JP4865155B2 - Droplet volume measuring method, droplet volume measuring apparatus, and inkjet printer manufacturing system including the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a droplet amount measuring method, a droplet amount measuring apparatus, and an inkjet printer manufacturing system including the same, and more particularly, to a droplet amount measuring method and a droplet amount measuring apparatus for ink droplets ejected from an inkjet printer. And an inkjet printer manufacturing system including the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a droplet discharge device such as an ink jet printer forms an image by causing 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. Was.
[0003]
Droplet ejection devices are required to have high definition and high image quality. If the amount of ejected droplets varies, it may affect density unevenness and color tone shift in color images, resulting in high definition and high image quality. It becomes an obstacle.
[0004]
In order to solve these problems, it is necessary to analyze the droplet discharge characteristics of the droplet discharge head, and regarding the droplet amount, it has been required to measure the variation in the amount of each discharged droplet. It was.
[0005]
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. For this reason, the method described below has been adopted.
[0006]
(Prior art 1)
By measuring the mass of the ink tank in advance, and then driving the specified head, and then measuring the mass of the ink tank, the average droplet discharge amount can be calculated from the droplet mass difference before and after the head drive operation. It was calculated.
[0007]
(Prior art 2)
Drop the droplet containing the dye on the transparent receiving layer formed on the glass substrate, irradiate the landing droplet with light, and estimate the amount of dye contained in the landing droplet from the measured value of the amount of light transmitted. . The amount of liquid droplets was calculated on the assumption that the ratio between the appropriate amount of liquid and the amount of dye contained therein was known.
[0008]
(Prior art 3)
As described in Japanese Patent Application Laid-Open No. 5-149869, a flying image of a droplet is photographed by a camera or the like, the photographed image is subjected to image processing, and the droplet amount is calculated from the size of the image.
[0009]
(Prior art 4)
As described in Japanese Patent Application Laid-Open No. 2000-153603, a discharged droplet is received on a petri dish-shaped medium having a predetermined depth and width and covered with a top plate. The size of the droplet that was crushed and deformed by the top plate was measured, and the droplet amount was calculated based on the measured value.
[0010]
[Problems to be solved by the invention]
However, in the prior art 1, what is calculated is the average value of a large number of drops, not the amount of one drop. For this reason, it is impossible to measure variations between droplets or transient changes in the appropriate amount of liquid.
[0011]
In the prior art 2, since variations in the surface energy of the receiving layer that receives the droplets affect how the droplets spread in the receiving layer, it is necessary to provide a sensor that measures the amount of transmitted light with high accuracy. . In addition, this method cannot be applied to transparent liquid droplets that do not absorb light, pigment ink that extremely reduces the amount of transmitted light, and the like. In addition, when an attempt is made to measure the amount of droplets ejected continuously at a high speed, the droplets that have landed on the substrate are connected as shown in FIG. 13, and the appropriate amount of each droplet cannot be measured. There is.
[0012]
In the prior art 3, the size of the droplet to be imaged 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 diameter error to be measured, and the amount error may increase unless the diameter measurement error is kept small. .
[0013]
In the prior art 4, it is difficult to keep the distance between the receiving substrate and the top plate surface sandwiching the droplets constant without variation due to the deflection and surface unevenness of the substrate. Furthermore, since it is difficult to make the wet state of both surfaces uniform and uniform, an error occurs in measurement. If an attempt is made to measure the amount of liquid droplets ejected continuously at a high speed, the liquid droplets that have landed on the substrate are connected as shown in FIG. 13, and the appropriate amount of liquid for each droplet cannot be measured. There is.
[0014]
Accordingly, an object of the present invention is to provide a discharge droplet measuring apparatus that accurately measures the amount of each discharge droplet.
[0015]
[Means for Solving the Problems]
In order to solve the above-described problems, a droplet amount measuring apparatus according to the present invention includes a measuring unit that measures the falling speed of a droplet in a gas, and the liquid that has been measured in advance with the dropping speed measured by the measuring unit. And a calculating means for calculating a droplet amount based on a droplet density and a viscosity coefficient of the gas.
[0016]
The inkjet printer manufacturing system of the present invention includes a droplet amount measuring device and an adjusting device that adjusts the ejection amount of the ink droplets of the inkjet printer based on the measurement result of the droplet amount measuring device. Features.
[0017]
Furthermore, the droplet amount measuring method of the present invention measures the drop velocity of a droplet in a gas, and based on the measured drop velocity, the droplet density measured in advance, and the viscosity coefficient of the gas. It is characterized by calculating a drop amount.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
(Embodiment 1)
"Configuration Description"
FIG. 1 is a schematic configuration diagram of a droplet measuring apparatus for a liquid discharge recording head according to the first embodiment of the present invention. FIG. 2 is a block diagram of FIG. As shown in FIGS. 1 and 2, the droplet measuring apparatus of the present embodiment drives a liquid discharge recording head (hereinafter referred to as “head”) 2 that discharges droplets 1 in a horizontal direction, for example, and the head 2. An image from the camera 3, a camera 3 that images the droplet 1 ejected from the head 2, an illumination light source 5 that illuminates the droplet 1, a magnifying lens 4 attached to the camera 3, and an image from the camera 3. An information processing apparatus 6 such as a personal computer that calculates the amount of the droplet 1 by measuring the falling speed of the droplet 1 based on the information is shown.
[0020]
The head 2 is of a type in which heat is applied to the droplet 1 by an electrothermal transducer in accordance with a command from the head controller 21, and a portion of the ink is foamed and ink is ejected from the nozzles opened in the orifice plate by the action force of the foaming. Something is used. Various types of nozzles are produced from 64 to 1408, and any of them may be used. In the present embodiment, 128 nozzles are used.
[0021]
The head 2 is set so that the orifice surface of the discharge port is vertical so that the droplet 1 is discharged in the horizontal direction. This is because if the droplet 1 is ejected obliquely, the operation of calculating the vertical component by vector decomposition of the movement vector of the droplet 1 is necessary, which is troublesome.
[0022]
The ejection frequency of the head 2 can be increased to about 10 kHz, but here it is set to about 5 Hz so that the resistance due to the gas in the atmosphere does not decrease due to the mutual influence of the droplets 1.
[0023]
The camera 3 is, for example, a Megaplus (trade name) manufactured by Kodak, and a magnifying lens 4 having a magnification of 5 is attached thereto. The image of the droplet 1 captured by the camera 3 is sent to the information processing device 6.
[0024]
The illumination light source 5 uses, for example, a nano pulse light (trade name) manufactured by Ebara Laboratories, and the illumination light is on the optical axis of the observation optical system through the light guide, passes through the droplet passage region, and the observation optical unit. It is installed to enter. In order to suppress an increase in ambient temperature due to illumination, the illumination light is emitted to the droplet 1 through an infrared cut filter after exiting the light guide.
[0025]
The information processing device 6 calculates the velocity of the droplet 1 based on the droplet position and the light emission time of the illumination light source 5 from the image of the droplet 1 captured by the camera 3, and based on the calculation result, the droplet Measure the amount of 1.
[0026]
Further, in order to measure the falling speed of the droplet 1 after the constant velocity, the entire observation system is installed so that the measurement region of the droplet 1 is located 50 to 70 mm below the ejection opening of the head 2.
[0027]
Furthermore, the path of the droplet 1 is covered with an acrylic plate in order to prevent disturbances such as airflow disturbance. A humidifier with a humidity measurement function is installed in the acrylic plate, and the atmosphere in the acrylic plate is controlled so that the relative humidity is about 70%.
[0028]
It has been observed that when the relative humidity is lower than 50%, some of the ejected droplets evaporate during flight. On the other hand, when the relative humidity is higher than 90%, water vapor condenses at the discharge port of the head 2, which causes an error in the amount of liquid droplets to be discharged and has an adverse effect of changing the discharge direction.
[0029]
In addition, a thermometer is installed in the acrylic plate, and the temperature is controlled to be 25 ° C., for example.
[0030]
"Description of operation"
FIG. 3 is a timing diagram of driving of the head 2 of FIG. 1, flashing of the illumination light source 5, and exposure of the camera 3. Each time the camera 3 is exposed, the illumination light source 5 is turned on to perform flashing. The exposure and flash of the camera 3 are driven for 4 pulses at a frequency of 30 Hz per droplet 1.
[0031]
The timing control shown in FIG. 3 is performed by a control unit connected to the information processing apparatus 6 as shown in FIGS. 1 and 2, and is controlled by each of the camera 3, the head 2, and the illumination light source 5. The signal is synchronized and output.
[0032]
Further, before the measurement, the first time when exposure is performed four times by the camera 3, the liquid droplet 1 is set to be positioned above the monitor, or the liquid is placed in the path of the liquid droplet 1 above the camera 3. A sensor for detecting the passage of the droplet 1 is provided, and a trigger signal for the first drive is generated based on the detection result of the sensor.
[0033]
Further, the droplet 1 ejected from the head 2 is almost constant with almost no variation in the time taken to reach the measurement region. Therefore, unless a series of experiments are performed for many hours, the speed of the droplet 1 does not increase as the image of the droplet 1 displayed on the screen of the information processing apparatus 6 becomes one.
[0034]
Image data captured by the camera 3 is stored in the memory of the information processing device 6. Image data is read from the memory, and the gravity center position coordinates of the droplet 1 are calculated by image processing software or the like.
[0035]
Prior to actual measurement, a camera substrate 3 is used for imaging with a glass substrate on which a lattice pattern having a predetermined interval is placed in the measurement region, and the lattice interval in units of pixels on the image is measured on the glass substrate. From the actual grid interval, calibration is performed to determine how long one pixel of image data corresponds to in real space.
[0036]
This calibration data is stored in the information processing device 6 and used when the droplet center of gravity position is calculated by image processing. The velocity is obtained by calculating the droplet centroid position for a plurality of continuous image data and dividing the difference between the centroid positions by the difference in time of photographing.
[0037]
When the droplet 1 is ejected horizontally from the head 2, it draws a trajectory that travels substantially straight by about 10 mm and then drops vertically. Since the measurement field of view is 1.8 mm square and the drop speed of the droplet 1 is about 12 mm / s, three or four images per droplet can be acquired by setting the imaging frequency to 30 Hz.
[0038]
The drop velocity can be determined by the above method if there are at least two images. When 3 or 4 images can be acquired per drop, 2 images are selected in multiple combinations, and the average of the fall speeds obtained from the selected 2 images is taken and measured. The falling speed of the liquid droplet.
[0039]
Actually, the diameter of the droplet 1 calculated from Equations (1) to (3) described later is about φ20 μm.
[0040]
By the way, the moving speed in the horizontal direction of the droplet 1 discharged from the head 2 decreases due to the resistance of the gas in the atmosphere and eventually becomes zero. Further, although the droplet 1 moves in the vertical direction due to the influence of gravity, the gravity and the resistance by the gas in the atmosphere balance after a certain time, and the velocity becomes constant according to the size of the droplet 1. Thereafter, the falling speed v is measured.
[0041]
Incidentally, when the liquid droplet 1 is ejected in the horizontal direction, the time constant governing the change in the drop velocity v of the liquid droplet is the same in both the horizontal direction and the vertical direction. The time taken to reach a measurable speed is considered equivalent.
[0042]
Here, the drop velocity v of the droplet 1 is expressed as follows: the density of the droplet 1 is ρ, the acceleration of gravity is g, the viscosity coefficient of the gas is η, the radius of the droplet 1 is a, the drag coefficient is Cd, and the Reynolds number is Re. When calculated, the following formulas (1) to (3) can be used to calculate the radius a of the droplet 1.
[0043]
Cd = 8ag / 3v ² (1)
Cd = f (Re) (2)
Re = 2avρ / η (3)
Further, when the Reynolds number Re is 1 or less, the drop velocity v of the droplet after a certain speed is expressed by the following formula (4) according to Stokes's law, assuming that the droplet mass is m.
[0044]
v = mg / 6πηa (4)
If the drop velocity v is measured and the density of the droplet 1 and the viscosity coefficient of the gas are obtained in advance, the point that the droplet radius a is obtained from Equations (1) to (3) or Equation (4) is 1 The amount of droplet 1 per droplet is measured.
[0045]
In this embodiment, since water is used as the droplet 1, the density of the droplet 1 is 1 g / cm ³ . The viscosity coefficient of gas is, for example, 18.2 × 10 ⁻⁶ Pa · S in air at 25 ° C.
[0046]
Equations (1) to (4) hold for a spherical object. Although the shape of the droplet immediately after the droplet discharge is a bullet instead of a sphere, it becomes a sphere within 100 μs after discharge due to the surface tension of the droplet 1, and then the camera 3 captures an image of the droplet 1. I am doing so.
[0047]
(Embodiment 2)
FIG. 4 is a schematic configuration diagram of a droplet measuring apparatus for a liquid discharge recording head according to the second embodiment of the present invention. FIG. 5 is a block diagram of FIG. 4 and 5, when the interval between the droplets 1 ejected from the head 2 is narrow, the wire electrode 7 that generates an electric field in a direction orthogonal to the path of the droplet 1, and power is supplied to the wire electrode 7. A feed circuit 20, a gutter 8 that stores the droplet 1 when no electric field is generated by the feed circuit 20, and a deflection plate 9 that controls the movement of the droplet 1 in the horizontal direction are shown. 4 and 5, the same parts as those shown in FIGS. 1 and 2 are denoted by the same reference numerals.
[0048]
The wire electrode 7 and the head 2 are aligned so that the liquid droplet 1 passes through the middle between the two wire electrodes 7.
[0049]
As described in the first embodiment, the mathematical expression (3) and the mathematical expression (4) include the viscous resistance coefficient η due to the gas in the atmosphere. For this reason, when the ejection frequency of the head 2 is small, the interval between the droplets 1 is wide, so that the turbulence caused by the gas in the atmosphere caused by the movement of a certain droplet 1 causes the next droplet 1 to be ejected. Does not affect movement.
[0050]
However, when the ejection frequency of the head 2 is high, the interval between the droplets 1 is narrow, so that the turbulence caused by the gas in the atmosphere caused by the movement of a certain droplet 1 causes the droplet 1 to be ejected next. May affect movement.
[0051]
By the way, since the droplet 1 ejected from the head 2 is charged, when the voltage is applied to the wire electrode 7 by the power feeding circuit 20, the droplet 1 passing between the wire electrodes 7 is deflected.
[0052]
Therefore, in this embodiment, when the interval between the droplets 1 ejected from the head 2 is narrow, an electric field is generated in the direction perpendicular to the path of the droplet 1 by the wire electrode 7 and the path is changed to the deflecting plate 9 side. The amount of the droplet 1 is measured by imaging the droplet 1 with the camera 3.
[0053]
When no voltage is applied to the wire electrode 7, the droplet 1 is collected in the gutter 8.
[0054]
FIG. 6 is a timing chart of driving of the head 2 of FIG. 4, exposure of the camera 3, flash of the illumination light source 5, and voltage application of the wire electrode 7. As shown in FIG. 6, a voltage for 20 μs, for example, at 2.4 kV is temporarily applied to the wire electrode 7 from the power supply circuit 20 to deflect some of the droplets 1 at the same timing as in the first embodiment. The camera 3 is exposed and the illumination light source 5 is flashed.
[0055]
By the way, when a 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 interval between the droplets 1 is 2 m, and there is no influence on each other. The viscous drag coefficient η due to gas can be considered constant as in the first embodiment.
[0056]
Furthermore, in this embodiment, a weak stationary electromagnetic field is generated in the path of the droplet 1 at right angles to the optical axis and the vertical axis of the observation system. Specifically, the deflecting plates 9 are arranged at a distance of several hundreds mm from the discharge port of the head 2 in the horizontal direction, and a voltage of about 100V is applied.
[0057]
When the droplet 1 enters this electric field region, the droplet 1 is pulled in the horizontal direction by the electrostatic force and moves obliquely downward rather than directly below. Therefore, when calculating the drop velocity v, the calculation is performed using the vertical component of the movement distance, not the distance of the droplet 1 that has moved within the specified time as in the first embodiment.
[0058]
This is to prevent the drop 1 from being unable to measure the drop velocity v due to the influence of the disturbance from time to time due to the absence of an electric field.
[0059]
(Embodiment 3)
FIG. 7 is a schematic configuration diagram illustrating an example of a droplet measuring device for a liquid discharge recording head according to the third embodiment of the present invention. FIG. 8 is a block diagram of FIG. 7 and 8, a laser 10 such as a several W-class green continuous-emitting laser that emits laser light that evaporates some of the ejected droplets 1 and the laser light emitted from the laser 10 are modulated. An acousto-optic modulator (AOM) 11, a reflection mirror 12 that reflects the laser light modulated by the AOM 11, a reduction lens 13 that collects the reflection light of the reflection mirror 12, and a reflection light that is collected by the reduction lens 13 1 shows a condensing unit 14 that irradiates 1.
[0060]
7 and 8, the same reference numerals are given to the same parts as in FIGS. 4 and 5, but in this embodiment, the diameter of the liquid droplets 1 discharged from the head 2 is 30 μm on average. A head with 64 nozzles is used. In addition, the head 2 and the camera 3 are aligned so that the image of the droplet 1 can be captured properly.
[0061]
FIG. 9 is a top view of the vicinity of the light collector 14 in FIG. As shown in FIG. 9, the path of the droplet 1 and the optical path of the reflected light that has passed through the condenser lens 13 are set to be orthogonal to each other. On the other hand, the reflected light reciprocates several times along the path of the droplet 1 so as not to be orthogonal to the line connecting the path of the droplet 1 and the center of the condenser 14.
[0062]
FIG. 10 is a timing chart of the driving of 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. As in the second embodiment, one flash is performed within one camera exposure time, and the camera 3 and the illumination light source 5 are driven for four pulses at a frequency of 30 Hz per droplet.
[0063]
Before the measurement, the timing 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 is adjusted as in the first embodiment.
[0064]
The droplet 1 ejected from the head 2 absorbs the laser beam and evaporates when it passes through the laser beam condensing unit 14. On the other hand, for example, an external pulse is input at a frequency of 5 Hz so that the deflection time per one is 50 μs, and the AOM 11 is driven to deflect the laser light.
[0065]
When the laser beam is deflected, the droplet 1 does not reach the orbit of the droplet 1, and the droplet 1 in the meantime advances without absorbing the laser beam. The drop velocity v of the droplet 1 that has progressed in this way is measured by the same method as in the second embodiment.
[0066]
(Embodiment 4)
In Embodiment 4 of the present invention, a droplet measuring apparatus according to a color filter manufacturing apparatus and a control apparatus that adjusts the droplet discharge amount of the color filter manufacturing apparatus based on the measurement result of the droplet measuring apparatus. A manufacturing system including the information processing apparatus 6 having a section will be described.
[0067]
FIG. 11 is a schematic configuration diagram of a manufacturing system according to the fourth embodiment of the present invention. In FIG. 11, the head 2 is transported between 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 print area 15 and the measurement area 16. A transport mechanism 18, a carry-in port 17 for carrying a substrate into the print area 15, and a shutter 19 for reducing disturbance during measurement in the measurement area 16 are shown. In FIG. 11, the same parts as those shown in FIG.
[0068]
FIG. 12 is a flowchart showing the operation of FIG. The head 2 is normally placed on a high-precision stage provided in the printing area 16. In this state, when the system is turned on or the user gives an instruction, the head 2 is transported to the measurement area 16 by the transport mechanism 18 in response to these instructions (step S1).
[0069]
In the measurement region 16, first, each nozzle of the head 2 is sequentially selected (step S2).
[0070]
Then, droplets are ejected from the nozzle selected by the method described in the first embodiment and the amount thereof is measured (step S3).
[0071]
Next, based on the measurement result, it is determined whether or not the amount of ejected droplets is within a predetermined design range (step S4).
[0072]
As a result of the determination, if the amount of ejected droplets is not within the predetermined design range, the driving parameter such as the driving voltage of the head 2 is adjusted by the control unit of the information processing device 6 so as to correct it ( Step S5).
[0073]
Specifically, if the measured droplet amount is smaller than a predetermined design value, the drive voltage is increased, and conversely if it is greater than the design value, the drive voltage is decreased.
[0074]
Then, the data at the time of adjustment is stored in the memory in the information processing device 6 (step S6).
[0075]
Then, it is determined whether or not the measurement of the droplet amount of all the nozzles of the head 2 has been completed (step S7).
[0076]
If the measurement of the droplet amount of all the nozzles is not completed, the process returns to step S2, and if completed, the head 2 is returned to the print area 15 (step S8).
[0077]
When the color filter is printed by the head 2 with the droplet amount adjusted, the information processing device 6 reads the data in the memory and drives the head 2 according to the data.
[0078]
In the present embodiment, the color filter manufacturing apparatus has been described as an example. However, the present invention is not limited to this as long as a head for discharging liquid droplets is provided. As described in the first embodiment and the like, an inkjet printer manufacturing apparatus is used. It can also be applied to an electron-emitting device manufacturing apparatus.
[0079]
(Embodiment 5)
In this embodiment, a method for producing a highly accurate head more efficiently by using the measurement method and apparatus of the present invention will be described.
[0080]
In the produced head, the droplet amount of all nozzles is measured by the measurement method and apparatus described above. The data is transmitted to each process section of the factory in real time via a LAN or the like.
[0081]
When the droplet amount outside the standard is measured, it is analyzed together with the inspection result in each process, and an early search for the cause of the defect is made. For example, when a measurement result is obtained that the discharge amount is larger than a specified value for some nozzles of a certain head, the diameter of the head nozzle and the resistance value of the heat conversion element corresponding to the head nozzle are examined.
[0082]
Therefore, for example, if 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 formation is performed so that the nozzle diameter of the specified design value can be manufactured. Process adjustments are made. By applying feedback of measurement data from the final product to each manufacturing process, a highly accurate head can be made more efficient. Moreover, the yield at the time of product launch can be improved.
[0083]
【Effect of the invention】
As described above, according to the present invention, it is possible to accurately measure the amount of each discharged droplet and to analyze the discharge amount of the liquid discharge device based on the measurement result. By adjusting the droplet amount so as not to vary, an image to be formed can have high details and high image quality.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a liquid droplet measuring apparatus for a liquid discharge recording head according to a first embodiment of the present invention.
FIG. 2 is a block diagram of FIG.
3 is a timing diagram of driving of the head 2 in 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 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.
6 is a timing chart of driving of the head 2 in FIG. 4, exposure of the camera 3, flash of the illumination light source 5, and voltage application of the wire electrode 7. FIG.
FIG. 7 is a schematic configuration diagram illustrating an example of a droplet measuring apparatus for a liquid discharge recording head according to a third embodiment of the present invention.
FIG. 8 is a block diagram of FIG.
FIG. 9 is a top view of the vicinity of the light collecting unit 14 in FIG. 7;
10 is a timing chart of driving of the head 2 in FIG. 7, exposure of the camera 3, flash of the illumination light source 5, and driving of the AOM 11. FIG.
FIG. 11 is a schematic configuration diagram of a manufacturing system according to a fourth embodiment of the present invention.
12 is a flowchart showing the operation of FIG.
FIG. 13 is a diagram showing a state of a droplet according to a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Droplet 2 Head 3 Camera 4 Magnifying lens 5 Illumination light source 6 Information processing apparatus 7 Wire electrode 8 Gutter 9 Deflection plate 10 Laser 11 AOM
DESCRIPTION OF SYMBOLS 12 Reflecting mirror 13 Reduction lens 14 Condensing part 15 Printing area 16 Measurement area 17 Carrying-in entrance 18 Conveying mechanism 19 Shutter 20 Feeding circuit 21 Head controller

Claims (7)

The amount of liquid droplets is calculated based on the measuring means for measuring the falling speed of the liquid droplets in the gas, the falling speed measured by the measuring means, the density of the liquid droplets measured in advance, and the viscosity coefficient of the gas. A measuring area of the measuring means is determined at a position where the drop speed of the droplet is constant,
A droplet amount measuring apparatus comprising a mechanism for extracting a droplet to be measured from the plurality of droplets.   2. The droplet amount measuring apparatus according to claim 1, further comprising an electric field generating means for generating an electric field in a direction perpendicular to the path of the droplet in front of the measurement region in the path of the droplet.   2. A droplet amount measuring apparatus according to claim 1, further comprising irradiation means for irradiating a laser for evaporating the droplet, wherein the condensing part of the laser is in front of the measurement region along the path of the droplet. .   A droplet amount measuring device according to any one of claims 1 to 3, and an adjusting device that adjusts a discharge amount of ink droplets of an ink jet printer based on a measurement result of the droplet amount measuring device. An inkjet printer manufacturing system. The drop velocity of the droplet in the gas is measured at a position where the drop velocity of the droplet is constant, and based on the measured drop velocity, the density of the droplet and the viscosity coefficient of the gas measured in advance. In calculating the droplet volume,
A droplet amount measuring method, comprising: measuring a drop speed of the extracted droplet after extracting a droplet to be measured from the plurality of droplets.   6. The droplet amount measuring method according to claim 5, wherein an electric field is generated in a direction orthogonal to a path of the droplet, and a drop speed of the droplet taken out from the path is measured.   6. The droplet amount measuring method according to claim 5, further comprising: irradiating a laser for evaporating the droplet to evaporate the non-measurement target droplet and then measuring a drop speed of the measurement target droplet.

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