JP4261896B2 - Recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording apparatus, and more particularly to an ink jet recording apparatus. Note that the recording apparatus here includes, in addition to a general recording apparatus that records an image on a recording medium such as a recording sheet, a manufacturing apparatus for a DNA chip or a display apparatus using an inkjet recording method.
[0002]
In addition, the recorded matter referred to in the present invention is, for example, a general recorded matter in which an image is recorded on a recording medium such as a recording paper, wallpaper having a pattern on the surface, clothes printed with a pattern, It includes a cloth, a DNA chip using an inkjet recording system, a display device, and the like.
[0003]
[Prior art]
Conventionally, methods for detecting the presence or absence of ink droplet ejection and the size of ink droplets have been proposed (see, for example, Patent Publication 1). By applying such a method, it is possible to optimize the cleaning frequency of the recording head and to suppress unevenness of the recording result due to the difference in the size of the ink droplets for each ejection port.
[0004]
[Patent Publication 1]
JP-A-11-170569.
[0005]
[Problems to be solved by the invention]
However, the method disclosed in the above-mentioned conventional patent publication 1 has the following problems.
[0006]
(1) For example, in an inkjet recording apparatus having a plurality of recording heads for simultaneously ejecting ink droplets of a plurality of colors, in order to increase the detection speed of the presence or absence of ink droplets and the size of the ink droplets, When a plurality of sensors are provided corresponding to the number of recording heads and simultaneous measurement is attempted for each recording head, the ejected ink may adhere across the plurality of sensors. Thereby, the electrical insulation between a plurality of sensors is broken, and accurate detection becomes impossible.
[0007]
(2) Since it is necessary for the ink droplets to collide with the sensor in order to detect the presence or absence of ink droplet ejection and the size of the ink droplets, this can be detected while effective recording is being performed on the recording medium. Absent. For this reason, in order to perform the detection, it is necessary to perform ink ejection separately from the actual recording.
[0008]
The present invention has been made in view of the above-mentioned problems with the conventional example, and while ink droplets are not in contact with the sensor, whether or not ink droplets are ejected at a higher speed and the size of the ink droplets. It is an object of the present invention to provide a recording apparatus capable of accurately detecting the above.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the recording apparatus of the present invention has the following configuration.
[0010]
That is, Ink jet recording head, scanning means for reciprocating the ink jet recording head in a first direction, and transport means for transporting a recording medium to a recording position by the recording head in a second direction different from the first direction And the inkjet Inside the recording head Provided in A first electrode electrically connected to the ink; When the recording medium is transported to the recording position by the transporting means, the recording medium is sandwiched between the first recording medium and the first recording medium. electrode On the opposite side of A closed circuit having a second electrode provided, a resistor, and a power source, wherein the capacitor formed by the first electrode and the second electrode, the resistor, and the power source are connected in series; With composition When the recording medium is sandwiched between the first electrode and the second electrode and ink is ejected to the recording medium by the inkjet recording head, A potential difference between both ends of the resistor is measured.
[0011]
The present invention can also be realized as a recorded matter manufacturing method. The recorded matter manufacturing method includes a first electrode electrically connected to the ink inside the recording head, a second electrode provided separately from the ink-side electrode, a resistor, and a power source. A closed circuit in which a capacitor, a resistor, and a power source formed by the first electrode and the second electrode are connected in series is configured, and a potential difference between both ends of the resistor is measured.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
More specifically, the above-described configuration of the solution is described in detail. The second electrode is disposed on the opposite side of the ink jet recording head with the recording medium interposed therebetween, so that the first electrode faces the first electrode. It is good to configure. Further, it is more preferable that the potential difference between both ends of the resistor is detected in a state where the recording medium is between the ink jet recording head and the second electrode.
[0013]
Furthermore, it is preferable to further include monitoring detection means for detecting and monitoring a potential difference between both ends of the resistor.
[0014]
The ink jet recording head includes a plurality of ink discharge nozzles, each of the plurality of ink discharge nozzles having an electrothermal conversion body, and the electrothermal conversion body according to the detection result detected by the monitoring detection means. It is further desirable to further have a control means for controlling the energization of.
[0015]
Various controls can be realized by adding the following configuration to the control means.
[0016]
For example, the control means includes drive means for generating ink discharge by applying power of a predetermined drive pattern to the electrothermal transducer at a predetermined timing, for example, immediately after the recovery operation of the ink jet recording head. It is preferable to have a comparison means for comparing a measured potential obtained by the monitoring detection means with a predetermined threshold value when driven by the drive means.
[0017]
Further, the control means further includes a determination means for determining whether the ink discharge nozzle having the electrothermal converter is an ink dischargeable nozzle or a non-dischargeable nozzle according to the comparison result by the comparison means; According to a determination result by the determination unit, a recording control unit that performs ink jetting using an ink discharge nozzle adjacent to the non-dischargeable nozzle and performs compensation recording may be provided.
[0018]
Alternatively, the control means further includes an estimation means for estimating the ink discharge amount indicated by the measured potential difference with reference to a table showing the relationship between the potential difference and the ink discharge amount according to the comparison result by the comparison means; When the ink discharge amount estimated by the estimation unit is equal to or less than a predetermined amount, the determination unit determines that the ink discharge nozzle having the electrothermal converter is an undischargeable nozzle, and the determination result by the determination unit And a recording control means for performing ink jetting using an ink jetting nozzle adjacent to the non-ejectionable nozzle and performing compensation recording.
[0019]
In this case, when the estimated ink discharge amount is larger than the predetermined amount, the control means further refers to the table showing the relationship between the drive pattern of the electrothermal transducer and the ink discharge amount, and It is further preferable to select an optimum drive pattern for the ink discharge nozzle having the heat converter.
[0020]
When the present invention is realized as a recorded product manufacturing method as described above, the configuration of the method invention is more specifically configured as follows.
[0021]
That is, the second electrode may be disposed so as to sandwich the recording medium together with the ink jet recording head. In that case, the ink jet recording head includes a plurality of ink discharge nozzles, each of which has an electrothermal transducer. Thus, it is preferable to control the energization to the electrothermal transducer according to the detection result detected by monitoring the potential difference between both ends of the resistor. Note that the potential difference between both ends of the resistor may be detected in a state where the recording medium is between the recording head and the second electrode.
[0022]
Then, the control is performed based on a comparison result between a measured potential difference obtained at that time and a predetermined threshold value by causing the electrothermal transducer to be supplied with electric power of a predetermined driving pattern at a predetermined timing to generate ink ejection. It is characterized by.
[0023]
The predetermined timing is preferably immediately after the recovery operation of the ink jet recording head.
[0024]
Further, the control determines whether the ink discharge nozzle having the previous electrothermal transducer is an ink dischargeable nozzle or a non-dischargeable nozzle according to the comparison result, and adjoins the non-dischargeable nozzle according to the determination result. It is preferable to include recording control for performing compensation recording by ejecting ink using an ink ejection nozzle.
[0025]
Alternatively, the control further estimates an ink discharge amount indicated by the measured potential difference according to the comparison result with reference to a table showing a relationship between the potential difference and the ink discharge amount, and the estimated ink discharge amount is determined. If it is less than the fixed amount, it is determined that the ink discharge nozzle having the electrothermal converter is a non-dischargeable nozzle, and ink is discharged using the ink discharge nozzle adjacent to the non-dischargeable nozzle according to the determination result. Recording control for performing compensation compensation recording may be included. In this case, if the estimated ink discharge amount is larger than the predetermined amount, the table indicating the relationship between the drive pattern of the electrothermal transducer and the ink discharge amount is referred to, and the electrothermal transducer is present. More preferably, the method includes a step of selecting an optimum driving pattern for the ink discharge nozzle.
[0026]
The term “electrically connected” means that an electric current is generated when a potential difference is applied between the ink and the side electrode in the ink liquid chamber. This includes not only the case of direct physical contact but also the case of being connected to each other by a conductor.
[0027]
Hereinafter, preferred embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings.
[0028]
In the embodiments described below, a recording apparatus using an inkjet recording head will be described as an example.
[0029]
In this specification, “recording” (sometimes referred to as “printing”) is not only for forming significant information such as characters and figures, but also for human beings visually perceived regardless of significance. Regardless of whether or not it has been manifested, it also represents a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or the medium is processed.
[0030]
“Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.
[0031]
Furthermore, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly in the same way as the definition of “recording (printing)” above. It represents a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing an ink (for example, solidification or insolubilization of a colorant in ink applied to the recording medium).
[0032]
Next, the overall configuration and operation of an ink jet recording apparatus that is a representative embodiment of the present invention will be described.
[0033]
FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus which is a typical embodiment of the present invention.
[0034]
In FIG. 1, a paper feed roller 1 rotates by using a driving force of a transport motor (not shown) and transports a recording medium 2 in the direction of arrow P (sub-scanning direction). The recording head 5 is detachably attached to the carriage 4, and the carriage 4 reciprocates in the direction of arrow C (main scanning direction) along the main scanning guide 3 using the driving force of a carrier motor (not shown). The recording medium 2 is scanned. As will be described in detail later, the interior of the recording head 5 is divided into three parts, coupled to ink tanks (not shown) connected to the respective sections, and supplied with ink. An electrode 6 is provided below the recording head 5, and the recording medium 2 is positioned between the electrode 6 and the recording head 5 during recording.
[0035]
Although not shown in FIG. 1, the ink jet recording apparatus has means for supplying a recording medium, means for recovering the recording head, and means for discharging the recording medium.
[0036]
The recording operation of this ink jet recording apparatus is performed as follows.
[0037]
First, when a recording start command signal is input to the inkjet recording apparatus from, for example, a host computer (hereinafter referred to as a host), the recording medium is fed from the upper right direction of FIG. The recording medium is supplied until it reaches the position of the feed roller 1, and then the recording medium is conveyed by the paper feed roller 1 so that the recording head 5 is positioned at the print start position on the recording medium in accordance with the recording signal. Subsequently, recording is performed by ejecting ink droplets onto the recording medium 2 while the carriage 4 on which the recording head 5 is mounted moves in the main scanning direction.
[0038]
Thereafter, when the recording with one movement in the main scanning direction is completed, the recording medium 2 is conveyed in the sub-scanning direction by a predetermined amount by the paper feed roller 2, and the carriage 4 is again moved in the main scanning direction. Ink droplets are ejected from the base station onto the recording medium 2.
[0039]
Recording is performed on the entire surface of the recording medium 2 by repeating the conveyance of the recording medium in the sub-scanning direction and the movement of the carriage 5 in the main scanning direction. Thereafter, the recording medium 2 is discharged in the lower left direction in FIG.
[0040]
Note that paper is often used as the recording medium 2. However, an OHP sheet, a compact disk, a DNA chip, a substrate for a color filter of a display device, or the like may be used as the recording medium.
[0041]
Next, a detection unit that detects whether ink droplets are ejected and the size of the ink droplets will be described.
[0042]
FIG. 2 is a view schematically showing the section of the recording head 5 during the recording operation cut along a plane orthogonal to the main scanning direction, with elements of the attached electric circuit added.
[0043]
First, the configuration of the detection unit will be described.
[0044]
In FIG. 2, a hatched portion 7 indicates one of a plurality of inks filled in one of the three sections described above. The ink 7 is supplied from an ink tank (not shown) through the ink supply port 7a. The space of the section is called an ink liquid chamber.
[0045]
As shown in FIG. 2, the ink 7 is divided into a plurality of nozzle portions 13 in a lower region of the ink liquid chamber, and a heater 14 is provided in each nozzle portion 13. Ink is ejected as ink droplets 15 by supplying power to the heater 14 in accordance with image information transmitted from the host. The recording medium 2 during the recording operation is disposed between the recording head 5 and the electrode 6, and ink droplets ejected from the recording head 5 adhere to the recording medium 2.
[0046]
In addition, an electrode 8 that is paired with the electrode 6 is disposed inside the recording head, and is in contact with ink in the ink liquid chamber. A terminal 10 for detecting the presence or absence of ink is connected to the electrode 8 side, and outputs the potential of the electrode 8 to a processing circuit described later. One end of the resistor 9 is connected to the electrode 8 and the terminal 10, and the other end is connected to the ground 12 and the power source 11. The ground 12 is a chassis of the ink jet recording apparatus, and its potential is the reference potential of the ink jet recording apparatus. One end of the power supply 11 is connected to the resistor 9 and the ground 12, and the other end is connected to the electrode 6.
[0047]
FIG. 3 is a diagram schematically showing the cross section of the recording head 5 shown in FIG. 2 cut along the sub-scanning direction with the elements of the attached electric circuit added.
[0048]
In FIG. 3, the same elements as those shown in FIG. 2 are denoted by the same reference numerals. As described above, the interior of the recording head 5 is divided into three sections, each of which is filled with a different type of ink. Each of the compartments is provided with electrodes as described with reference to FIG. 2, and as shown in FIG. 3, resistors and terminals are respectively connected to the electrodes, and one end of each of the resistors is commonly used as a power source. 11 and the ground 12.
[0049]
There are three compartments inside the recording head 5, and each compartment is filled with ink and electrodes are arranged, and resistors and terminals are similarly connected to these electrodes. The numbers are the same as those mentioned, with “′” and “″” appended to the numbers to distinguish each element with respect to the three sections.
[0050]
Next, the operation of the detection unit will be described.
[0051]
As can be understood from the configuration shown in FIGS. 2 and 3, the ink 7 (7 ′, 7 ″), the electrode 6, the space between them, and the recording medium 2 form a capacitor, each serving as a capacitor electrode. The capacitor thus formed, the electrode 8 (8 ′, 8 ″), the resistor 9 (9 ′, 9 ″), and the power source 11 form an electric circuit.
[0052]
In the steady state, the same potential difference as the potential difference generated at both ends of the power supply is generated between the ink 7 (7 ′, 7 ″) corresponding to the electrode plate of the capacitor and the electrode 6. This potential difference causes the ink 7 (7 ′, 7 ″) and the electrode 6 have opposite polarities. When power is supplied to the heater 14 in this state and ink droplets are ejected, part of the charge on the ink side is taken away from the ink 7 (7 ', 7 ") in the recording head 5 together with the ink droplets. .
[0053]
For this reason, the ink potential temporarily rises by an amount proportional to the amount of ejected ink. Thereafter, the potentials of the ink 7 (7 ′, 7 ″) and the electrode 8 (8 ′, 8 ″) are supplied from the capacitor, the electrode 8 (8 ′, 8 ″), the resistor 9 (9 ′, 9 ″), and the power source 11. Electric charges are supplied by the formed electric circuit to return to a steady state potential.
[0054]
On the other hand, the ink droplet 15 adheres to the recording medium 2.
[0055]
Therefore, if the potential change is monitored, the presence / absence of ink droplet ejection and the size of the ink droplet can be known from the variation amount.
[0056]
According to the above configuration, the electrode 8 (8 ′, 8 ″) in the recording head and the electrode 6 which is opposite to the recording head 2 and is provided outside the recording head and immediately below the recording medium 2 are used. When detecting the presence or absence of ink droplets or measuring the amount of ink ejected, it is impossible for the ejected ink to adhere to more than one sensor because of its structure. There is an advantage that the mechanical insulation is not destroyed.
[0057]
In addition, unlike the conventional example, it is not necessary for the ink droplets to collide with the sensor to detect the presence or absence of ink droplet ejection and the size of the ink droplets, so the recording medium records the detection of the potential difference across the resistor. By performing in a state between the head and the second electrode, it is possible to apply effective ink droplets to the recording medium, that is, to detect the presence or size of ink droplets simultaneously with recording.
[0058]
<Description of control configuration>
Next, a control configuration for executing the recording control of the above-described apparatus will be described.
[0059]
FIG. 4 is a block diagram showing the configuration of the control circuit of the ink jet recording apparatus.
[0060]
In the figure showing a control circuit, 1700 is an interface for inputting a recording signal, 1701 is an MPU, 1702 is a ROM for storing a control program executed by the MPU 1701, 1703 is various data (the recording signal and recording data supplied to the head). Etc.). Reference numeral 1704 denotes a gate array (GA) that controls supply of recording data to the recording head 5 and also performs data transfer control among the interface 1700, MPU 1701, and RAM 1703. Reference numeral 1710 denotes a carrier motor for conveying the recording head 5, and reference numeral 1709 denotes a conveyance motor for conveying the recording medium. Reference numeral 1705 denotes a head driver for driving the recording head 5, and reference numerals 1706 and 1707 denote motor drivers for driving the transport motor 1709 and the carrier motor 1710, respectively.
[0061]
The operation of the control configuration will be described. When a recording signal enters the interface 1700, the recording signal is converted into recording data for printing between the gate array 1704 and the MPU 1701. The motor drivers 1706 and 1707 are driven, and the recording head 5 is driven in accordance with the recording data sent to the head driver 1705 to perform recording.
[0062]
The MPU 1701 receives the output potentials from the terminals 6 and 10, monitors the potential change, and detects the presence / absence of ink discharge and the size of the ink droplet (ink discharge amount) from the change.
[0063]
The ROM 1702 stores a program for executing various processes using the detection of the presence / absence of ink droplets and the detection of the ink discharge amount, which will be described below.
[0064]
Next, processing using detection of whether or not ink droplets are ejected will be described with reference to the flowcharts shown in FIGS. First, an overview of the whole will be described first, and then details of each process will be described.
[0065]
FIG. 5 is a flowchart showing the overall flow of the recording operation using detection of whether or not ink droplets are ejected.
[0066]
The recording operation is started when a recording signal is input to the ink jet recording apparatus.
[0067]
First, in step S100, it is checked whether it is necessary to detect whether or not ink discharge is possible. From the aspect of detection accuracy, it is desirable to detect whether or not ejection is possible at every recording, but in this embodiment, whether or not ejection is possible only in the recording immediately after the recovery operation is performed in consideration of ink consumption associated with the ejection availability detection. Detection is performed. If it is determined that it is necessary to detect whether or not discharge is possible, the process proceeds to step S200, where discharge enable / disable detection, which will be described in detail later, and further, a non-discharge compensation method is determined in step S300.
[0068]
In step S400, a recording operation is performed in which ink droplets are sprayed onto the recording medium while performing non-discharge compensation in accordance with the non-discharge compensation method determined in step S300.
[0069]
On the other hand, if it is determined in step S100 that it is not necessary to detect ink discharge, the process skips step S200 and step S300, proceeds to step S400, and at the time of previous ink discharge permission detection. The recording operation is performed while performing non-discharge compensation in accordance with the determined non-discharge compensation method.
[0070]
Next, details of the discharge availability detection in step S200 will be described.
[0071]
FIG. 6 is a flowchart showing details of the discharge availability detection.
[0072]
First, in step S210, it is checked whether there is a nozzle that has not detected whether or not ejection is possible with respect to the ink ejection nozzle of the recording head 5. Here, if it is determined that there is no undetected nozzle and detection for all nozzles has been completed, the discharge propriety detection process is terminated. If it is determined that there are still undetected nozzles, the process proceeds to step S220. Select one of the undetected nozzles.
[0073]
Next, in step S230, 20 ink droplets are ejected from the selected nozzle at a time interval of 10 ms, and in step S240, the ink-side electrode 8 (8 ′, 8 ″) is simultaneously ejected with the final ink droplet ejection. In step S250, the measured potential is compared with a predetermined reference value, and as a result, if the measured potential is equal to or higher than the reference value, the process proceeds to step S260, and the nozzle is ejected. If it is determined that it is possible and the measured potential is less than the reference value, the process proceeds to step S270, and the nozzle is determined to be non-ejection (non-ejection).
[0074]
When the process of step S260 or step S270 ends, the process returns to step S210, and the above process is repeated for all nozzles.
[0075]
Next, details of determining the non-ejection compensation method in step S300 will be described.
[0076]
FIG. 7 is a flowchart showing details of determining the non-ejection compensation method.
[0077]
First, in step S310, it is checked whether there is a nozzle for which the non-ejection compensation method has not been determined for the ink ejection nozzle of the recording head 5. If it is determined that there are no undetermined nozzles and all the nozzles have been determined, the non-ejection compensation method determination process ends. If it is determined that there are still undetermined nozzles, the process proceeds to step S320. Proceed and select one of the undetermined nozzles.
[0078]
Next, in step S330, it is checked whether or not the selected nozzle can be discharged. This determination is based on the processing result of step S260 or step S270 described above. If the selected nozzle is a dischargeable nozzle, the process returns to step S310. However, if the selected nozzle is a non-dischargeable nozzle, the process proceeds to step S340, and the nozzles on both sides of the corresponding nozzle are discharged. Confirm whether it is possible, and determine the non-discharge compensation method accordingly.
[0079]
The non-ejection compensation method is determined as follows.
[0080]
If both of the adjacent nozzles are unable to eject, the process proceeds to step S350, and the recording medium (paper) is shifted in the sub-scanning direction in the portion where the recording density generated due to the ejection impossible nozzle is low. The non-ejection compensation method is determined so that non-ejection compensation is performed by overwriting with a nozzle capable of ejection.
[0081]
If only one of the adjacent nozzles can be ejected, the process proceeds to step S360, and the non-ejection compensation method is performed so that the nozzle of interest is ejected by the ejectable adjacent nozzle. To decide.
[0082]
Furthermore, when both of the adjacent nozzles can discharge, the process proceeds to step S370, and the non-discharge compensation method is determined so that the discharge of the nozzle of interest is performed by the dischargeable adjacent nozzle. To do. In this case, since compensation discharge is performed by the two nozzles on both sides, each nozzle is responsible for half of the compensation amount. Accordingly, each nozzle controls the ink discharge amount to be compensated by drop modulation or the like.
[0083]
In addition, although ink droplets adhere to a position slightly deviated from the original position on the recording medium by the processing in steps S360 and S370, the recording resolution of the recent recording head is very high and is as narrow as about one nozzle. The deviation of the recording position caused by the interval can be ignored in practice.
[0084]
When any of the processes of step S350, step S360, or step S370 ends, the process returns to step S310, and the above process is repeated until the determination process is performed for all the nozzles.
[0085]
Now, the recording operation in step S400 is executed reflecting the non-ejection compensation method determination method determined in step S300. At this time, for the nozzle that is determined to be undischargeable in step S200, power is not supplied to the heater that is an electrothermal conversion element provided in the nozzle.
[0086]
Therefore, according to the embodiment described above, even if the nozzle is determined to be unable to eject, when a heater is turned on, a very small amount of ink is actually ejected, so power is supplied to such a nozzle. By not performing the recording, it is possible to prevent the recording image quality from being deteriorated due to minute ink ejection.
[0087]
Further, since power is not supplied to the heaters of the nozzles that cannot be ejected due to causes other than the heater not operating (for example, ink clogging), wasteful power consumption can be suppressed. Furthermore, with such power supply control, it is no longer necessary to repeatedly supply power to the heaters of nozzles that are unable to discharge due to causes other than the heater not operating, preventing the heater from being damaged and resulting from the damage. The occurrence of various troubles can be prevented.
[0088]
[Other Embodiments]
In the above-described embodiment, compensation for non-ejection of ink has been described, but in this embodiment, variation in ink droplet amount (hereinafter referred to as “ejection amount”) for each nozzle and deviation from a design value are also compensated. An example to be performed will be described.
[0089]
The overall configuration and operation of the ink jet recording apparatus and the recording head, the presence / absence of ejection of ink droplets from the recording head, and the method for detecting the size of the ink droplets are the same as those in the above-described embodiment, and thus description thereof is omitted. To do.
[0090]
Next, processing using detection of whether ink droplets are ejected or not according to this embodiment will be described with reference to the flowcharts shown in FIGS. First, an overview of the whole will be described first, and then details of each process will be described. In the flowcharts of FIGS. 8 to 10, the same processing steps as those already described with reference to FIGS.
[0091]
FIG. 8 is a flowchart showing the overall flow of a recording operation using detection of whether or not ink droplets are ejected.
[0092]
The recording operation is started when a recording signal is input to the ink jet recording apparatus.
[0093]
First, in step S101, it is checked whether it is necessary to measure the ink discharge amount. From the viewpoint of measurement accuracy, it is desirable to detect whether or not ejection is possible for each recording, but in this embodiment, ejection is performed only in recording immediately after performing recovery operation in consideration of ink consumption associated with ink ejection amount measurement. Measure quantity. If it is determined that it is necessary to measure the ink discharge amount, the process proceeds to step S201, where the ink discharge amount measurement, which will be described in detail later, and the determination of the discharge amount compensation amount are performed in step S301.
[0094]
In step S400, a recording operation is performed in which ink droplets are sprayed onto the recording medium while performing discharge amount compensation in accordance with the discharge amount compensation amount determined in step S301.
[0095]
On the other hand, if it is determined in step S101 that it is not necessary to measure the ink discharge amount, the process skips step S201 and step S301, proceeds to step S400, and measures the previous ink discharge amount. The recording operation is performed while compensating the ejection amount in accordance with the determined ejection amount compensation method.
[0096]
Next, details of the ink discharge amount measurement in step S201 will be described.
[0097]
FIG. 9 is a flowchart showing details of the ink discharge amount measurement process.
[0098]
First, in step S211, it is checked whether there is a nozzle whose ejection amount is not measured for the ink ejection nozzles of the recording head 5. Here, if it is determined that there are no unmeasured nozzles and detection for all nozzles is completed, the ink amount measurement process is terminated. If it is determined that there are still unmeasured nozzles, the process proceeds to step S221. Select one of the unmeasured nozzles.
[0099]
Next, the processes of steps S230 to S250 described above are executed according to a voltage pattern of an electric signal applied to a predetermined heater (hereinafter referred to as a standard drive pattern). As a result, if the measured potential is equal to or higher than the reference value, the process proceeds to step S261, and the discharge amount-potential table stored in the ROM 1702 is referred to. The amount of discharge is determined. On the other hand, if the measured potential is less than the reference value, the process proceeds to step S271, and the discharge amount of the nozzle is determined to be “0”.
[0100]
When the process of step S262 or step S271 ends, the process returns to step S211 and the above-described process is repeated for all nozzles.
[0101]
Next, details of the discharge amount compensation amount determination processing in step S301 will be described.
[0102]
FIG. 10 is a flowchart showing details of determining the discharge amount compensation amount.
[0103]
First, in step S298, it is checked whether there is a nozzle whose ejection amount measured for the ink ejection nozzle of the recording head 5 is a predetermined threshold value or less. If it is determined that there is no such nozzle, the process proceeds to step S302. If it is determined that there is a nozzle whose ink discharge amount is equal to or smaller than a predetermined threshold, the process proceeds to step S299, and such a nozzle is used. Is determined as being impossible to discharge, and the non-discharge compensation method determination process in step S300 described above is executed. Thereafter, the process proceeds to step S302.
[0104]
In step S302, it is checked whether there is a nozzle whose ejection amount compensation amount has not been determined for the ink ejection nozzles of the recording head 5. If it is determined that there are no undetermined nozzles and the compensation amount for all the nozzles has been determined, this process ends. If it is determined that there are still undetermined nozzles, the process proceeds to step S303, Select one of the decision nozzles.
[0105]
Next, in step S304, a table indicating the relationship between the discharge amount corresponding to the above-described standard drive pattern and the voltage pattern of the electrical signal applied to the heater in order to keep the discharge amount of the selected nozzle at the design value (also this table). A voltage pattern (referred to as a heater driving pattern) of an electric signal applied to the heater is determined using the data stored in the ROM 1702. The determination of such a heater drive pattern means that a compensation amount for ink ejection has been determined.
[0106]
Thereafter, the process returns to step S302, and the above-described process is repeated for the nozzles whose discharge amount has not been determined.
[0107]
Now, the printing operation in step S400 is executed by reflecting the discharge amount compensation amount determined in step S301. At this time, for a nozzle that is determined to be undischargeable in step S299, power is not supplied to a heater that is an electrothermal conversion element provided in the nozzle.
[0108]
Therefore, according to the above-described embodiment, it is possible to prevent the recording image quality from being deteriorated due to minute ink ejection by not supplying power to the heater of the nozzle that ejects only a small amount of ink below the reference. . Further, since the discharge amount compensation amount is determined for each nozzle even for nozzles whose ink discharge amount is not less than the reference value, there is no discharge amount variation for each nozzle, and high-quality image recording is possible.
[0109]
In addition, the same effect as achieved in the above-described embodiment can be obtained.
[0110]
Further, in the above embodiment, the liquid droplets ejected from the recording head are described as ink, and the liquid stored in the ink tank is described as ink. However, the storage object is limited to ink. It is not a thing. For example, a treatment liquid discharged to the recording medium may be accommodated in the ink tank in order to improve the fixability and water resistance of the recorded image or to improve the image quality.
[0111]
The above embodiment includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for performing ink discharge, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.
[0112]
As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. 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, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recorded information and applying a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording head This is effective because film boiling occurs on the heat acting surface of the liquid, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. When the drive signal is pulse-shaped, the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve the discharge of liquid (ink) with particularly excellent responsiveness.
[0113]
As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.
[0114]
As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, the liquid path, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an opening that absorbs a pressure wave of thermal energy is discharged to a plurality of electrothermal transducers. A configuration based on Japanese Patent Laid-Open No. 59-138461 disclosing a configuration corresponding to each part may be adopted.
[0115]
Furthermore, 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 satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration or a configuration as a single recording head formed integrally may be used.
[0116]
In addition to the cartridge-type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being attached to the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.
[0117]
In addition, it is preferable to add recovery means, preliminary means, and the like for the recording head to the configuration of the recording apparatus described above because the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.
[0118]
Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.
[0119]
In the embodiment described above, the description is made on the assumption that the ink is a liquid, but it may be an ink that is solidified at room temperature or lower, or an ink that is softened or liquefied at room temperature, Alternatively, the ink jet method generally controls the temperature of the ink so that the viscosity of the ink is within a stable discharge range by adjusting the temperature within a range of 30 ° C. or higher and 70 ° C. or lower. It is sufficient if the ink sometimes forms a liquid.
[0120]
In addition, it is solidified in a stand-by state in order to actively prevent temperature rise by heat energy as energy for changing the state of ink from the solid state to the liquid state, or to prevent ink evaporation. Ink that is liquefied by heating may be used. In any case, by applying heat energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case of using ink having the property of being liquefied for the first time. In such a case, the ink is held as a liquid or solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260, It is good also as a form which opposes with respect to an electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.
[0121]
In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like, and a transmission / reception function are provided as an image output terminal of an information processing apparatus such as a computer or the like. It may take the form of a facsimile machine.
[0122]
【The invention's effect】
As described above, according to the present invention, there is an effect that it is possible to detect whether or not ink droplets are ejected at a higher speed and the size of the ink droplets.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus according to a representative embodiment of the present invention.
FIG. 2 is a diagram schematically showing a cross section of the recording head 5 during a recording operation taken along a plane perpendicular to the main scanning direction with elements of an attached electric circuit added thereto.
FIG. 3 is a diagram schematically showing the section of the recording head 5 shown in FIG. 2 cut along the sub-scanning direction with elements of an attached electric circuit added thereto.
FIG. 4 is a block diagram illustrating a configuration of a control circuit of the ink jet recording apparatus.
FIG. 5 is a flowchart illustrating an overall flow of a recording operation using detection of whether or not ink droplets are ejected.
FIG. 6 is a flowchart showing details of discharge availability detection.
FIG. 7 is a flowchart showing details of determination of a non-ejection compensation method.
FIG. 8 is a flowchart illustrating an overall flow of a recording operation using detection of whether or not ink droplets are ejected.
FIG. 9 is a flowchart showing details of an ink ejection amount measurement process.
FIG. 10 is a flowchart showing details of determining a discharge amount compensation amount.
[Explanation of symbols]
1 Paper feed roller
2 recording media
3 Main scanning guide
4 Carriage
5 Recording head
6 Counter electrode
7,7 ', 7 "ink
8,8 ', 8 "electrode
9,9 ', 9 "resistance
10, 10 ', 10 "terminals
11 Power supply
12 ground
13 nozzles
14 Heater
15 Ink droplet

Claims (1)

An inkjet recording head;
Scanning means for reciprocating the inkjet recording head in a first direction;
Transport means for transporting the recording medium in a second direction different from the first direction to the position of recording by the recording head;
A first electrode provided in the ink jet recording head and electrically connected to the ink;
When the recording medium is transported to the recording position by the transporting means , the second electrode is provided at a position opposite to the first electrode with the recording medium sandwiched therebetween ,
A resistor,
Power supply,
The capacitor formed by the first electrode and the second electrode, the resistor, and the power supply constitute a closed circuit, and the recording medium includes the first electrode and the second electrode And a potential difference between both ends of the resistor is measured when ink is ejected to the recording medium by the ink jet recording head .

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