JPH10175303A - Method for measuring amount of discharged ink, printing apparatus, and method for measuring amount of discharged ink in printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the amount of ink discharged from a nozzle instantaneously by exposing an ink-absorbing member so that a part of an ink-absorbing property is shaped into a predetermined pattern and obtaining the amount from a density measured when the ink is discharged to the part. SOLUTION: A layer 12 of a composition which has an ink-absorbing property and is changed not to absorb ink when exposed to light is applied on a glass substrate 10. The layer is exposed with the use of an exposing apparatus to form lines conforming to a pitch of nozzles of an ink-jet head. A part of the layer 12 not exposed at this time uniformly absorbs the ink discharged from each nozzle, with forming an edge part of a sharp line pattern. A magnifying optical system is focused on the edge part and an image of the edge part is taken into an image-processing apparatus via a line sensor camera having a magnification and an intensity of a transmission light source set. A density of the line pattern is detected from an absorbance of the transmission light and the amount of discharged ink is detected from the density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer for measuring the amount of ink ejected from each nozzle in a unit of one dot in a device such as an ink jet printer which ejects a small amount of ink from a fine nozzle. The present invention relates to a method for measuring an amount, a printing apparatus, and a method for measuring an ink ejection amount in a printing apparatus.

[0002]

2. Description of the Related Art In an apparatus such as an ink-jet printer having a head composed of a plurality of fine nozzles, it is extremely important to stabilize the print quality to make the ink ejection amount from each nozzle uniform. . For this purpose, it is desired that the amount of ink ejected from each nozzle be determined accurately and instantaneously.

Conventionally known methods for measuring the amount of a minute amount of colored droplets (such as color ink) are (1) a gravimetric method and (2) an absorbance method.

The case where the ink ejection amount from one nozzle of an ink jet printer is measured by these two methods will be described below. (1) Gravity method Ink is ejected at constant intervals for a certain period of time, and the used amount (weight) of the ink during that time is measured with an analytical balance or the like. Is). Thereafter, by dividing the amount of ink used by the number of times of ink ejection, an average droplet amount per ejection (average ejection amount) can be obtained. (2) Absorbance method This method utilizes the relationship between solution concentration and light absorption known as Lambert-Beer's law.
That is, a solution of a certain concentration is sealed in a transparent container having a certain thickness, and light of intensity I0 is irradiated from one side of the container. And its strength is weakened. And
It is known that the intensity decrease is proportional to the density of the ink. A relational expression representing this rule is represented by A = -Log (I0 / I) = abc, where A is the absorbance. Here, a is a proportionality constant, b is the solution thickness, and c is the solution concentration. First, a calibration curve indicating the relationship between the concentration and the absorbance of the ink to be used is obtained from this relational expression. Next, the ink is ejected to a transparent solvent having a certain capacity (preferably one that absorbs light as little as possible) using one nozzle, and the absorbance corresponding to the number of ejections is measured. The concentration of the solvent in which the ink is dissolved is determined from the absorbance and the calibration curve already determined, and the amount of the ink dissolved in the solvent is determined in consideration of the capacity of the solvent itself. By dividing the amount of ink by the number of ejections, an average ejection amount per ejection can be obtained.

[0005]

However, the above-mentioned 2
In the two conventional examples, it is necessary to discharge ink to some extent, and it is not possible to instantaneously determine the amount of ink discharged per nozzle. Incidentally, when we measured the ink ejection amount per nozzle by the gravimetric method,
The ink for the dots was ejected, and it took 12 minutes. Therefore, in the case of an ink jet printer having an ink discharge head composed of 64 or 128 fine nozzles, it takes an enormous amount of time to measure the discharge amount of each nozzle. Further, in the above two methods, it is impossible to measure the true ejection amount per nozzle since the ink ejection amount per ejection is averaged.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a method of measuring the amount of ink ejected from a nozzle which can instantaneously determine the amount of ink ejected from a nozzle.

Another object of the present invention is to provide a printing apparatus provided with a measuring device capable of instantaneously determining the ejection amount from a nozzle, and a method of measuring the ink ejection amount in the printing apparatus.

[0008]

In order to solve the above-mentioned problems and achieve the object, a method for measuring the amount of ink discharged according to the present invention is to measure the amount of ink discharged each time from an ink jet type head. A method for measuring an ink ejection amount for measuring, wherein a portion irradiated with light by exposure having ink absorbency has an ink absorbing member that loses ink absorbency, and a portion having ink absorbency has a predetermined pattern. An exposure step of exposing to a shape, a drawing step of discharging ink from the head to the portion having the ink absorbency, and drawing a predetermined pattern on the ink absorbing member, and drawing in the drawing step. A density measuring step of measuring the density of a predetermined pattern, and the ejection amount of the ink based on the density of the predetermined pattern measured in the density measuring step It is characterized by comprising an ink discharge amount detection step of determining.

In the method of measuring an ink ejection amount according to the present invention, before the density measuring step, a correlation between an ink ejection amount per one time and a density of an ink dot formed by the ink is previously tested. It is characterized by further comprising a preliminary measurement step previously determined.

In the method of measuring an ink ejection amount according to the present invention, the ink absorbing member is a transparent member, and in the density measuring step, the ink absorbing member having passed through the predetermined pattern is used. The method is characterized in that the density of the predetermined pattern is measured by analyzing light from a light source disposed on the back by image processing.

In the method for measuring an ink ejection amount according to the present invention, after the ink ejection amount detection step, the ink ejection amount is set to a desired ejection amount based on the ink ejection amount detected in the detection step. The method further comprises a discharge amount adjustment step of adjusting the discharge amount.

Further, the method for measuring an ink ejection amount according to the present invention is characterized in that the method further comprises a step of ejecting ink to a print medium after the ejection amount adjusting step.

The method for measuring the amount of ink discharged according to the present invention is a method for measuring the amount of ink discharged from an ink jet type head.
A method for measuring an ink ejection amount for measuring an ink ejection amount per time, wherein the ink ejection amount per time from a plurality of ink ejection nozzles of the head under predetermined conditions is measured in advance. A preliminary measurement step to be performed, ink is ejected from a plurality of ink ejection nozzles of the plurality of ink ejection nozzles having different ejection amounts onto a predetermined member under the predetermined conditions, and an ink dot formed by each ink is formed. A first density measurement step of measuring density, density data of ink dots formed by two or more inks obtained in the first density measurement step, and the two density values obtained in the preliminary measurement step. A calibration curve generating step for obtaining a calibration curve which is a graph showing a correlation between the ink ejection quantity per one time and the density of ink dots from the data of the ink ejection quantity described above; An ink absorbing member which light strikes portion loses ink absorption by exposing has Osamusei,
An exposure step of exposing the portion having ink absorbency to have a predetermined pattern shape, and a drawing process of discharging ink from the head to the portion having ink absorbency to draw a predetermined pattern on the ink absorbing member. Step, a second density measurement step of measuring the density of the predetermined pattern drawn in the writing step, and density data of the predetermined pattern measured in the second density measurement step and the calibration curve. An ink ejection amount detection step for calculating an ejection amount of ink ejected from the arbitrary nozzle under the arbitrary condition.

Further, in the method for measuring an ink ejection amount according to the present invention, in the preliminary measurement step, the ink ejection amount from the plurality of ink ejection ports is measured by a gravimetric method or an absorbance method.

In the method of measuring an ink ejection amount according to the present invention, the ink absorbing member is a transparent member, and in the second density measuring step, the ink having passed through the predetermined pattern is used. The method is characterized in that the density of the predetermined pattern is measured by analyzing light from a light source disposed on the back of the absorbing member by image processing.

In the method for measuring an ink ejection amount according to the present invention, after the ink ejection amount detection step, the ink ejection amount is set to a desired ejection amount based on the ink ejection amount detected in the detection step. The method further comprises a discharge amount adjustment step of adjusting the discharge amount.

Further, the method for measuring an ink ejection amount according to the present invention is characterized in that the method further comprises a step of ejecting ink to a print medium after the ejection amount adjusting step.

Further, the printing apparatus according to the present invention has a function of measuring the amount of ink discharged each time from an ink jet type head, and performs printing using an ink jet head which discharges ink by the ink jet type. In a printing apparatus, in order to expose an ink-absorbing member in which a portion irradiated with light by exposure to ink and loses ink absorption loses ink absorption, so that the portion having ink absorption has a predetermined pattern shape. Exposure means, density detection means for detecting the density of a pattern drawn on the ink-absorbing portion of the ink absorbing member by ink discharged from the ink-jet head, Indicating the correlation with the density of the ink dots formed on the ink absorbing member. Storage means for storing a calibration curve, which is a buffer, and calculation means for calculating the ink ejection amount based on the density of the drawing pattern detected by the density detection means and the calibration curve. It is characterized by.

Further, in the printing apparatus according to the present invention, the density detecting means includes a camera for picking up the drawing pattern and an image processing device for analyzing an image from the camera.

In the printing apparatus according to the present invention, the ink absorbing member is a transparent member, and further includes a light source for illuminating the drawing pattern from behind the ink absorbing member.

In the printing apparatus according to the present invention, the ink absorbing member is moved relative to the camera, and the densities of a plurality of drawing patterns formed on the ink absorbing material are automatically and continuously measured. An XY stage for continuously obtaining the ejection amount of the ink on which the plurality of drawing patterns are formed is further provided.

In the printing apparatus according to the present invention, the printing apparatus may further include an adjusting means for adjusting an ink ejection amount ejected from the ink jet head based on the ink ejection amount calculated by the arithmetic means. Features.

The method for measuring the amount of ink discharged in a printing apparatus according to the present invention is a method for measuring the amount of ink discharged in a printing apparatus having an ink jet type head. An exposure step of exposing an ink-absorbing member having an ink-absorbing portion to a portion having the ink-absorbing property so that the ink-absorbing portion has a predetermined pattern shape, and discharging ink from the head to the ink-absorbing portion. A drawing step of drawing a predetermined pattern on the ink absorbing member; a density measurement step of measuring the density of the predetermined pattern drawn in the drawing step; and the predetermined pattern measured in the density measurement step. An ink discharge amount detecting step of obtaining the ink discharge amount based on the density of the ink. .

In the method for measuring an ink ejection amount in a printing apparatus according to the present invention, before the ink ejection amount detecting step, the ink ejection amount per one time and the density of ink dots formed by the ink are determined. It is characterized in that it further comprises a preliminary measurement step of experimentally obtaining the correlation in advance.

In the method for measuring an ink ejection amount in a printing apparatus according to the present invention, the ink absorbing member is a transparent member, and in the density measuring step, the ink having passed through the predetermined pattern is used. The method is characterized in that the density of the predetermined pattern is measured by analyzing light from a light source disposed on the back of the absorbing member by image processing.

In the method for measuring an ink ejection amount in a printing apparatus according to the present invention, after the ink ejection amount detecting step, a desired ink ejection amount is determined based on the ink ejection amount detected in the detecting step. The method further comprises a discharge amount adjusting step of adjusting the discharge amount.

Further, the method of measuring the ink ejection amount in the printing apparatus according to the present invention is characterized in that the method further comprises a step of ejecting ink to a print medium after the ejection amount adjusting step.

A method for measuring an ink ejection amount in a printing apparatus according to the present invention is a method for measuring an ink ejection amount in a printing apparatus having an ink-jet type head. A pre-measurement step of preliminarily measuring the amount of each ink ejection from the ejection nozzles, and from a plurality of ink ejection nozzles of the plurality of ink ejection nozzles having different ejection amounts on a predetermined member. A first density measurement step of discharging ink under the predetermined conditions and measuring the density of the ink dots produced by each ink; and an ink dot produced by the two or more inks determined in the first density measurement step. From the density data and the data on the ejection amount of the two or more inks obtained in the preliminary measurement step, the ink ejection A calibration curve generating step for obtaining a calibration curve which is a graph showing a correlation between the amount and the density of the ink dots, and an ink absorbing member in which a portion irradiated with light by exposure having ink absorbability loses ink absorbability. An exposure step of exposing a portion having an ink absorbing property to a predetermined pattern shape, and discharging a predetermined pattern on the ink absorbing member by discharging ink from the head to the portion having the ink absorbing property. A drawing step, a second density measuring step of measuring the density of the predetermined pattern drawn in the drawing step, density data of the predetermined pattern measured in the second density measuring step, and the calibration curve. An ink ejection amount detection step of calculating an ejection amount of ink ejected from the arbitrary nozzle under the arbitrary condition based on the .

Further, in the method for measuring an ink ejection amount in a printing apparatus according to the present invention, in the preliminary measurement step, the ink ejection amount from the plurality of ink ejection ports is measured by a gravimetric method or an absorbance method. And

In the method for measuring an ink ejection amount in a printing apparatus according to the present invention, the ink absorbing member is a transparent member, and in the second density measuring step, the light is transmitted through the predetermined pattern. The density of the predetermined pattern is measured by analyzing light from a light source disposed on the back of the ink absorbing member by image processing.

In the method for measuring an ink ejection amount in a printing apparatus according to the present invention, after the ink ejection amount detecting step, the ink ejection amount is determined based on the ink ejection amount detected in the detecting step. The method further comprises a discharge amount adjusting step of adjusting the discharge amount.

Further, the method for measuring the ink discharge amount in the printing apparatus according to the present invention is characterized in that the method further comprises a step of discharging ink onto a print medium after the discharge amount adjusting step.

[0033]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a figure showing composition of a measuring device of an embodiment. In FIG. 1, 1 is an image processing device for measuring density, 2 is a personal computer (hereinafter, PC) that controls the image processing device and the XY control stage 4, 3 is an enlargement optical system for enlarging an image, and 4 is a measurement device. An XY control stage for continuously measuring the density of the object, 5 is a line sensor camera for taking an image of the object to be measured into the image processing apparatus, and 6 is a transmission light source installed below the XY control stage 4. The center surface of the stage surface of the XY control stage 4 is made of glass, and the object to be measured can be taken into the line sensor camera 5 by transmission illumination using the transmission light source 6. This allows
In this configuration, the positional relationship between the line sensor camera 5 and the transmission light source 6 is fixed. PC2 sets XY control stage 4 to RS2
The image processing apparatus 1 is controlled while controlling using the 32C or GPIB interface.

FIG. 2 shows a line pattern formed by discharging ink from a plurality of different nozzles onto a transparent glass substrate 10 using an ink jet printer. In addition, the same nozzle direction and different nozzle directions in the drawing indicate the extension direction of the line pattern formed by ink ejected from the same nozzle and the arrangement direction of the line pattern formed by ink ejected from different nozzles. Here, even if the ink is simply ejected onto the glass substrate, the ink is repelled, so that a special treatment for receiving the ink is applied on the glass substrate 10 (in the present embodiment, the ink-absorbing composition layer 12 is applied). Is performed, and exposure is performed in a line shape suitable for the pitch between nozzles of the inkjet head using an exposure apparatus. As the composition layer 12, a material that changes to a property that does not absorb ink when exposed (for example, a photo-curable resin) is used. As a result, the ink ejected from each nozzle of the inkjet head is uniformly absorbed in the line-shaped unexposed portions of the composition layer 12, forming a very sharp line pattern as shown in FIG. I do. Needless to say, it is desirable that the composition layer 12 is as colorless and transparent as possible (does not absorb transmitted light).

With the magnification of the optical system 3 focused on the line pattern formed as shown in FIG. 2 and the magnification and the intensity of the transmission light source 6 appropriately set, the image is transmitted to the image processing apparatus 1 through the line sensor camera 5. take in. In this embodiment, the magnification is set to 5 times, but it is needless to say that the present invention is not limited to this.

The line sensor camera 5 used was a monochrome one. The image captured from the line sensor camera 5 is constituted by the minimum pixel unit that can be decomposed by the image processing apparatus (in the present embodiment, an 8-bit A / D conversion element is used). It is configured so that 256 levels of luminance levels from 0 to 255 can be expressed according to the intensity of transmitted light at a pixel point.

Next, a method for measuring the density of the line pattern thus formed will be described.

In the present embodiment, the density of a line pattern is determined based on how much transmitted light is absorbed when passing through a line pattern to be measured having a color (density). That is, the higher the density of the line pattern to be measured, the more the transmitted light is absorbed and weakened. That is, the luminance level of the smallest pixel within the range of the line pattern to be measured becomes low. Conversely, if the density is low, the luminance level of the minimum pixel should be high. In the present embodiment, attention is paid to this point, and the density is replaced with the absorptance of transmitted light (although the luminance level is actually obtained by image processing). This is also the same as in the first embodiment.

As described above, a fixed-size frame (hereinafter, referred to as a window) as shown in FIG. 3 is applied to the image of the line pattern to be measured captured by using the line sensor camera. As described above, since the line pattern is drawn on the exposed substrate, the ink is absorbed only in the unexposed portions, and the edge of the line pattern is very sharp, and the window is very close to this edge. Can be used.

Before obtaining the integrated luminance of the line pattern shown in FIG. 3, a window having the same size as that of the window (shown by a broken line) is first placed in a place where there is no line pattern (a portion where only the composition layer 12 is applied). Is multiplied to obtain the integrated luminance therein, and this is set as a reference integrated luminance which means a state where the absorptance of transmitted light is the smallest (that is, the density is the lowest). Then, the integrated luminance of the actually measured line pattern to be measured is divided by the reference integrated luminance, and the common logarithm of the reciprocal of the divided value is taken as the absorption rate (density data) of the line to be measured.

That is, absorbance (concentration data) = Log ((reference integrated luminance) ÷
(Integrated luminance)).

FIG. 4 shows the case where the reference integrated luminance is obtained near the line pattern. In the experiment conducted by the present inventors, the case where the reference integrated luminance is obtained at a position away from the line pattern as shown in FIG. Better results were obtained compared to. It is considered that the reason is that the positional light quantity distribution of the transmission light source has an influence.

Thereafter, by applying a window of the same size to each line pattern, the absorbance (density data) can be similarly obtained.

Then, by controlling the XY control stage 4 using the PC 2, the line patterns are continuously read, and thereafter, by applying a window, the absorbances of all the line patterns can be obtained. And
By using the calibration curve described later, it is possible to easily convert the density of the line pattern into one ejection amount by using the PC2.

It should be noted that setting the window to the very edge means that only the portion related to the original line density is measured, which leads to an improvement in measurement accuracy.

Next, a description will be given of a method of obtaining a calibration curve as a reference for measuring the amount of ink ejected from an arbitrary nozzle of an ink jet head under arbitrary conditions. Here, the ink ejection amount per one time usually indicates the amount of one drop of ink. However, in some cases, the ink does not form a droplet, so that it is not expressed as one drop but one time. The expression is the amount of ink ejected per hit.

First, as a first operation, among the plurality of nozzles of the ink jet head whose discharge amount is to be measured, the discharge amounts of at least two or more nozzles whose discharge amount under a certain condition is as different as possible are already determined. It is determined by the gravimetric method or the absorbance method described in the section of the prior art.

In the present embodiment, the discharge amount per operation of four nozzles having different discharge amounts under a predetermined condition was previously obtained by a gravimetric method.

Next, ink is ejected from the four nozzles for which the ejection amount per one time has been determined in the above manner 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 measured is measured by the method described above. By performing such a measurement, the ejection amount of ink from the four nozzles and the density of the ink dots formed by the ink are obtained in a one-to-one correspondence. The density data of the ink dots formed by the four nozzles was obtained by sampling 50 printed dots and calculating the average value. The standard deviation of the density data at that time was within 5% of the average value.

FIG. 5 is a graph plotting the relationship between the amount of one ejection of ink and the density of ink dots formed on the glass substrate 10 by the ink for the above four nozzles. In FIG. 5, those indicated by black circles are:
This is a point showing the ink ejection amount and the ink dot density of the four nozzles. This figure shows that the four points are substantially on a straight line. Therefore, if a straight line passing through these four points is drawn, the density of the ink dot for an arbitrary ejection amount can be uniquely obtained as a point on the straight line. This straight line is called a calibration curve.

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

Thereafter, the dot density of the ink ejected from an arbitrary nozzle under an arbitrary condition is measured by the above-described method.
The ink ejection amount of the nozzle can be obtained from the above calibration curve.

Further, by controlling the XY control stage 4 by using the PC 2, it is possible to continuously measure the line pattern density. For example, printing is performed at a line pattern pitch as shown in FIG. 2, the alignment is performed on the XY control stage 4, and then the movement pitch of the stage is designated. Thus, the density of the line pattern of the different nozzle can be measured continuously. Then, the equation for converting the density into the ejection amount is obtained from the previously obtained calibration curve, and the instantaneous conversion of the density measurement data of the line pattern into the ejection amount data can be easily realized by using the PC2. . The data of the calibration curve once obtained is stored in a memory in the PC 2.

Next, a printing apparatus having the above-described function of measuring the discharge amount will be described.

FIG. 6 is a view showing a printing apparatus incorporating the above-described apparatus for measuring the discharge amount. In FIG. 6, reference numeral 51 denotes an image processing function, and a personal computer (hereinafter, referred to as a PC) for controlling a printing apparatus and a discharge amount measuring section; 52, a printer main body; 53, a printer stage on which a print target is placed; In this embodiment, printing is performed while the head moves left and right in this embodiment. 55 is a printing object such as paper, 56 is a line sensor camera, 57 is a microscope for enlarging a printing line pattern, 58 is a microscope stage (hollow so that a transmission light source can be used), 59 is a transmission light source, 6
Reference numeral 0 denotes a transparent substrate such as glass, 61 denotes a roller for moving the transparent substrate 60 on the microscope stage 58, and 62 denotes an exposure device for exposing the resin composition layer of the transparent substrate 60 in a predetermined pattern.

In the above-described apparatus, printing is performed on the print target 55 while the print head 54 moves left and right. After printing for a predetermined time or a predetermined number of lines throughout the printing period, the print head 54 moves onto the transparent substrate 60 and prints a line pattern using the nozzles currently used for printing. The density of the printed line pattern is measured by moving the transparent substrate 60 under the microscope 57 and using the transmission light source 59 and the CCD camera 56 by the method described above. Next, the PC 51 instantaneously converts the measured density into an ink ejection amount based on the calibration curve already obtained, and if the ink ejection amount exceeds a specified range, the pulse given to the head nozzle The width and the like are changed to control the ink discharge amount to be appropriate. The transparent substrate 60
Is exposed to a predetermined pattern by the exposure device 62 in advance.

Here, the print head 54 is connected to the transparent substrate 6.
After printing the line pattern at 0 and until the ejection amount is calculated, the printer does not need to interrupt the printing operation, and the calculation of the ink ejection amount and the printing operation can be performed simultaneously.

Further, by developing print patterns for several lines on a built-in image memory in advance, the PC 51 can predict how continuously each nozzle is used. The timing for measuring the ink ejection amount is determined based on the prediction. Therefore, depending on the printing pattern, there may be a case where the ink ejection amount is not measured at all during the printing period. These series of controls are performed by PC
Any change can be made by rewriting the control program on 51.

The structure of the ink jet head and a method of controlling the amount of ink ejected from the ink jet head will be described below.

FIG. 7 is a view showing the structure of the ink jet head IJH.

In FIG. 7, the ink jet head IJ
H generally includes a heater board 104 on which a plurality of heaters 102 for heating the ink are formed, and a top plate 106 overlaid on the heater board 104. A plurality of discharge ports (nozzles) 108 are formed in the top plate 106, and a tunnel-like liquid path 11 communicating with the discharge ports 108 is provided behind the discharge ports 108.
0 is formed. Each liquid channel 110 is separated from an adjacent liquid channel by a partition 112. Each liquid path 110 is connected in common to one ink liquid chamber 114 at the rear thereof, and ink is supplied to the ink liquid chamber 114 through an ink supply port 116.
Are supplied to the respective liquid passages 110.

The heater board 104 and the top plate 106
The heaters 102 are positioned so that each heater 102 comes to a position corresponding to each liquid path 110, and assembled as shown in FIG.
Although only two heaters 102 are shown in FIG. 7, one heater 102 corresponds to each
Are arranged one by one. When a predetermined drive pulse is supplied to the heater 102 in the assembled state as shown in FIG. 7, film boiling occurs in the ink on the heater 102 to form bubbles, and the ink expands at the ejection port due to volume expansion of the bubbles. 10
8 and is ejected. Therefore, the heater 102
The size of the bubbles can be adjusted by controlling the drive pulse applied to the ink, for example, by controlling the magnitude of the electric power, and the volume of the ink ejected from the ejection port can be freely controlled.

FIG. 8 is a diagram for explaining a method of controlling the amount of ink ejection by changing the electric power applied to the heater.

In this embodiment, two types of constant voltage pulses are applied to the heater 102 in order to adjust the ink ejection amount. As shown in FIG. 8, the two pulses are a preheat pulse and a main heat pulse (hereinafter, referred to as a main heat pulse).
Simply called a heat pulse). The preheat pulse is a pulse for warming the ink to a predetermined temperature before actually discharging the ink, and is set to a value shorter than the minimum pulse width t5 required for discharging the ink. Therefore, no ink is ejected by this preheat pulse. Preheat pulse to heater 102
Is added to increase the initial temperature of the ink to a constant temperature so that the ink ejection amount when a constant heat pulse is applied later is always constant. Conversely, by adjusting the length of the pre-heat pulse, the temperature of the ink can be adjusted in advance, and even when the same heat pulse is applied, the ejection amount of the ink can be made different. In addition, by warming the ink prior to the application of the heat pulse, the ink also has the function of accelerating the temporal rise of ink ejection when the heat pulse is applied and improving the responsiveness.

On the other hand, the heat pulse is a pulse for actually discharging ink, and is set to be longer than the minimum pulse width t5 required for discharging the ink. Since the energy generated by the heater 102 is proportional to the width of the heat pulse (application time), by adjusting the width of the heat pulse,
Can be adjusted.

It is also possible to adjust the discharge amount of ink by adjusting the interval between the preheat pulse and the heat pulse and controlling the state of heat diffusion by the preheat pulse.

As can be understood from the above description, the ink ejection amount can be controlled by adjusting the application time of the preheat pulse and the heat pulse, and the application interval of the preheat pulse and the heat pulse can be adjusted. It is also possible by doing. Therefore, by adjusting the application time of the pre-heat pulse and the heat pulse and the application interval of the pre-heat pulse and the heat pulse as necessary, it is possible to freely adjust the ink ejection amount and the responsiveness of the ink ejection to the application pulse. It becomes possible.

Next, the adjustment of the ink ejection amount will be specifically described.

For example, as shown in FIG.
The case where the ejection amounts of the inks 108a, 108b, and 108c are different when the same energy is applied will be described. Specifically, when constant energy is applied at a constant temperature, the ink discharge amount of the nozzle 108a is 36 pl.
(Picoliter), the ink discharge amount of the nozzle 108b is 4
0 pl, the ink ejection amount of the nozzle 108c is 40 pl, and the resistance values of the heater 102a corresponding to the nozzle 108a and the heater 102b corresponding to the nozzle 108b are 200
Ω, the resistance value of the heater 102c corresponding to the nozzle 108c is 210Ω. Then, the discharge amount of each of the nozzles 108a, 108b, 108c is set to 40p.
Suppose you want to match l.

Each of the nozzles 108a, 108b, 1
In order to adjust the ejection amount of 08c to the same amount, the width of the preheat pulse and the width of the heat pulse may be adjusted, but various combinations of the width of the preheat pulse and the width of the heat pulse are conceivable. Here, the amount of energy generated by the heat pulse is set to be the same for the three nozzles, and the discharge amount is adjusted by adjusting the width of the preheat pulse.

First, the resistance value of the heater 102a of the nozzle 108a and the resistance value of the heater 102b of the nozzle 108b are the same.
In order to make the energy generated by the heat pulse the same, a voltage pulse having the same width may be applied to the heaters 102a and 102b. Here, the width of the voltage pulse is set to t3 longer than t5 described above. on the other hand,
The nozzles 108a and 108b output different amounts of 36 pl and 40 pl when the same energy is applied.
A preheat pulse of t2 longer than the preheat pulse width t1 of the heater 102b is applied to a. In this way, the ejection amounts of the nozzles 108a and 108b are
pl.

On the other hand, since the resistance value of the heater 102c of the nozzle 108c is 210Ω which is higher than the resistance values of the other two heaters 102a and 102b, the heater 102c generates the same energy as that of the other two heaters. Requires a longer heat pulse width. Therefore, here, the width of the heat pulse is set to t4 which is longer than t3 described above. Further, regarding the width of the preheat pulse, the nozzle 10 when a certain energy is applied is used.
8b and 108c have the same discharge amount,
2b, and a preheat pulse having a width of t1 is applied.

As described above, the three nozzles 108 having different ink ejection amounts when a resistance value and constant energy are applied.
The same amount of ink can be ejected from a, 108b, and 108c. Further, it is also possible to intentionally change the ink ejection amount by the same method. The reason why the preheat pulse is used is to reduce the variation in the discharge of each nozzle.

Next, two representative methods for reducing printing unevenness in printing with an ink jet head will be described.

FIGS. 9 to 11 are diagrams showing a method (hereinafter, referred to as bit correction) for correcting a difference in ink discharge amount between each nozzle of an ink jet head IJH having a plurality of ink discharge nozzles.

First, as shown in FIG. 9, ink is discharged from a nozzle 1, a nozzle 2, and a nozzle 3, for example, three nozzles of an ink jet head IJH onto a predetermined substrate.
The size of the ink dots formed on the substrate P by the ink discharged from each nozzle is measured, and the amount of ink discharged from each nozzle is measured. At this time, the heat pulse (see FIG. 8) applied to the heater of each nozzle has a fixed width, and the width of the preheat pulse (see FIG. 8) is changed as described above. As a result, a curve showing the relationship between the preheat pulse width (shown as the heating time in FIG. 10) and the ink ejection amount as shown in FIG. 10 is obtained. Here, for example, assuming that the ink ejection amount from each nozzle is to be unified to 20 ng, the width of the preheat pulse applied to the nozzle 1 is 1.0 μs, that of the nozzle 2 is 0.5 μs, It can be seen that the time is 0.75 μs. Therefore,
By applying a pre-heat pulse having such a width to the heater of each nozzle, the amount of ink discharged from each nozzle can be made uniform to 20 ng as shown in FIG. Correcting the ink ejection amount from each nozzle in this manner is called bit correction. In the present embodiment, the width of the preheat pulse is changed in four steps to achieve a correction width of about 30%. The resolution of the correction is 2-3%.

Next, FIGS. 12 to 14 show a method of correcting the density unevenness in the scanning direction of the ink jet head by adjusting the ink discharge density from each ink discharge nozzle (hereinafter referred to as shading correction). It is.

For example, as shown in FIG. 12, based on the ink discharge amount of the nozzle 3 of the ink jet head, the ink discharge amount of the nozzle 1 is -10%, and the ink discharge amount of the nozzle 2 is + 20%. Suppose. At this time, while scanning the inkjet head IJH, as shown in FIG. 13, a heat pulse is applied to the heater of the nozzle 1 once every 9 times of the reference clock, and the heater of the nozzle 2 is applied to 12 times of the reference clock as shown in FIG. The heat pulse is applied once each time, and the heater pulse of the nozzle 3 is applied once every ten times of the reference clock. By doing so, the number of ink ejections in the scanning direction is changed for each nozzle, and as shown in FIG. 14, the ink density in the scanning direction can be kept constant, and density unevenness can be prevented. Correcting the ink ejection density in the scanning direction in this manner is called shading correction. In this embodiment, a correction width of about 40% is realized by this correction. Further, the resolution of the correction can be finely and unlimitedly controlled, but there is a restriction that the data becomes large and the speed becomes slow. In practice, the limit is about 10%.

When the ink ejection amount is measured by the measuring device of the first embodiment and actual printing is performed by the printing device based on the measurement result, a method of changing the preheat pulse width as described above, The density unevenness caused by the difference in the ink ejection amount can be corrected by appropriately adjusting the ejection amount of the ink using a method of changing the ejection density of the ink.

(Second Embodiment) In the first embodiment,
Although the line sensor camera is used for reading the image of the line pattern, a CCD camera or another area sensor may be used instead. Further, the gradation of the luminance level in the image processing (8-bit A / D in the first embodiment)
The accuracy of the measurement data can be further improved by setting a higher value, for example, 16 bits or the like, for the conversion element to 256 gradations.

The present invention can be applied to a modification or modification of the above embodiment without departing from the spirit thereof.

The present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. The printing apparatus of the type that causes a change in the state of the ink has been described.
High definition can be achieved.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the film boiling to an electrothermal transducer arranged corresponding to the sheet or the liquid path in which Since thermal energy is generated in the electrothermal transducer and film boiling occurs on the heat-acting surface of the recording head, bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis can be formed. It is valid. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped driving signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

The configuration of the recording head is not limited to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications. A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600, which discloses a configuration in which a heat acting surface is arranged in a bent region, is also included in the present invention. In addition, for multiple electrothermal transducers,
JP-A-59-123670 which discloses a configuration in which a common slot is used as a discharge part of an electrothermal transducer, and JP-A-59-123670 which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge part. A configuration based on 138461 may be adopted.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is determined by combining a plurality of recording heads as disclosed in the above specification. This may be either a configuration satisfying the above requirements or a configuration as a single recording head formed integrally.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or is integrated with the print head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.

It is preferable to add recovery means for the recording head, preliminary auxiliary means, and the like provided as components of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. . If these are specifically mentioned, capping means for the recording head, cleaning means, pressurizing or suction means, preheating means using an electrothermal transducer or another heating element or a combination thereof, and printing Performing a preliminary ejection mode for performing another ejection is also effective for performing stable printing.

In the embodiment of the present invention described above,
Although the ink is described as a liquid, an ink that solidifies at or below room temperature, or a material that softens or liquefies at room temperature may be used. In general, the temperature is adjusted within the following range to control the temperature so that the viscosity of the ink is in the stable ejection range. Therefore, it is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, in order to positively prevent the temperature rise due to thermal energy as energy for changing the state of the ink from the solid state to the liquid state,
Alternatively, in order to prevent evaporation of the ink, an ink which solidifies in a standing state and liquefies by heating may be used. In any case, the application of heat energy causes the ink to be liquefied by application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify when reaching the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, as described in JP-A-54-56847 or JP-A-60-71260, the ink is held in a liquid state or a solid state in the concave portion or through hole of the porous sheet. It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0092]

As described above, according to the present invention, the density of the line pattern formed by the ink ejected from the head is detected, and the ink ejection amount is obtained from this density to obtain the ink dot. The ink ejection amount can be obtained instantaneously for each dot. When drawing a line pattern, the edge of the line pattern can be sharpened by limiting the portion where ink can be absorbed by exposing the ink absorbing member in advance by pattern exposure, so that the edge of the window is overwhelmed. Therefore, the measurement accuracy of the density of the line pattern can be improved.

Further, the correlation between the ink ejection amount and the density of the ink dots formed by the ink is obtained in advance, and the correlation and the measured density of the line pattern from an arbitrary nozzle can be easily determined. The ink discharge amount of an arbitrary nozzle can be obtained.

Further, by forming a line pattern on a transparent substrate, irradiating the line pattern with transmitted light, photographing with a camera, and performing image processing, the density of the line pattern can be obtained instantaneously.

Further, two or more nozzles having the determined ejection amount are prepared, ink is ejected from the two or more nozzles, and a calibration curve between the density of ink dots formed by the ink and the ink ejection amount is obtained. By doing so, it is possible to easily measure the amount of ink ejected under arbitrary conditions from the calibration curve and the density of a line pattern formed by ink ejected from arbitrary nozzles under arbitrary conditions.

When the ejection amount of the nozzle is determined in advance, the ejection amount of the nozzle can be accurately obtained by using the gravimetric method or the absorbance method.

Further, by providing the XY stage or the X stage so that the ink receiving member can be moved with respect to the camera for performing image processing, the density of a plurality of line patterns can be continuously measured, and the plurality of line patterns can be continuously measured. Even in a head having nozzles, the ejection amount of ink ejected from a plurality of nozzles can be continuously obtained.

Further, by incorporating a device for measuring the amount of ink discharged into the printing apparatus, data on the amount of discharged ink obtained by this measuring device can be fed back to control for uniformizing the amount of discharged ink from the head. Print quality can be improved.

[0099]

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a line pattern created using an inkjet printer.

FIG. 3 is a diagram showing an example in which a fixed-size window is applied to a line pattern to be measured.

FIG. 4 is a diagram illustrating an example of measuring a reference integrated luminance near a line pattern.

FIG. 5 is a diagram showing an example of a calibration curve obtained in an experiment based on the present embodiment.

FIG. 6 is a diagram illustrating a printer device having a built-in device for measuring an ink discharge amount.

FIG. 7 is a diagram illustrating a structure of an inkjet head.

FIG. 8 is a diagram for explaining a method of controlling the amount of ink ejection by changing the power applied to the heater.

FIG. 9 is a diagram for explaining a method of correcting a difference in the ejection amount of each nozzle.

FIG. 10 is a diagram for explaining a method of correcting a difference in the ejection amount of each nozzle.

FIG. 11 is a diagram for explaining a method of correcting a difference in ejection amount for each nozzle.

FIG. 12 is a diagram for explaining a method of changing the ink ejection density.

FIG. 13 is a diagram for explaining a method of changing the ink ejection density.

FIG. 14 is a diagram for explaining a method of changing the ink ejection density.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image processing apparatus 2 Personal computer 3 Magnifying optical system 4 XY stage 5 Line sensor camera 6 Transmission light source 7 Window 10 Glass substrate 12 Composition layer

Claims (25)

[Claims] An ink ejection amount measuring method for measuring an ink ejection amount per one time ejected from an ink jet type head, comprising a portion irradiated with light by exposure having an ink absorbing property. An exposure step of exposing an ink absorbing member that has lost ink absorbency so that a portion having ink absorbency has a predetermined pattern shape, and discharging ink from the head to the portion having ink absorbency, A drawing step of drawing a predetermined pattern on the ink absorbing member; a density measuring step of measuring the density of the predetermined pattern drawn in the drawing step; and a density measuring step of measuring the density of the predetermined pattern measured in the density measuring step. An ink ejection amount detecting step of obtaining the ink ejection amount by the above method. 2. The method according to claim 1, further comprising, before the density measuring step, a preliminary measurement step in which a correlation between an ink ejection amount per one time and a density of an ink dot formed by the ink is experimentally obtained in advance. 2. The method for measuring an ink ejection amount according to claim 1, wherein: 3. The ink absorbing member is a transparent member, and in the density measuring step, light from a light source disposed behind the ink absorbing member, which has passed through the predetermined pattern, is used as an image. 2. The method according to claim 1, wherein the density of the predetermined pattern is measured by analyzing through processing. 4. The method according to claim 1, further comprising, after the ink ejection amount detection step, an ejection amount adjustment step of adjusting the ink ejection amount to a desired ejection amount based on the ink ejection amount detected in the detection step. 2. The method for measuring an ink ejection amount according to claim 1, wherein: 5. The method according to claim 4, further comprising a step of discharging ink onto a print medium after the step of adjusting the discharge amount. 6. A method for measuring an amount of ink ejected from an ink jet type head per one time, the method comprising: measuring a quantity of ink ejected from a plurality of ink ejection nozzles of the head under predetermined conditions. A preliminary measurement step of preliminarily measuring an ink discharge amount per each time; and a predetermined condition from at least two ink discharge nozzles of the plurality of ink discharge nozzles having different discharge amounts on a predetermined member. A first density measurement step of measuring the density of the ink dots created by each ink by ejecting the ink at the following; density data of the ink dots created by the two or more inks determined in the first density measurement step; From the data of the two or more ink ejection amounts obtained in the preliminary measurement step, the correlation between the ink ejection amount per one time and the ink dot density is determined. A calibration curve generating step of obtaining a calibration curve which is a graph representing the ink absorbing member having ink absorbability and being exposed to light by exposure to the ink absorbing member losing ink absorbency, and a portion having ink absorbency having a predetermined pattern. An exposure step of exposing to a shape, a drawing step of discharging ink from the head to the ink absorbing portion to draw a predetermined pattern on the ink absorbing member, and a drawing step of drawing in the drawing step. A second density measurement step of measuring the density of a predetermined pattern; and the arbitrary nozzle from the arbitrary nozzle based on the density data of the predetermined pattern measured in the second density measurement step and the calibration curve. An ink ejection amount detecting step of obtaining an ejection amount of ink ejected under conditions. 7. The method according to claim 6, wherein in the preliminary measurement step, the amount of ink discharged from the plurality of ink discharge ports is measured by a gravimetric method or an absorbance method. 8. The ink absorbing member is a transparent member, and in the second density measuring step, light from a light source disposed on the back of the ink absorbing member that has passed through the predetermined pattern. 7. The method according to claim 6, wherein the density of the predetermined pattern is measured by analyzing the density of the predetermined pattern by image processing. 9. An ink ejection amount adjusting step for adjusting the ink ejection amount to a desired ejection amount based on the ink ejection amount detected in the detection step after the ink ejection amount detecting step. 7. The method for measuring an ink ejection amount according to claim 6, wherein: 10. The method according to claim 9, further comprising a step of discharging ink onto a print medium after the step of adjusting the discharge amount. 11. A printing apparatus which has a function of measuring an ink ejection amount per one time ejected from an inkjet head and performs printing using an inkjet head which ejects ink by an inkjet method. Exposure means for exposing an ink-absorbing member in which a portion irradiated by exposure to light loses ink absorbability so that the portion having ink absorbency has a predetermined pattern shape, and the inkjet head Density detecting means for detecting the density of a pattern drawn on the ink absorbing portion of the ink absorbing member by the ink discharged from the ink absorbing member; and forming the ink on the ink absorbing member by the ink discharge amount per time and the ink. The calibration curve is a graph showing the correlation with the density of the ink dots to be stored. A printing apparatus, comprising: a storage unit; and a calculation unit that calculates the ink ejection amount based on the density of the drawing pattern detected by the density detection unit and the calibration curve. 12. The printing apparatus according to claim 11, wherein the density detecting unit includes a camera that captures the drawing pattern and an image processing device that analyzes an image from the camera. 13. The ink absorbing member according to claim 1, wherein the ink absorbing member is a transparent member, and further includes a light source for illuminating the drawing pattern from behind the ink absorbing member.
3. The printing device according to 2. 14. The ink absorbing member is relatively moved with respect to the camera, and the density of the plurality of drawing patterns formed on the ink absorbing material is automatically and continuously measured, and the plurality of drawing patterns are measured. 13. The printing apparatus according to claim 12, further comprising an XY stage for continuously obtaining a discharge amount of the formed ink. 15. The image forming apparatus according to claim 11, further comprising an adjusting unit that adjusts an amount of ink ejected from the inkjet head based on the amount of ink ejection calculated by the calculating unit. Printing equipment. 16. A method for measuring an ink ejection amount in a printing apparatus having an ink-jet type head, comprising: an ink absorbing member which has an ink absorbing property, and which is exposed to light by exposure and loses the ink absorbing property. An exposure step of exposing the portion having ink absorbency to have a predetermined pattern shape; and a drawing step of discharging ink from the head to the portion having ink absorbency to draw a predetermined pattern on the ink absorbing member. A density measuring step of measuring the density of the predetermined pattern drawn in the drawing step; and an ink discharge amount for obtaining the discharge amount of the ink based on the density of the predetermined pattern measured in the density measuring step. A method for measuring the amount of ink ejected in a printing apparatus, comprising: a detecting step. 17. The method according to claim 17, wherein:
17. The printing apparatus according to claim 16, further comprising a preliminary measurement step of previously experimentally determining a correlation between an ink ejection amount per operation and a density of an ink dot formed by the ink. A method for measuring the ink ejection amount. 18. The ink-absorbing member is a transparent member, and in the density measuring step, light from a light source disposed behind the ink-absorbing member that has passed through the predetermined pattern is used as an image. 17. The method according to claim 16, wherein the density of the predetermined pattern is measured by analyzing the processing. 19. An ink ejection amount adjusting step for adjusting the ink ejection amount to a desired ejection amount based on the ink ejection amount detected in the detecting step after the ink ejection amount detecting step. The method according to claim 16, wherein the ink ejection amount is measured by the printing apparatus. 20. The method according to claim 19, further comprising a step of discharging ink onto a print medium after the step of adjusting the discharge amount. 21. A method for measuring an ink ejection amount in a printing apparatus having an ink-jet type head, comprising: determining a predetermined amount of ink ejection from each of a plurality of ink ejection nozzles of the head under predetermined conditions. A preliminary measurement step of pre-measurement; and discharging ink under predetermined conditions from two or more ink discharge nozzles of the plurality of ink discharge nozzles having different discharge amounts from each other to form predetermined ink. A first density measurement step of measuring the density of the ink dots; density data of ink dots formed by two or more inks obtained in the first density measurement step; A calibration curve representing a correlation between the ink ejection amount per one time and the ink dot density from the data of the two or more ink ejection amounts. A calibration curve generating step of obtaining the ink absorption member, which is exposed to light by ink absorption and exposed so that the ink absorbing member loses ink absorption so that the ink absorbing portion has a predetermined pattern shape. An exposure step of causing the ink to be ejected from the head to the portion having the ink absorbency to draw a predetermined pattern on the ink absorbing member; and a density of the predetermined pattern drawn in the drawing step. A second density measuring step of measuring, based on the density data of the predetermined pattern measured in the second density measuring step and the calibration curve, the liquid is ejected from the arbitrary nozzle under the arbitrary condition. An ink ejection amount detecting step for obtaining an ink ejection amount. A method for measuring an ink ejection amount in a printing apparatus, comprising: 22. The printing apparatus according to claim 21, wherein in the preliminary measurement step, the ink ejection amount from the plurality of ink ejection ports is measured by a gravimetric method or an absorbance method. Measuring method. 23. The ink-absorbing member is a transparent member, and in the second density measuring step, light from a light source disposed on the back of the ink-absorbing member after passing through the predetermined pattern. 22. The method according to claim 21, wherein the density of the predetermined pattern is measured by analyzing the density of the predetermined pattern by image processing. 24. The method according to claim 24, further comprising, after the ink ejection amount detecting step, an ejection amount adjusting step of adjusting the ink ejection amount to a desired ejection amount based on the ink ejection amount detected in the detecting step. 22. The method of measuring an ink ejection amount in a printing apparatus according to claim 21, wherein 25. The method according to claim 24, further comprising the step of discharging ink onto a print medium after the step of adjusting the discharge amount.