JP2003028696A - Droplet quantity measuring method and apparatus and system for manufacturing ink-jet printer provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for measuring the quantity of droplets to be discharged capable of accurately measuring the quantity of each droplet to be discharged. SOLUTION: The apparatus for measuring the quantity of droplets to be discharged is provided with a liquid discharge recording head 2 for discharging the droplets 1, for example, in a horizontal direction, a head controller 21 for driving the head 2, a camera 3 for picking up the images of the droplets 1 discharged from the head 2, an illumination light source 5 for illuminating the droplets 1, a magnifying lens 4 mounted to the camera 3, and an information processor 6 such as a personal computer for computing the quantity of the droplets 1 by measuring the fall velocity of the droplets 1 on the basis of the images from the camera 3 and by analyzing the images.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a droplet amount measuring method,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a droplet amount measuring device and an inkjet printer manufacturing system including the same, and more particularly to a droplet amount measuring method for ink droplets ejected from the inkjet printer, a droplet amount measuring device, and an inkjet printer manufacturing system including the same. It is about.

[0002]

2. Description of the Related Art Conventionally, a droplet discharge device such as an inkjet printer causes droplets discharged from a discharge port of a liquid discharge recording head (hereinafter referred to as a recording head) to land on a recording medium such as paper or an OHP sheet. This formed an image.

The droplet discharge device is required to have high definition and high image quality, and if the discharged droplet amount varies,
This affects density unevenness and color tone deviation in a color image, which hinders high definition and high image quality.

In order to solve such a problem, it is necessary to analyze the droplet discharge characteristics of the droplet discharge head, and it is necessary to measure the variation in the amount of each discharged droplet with respect to the droplet amount. I have been asked.

However, since the droplet diameter is as small as 20 μm and the amount is about 4 pl, it is difficult to measure the amount of one droplet. Therefore, the method described below has been adopted.

(Prior Art 1) The mass of the ink tank is measured in advance, and then the specified head drive is performed, and the mass of the ink tank is measured to obtain the difference in the droplet mass before and after the head drive operation. The average droplet discharge amount was calculated.

(Prior Art 2) A droplet containing a dye is landed on a transparent receptive layer formed on a glass substrate, and the landing drop portion is irradiated with light. Estimate the amount of dye contained in. Then, the droplet amount was calculated assuming that the ratio between the proper amount of liquid and the amount of dye contained therein is known.

(Prior Art 3) As described in Japanese Patent Laid-Open No. 149869/1993, a flying image of a liquid droplet is photographed by a camera, the photographed image is image-processed, and the droplet amount is calculated from the size of the image. Was.

(Prior Art 4) Japanese Patent Laid-Open No. 2000-15360
As described in Japanese Patent Publication No. 3, a petri dish-shaped medium having a predetermined depth and width receives discharged droplets and is covered with a top plate. The size of the droplet deformed by being crushed by the top plate was measured, and the droplet amount was calculated based on the measured value.

[0010]

However, the prior art 1
Is the average value of a large number of droplets, not the droplet amount of each droplet. Therefore, it is not possible to measure variations between droplets or transient changes in the appropriate amount of liquid.

In the prior art 2, variations in surface energy unevenness of the receiving layer that receives the droplets affect how the droplets spread in the receiving layer, so that the sensor for measuring the amount of transmitted light has high accuracy. There is a need. Further, this method cannot be applied to transparent droplets that do not absorb light, pigment ink or the like in which the amount of transmitted light is extremely low. When it is attempted to measure the amount of liquid droplets that are continuously ejected at high speed, the liquid droplets that have landed on the substrate are connected to each other as shown in FIG. 13, and it is not possible to measure the appropriate liquid amount for each liquid droplet. There is.

In the prior art 3, the size of the imaged droplet changes depending on the illumination method, that is, the intensity and direction of the illumination light. In addition, since the amount is calculated from the droplet diameter in this method, the amount error is proportional to the 3/2 power of the measured diameter error,
If the diameter measurement error is not kept small, the amount error may increase.

In the prior art 4, it is difficult to make the distance between the receiving substrate sandwiching the liquid drop and the top plate surface uniform without variation because of the deflection and surface unevenness of the substrate. Further, it is difficult to make the wet state on both sides uniform without variation, and therefore an error occurs in the measurement. When an attempt is made to measure the amount of liquid droplets that are continuously ejected at a higher speed, the liquid droplets that have landed on the substrate are connected to each other as shown in FIG. 13, and it is not possible to measure the appropriate liquid amount for each liquid droplet. There is.

Therefore, it is an object of the present invention to provide an ejected liquid droplet measuring device which accurately measures the amount of each ejected liquid droplet.

[0015]

In order to solve the above problems, a droplet amount measuring device of the present invention comprises a measuring means for measuring the falling velocity of droplets in a gas, and a drop measured by the measuring means. It is characterized by comprising a calculating means for calculating the droplet amount based on the velocity and the density of the droplet and the viscosity coefficient of the gas measured in advance.

The ink jet printer manufacturing system of the present invention includes a droplet amount measuring device and an adjusting device for adjusting the ejection amount of ink droplets of the ink jet printer based on the measurement result of the droplet amount measuring device. It is characterized by being provided.

Further, in the droplet amount measuring method of the present invention, the drop velocity of the droplet in the gas is measured, and the measured drop velocity and the previously measured density of the droplet and the viscosity coefficient of the gas are measured. It is characterized in that the droplet amount is calculated based on the above.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) "Description of Configuration" FIG. 1 is a schematic configuration diagram of a droplet measuring apparatus for a liquid discharge recording head according to Embodiment 1 of the present invention. Figure 2
FIG. 3 is a block diagram of FIG. 1. As shown in FIGS. 1 and 2, the droplet measuring apparatus of the present embodiment drives a head 2 and a liquid ejection recording head (hereinafter, referred to as “head”) 2 that ejects a droplet 1 in a horizontal direction, for example. The head controller 21, the camera 3 for capturing the droplet 1 ejected from the head 2, the illumination light source 5 for illuminating the droplet 1, the magnifying lens 4 attached to the camera 3, and the image from the camera 3. It shows an information processing device 6 such as a personal computer that calculates the amount of the droplet 1 by measuring the drop velocity of the droplet 1 based on it.

In accordance with a command from the head controller 21, the head 2 applies heat to the droplet 1 by the electrothermal converter to foam a part of the ink, and the foaming action force ejects the ink from the nozzle opened on the orifice plate. I am using the type that makes me. Number of nozzles from 64 to 140
Various types are produced up to eight, and any type may be used, but in the present embodiment, 128 types are used.

The head 2 is installed so that the orifice surface of the ejection port is vertical so that the droplet 1 is ejected in the horizontal direction. This is because if the droplet 1 is discharged obliquely, it is troublesome to perform a vector decomposition of the movement vector of the droplet 1 to calculate the vertical component.

The ejection frequency of the head 2 can be increased up to about 10 kHz, but here, in order not to reduce the resistance due to the gas in the atmosphere due to the mutual influence of the droplets 1,
It is set to about 5 Hz.

The camera 3 is, for example, a Kodak Megaplus (trademark), and is equipped with a magnifying lens 4 of 5 times. The image of the droplet 1 captured by the camera 3 is sent to the information processing device 6.

As the illumination light source 5, for example, a nano pulse light (trade name) manufactured by Sugawara Laboratories is used, and the illumination light is on the optical axis of the observation optical system through the light guide and passes through the droplet passage area. It is installed so as to enter the observation optical section. In order to prevent the ambient temperature from rising due to illumination, the illumination light exits the light guide and then passes through the infrared cut filter to form droplets 1.
I am trying to irradiate.

The information processing device 6 calculates the velocity of the droplet 1 from the image of the droplet 1 taken by the camera 3 based on the droplet position and the light emission time of the illumination light source 5, and based on the calculation result. Then, the amount of the droplet 1 is measured.

Further, in order to measure the falling velocity of the droplet 1 after the constant velocity, the measurement area of the droplet 1 is 5 from the ejection port of the head 2.
The entire observation system is installed so as to be located 0 to 70 mm below.

Further, the path of the droplet 1 is covered with an acrylic plate in order to prevent disturbance such as turbulence of the air flow. A humidifier with a humidity measuring function is installed in the acrylic plate, and the atmosphere in the acrylic plate is controlled so that the relative humidity is about 70%.

It has been observed that when the relative humidity is lower than 50%, a part of the ejected droplets evaporates during flight. When the relative humidity is higher than 90%, water vapor is condensed at the ejection port of the head 2 to cause an error in the amount of ejected liquid droplets and adversely change the ejection direction.

Further, a thermometer is installed in the acrylic plate,
The temperature is controlled to be 25 ° C., for example.

[Explanation of Operation] FIG. 3 is a timing chart for driving the head 2 in FIG. 1, flashing the illumination light source 5, and exposing the camera 3. Each time the camera 3 exposes, the illumination light source 5 is turned on and flashing is performed. The exposure and the flash of the camera 3 are driven by 4 pulses at a frequency of, for example, 30 Hz per one droplet of one droplet.

The control of the timing shown in FIG. 3 is performed by the control unit connected to the information processing device 6 as shown in FIGS. 1 and 2, and the camera 3, the head 2 and the illumination light source 5 are controlled. The control signals are output in synchronization with each other.

Before the measurement, the camera 1 is set so that the droplet 1 is positioned above the monitor at the first exposure when the camera 3 is exposed four times, or the droplet 1 is positioned above the camera 3. A sensor for detecting the passage of the droplet 1 is provided on the path, and a trigger signal for the first drive is generated based on the detection result of this sensor.

The droplet 1 discharged from the head 2 is
There is almost no variation in the time taken to reach the measurement area, and the time is almost constant. Therefore, unless a series of experiments are performed for many hours, the speed of the droplet 1 does not increase so much that the number of images of the droplet 1 displayed on the screen of the information processing device 6 becomes one.

The image data taken by the camera 3 is stored in the memory of the information processing device 6. The image data is read from the memory, and the barycentric position coordinates of the droplet 1 are calculated by image processing software or the like.

Prior to the actual measurement, a camera 3 is used to pick up an image with a glass substrate on which a grid pattern having a predetermined interval is drawn in the measurement area, and the grid interval in pixel units on the image and the glass are measured. From the actual grid spacing on the substrate, calibration is performed to determine how long one pixel of image data corresponds to in real space.

This calibration data is stored in the information processing device 6 and used when the position of the center of gravity of the droplet is calculated by image processing. The velocity is obtained by calculating the position of the center of gravity of the droplet for a plurality of consecutive image data and dividing the difference between the positions of the center of gravity of the droplets by the difference in the time of photographing.

When the liquid droplet 1 is ejected horizontally from the head 2, it travels approximately 10 mm in a straight line, and then draws a trajectory that drops vertically. Since the measurement visual field is 1.8 mm square and the drop velocity of the droplet 1 is about 12 mm / s, the imaging frequency is 30
By setting it to Hz, it is possible to acquire three or four images per drop.

The drop velocity of the droplet can be obtained by the above method if there are at least two images. 3 or 4 per drop
When one image can be obtained, two images among them are selected by a plurality of combinations, the drop velocity obtained from the selected two images is averaged, and the average drop velocity is measured as the drop velocity. To do.

Actually, the following equations (1) to (3)
The diameter of the droplet 1 calculated from the above is approximately 20 μm.

By the way, the droplet 1 ejected from the head 2
The horizontal moving speed of is decreased by the resistance due to the gas in the atmosphere and eventually becomes zero. Further, the droplet 1 also moves vertically due to the influence of gravity, but after a certain period of time, the gravity and the resistance due to the gas in the atmosphere are balanced, and the velocity becomes constant according to the size of the droplet 1. Then, the falling speed v is measured.

Incidentally, when the droplet 1 is ejected in the horizontal direction, the time constant governing the degree of change of the drop velocity v of the droplet is the same in both the horizontal direction and the vertical direction. It is considered that the time required for the speeds to be regarded as constant is the same.

Here, the drop velocity v of the droplet 1 is the density of the droplet 1, ρ, the gravitational acceleration g, the viscosity coefficient of the gas η, the radius of the droplet 1 a, the drag coefficient Cd, and the Reynolds number. When Re is Re, it can be calculated using the following mathematical formulas (1) to (3), and thus the radius a of the droplet 1 can be calculated.

Cd = 8ag / 3v ² (1) Cd = f (Re) (2) Re = 2avρ / η (3) When the Reynolds number Re is 1 or less, the liquid after a constant speed is obtained. The drop velocity v of the drop is expressed by the following equation (4) according to Stokes' law, where m is the mass of the drop.

V = mg / 6πηa (4) If the drop velocity v is measured and the density of the liquid droplet 1 and the viscosity coefficient of the gas are obtained in advance, the following formulas (1) to (3) or (4) can be used. Paying attention to the point that the droplet radius a can be obtained, the amount of the droplet 1 for each droplet is measured.

Since water is used as the droplet 1 in this embodiment, the density of the droplet 1 is 1 g / cm ³ . The viscosity coefficient of gas is 18.2 × 10 ^{−6 in} air at 25 ° C.
Pa · S.

The expressions (1) to (4) hold for a spherical object. The shape of the droplet immediately after the droplet is discharged is not a sphere but a bullet shape.
Since it becomes a sphere within 0 μs, after that, the camera 3 captures an image of the droplet 1.

(Second Embodiment) FIG. 4 is a schematic configuration diagram of a liquid droplet measuring apparatus for a liquid discharge recording head according to a second embodiment of the present invention. FIG. 5 is a block diagram of FIG. 4 and 5, a wire electrode 7 that generates an electric field in a direction orthogonal to the path of the droplet 1 when the distance between the droplets 1 ejected from the head 2 is narrow, and power is supplied to the wire electrode 7. Power supply circuit 20
2 shows a gutter 8 that accommodates the droplet 1 when an electric field is not generated by the power supply circuit 20, and a deflection plate 9 that controls the horizontal movement of the droplet 1. 4 and 5
Then, the same parts as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

The wire electrode 7 and the head 2 are arranged so that the droplet 1 passes through the center between the two wire electrodes 7.
It is aligned.

As described in the first embodiment, the equations (3) and (4) include the viscous resistance coefficient η due to the gas in the atmosphere. Therefore, when the ejection frequency of the head 2 is small, the interval between the droplets 1 is wide, and therefore the turbulence due to the gas in the atmosphere caused by the movement of a certain droplet 1 causes the next ejected droplet 1 to be disturbed. It does not affect movement.

However, when the ejection frequency of the head 2 is high, the interval between the droplets 1 is narrow, so that the turbulence due to the gas in the atmosphere caused by the movement of a certain droplet 1 causes the next ejected liquid. This may affect the movement of the drop 1.

By the way, the droplet 1 ejected from the head 2
Are charged, the droplet 1 just passing between the wire electrodes 7 is deflected when a voltage is applied to the wire electrodes 7 by the power supply circuit 20.

Therefore, in the present embodiment, when the distance between the droplets 1 ejected from the head 2 is narrow, an electric field is generated by the wire electrode 7 in the direction orthogonal to the path of the droplets 1 and the deflection plate 9 side. The amount of the droplet 1 is measured by capturing an image of the droplet 1 whose course has been changed with the camera 3.

When no voltage is applied to the wire electrode 7, the droplet 1 is collected in the gutter 8.

FIG. 6 shows the drive of the head 2 and the camera 3 of FIG.
6 is a timing chart of exposure of the light source, flash of the illumination light source 5, and voltage application to the wire electrode 7. As shown in FIG.
To the wire electrode 7 from 20μ at 2.4kV
applying a voltage between s to deflect some of the droplets 1,
The exposure of the camera 3 and the flash of the illumination light source 5 are performed at the same timing as in the first embodiment.

By the way, when the voltage is applied to the wire electrode 7 at a frequency of 5 Hz as shown in FIG. 5 while the head 2 is driven at 10 kHz, the distance between the liquid droplets 1 becomes 2 m and they do not affect each other. The viscous resistance coefficient η due to the gas in the atmosphere can be considered to be constant as in the first embodiment.

Further, in the present embodiment, in the path of the droplet 1,
A weak stationary electromagnetic field is generated at right angles to the optical axis and vertical axis of the observation system. More specifically, the deflection plates 9 are placed at a distance of about 10 mm from the ejection port of the head 2 in the horizontal direction.
They are arranged at a distance of 00 mm, and these voltages of about 100 V are applied.

When the liquid droplet 1 enters this electric field region, the liquid droplet 1 is attracted in the horizontal direction by the electrostatic force and moves not obliquely downward but obliquely downward. Therefore, when calculating the falling velocity v, the vertical component of the moving distance is used instead of the distance of the droplet 1 that has moved within a specified time as in the first embodiment.

This is because, by not applying an electric field, the droplet 1 is sometimes influenced by disturbance and the course becomes oblique, resulting in a drop velocity v.
This is to prevent that the measurement of is not possible.

(Embodiment 3) FIG. 7 is a schematic diagram showing an example of a droplet measuring apparatus for a liquid discharge recording head according to Embodiment 3 of the present invention. FIG. 8 is a block diagram of FIG. 7. In FIGS. 7 and 8, a laser 10 such as a green continuous emission laser of several W class that emits a laser beam that evaporates some of the ejected droplets 1 and a laser beam emitted from the laser 10 are modulated. Acousto-optic modulator (AOM) 11 and AOM
Reflection mirror 12 for reflecting the laser light modulated by 11
And a reduction lens 13 that collects the light reflected by the reflection mirror 12.
And the reflected light collected by the reduction lens 13 to the droplet 1
The light condensing unit 14 for irradiating the light is shown.

In FIGS. 7 and 8, the same parts as those in FIGS. 4 and 5 are designated by the same reference numerals, but in the present embodiment, the diameter of the droplet 1 ejected from the head 2 is an average φ. Is 30
A head having a size of μm and 64 nozzles is used. In addition, the head 2 is used so that the image of the droplet 1 can be captured properly.
Is aligned with the camera 3.

FIG. 9 is a top view of the vicinity of the light collecting section 14 of FIG. As shown in FIG. 9, the path of the droplet 1 and the condenser lens 1
The optical path of the reflected light that has passed through 3 is orthogonal. On the other hand, the reflected light makes several round trips in the path of the droplet 1 so that the path of the droplet 1 and the line connecting the centers of the light condensing units 14 are not orthogonal to each other.

FIG. 10 is a timing chart of driving the head 2, the exposure of the camera 3, the flash of the illumination light source 5, and the driving of the AOM 11 in FIG. Similar to the second embodiment, the flash light is emitted once within one camera exposure time, and the camera 3 and the illumination light source 5 are illuminated.
Drives for 4 pulses at a frequency of 30 Hz per droplet of one droplet.

Before the measurement, as in the first embodiment,
The timings of the drive signal of the AOM 11, the exposure signal of the camera 3, and the flash control signal of the illumination light source 5 are adjusted.

The droplets 1 ejected from the head 2 absorb the laser light and evaporate when passing through the laser light focusing portion 14. On the other hand, at a frequency of, for example, 5 Hz, an external pulse is input so that each deflection time is 50 μs, the AOM 11 is driven, and the laser light is deflected.

When the laser light is deflected, it does not reach the orbit of the droplet 1, so that the droplet 1 during that time proceeds without absorbing the laser light. The drop velocity v of the droplet 1 that has proceeded in this way is measured by the same method as in the second embodiment.

(Embodiment 4) In Embodiment 4 of the present invention,
A droplet measuring device relating to a color filter manufacturing device; and an information processing device 6 having a control unit which is an adjusting device for adjusting the discharge amount of droplets of the color filter manufacturing device based on the measurement result of the droplet measuring device. A manufacturing system provided with will be described.

FIG. 11 is a schematic configuration diagram of a manufacturing system according to the fourth embodiment of the present invention. In FIG. 11, the print area 15 on which the substrate on which the color filter is formed is placed, the measurement area 16 for measuring the droplet amount, and the head 2 is conveyed between the print area 15 and the measurement area 16. A transport mechanism 18,
A carry-in port 17 for loading the substrate into the print region 15 and a shutter 19 for reducing disturbance during measurement in the measurement region 16 are shown. In FIG. 11, the same parts as those shown in FIG. 1 are designated by the same reference numerals.

FIG. 12 is a flow chart showing the operation of FIG. The head 2 is normally mounted on a high-precision stage provided in the print area 16. In this state, when the power of the system is turned on or there is a user's instruction, the head 2 is transported to the measurement region 16 by the transport mechanism 18 triggered by these (step S1).

In the measurement area 16, first, each nozzle of the head 2 is sequentially selected (step S2).

Then, a droplet is ejected from the nozzle selected by the method described in the first embodiment and the amount thereof is measured (step S3).

Next, based on the measurement result, it is judged whether or not the ejected droplet amount is within a predetermined design range (step S4).

As a result of the discrimination, if the ejected droplet amount is not within the predetermined design range, the driving parameter such as the driving voltage of the head 2 is set so as to correct it.
Is adjusted by the control section of (step S5).

Specifically, if the measured droplet amount is smaller than a predetermined design value, the drive voltage is increased, and conversely, if it is larger than the design value, the drive voltage is decreased.

Then, the data at the time of adjustment is stored in the memory in the information processing device 6 (step S6).

Then, it is judged whether or not the measurement of the droplet amounts of all the nozzles of the head 2 has been completed (step S7).

If the measurement of the droplet amounts of all the nozzles is not completed, the process returns to step S2, and if the measurement is completed, the head 2 is returned to the print area 15 (step S8).

When the color filter is printed by the head 2 of which the droplet amount is adjusted, the information processing device 6 reads the data in the memory and drives the head 2 according to the data.

In the present embodiment, the color filter manufacturing apparatus has been described as an example, but the present invention is not limited to this as long as it has a head for ejecting droplets, and the ink jet printer as described in Embodiment 1 and the like. Can also be applied to the manufacturing apparatus for the above and the manufacturing apparatus for the electron-emitting device.

(Embodiment 5) In this embodiment, a method for producing a highly accurate head more efficiently by using the measuring method and apparatus of the present invention will be described.

The produced head is subjected to droplet amount measurement of all nozzles by the measuring method and apparatus described above. The data is transmitted to each process section of the factory in real time via LAN or the like.

When the non-standard droplet amount is measured, it is analyzed together with the inspection result in each process, and the cause of the defect is searched early. For example, when the measurement result that the ejection amount of a part of the nozzles of a certain head is larger than the specified value is obtained, the diameter of the head nozzle and the resistance value of the heat conversion element corresponding to the head nozzle are examined.

Therefore, for example, when the nozzle diameter of the nozzle whose discharge amount is larger than the specified value is larger than the design value,
The manufacturing parameters are rechecked in the nozzle forming process, and the nozzle forming process is adjusted so that the nozzle diameter of the design specified value can be manufactured. By feeding back measurement data from the final product to each manufacturing process, a highly accurate head can be made more efficient. In addition, the yield at the time of product startup can be accelerated.

[0083]

As described above, according to the present invention,
It is possible to accurately measure the amount of each of the ejected droplets and analyze the ejection amount of the liquid ejecting apparatus based on the measurement result. Therefore, it is adjusted so that there is no variation in the ejected droplet amount. As a result, the image to be formed can have high detail and high image quality.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a droplet measuring device of a liquid ejection recording head according to a first embodiment of the present invention.

FIG. 2 is a block diagram of FIG.

3 is a timing chart of driving of the head 2 of FIG. 1, exposure of the camera 3, and flashing of the illumination light source 5. FIG.

FIG. 4 is a schematic configuration diagram of a droplet measuring device of a liquid ejection recording head according to a second embodiment of the present invention.

FIG. 5 is a block diagram of FIG.

6 is a timing chart of driving the head 2, exposing the camera 3, flashing the illumination light source 5, and applying a voltage to the wire electrode 7 in FIG.

FIG. 7 is a schematic configuration diagram showing an example of a droplet measuring device of a liquid ejection recording head according to a third embodiment of the present invention.

FIG. 8 is a block diagram of FIG. 7.

9 is a top view of the vicinity of the light collecting unit 14 of FIG. 7. FIG.

10 is a timing chart of driving the head 2, exposing the camera 3, flashing the illumination light source 5, and driving the AOM 11 in FIG.

FIG. 11 is a schematic configuration diagram of a manufacturing system according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart showing the operation of FIG. 11.

FIG. 13 is a diagram showing a state of droplets according to a conventional technique.

[Explanation of symbols]

1 droplet 2 heads 3 cameras 4 magnifying lens 5 Illumination light source 6 Information processing equipment 7 wire electrode 8 gutter 9 Deflection plate 10 laser 11 AOM 12 reflective mirror 13 Reduction lens 14 Focusing section 15 print area 16 measurement area 17 carry-in entrance 18 Transport mechanism 19 shutters 20 power supply circuit 21 head controller

Continued front page    F term (reference) 2C056 EA06 EB07 EB27 EB30 EB31                       EB35 EB48 EC07 EC30 EC41                       HA58 KD06                 2F030 CA02 CC01 CE04                 2F035 JB02 JB05

Claims (25)

[Claims] 1. A measuring means for measuring a drop velocity of a droplet in a gas, and a drop velocity measured by the measuring means, a density of the droplet and a viscosity coefficient of the gas which are measured in advance. A droplet amount measuring device comprising: a calculating unit that calculates the droplet amount. 2. The calculating means calculates the density of the droplet by ρ,
When gravitational acceleration is g, viscosity coefficient of gas is η, radius of droplet is a, drop velocity of droplet is v, drag coefficient is Cd, and Reynolds number is Re, The droplet amount measuring device according to claim 1, wherein the amount is calculated. Cd = 8ag / 3v ² Cd = f (Re) Re = 2avρ / η 3. The Reynolds number Re is 1 in the calculating means.
Where m is the weight of the droplet, g is the gravitational acceleration,
3. The droplet amount is calculated using the following mathematical expression, where η is the viscosity coefficient of gas, a radius of the droplet is a, and a drop velocity of the droplet is v. Droplet amount measuring device. v = mg / 6πηa 4. The liquid amount measurement according to claim 1, wherein the drop velocity of the droplet is measured by the measuring means after the drop velocity of the droplet becomes constant. apparatus. 5. The measuring means includes a light source that irradiates the droplet with light, and an image capturing means that captures an image of the droplet irradiated with the light from the light source.
5. The droplet amount measuring device according to any one of 1 to 4. 6. A generator for generating an electric field in a direction orthogonal to a path of the liquid droplet when the space between the liquid droplets discharged by the discharging device for discharging the liquid droplet into the gas is small, 6. The dropping speed of a droplet to be measured taken out from the path by the electric field generated by the means is measured by the measuring means.
The liquid amount measuring device according to the item. 7. A droplet that is not measured by the beam emitted from the irradiation means, the irradiation means irradiating with a beam that evaporates the droplet when the distance between the droplets ejected by the ejection means is narrow. The liquid amount measuring device according to any one of claims 1 to 6, wherein the drop velocity of the droplet to be measured is measured by the measuring means after evaporating the liquid. 8. The liquid amount measuring device according to claim 1, wherein the liquid droplets are ejected horizontally from the ejection means. 9. The liquid amount according to claim 8, wherein the drop velocity of the droplet is measured by the measuring unit after the horizontal moving velocity of the droplet discharged by the discharging unit becomes constant. measuring device. 10. A wet thermometer is provided in the installation area of the discharge means and the measuring means, and a wet temperature adjusting means for adjusting the wet temperature based on the measurement result of the wet thermometer is provided. Item 10. The droplet amount measuring device according to any one of items 1 to 9. 11. The droplet amount measurement according to claim 10, wherein the humidity temperature adjusting means adjusts the humidity so that the relative humidity measured by the humidity thermometer is 50% to 90%. apparatus. 12. The droplet amount measuring device according to claim 1, wherein the droplets are ink droplets ejected from an inkjet printer. 13. A droplet amount measuring device according to claim 1, and an adjusting device for adjusting the ejection amount of ink droplets of an inkjet printer based on a measurement result of the droplet amount measuring device. An inkjet printer manufacturing system comprising: 14. A drop velocity of a droplet in a gas is measured, and a drop amount is calculated based on the measured drop velocity, a density of the droplet and a viscosity coefficient of the gas which are measured in advance. Characteristic droplet amount measuring method. 15. The density of the droplet is ρ, the acceleration of gravity is g, the viscosity coefficient of the gas is η, the radius of the droplet is a, the drop velocity of the droplet is v, the drag coefficient is Cd, and the Reynolds number is Re. 15. The liquid drop amount measuring method according to claim 14, wherein the liquid drop amount is calculated using the following mathematical formula. Cd = 8ag / 3v ² Cd = f (Re) Re = 2avρ / η 16. The Reynolds number Re is 1 or less,
When the weight of the droplet is m, the gravitational acceleration is g, the viscosity coefficient of the gas is η, the radius of the droplet is a, and the drop velocity of the droplet is v, the droplet amount is calculated using the following mathematical formula. The liquid droplet amount measuring method according to claim 14 or 15, wherein v = mg / 6πηa 17. The liquid amount measuring method according to claim 14, wherein the drop velocity of the droplet is measured after the drop velocity of the droplet becomes constant. 18. The droplet amount measuring method according to claim 14, wherein an image of the droplet is captured while the droplet is irradiated with light. 19. The liquid to be measured, which is taken out from the path by generating an electric field in a direction orthogonal to the path of the droplet when the interval between the droplets when the droplet is discharged into the gas is narrow. The liquid amount measuring method according to any one of claims 14 to 18, wherein a drop velocity of the droplet is measured. 20. When the distance between the ejected droplets is narrow, a beam for evaporating the droplets is irradiated, and the drop velocity of the droplets to be measured is measured after the droplets to be non-measured are vaporized. The liquid amount measuring method according to any one of claims 14 to 19. 21. The liquid amount measuring method according to claim 14, wherein the droplet is discharged horizontally. 22. The liquid amount measuring method according to claim 21, wherein the drop velocity of the droplet is measured after the horizontal movement velocity of the ejected droplet becomes constant. 23. The liquid drop amount measuring method according to claim 14, wherein the wet temperature in the vicinity of the liquid discharge position and the liquid drop amount measuring position is adjusted. 24. The relative humidity is between 50% and 9 for said humidity temperature.
The droplet amount measuring method according to claim 23, wherein the humidity is adjusted so as to be 0%. 25. The droplet amount measuring method according to claim 14, wherein the droplet is an ink droplet ejected from an inkjet printer.