microscope, the density of the peripheral portion is low and it is extremely difficult to determine the boundary with the background. Therefore, a window is sized so that the dots to be measured are surely included (including the peripheral portion), and the density levels of all the pixels in the window are integrated to obtain the integrated density of the dots to be measured.

The window size is appropriately determined in consideration of the size of dots to be measured. If the window size is too large, the background density level, which is essentially unrelated to the dot density, increases and the accuracy of the measurement data decreases as a whole.If the window size is too small, the measurement dots fall out of the window and measurement is impossible or erroneous measurement. Is more likely to occur.

Before obtaining the integrated density of dots shown in FIG. 3, first, the window is applied to a place where there is no print dot, and the integrated brightness in the window is found, and this is the lowest absorption factor of transmitted light (that is, the highest density). It is set as a reference integrated luminance that means a (light) state. Then, the actually obtained brightness of the measurement target dot is divided by the reference integrated brightness, and the reciprocal of the value is taken as the absorption rate (density data) of the measurement target dot.

Next, a method for obtaining a calibration curve that serves as a reference for measuring the amount of ink ejected from an arbitrary nozzle of an ink jet head under an arbitrary condition will be described. First of all, as the first work, of the multiple nozzles of the inkjet head that is to measure the discharge amount,
The discharge amount of at least two nozzles, which are different from each other as much as possible under a constant condition, is obtained by the above-described ink weight measuring method. That is, the ink is ejected from a desired nozzle a predetermined number of times, the total weight of the ejected ink is measured, and this is divided by the number of ejections to obtain
Calculate the discharge amount per time.

Next, ink is ejected from the plurality of nozzles for which the ejection amount per ejection is known in this way under the same conditions as when the ejection amount was obtained, and these inks are formed on the glass substrate 10. The density of the ink dot to be used is measured by the method as described above. By performing such a measurement, the ejection amount of ink from the plurality of nozzles and the density of the ink dots formed by the ink are obtained in a one-to-one correspondence.

FIG. 4 is a graph plotting the relationship between the amount of ink ejected once for four different nozzles and the density of ink dots formed on the glass substrate by the ink. In FIG. 4, black circles are points indicating the ink ejection amount and the ink dot density of the four nozzles. From this figure, it can be seen that the four points are on a substantially straight line. Therefore, if a straight line passing through these four points is drawn, the density of the ink dot for a given ejection amount can be uniquely obtained as a point on this straight line. This straight line will be called a calibration curve.

Since this calibration curve is represented by a straight line, at least two points can be plotted on the graph in order to obtain the calibration curve. Therefore, without using four different nozzles as described above, it is possible to obtain a calibration curve by using at least two nozzles. However, in this example, since the data of the ink ejection amount by the gravimetric method or the absorbance method is used in obtaining the calibration curve, the accuracy of each measuring method directly affects the accuracy of the ejection amount measurement in this example. Therefore, it is more desirable to obtain the calibration curve by using three or more nozzles. Further, the calibration curve needs to be obtained again each time the ink used changes.

Thereafter, the dot density of the ink ejected from any nozzle under any conditions was measured by the above method,
The ink ejection amount of the nozzle can be obtained from the above calibration curve.

By controlling the XY control stage, it is possible to continuously measure the dot density.
For example, printing is performed with a pitch between dots as shown in FIG. 2, alignment is performed on the XY control stage, and then a movement pitch in the X direction and the Y direction of the stage is designated. Thereby, the densities of ink dots of the same nozzle or ink dots of different nozzles can be continuously measured. Then, an equation for converting the density into the ejection amount can be obtained from the previously obtained calibration curve, and the dot density measurement data can be instantaneously converted into the ejection amount data.

FIG. 5 is a diagram showing a printing apparatus incorporating the above-mentioned discharge amount measuring apparatus. In FIG. 5, reference numeral 51 denotes an image processing function, a personal computer (hereinafter referred to as a PC) for controlling a printing apparatus and a discharge amount measuring portion, 52 a printer main body, 53 a printer stage on which an object to be printed is placed, and 54 an inkjet. In this example, the printing is performed by moving the head from side to side. 55 is an object to be printed such as paper, 5
6 is a CCD camera, 57 is a microscope for enlarging print dots, 58 is a microscope stage (hollow so that a transmission light source can be used), 59 is a transmission light source, 60 is a transparent substrate such as glass, 61 is a transparent substrate 60 is a microscope A roller for moving on the stage 58.

In the above apparatus, the print head 54 moves left and right to print on the print object 55. When a predetermined time or a predetermined number of lines is printed during the printing period, the print head 54 moves onto the transparent substrate 60 and prints dots using the nozzles currently used for printing. The transparent substrate 60 moves under the microscope 57, and the density of the printed dot is measured by the method described above using the transmissive light source 59 and the CCD camera 56. Next, the PC 51 instantly converts the measured density into an ink ejection amount based on the calibration curve that has already been obtained, and if the ink ejection amount exceeds the specified range, a pulse is given to the head nozzle. The width and the like are changed to control so as to obtain an appropriate ink ejection amount.

By the above method, in the color filter manufacturing apparatus, the discharge amount of each nozzle can be accurately measured.

However, the situation is different when an electron-emitting device and an electron source substrate, an electron source, a display panel, etc. using the device are manufactured by the same method using an inkjet drawing apparatus.

Even if a droplet of a solution containing a metal element is applied to the substrate by the method described above, the solution is not colored like the color filter ink.
If the metal-containing solution does not contain a dye component or a color-forming component, the liquid droplets or dots applied on the substrate will be nearly transparent. The closer the color of the droplet is to the transparent color, the lower the accuracy of the measuring method used in the above-described color filter manufacturing apparatus, which is to measure the amount of the droplet based on the density of the image captured by the CCD camera.

On the other hand, in the ink weight measuring method which is an alternative to the optical density measuring method, the measuring accuracy is low and the amount of liquid droplets for each coating liquid cannot be easily measured. It is necessary and important to measure the discharge amount variation of each discharge once in order to evaluate the coating stability of the liquid coating device and ensure the quality of the display panel.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to be able to measure the amount of ink discharged from the nozzle of the liquid application device for each time. .

[0058]

[Means for Solving the Problems]
In order to achieve the object, a liquid coating apparatus according to the present invention includes a liquid discharge nozzle that discharges a liquid coating substance, and a coloring material or an optical functional substance that is applied to a target object by the liquid discharge nozzle. A concentration measuring means for measuring the optical density of an image formed by the coating substance, and a control means for controlling the discharge amount of the coating substance from the liquid discharge nozzle based on the measurement result by the concentration measuring means. It is characterized by having.

Further, in the liquid coating apparatus according to the present invention, the control means calculates the discharge amount of the coating substance from the liquid discharge nozzle based on the measurement result by the concentration measuring means.

Further, in the liquid coating apparatus according to the present invention, the control means controls the coating substance so that the amount of the coating substance coated within a predetermined area of the surface of the object to be coated is substantially constant. The feature is that the discharge amount is controlled.

Further, in the liquid coating apparatus according to the present invention, a plurality of the liquid discharge nozzles are provided, and the control means controls the amount of the coating substance discharged from a part or all of the plurality of liquid discharge nozzles. It is characterized in that the discharge amount of the coating substance from the liquid discharge nozzle is controlled so as to be substantially constant.

In the drawing apparatus according to the present invention, an ink discharge nozzle for discharging transparent or nearly transparent ink, and a color material or an optical functional substance added to the ink discharge nozzle are discharged onto an object to be drawn. A density measuring unit that measures the optical density of the image formed by the ink; and a control unit that controls the discharge amount of the ink from the ink discharge nozzle based on the measurement result of the density measuring unit. It has a feature.

Further, in the drawing apparatus according to the present invention, the control means calculates the ink ejection amount from the ink ejection nozzle based on the measurement result by the density measuring means.

Further, in the drawing apparatus according to the present invention, the control means controls the ejection amount of the ink so that the amount of the ink ejected within a predetermined area of the surface of the drawing object becomes substantially constant. It is characterized by controlling.

Further, in the drawing apparatus according to the present invention, a plurality of the ink ejection nozzles are provided, and the control means has a substantially constant amount of the ink ejected from a part or all of the plurality of ink ejection nozzles. The amount of ink discharged from the ink discharge nozzle is controlled so that

Further, the liquid coating method according to the present invention is a liquid coating method for discharging a liquid coating substance from a liquid discharge nozzle and coating it on an object to be coated. An adding step of adding an optical functional member, a coating step of discharging the coating material added with the color material or the optical functional member from the liquid discharge nozzle to coat the object to be coated, and a coating step performed in the coating step. A density measuring step of measuring an optical density of an image formed by the coating substance on the object to be coated, and controlling a discharge amount of the coating substance from the liquid discharging nozzle based on a measurement result in the concentration measuring step. And a control step for performing the same.

In the drawing method according to the present invention, transparent or nearly transparent ink is ejected from the ink ejection nozzle,
A drawing method for drawing on an object to be drawn, comprising the step of adding a coloring material or an optical functional member to the ink, and the ink containing the coloring material or the optical functional member from the ink discharge nozzle Based on the discharge step of discharging onto the drawing object, the density measuring step of measuring the optical density of the image formed on the drawn object by the ink discharged in the discharging step, and the measurement result in the density measuring step And a control step of controlling the ejection amount of the ink from the ink ejection nozzle.

[0068]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In this embodiment, an electron emitting portion forming region is formed by using a substrate (X wiring 72 and Y wiring 73) in which the device electrodes shown in FIG. 10 are formed in a matrix by the photolithography described below. An electron emitting portion is formed in 1201 to manufacture an electron source substrate in which a plurality of surface conduction electron emitting devices are arranged. The X wiring and the Y wiring are electrically insulated by an insulating member (not shown) at the intersection.

FIG. 7 is a diagram showing a manufacturing procedure of the surface conduction electron-emitting device. Further, FIG. 6 is a plan view and a cross-sectional view of the surface conduction electron-emitting device manufactured in this embodiment.

Device electrodes are formed on the substrate by photolithography in the following procedure. (1) A quartz substrate is used as the insulating substrate 1, and the quartz substrate is thoroughly washed with an organic solvent. After that, a general vacuum film forming technique and a photolithography technique are applied to the substrate 1.
The electrodes 2 and 3 made of Ni are formed. (2) Next, one droplet (24 dots) of the organopalladium-containing solution is deposited between the electrodes 2 and 3 (1 dot) by using an ink jet ejecting device using a piezoelectric element as the droplet deposition device 7. (3) Next, heat treatment is performed to form palladium oxide (Pd
O) A fine particle film made of fine particles is formed to form the thin film 4.
The fine particle film described here is a film in which a plurality of fine particles are aggregated, and its fine structure means not only a state in which fine particles are individually dispersed and arranged but also a state in which fine particles are adjacent to each other or overlap each other. (4) Next, a voltage is applied between the electrodes 2 and 3 to energize the thin film 4 (energizing forming process) to form the electron-emitting portion 5.

Using the electron source substrate thus manufactured,
A face plate, a support frame, and a rear plate form an envelope, which is then sealed to form a display panel and an NTSC.
An image forming apparatus having a driver circuit for performing television display based on a television signal of a system is manufactured.

As a result, it is possible to manufacture the electron-emitting device manufactured by the manufacturing method of this embodiment and the electron source substrate, the display panel and the image forming apparatus manufactured by using the electron-emitting device.

FIG. 1 shows an external view of a liquid coating apparatus for manufacturing a surface conduction electron-emitting device, that is, an ink jet ejecting apparatus.

In FIG. 1, 101 is a housing for housing the control device, 102 is a monitor for a personal computer housed in the housing,
Reference numeral 103 is a personal computer keyboard or operation panel, 104 is a stage on which a substrate is mounted, 105 is an inkjet head for ejecting a liquid, 106 is a substrate on which a surface conduction electron-emitting device is formed, 107 is any substrate on the substrate 106. An XY stage that moves freely in both vertical and horizontal directions so that droplets can be applied to the position, 108 is a surface plate that holds the entire inkjet ejection device, and 109 is an alignment camera for aligning the droplet application position on the substrate 106. is there.

FIG. 13 is a schematic block diagram of an ejection control system in forming a thin film by the ink jet method.
Reference numeral 1 is a substrate in each unit cell, and 2 and 3 are element electrodes facing each other. Reference numeral 1501 is a discharge nozzle of the inkjet ejection device, and 1502 is a droplet information detection optical system. Reference numeral 1503 denotes a displacement control mechanism equipped with an ink jet cartridge including a discharge nozzle, an ink tank, and a supply system, and a detection optical system. The displacement control mechanism includes a coarse movement mechanism for carrying between unit cells on a matrix wiring electrode substrate and an inside unit cell. And a fine movement mechanism for finely adjusting the horizontal position and adjusting the distance between the substrate and the discharge nozzle. For example, in a piezo type inkjet device, the ejection amount per time is determined by the pulse height, pulse width, pulse timing, the number of pulses, etc. of the voltage pulse supplied to the piezo element that pushes out the metal-containing liquid.

A coloring material having a predetermined content is attached to the metal-containing liquid in advance. As a coloring material to be attached, a blue dye is relatively easily dissolved, and when an image is captured by a CCD camera using a light source of a complementary red filter, a relatively good measurement accuracy can be obtained.

However, the color of the attached coloring material may be green or red instead of blue. For the color of the light source for the camera, relatively good measurement accuracy can be obtained by using a complementary color of the color of the attached coloring material.

The attached coloring material may be a pigment instead of a dye, or may be another coloring material. .

Instead of attaching a coloring material, a luminescent substance such as a phosphor may be used. If a luminescent substance such as a phosphor is used, it is possible to realize a more accurate droplet amount measuring means with a smaller content.

In short, for a liquid having a low optical density, a coloring material or an optical functional substance which can be easily recognized by the optical detecting portion of the droplet amount measuring means is added by adding a predetermined amount to the liquid. The effect of the invention can be obtained.

The detection optical system 1502 is composed of a CCD camera or the like. Using the output of the detection optical system, the optical information detection circuit 1504 detects the density of the applied droplet and sends the signal to the reference signal ratio circuit 1505. The reference signal ratio circuit 1505 compares it with a reference value. The reference value is set in advance by experimentally obtaining the optical density corresponding to the thickness of the droplet so that the film thickness after firing becomes a desired value. The ejection condition correction circuit 1506 corrects the ejection condition from the comparison data of the measured optical density and the reference value and the calibration curve previously obtained experimentally as shown in FIG.

A fixed size frame (hereinafter referred to as a window) as shown in FIG. 3 is applied to the image of the dot to be measured captured by the measuring camera. A window is sized so that the dots to be measured are surely included (including the peripheral portion), and the density levels of all the pixels in the window are integrated to obtain the integrated density of the dots to be measured.

The window size is appropriately determined in consideration of the dot size to be measured. If the window size is too large, the background brightness level, which is not originally related to the dot density, increases and the accuracy of the measurement data decreases as a whole.If the window size is too small, the measurement dots fall out of the window and measurement is impossible or erroneous measurement. Is more likely to occur.

Before obtaining the dot integrated density shown in FIG. 3, first, the window is applied to a place where there is no print dot, and the integrated brightness in the window is found. It is set as a reference integrated luminance that means a (light) state. Then, the actually calculated integrated brightness of the measurement target dot is divided by the reference integrated brightness, and the reciprocal of the value is used as the absorption rate (density data) of the measurement target dot.

The integrated density value of all the areas in the window is obtained by the above method. The integrated density value of the entire area within this window is approximately equal to the integrated density value of the entire area within the dot, and this integrated density value is approximately proportional to the applied droplet amount.

Further, the image recognizing means may be used to find the contour of the dot, and instead of finding the integrated density value of the entire area in the window, the integrated density value of the dot contour may be found. If it is possible to accurately recognize the contour position of the dot by using a sophisticated image recognition means, the accuracy of the droplet amount measurement will be higher in this method.

The discharge condition control circuit 1507 discharges from the discharge nozzle 1501 by controlling any of the pulse height, pulse width, pulse timing and pulse number of the voltage pulse supplied to the piezo element for pushing out the metal-containing liquid. The amount of droplets to be controlled is controlled to be a desired value.

By the above method, the amount of liquid droplets ejected from all the used nozzles becomes a constant desired value.

FIG. 9 shows the circuit configuration of the ejection condition correction circuit of this embodiment.

A circuit connected to the head 303 is a coating pattern data serial / parallel conversion circuit 322 for converting the coating pattern serial data 319 for selecting the presence / absence of ejection of the nozzles of each CH from the drawing control unit 311 into parallel data. , And an image data latch circuit 321 that latches the converted data with a data latch signal 318. The nozzle of each CH is selected based on this latch data, and the drive signal for driving the ejection drive element 309 of this nozzle is based on the drive timing signal 317 and passes through the drive signal pattern output circuit 320. It is supplied to the head from the output charge / discharge circuit 316 of the nozzle drive circuit 304. The ejection driving element corresponds to a piezoelectric element used on the ejection driving side wall of the ink chamber of the nozzle in the piezo head.

At this time, the circuit configuration for controlling the ejection amount described in the present embodiment has the signal reference voltage circuit 314 and the signal voltage for controlling the ejection amount by the pulse of the voltage pulse supplied to the piezo element. A control circuit 313 and an output voltage amplifier circuit 315 are provided. A signal reference voltage circuit 314,
The signal voltage control circuit 313 receives a command for the set control voltage value from the drawing control unit, the signal reference voltage circuit 314 sets the center value of the drawing voltage, and the signal voltage control circuit corrects the center voltage value of each nozzle. Set the voltage.

The output voltage amplifier circuit 315 supplies a drive voltage to the output charge / discharge circuit 316 based on the corrected control voltage.

FIG. 8 shows a circuit example of the output charge / discharge circuit 316 shown in FIG.

In FIG. 10, Tr is a transistor or a FET. IN1 is a TTL level drive signal. Vcc is a DC stable voltage set to an arbitrary voltage value.

In FIG. 8, when IN1 is high level, Tr1 and Tr
2 and ON, TR3 is ON and Tr4 is OFF, current is discharged from OUT1 and OUT1 becomes the desired voltage.

In FIG. 8, when IN1 is low level, Tr1 and Tr
2 and OFF, TR3 is OFF, Tr4 is ON, OUT1
The current is drawn into and OUT1 becomes the ground level or low voltage level. As a result, the corrected drive signal is output to the head from the output charge / discharge circuit independently for each nozzle,
The ejection amount of the head is controlled.

In controlling the ejection amount of each nozzle by using the above ejection amount control means of each nozzle, first, the ejection amount of each nozzle of the head and the variable condition (here, the ejection amount is varied by the drive voltage) are changed. Measure the property.

The nozzle is measured under the condition of the voltage range in which the characteristics before and after the voltage value to be used for controlling the discharge amount can be predicted. For example, a voltage value with a small discharge amount and a voltage value with a large discharge amount are set to two or more points at least, and the drawing for checking the discharge amount under the condition of the drive signal of the same pulse width used at the time of drawing is performed on the glass Do on the substrate.

Next, the ejection amount of ink on the glass substrate is measured by the amount of transmitted light.

Next, the amount of change in the amount of ejection (here, referred to as the correction sensitivity K) when the voltage is varied is calculated from the voltage value difference between the points of large and small amounts of ejection.

Next, the discharge amounts of all the nozzles are measured from the drawing results of all the nozzles under the used drawing conditions, and the average discharge amount of the discharge amounts is calculated. The correction amount is calculated from the difference between the discharge amount of each nozzle and the average discharge amount and the correction sensitivity K. The correction amount VdnNY is set in the signal voltage control circuit 313. After setting, the ejection amounts of all the nozzles whose ejection drive has been corrected are made uniform.

The liquid drop amount is measured immediately after the liquid application in the same method as the first method in which the liquid drop amount is measured in the previous step of the liquid application step, and each time it is measured. There is a second method of giving feedback to the ejection condition control circuit in real time.

In the first method, the droplet amount is measured at the time of changing the coating head or when the environmental condition changes, and the pulse of the voltage pulse for feeding the piezo element until the next droplet amount measurement. The height, pulse width, pulse timing, and pulse number are controlled under the same conditions. In the first method, the substrate to be coated is a substrate dedicated to measuring a predetermined amount of droplets, for example, an unpatterned transparent glass substrate coated with only the ink receiving layer. For example, a transparent glass substrate having no pattern is applied at a pitch between dots as shown in FIG. 2, and after alignment is performed on an XY control stage, the movement pitch of the stage in the X and Y directions is designated. Thereby, the densities of ink dots of the same nozzle or ink dots of different nozzles can be continuously measured. Then, an equation for converting the density into the ejection amount is obtained from the calibration curve obtained previously, and the dot density measurement data is converted into the ejection amount data. From this data, any one of the pulse height, pulse width, pulse timing, and pulse number of the voltage pulse supplied to the piezo element is controlled so that the ejection amount for each nozzle becomes a constant desired value.

In the second method, the amount of liquid applied at that time is measured every time one position or a predetermined number of positions are applied, and the discharge amount is corrected each time. This method has an advantage that it can be surely applied while confirming that each dot or several dots is correctly applied. However, in the second method, it is difficult to obtain the integrated concentration of only the droplet portion because the image of the device electrode and the like is included in the measurement window imaged by the CCD camera. Therefore, the droplet amount measurement is performed. It can be said that the accuracy is also poor.

Generally, the first method and the second method are used together, the first method compensates for the variation in the ejection amount between the nozzles of different heads, and the second method performs the timed ejection. The method of compensating for the fluctuation of the amount and confirming the operation as to whether or not the ink is ejected correctly are the best method.

After the liquid droplets have been formed by the above method, a voltage is sequentially applied between the device electrodes, and the thin film is energized (forming process).
By doing so, an electron emitting portion is formed in the central portion of the device electrode gap of each cell.

When the electron source substrate thus formed is attached to an electron emission characteristic evaluation device to emit electrons, the electron emission characteristics of all the elements become uniform.

Further, by using the electron source substrate thus formed, an envelope is formed by a face plate, a support frame, a rear plate and the like, and sealing is performed to display a display panel and further a television display. When an image forming apparatus having a driving circuit of is created, all elements emit electrons,
The characteristics are uniform. As a result, it is possible to form a good TV image with no brightness variation.

Further, the present invention is not limited to the case of manufacturing an electron source substrate for a display panel, and a transparent or nearly transparent liquid is ejected from each nozzle of the droplet applicator by the droplet applicator. By controlling the amount, it is useful when trying to apply uniformly on the object to be coated.

As described above, according to the above-described embodiment, since it is possible to accurately measure the coating amount of each drop and control the coating with high accuracy, it is possible to accurately control the liquid coating method and the liquid coating apparatus. Can be realized.

Furthermore, when the electron-emitting portion of the display panel is manufactured by using the method of the above-described embodiment, the conductive thin film forming the electron-emitting device can be uniformly arranged, so that high image quality can be obtained. The display panel can be manufactured.

[0113]

As described above, according to the present invention,
It is possible to measure the amount of ink discharged from each nozzle of the liquid application device.

[Brief description of drawings]

FIG. 1 is an external view of a liquid application device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a droplet application pattern when measuring the amount of droplets according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating a method of measuring concentration data of a coating liquid used in an embodiment of the present invention.

FIG. 4 is a diagram illustrating a calibration curve used in the droplet amount measuring method according to the embodiment of the present invention.

FIG. 5 is a printing device for manufacturing a color filter, which has a built-in discharge amount measuring device.

FIG. 6 is a schematic diagram showing an example of an electron-emitting device to which the inkjet ejection device according to the embodiment can be applied.

FIG. 7 is a diagram showing an example of a surface conduction electron-emitting device that can be manufactured using an inkjet ejection device.

FIG. 8 is a diagram showing an example of a circuit configuration of an output charge / discharge circuit.

FIG. 9 is a diagram showing an example of a circuit configuration of an ejection condition correction circuit.

FIG. 10 is a schematic view of an electron source substrate for a display panel.

FIG. 11 is a schematic view showing an example of a droplet applying step.

FIG. 12 is a flowchart showing a flow of a manufacturing method according to an embodiment of the present invention.

FIG. 13 is a block diagram showing an example of the configuration of a discharge control system.

[Explanation of symbols]

1 substrate 2,3 element electrodes 4 Conductive thin film 5 Electron emission part 6 Droplet application device (inkjet ejection device) 7 droplets 8 light emitting means 9 Light receiving means 10 stages 11 Controller 12 Control means 24 droplets 25 Conductive thin film before energization forming 303 inkjet head 304 head drive circuit 309 drive element 311 Drawing control control unit 312 Nozzle drive output circuit 313 Voltage control circuit 314 Signal reference voltage 315 Output voltage amplification circuit 316 Output charge / discharge circuit 317 Drive timing signal 318 Data latch signal 319 image serial data 320 Drive signal pattern generation output circuit 321 Image data latch output circuit 322 Image data serial-parallel conversion circuit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B05D 3/00 B05D 3/00 D 5C127 7/24 301 7/24 301M B41J 2/01 B41J 3/04 101Z F term (reference) 2C056 EA04 EB48 FB01 4D075 AC06 AC07 BB92Z BB99Z CB01 DB13 DC24 EA33 EA43 EC11 4F033 BA03 CA04 DA05 EA05 GA06 JA06 LA13 4F041 AA05 AB02 BA34 BA22 BA34 BA56 4F042 AA06 5A07 CC12 BA22

Claims (10)

[Claims] 1. A liquid ejection nozzle for ejecting a liquid coating substance, and an optical image formed by the coating substance which is applied to an object to be coated by the liquid ejection nozzle by adding a coloring material or an optical functional substance. A liquid coating apparatus comprising: a concentration measuring unit that measures a concentration; and a control unit that controls a discharge amount of the coating substance from the liquid discharging nozzle based on a measurement result of the concentration measuring unit. 2. The drawing apparatus according to claim 1, wherein the control unit calculates the discharge amount of the coating substance from the liquid discharge nozzle based on the measurement result of the concentration measuring unit. 3. The control means controls the discharge amount of the coating substance so that the amount of the coating substance coated in a predetermined region of the surface of the coating target object becomes substantially constant. The liquid application device according to claim 1. 4. A plurality of the liquid discharge nozzles are provided, and the control means discharges the liquid so that the amount of the coating substance discharged from a part or all of the plurality of liquid discharge nozzles is substantially constant. The liquid coating apparatus according to claim 1, wherein the amount of coating material discharged from the nozzle is controlled. 5. An optical image of an image formed by an ink ejection nozzle for ejecting a transparent or nearly transparent ink, and an ink formed by adding a coloring material or an optical functional substance and ejected onto an object to be drawn by the ink ejection nozzle. An image drawing apparatus comprising: a density measuring unit that measures the density; and a control unit that controls the ejection amount of the ink from the ink ejection nozzle based on the measurement result of the concentration measuring unit. 6. The drawing apparatus according to claim 5, wherein the control unit calculates an ink ejection amount from the ink ejection nozzle based on a measurement result by the density measuring unit. 7. The control means controls the ejection amount of the ink so that the amount of the ink ejected within a predetermined region of the surface of the drawing object becomes substantially constant. Item 5. The drawing device according to item 5. 8. A plurality of the ink ejection nozzles are provided, and the control means is configured to control the ink ejection nozzles so that the amount of the ink ejected from a part or all of the plurality of ink ejection nozzles is substantially constant. The drawing apparatus according to claim 5, wherein the amount of ink ejected from the printer is controlled. 9. A liquid coating method for discharging a liquid coating substance from a liquid discharge nozzle to coat an object to be coated, comprising an adding step of adding a coloring material or an optical functional member to the coating substance. A coating step of discharging the coating material added with the coloring material or the optical functional member from the liquid discharge nozzle to coat the coating object, and the coating material coated in the coating step on the coating object. A density measuring step of measuring the optical density of the image formed on the substrate, and a control step of controlling the discharge amount of the coating substance from the liquid discharging nozzle based on the measurement result in the density measuring step. Characteristic liquid application method. 10. A drawing method for drawing a transparent or nearly transparent ink from an ink discharge nozzle to draw on a drawing object, and an adding step of adding a coloring material or an optical functional member to the ink, An ejection step of ejecting the ink, to which the coloring material or the optical functional member is added, from the ink ejection nozzle to the drawing object, and an optical image of an image formed by the ink ejected in the ejection step on the drawing object. A drawing method comprising: a density measuring step of measuring a static density, and a control step of controlling a discharge amount of the ink from the ink discharging nozzle based on a measurement result in the density measuring step.