JP2002264357A - Ink jet printer and method for detecting discharge absence of printing head for the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the accuracy for detecting an unrecoverable discharge absence state in an ink jet printer which carries out printing to a printing medium with the use of a printing head having a plurality of nozzles for discharging ink, and which has a discharge detecting means for detecting an ink discharge/discharge absence state for each of the plurality of nozzles. SOLUTION: The number of discharge absence nozzles detected by a previous detection operation is compared with the number of discharge absence nozzles detected newly (S2). When the number of the discharge absence nozzles increases, the discharge absence is judged as caused by a removable temporary factor. After a recovery process (S3) is executed, the detection operation is carried out again (S11), and the result is stored (S4).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing apparatus for forming an image using a print head in the form of an ink jet head for discharging ink onto a print medium such as paper, and a non-discharge determination method for the print head for the apparatus. It is about.

[0002]

2. Description of the Related Art Paper, cloth,
An inkjet printing system that prints on print media such as plastic sheets and OHP sheets is one type of non-impact printing system that performs high-density and high-speed printing operations with low noise. Is possible.

[0003] As a conventional ink jet printing apparatus, there is an apparatus having means for detecting non-ejection of ink from an ejection port provided in a print head. In such an ink jet printing apparatus, a nozzle that has fallen into a non-discharge state based on the result of a single non-discharge detection operation (hereinafter, unless otherwise specified, a discharge port or a liquid path and an ink discharge communicating therewith). By displaying or storing information relating to the elements that generate the energy used, the printhead can be used for processing such as a printhead failure determination process.

[0004] In addition, the ink jet printing apparatus may cause non-ejection due to insufficient filling of ink in a liquid path or non-ejection due to increase in viscosity of ink near the ejection port or adhesion of dust. In general, a recovery processing unit for forcibly discharging the ink from the ink discharge port is provided in order to remove the cause of the discharge failure or non-discharge and maintain the discharge performance in a good condition.

[0005]

In the non-ejection detection operation,
Not only is irrecoverable non-ejection due to nozzle failure or the like, which is the primary purpose, but also temporary non-ejection due to removable factors detected. Therefore, in the determination based on only one non-ejection detection operation, even in the latter case where the recovery can be performed by the operation of the recovery unit, there is a possibility that the processing may be performed assuming that an unrecoverable nozzle failure has occurred.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the detection accuracy of non-recoverable non-discharge nozzles, and to appropriately reflect such problems in measures against non-discharge nozzles.

[0007]

For this purpose, the present invention provides:
In an ink jet printing apparatus that performs printing on a print medium using a print head having a plurality of discharge ports for discharging ink, it is determined whether or not ink is normally discharged for each of the plurality of discharge ports. Discharge detection means for detecting the discharge state, and storage means for storing information on the discharge state detected by at least one past detection operation of the discharge detection means.

Here, it is possible to provide a means for presenting information relating to the ejection port whose ejection state cannot be recovered based on the information stored in the storage means.

According to the present invention, there is provided a method for determining non-ejection of a print head which is used in an ink jet printing apparatus and has a plurality of ejection ports for ejecting ink. A discharge detecting step of detecting a discharge state of whether or not the liquid is discharged, and based on information stored in storage means for storing information relating to a discharge state detected by at least one previous discharge detection step. Presenting information about the ejection port from which the ejection state cannot be recovered.

In the above, there is provided a non-discharge countermeasure or step for performing a process of replacing a discharge port whose recovery state cannot be recovered with another discharge port or a process of prompting replacement of the print head based on the presented information. Can be obtained.

In any one of the above-mentioned embodiments, the apparatus further includes a recovery processing unit for performing a recovery process for obtaining a good ink discharge state from the plurality of discharge ports. Comparing the information indicating the ejection state newly detected by the ejection detection means or the process, and comparing or judging whether or not there is a predetermined change between the information; and based on the result of the judgment. Control means or a step of determining whether to activate the recovery processing means.

Here, the control means or the step activates the recovery processing means when it is determined that there is the predetermined change, and performs the ejection detection after the recovery processing.
Thus, information indicating the detected ejection state can be stored in the storage unit.

[0013] When the comparison determination means or step recognizes that the number of ejection ports in which non-ejection has occurred has increased as a result of the comparison, the comparison determination means or step determines that the predetermined change has occurred. Can be.

Alternatively, the comparison determining means or step may determine that the number of discharge ports in which non-discharge has occurred has increased by a predetermined number or more as a result of the comparison, When it is recognized that the ratio of the number of outlets to the total number of outlets is equal to or greater than a predetermined ratio, it may be determined that the predetermined change exists.

Alternatively, the comparison determination means or step may determine that the predetermined change has occurred when recognizing that the information indicating the position of the discharge port where the non-discharge has occurred has changed. Can be.

Alternatively, the comparison judging means or step recognizes that the information indicating the position of the discharge port where the non-discharge has occurred has changed as a result of the comparison, and newly performs the non-discharge When the number of ejection ports detected is recognized as being equal to or greater than a predetermined number, or the ratio of the number of ejection ports in which non-ejection is newly detected by the current detection operation to the total number of ejection ports is equal to or greater than a predetermined rate. When it is recognized that there is the predetermined change.

In the above, the recovery means may include means for forcibly discharging ink from the plurality of discharge ports, and the means for forcibly discharging ink from the plurality of discharge ports. Or a means for pressing the ink supply system leading to the print head.

Further, the discharge detecting means or step comprises:
Means for optically or electrically detecting the discharge state of the discharge port may be used.

In addition, the storage means may include a nonvolatile memory.

[0020] In addition, the print head may include a heating element for generating heat energy for causing film boiling of the ink as energy used for discharging the ink.

In the present specification, the term “print” means not only the case where significant information such as characters and figures are formed, but also the meaning that it can be perceived by humans irrespective of significance or insignificance. Irrespective of whether or not the image is formed, a case where an image, a pattern, a pattern or the like is widely formed on a print medium or a case where the medium is processed is also referred to.

The term "print medium" refers to not only paper used in general printing apparatuses but also a wide range of cloths, plastic films, metal plates, etc. that can accept ink ejected by a head. Shall be.

Further, "ink" refers to the above "print"
Is a liquid that can be applied to a print medium to form an image, a pattern, a pattern, or the like, or to process the print medium.

In addition, the term "non-ejection" refers to not only a state where ink is not actually ejected from a nozzle but also a state where a predetermined amount of ink is not properly ejected in a predetermined direction, that is, a state of so-called ejection failure. .

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

(Overall Configuration) FIG. 1 shows an example of a main configuration of an inkjet printing apparatus (inkjet printer) including a mechanism for detecting non-ejection. The detection of non-discharge is to detect and detect the discharge state of whether or not the ink is normally discharged. Hereinafter, simply, “discharge detection”, “non-discharge detection” or “discharge state” Detection"
This will be described.

The print head 113 performs a printing operation when moving (main scanning) in the direction of arrow 2 (forward direction) indicated by a solid line, and also when moving in the direction of arrow 3 (returning direction) indicated by a broken line. Perform print operation. This print head 1
Reference numeral 13 may be, for example, a type that ejects ink using thermal energy. That is, an electrothermal converter (ejection heater) that generates thermal energy in response to energization is provided corresponding to the ejection port, and the heat energy applied by the ejection heater causes film boiling in the ink. Printing can be performed by discharging ink from the discharge port by using the pressure of the generated bubble.

Reference numeral 4 denotes a print medium, such as paper or cloth, which is intermittently sub-scanned (paper feed) in the direction of arrow 5. The hatched portion 4a has been printed, while the non-hatched portion 4b is to be printed. To detect the position of the head in the main scanning, a scale of a linear encoder 7 fixed to the apparatus main body by a position reading unit (pickup unit) 6 attached to a carriage (not shown) on which the head is mounted. Can be read. The encoder 7 serves as a reference when performing an image printing operation, and is provided for the purpose of realizing ideal landing of ink on the print medium 4 and improving image quality.

The dashed line indicated by reference numeral 111a is
A light beam (for example, a laser beam) narrowly outputted from 1 and the ink droplets 113a, 113a,
.. Are discharged. The light beam 111a is received by the light receiving unit 112, and the light intensity is detected. Reference numeral 11 denotes a member that receives ink ejected for ink droplet detection during the processing.

Reference numeral 114 denotes a recovery processing unit, which is a cap member for capping the discharge port forming surface of the print head, a suction means such as a pump for forcibly discharging ink from the discharge ports by sucking the inside of the cap, and a discharge unit. It is composed of a member for wiping the outlet forming surface.

In the drawing, only one print head is shown for discharging one color (for example, black (K)) ink, but other print heads for cyan (C),
A plurality of print heads may be provided corresponding to each color such as magenta (M) and yellow (Y). Also, in addition to providing print heads for each color like that,
A nozzle group that ejects K ink and a nozzle group that ejects Y, M, and C inks may be arranged side by side in one print head, or a print head that has a nozzle group that ejects K ink and Y , M, and C may be independently juxtaposed with a print head having a nozzle group for discharging ink.

Further, the print head may be configured integrally with an ink tank serving as an ink supply source, or may receive ink supply from an ink tank provided at another portion of the apparatus via a tube or the like. When the print head and the ink tank are integrated, the cartridge may be in the form of a cartridge that can be attached to and detached from the apparatus main body (carriage), and both can be separated so that, for example, only the ink tank can be replaced alone. May be done.

(Configuration of Control System of Apparatus) FIG. 2 is a configuration example of a control system of the ink jet printing apparatus shown in FIG. In FIG. 1, reference numeral 12 denotes a print head control circuit for electrically controlling the print head 113 and ejecting ink in accordance with image data. An ejection detection sensor 13 detects an ink ejection state.
And a light receiving unit 112. 14 is a discharge detection sensor 13
Is a discharge detection control device that replaces a signal from the nozzle with a discharge state signal for each nozzle.

A main scanning motor 16 serves as a driving source for scanning the print head 113 in the directions of arrows 2 and 3 shown in FIG. 1, and a sub-scanning motor 17 serves as a driving source for conveying the print medium 4. , 18 are recovery operation motors serving as a drive source for operating the recovery processing unit 114. Reference numeral 19 denotes a recovery operation actuator for driving the recovery processing unit 114, and reference numeral 20 denotes a recovery operation sensor for detecting an operation state of the recovery processing unit 114. 21
These are mechanism control circuits that control and manage various motors, actuators, and sensors.

A CPU 15 controls the overall operation of each unit in accordance with a processing procedure described later.
This is a ROM that stores a program corresponding to a processing procedure executed by U15. Reference numeral 23 denotes a RAM having an area for temporarily storing parameters while the CPU 15 executes the processing procedure, and reference numeral 24 denotes a nonvolatile memory such as an EEPROM for storing the ejection detection state even when the apparatus power is turned off.

Reference numeral 25 denotes an operation / display unit, for example, when power is turned on,
It has a switch for the user to perform required operations such as online / offline setting with the host device H, and a display for presenting the device status and the like to the user. The host device H serves as a supply source of image data to the inkjet printing apparatus, and is a computer that performs creation and processing of data such as images related to printing, a reader unit for reading images, or It may be in the form of a digital camera or the like. Image data, other commands,
Status signals and the like are transmitted and received via an interface (I / F) 26.

(Embodiment of non-ejection nozzle information storage processing)
In the above configuration, the main scanning motor 16 is driven to move the print head 113 to the detection range of the ejection detection sensor 13 (FIG. 1).
From the print head control circuit 12 to the print head 113
, The ink ejection operation from the nozzles is sequentially performed, and based on the output of the ejection detection sensor 13 and the ink ejection timing signal from the print head control circuit 12, the ejection detection control circuit 14 controls the ejection state of each nozzle. The information is converted into information (non-ejection nozzle information) and the information is temporarily stored in the RAM 23.

Here, conventionally, as shown in FIG. 3, after the ejection detection processing for all the nozzles (step S1) is performed once, the ejection state information for each nozzle is immediately stored (step S4). .

On the other hand, in this embodiment, after the ejection detection process for all the nozzles is performed once,
4 and the non-ejection nozzle information detected this time and temporarily stored in the RAM 23 is compared. Here, if the predetermined change is not recognized between the two information, the non-ejection nozzle information temporarily stored in the RAM 23 is stored in the EEPROM 24, and the process ends.

On the other hand, when a predetermined change is found between the two information, the main scanning motor 16 is driven to move the print head 113 to the position of the recovery processing unit 114, and the output of the recovery operation sensor 20 is monitored. While operating, the recovery operation actuator 19 and the recovery operation motor 18 are operated. Accordingly, when non-ejection occurs due to temporary clogging of the nozzles of the print head or a state in which ink is not filled, those factors are eliminated.

After the completion of the recovery processing, the main scanning motor 1
6, the print head is moved to the detection range of the ejection detection sensor 13, a signal is sent from the print head control circuit 12 to the print head 113, and the ink ejection operation from the nozzles is sequentially performed.
Is converted into ejection state information (non-ejection nozzle information) for each nozzle in the ejection detection control circuit 14 based on the output of the print head control circuit 12 and the ink ejection timing signal from the print head control circuit 12, and the information is converted to the current non-ejection nozzle information. As EE
It is stored in the PROM 24.

Next, various examples of the non-ejection nozzle information storage processing procedure will be described.

FIG. 4 shows a first example. In the figure, step S1 is the above-described ejection detection operation, and step S2 is a comparison determination operation between the previous non-ejection nozzle information and the current non-ejection nozzle information. In this example, the number of currently detected non-ejection nozzles is It is determined whether the number is larger than the number of non-ejection nozzles.

If it is determined that the current number of non-ejection nozzles has increased with respect to the number of non-ejection nozzles detected in the previous ejection detection operation, the ejection recovery process (step S
After performing 3), the ejection detection operation is performed again (step S11).
Is performed, and the non-ejection nozzle information obtained therefrom is stored (step S4). On the other hand, as a result of comparing the number of non-ejection nozzles, the
Alternatively, if it has decreased, the non-ejection nozzle information obtained immediately before (this time) is stored (step S4).

FIG. 5 shows a second example of the non-ejection nozzle information storage processing procedure. In this example, the ejection detection operation (step S1)
Is performed, as the non-ejection nozzle information, a comparison between the information indicating the position of the non-ejection nozzle stored last time and the information indicating the position of the current non-ejection nozzle measured immediately before (step S5). is there.

FIG. 6 is a diagram for explaining a change in information indicating the position of a non-ejection nozzle. Here, the schematically illustrated white nozzles 32 on the print head 113 indicate that normal ink ejection is performed, and the hatched nozzles 33 indicate that non-ejection has been detected. Is different between the previous measurement and the current measurement. Therefore, by storing the discharge / non-discharge detection state of each nozzle corresponding to the nozzle position, the information indicating the position of the previous non-discharge nozzle and the information indicating the current position of the non-discharge nozzle can be compared. It can be performed.

As a result of the comparison, when it is determined that the information has changed, that is, when it is determined that the nozzles that did not discharge the previous time and the current time are different, the discharge recovery processing (step After performing S3), the ejection detection operation (Step S11) is executed again, and the information indicating the position of the non-ejection nozzle obtained therefrom is stored (Step S4).
On the other hand, as a result of the comparison, when there is no change between the information indicating the position of the previous non-ejection nozzle and the information indicating the current position of the non-ejection nozzle (there is a change, but the number of non-ejection nozzles has decreased. Case may be included), the information indicating the position of the non-ejection nozzle obtained immediately before is stored in the detection result storing operation (step S
Store in 4).

According to this example, the storage process can be performed more accurately than in the first example in which the number of non-ejection nozzles is compared between the previous time and the current time. That is, for example, as shown in FIG. 6, when the nozzle in which the non-ejection is detected is different between the previous measurement and the current measurement, the number of the non-ejection nozzles does not change, so the processing of the first example is performed. Now, the recovery process (step S
Do not shift to 3). On the other hand, in the second example, the recovery process is performed by comparing the information indicating the position of the previous non-ejection nozzle with the information indicating the current position of the non-ejection nozzle,
This is because the ejection detection operation is performed again after the non-ejection due to a temporary factor is removed, and the non-ejection nozzle information obtained therefrom is stored.

FIG. 7 shows a third example of the non-ejection nozzle information storage processing procedure. This example corresponds to step S2 in the first example.
Is a comparison operation of comparing the difference between the previous number of non-ejection nozzles and the current number of non-ejection nozzles with a predetermined value (step S
6), and if it is determined that the number of non-ejection nozzles has increased beyond a predetermined value, a recovery process (step S3)
The following processing is performed. Other procedures are the same as in the first example.

FIG. 8 shows a fourth example of the non-ejection nozzle information storage processing procedure. This example corresponds to step S2 in the first example.
Is replaced with an operation (step S7) of comparing the ratio of the difference between the previous number of non-ejection nozzles and the current number of non-ejection nozzles to the total number of nozzles with a predetermined ratio. If it is determined, the process after the recovery process (step S3) is performed. Other procedures are the same as in the first example.

FIG. 9 shows a fifth example of the non-ejection nozzle information storage processing procedure. This example corresponds to step S5 in the second example.
Is replaced with step S8, and in comparing the information indicating the position of the previous non-ejection nozzle with the information indicating the current position of the non-ejection nozzle, the content of the detection information regarding the ejection / non-ejection is The number of nozzles changed is taken into account. In other words, when a change in the information indicating the position of the non-ejection nozzle is determined, if the number of nozzles for which non-ejection is newly detected this time is equal to or greater than a predetermined value, the processing after the recovery processing (step S3) is performed. It was made.

FIG. 10 shows a sixth example of the non-ejection nozzle information storage processing procedure. This example corresponds to step S in the second example.
In step S8, the comparison determination operation of No. 5 is replaced with the information indicating the position of the previous non-ejection nozzle and the information indicating the current position of the non-ejection nozzle. The ratio of the changed number of nozzles to the total number of nozzles is taken into account. That is, when a change in the information indicating the position of the non-ejection nozzle is determined, if the ratio of the number of newly detected non-ejection nozzles to the total number of nozzles is equal to or more than a predetermined ratio, the recovery process (step S3) ) The following processing is performed.

(Embodiment for Non-ejection Handling) The non-ejection nozzle information stored by the above-described processing can be reflected in the following processing.

For example, the non-ejection nozzle information is displayed on the display of the operation / display unit 25 of the printing apparatus or the display device of the host apparatus in association with the nozzle position.
By presenting appropriate information, it is possible to provide the user with a judgment on whether or not the print head needs to be replaced. In addition, in order to facilitate the necessity determination, a test pattern for confirming how much image quality deteriorates may be formed by a print head.

Further, based on the non-ejection nozzle information, processing for replacing the non-ejection nozzle with another normal ejection nozzle to perform complementary printing, for example, by appropriately changing the sub-scanning amount after the main scanning (print medium conveyance amount), The processing for performing complementary printing in the next main scan may be performed such that the normal ejection nozzle faces the area on the print medium that has opposed the non-ejection nozzle. Here, in an apparatus that performs so-called multi-pass printing, the number of passes may be changed as appropriate so that normal ejection nozzles face each other. Such complementary print processing is performed by the CPU 15 based on the non-ejection nozzle information.
May be implemented automatically by the device under the control of
The processing may be performed after the judgment of the user or the setting using the switch of the operation / display unit 25 or the input device on the host device side.

(Others) In the above-described embodiment, only the previous non-ejection nozzle information is used as a comparison target for the current non-ejection nozzle. Good. That is, for example, the non-discharge nozzle information accumulated and stored may be analyzed and reflected in subsequent processing (recovery processing or non-discharge countermeasure processing).

Further, in the above-described embodiment, the light emitting section 111 for irradiating a light beam in a direction different from the arrangement direction of the plurality of discharge ports and in a direction crossing the trajectory of the ink;
Using a discharge detection sensor 13 having a light receiving unit 112 for receiving the irradiated light beam, ink is sequentially discharged from a plurality of discharge ports while moving a print head between the light emitting unit and the light receiving unit. The ejection state information (non-ejection nozzle information) for each nozzle is obtained based on the acceptance state of the light beam in the unit 112.

However, the form of the ejection detection sensor or the ejection state information acquiring means for each nozzle is not limited to the above embodiment, but may be various. For example, a light emitting unit that irradiates a light beam in the same direction as the arrangement direction of the plurality of discharge ports and a discharge detection sensor having a light receiving unit that receives the irradiated light beam are used. The print head may be stopped in between to sequentially eject ink from the plurality of ejection openings, and ejection state information (non-ejection nozzle information) for each nozzle may be obtained based on the acceptance state of the light beam at the light receiving section. . Alternatively, a predetermined test pattern may be formed by a print head, and the test pattern may be read by an optical sensor to obtain ejection state information (non-ejection nozzle information) for each nozzle.

Further, in addition to those using such optical detecting means, electric detecting means can be used. For example, in a print head that ejects ink using thermal energy, if nozzles are clogged and ink is not ejected, thermal energy is accumulated and the temperature rises. It is also possible to provide a thermistor-type temperature sensor in units of nozzles and verify the output of the thermistor at the time of driving the nozzle to obtain ejection state information (non-ejection nozzle information) for each nozzle.

In the above-described embodiment, the recovery member includes the cap member for capping the discharge port forming surface of the print head, and a suction unit such as a pump for forcibly discharging ink from the discharge ports by sucking the inside of the cap. Although the processing unit is used, a recovery unit having means for forcibly discharging ink from the discharge port by pressurizing the ink supply system reaching the print head may be used.

In addition, in the above-described embodiment, the non-ejection nozzle information is stored in the EEPROM-type nonvolatile memory for comparison in the next process. This is because it is effective in a case where the comparison is performed with the power supply off period interposed therebetween. However, if only comparison within the ON period of the device power supply is sufficient, such a nonvolatile memory does not necessarily have to be used. The non-ejection nozzle information storage processing including the above-described ejection detection and recovery processing can be started at an appropriate timing.

In addition, the present invention is applicable not only to an ink jet printing apparatus using a print head of a type in which ink is discharged by utilizing thermal energy generated by a discharge heater, but also to other energy, for example, an electromechanical conversion such as a piezo element. It is needless to say that the present invention can be applied to an ink jet printing apparatus using a print head in which ink is ejected using mechanical energy generated by the body.

The form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an image data supply apparatus such as a computer, a scanner, and a digital camera, but also, for example, a copying machine in which a scanner and a printer are integrated, A facsimile apparatus in which a data transmitting / receiving device and a printer are integrated, a word processor or an electronic typewriter having an integrated printer, or a digital camera having an integrated printer may be used.

[0064]

As described above, according to the present invention,
The non-ejection nozzle information obtained in the current measurement can be compared with the non-ejection nozzle information obtained in the past measurement, thereby improving the detection accuracy of non-recoverable non-ejection nozzles. That is, for example, when a predetermined change (increase in the number of non-ejection nozzles or change in information indicating the position of the non-ejection nozzle) is recognized, it is determined that there is a high possibility of a temporary ejection failure of the nozzle, and the recovery process is performed. Then, the ejection detection operation is executed again, and the non-ejection nozzle information obtained therefrom is stored as the current non-ejection nozzle information. Therefore, the detection accuracy of the non-recoverable non-discharge nozzle is improved, and it can be appropriately reflected in measures against non-discharge.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating an example of a configuration of a main part of an inkjet printing apparatus including a mechanism for detecting ejection failure according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a control system of the inkjet printing apparatus in FIG. 1;

FIG. 3 is a flowchart illustrating a conventional non-ejection nozzle information storage processing procedure;

FIG. 4 is a flowchart illustrating a first example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

FIG. 5 is a flowchart illustrating a second example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram for explaining a change in information indicating the position of a non-ejection nozzle to be compared in the second example shown in FIG. 5;

FIG. 7 is a flowchart illustrating a third example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

FIG. 8 is a flowchart illustrating a fourth example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

FIG. 9 is a flowchart illustrating a fifth example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

FIG. 10 is a flowchart illustrating a sixth example of a non-ejection nozzle information storage processing procedure according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 4 print medium 12 print head control circuit 13 discharge detection sensor 14 discharge detection control circuit 15 CPU 16 main scanning motor 17 sub-scanning motor 18 recovery operation motor 19 recovery operation actuators 20 recovery operation sensors 21 mechanism control circuit 22 ROM 23 RAM 24 EEPROM 25 Operation / display unit 26 Interface (I / F) 32 Normal ejection nozzle 33 Non-ejection nozzle 111 Light emitting unit 111a Light beam 112 Light receiving unit 113 Print head 113a, 113b, 113c Ink droplet 114 Recovery processing unit H Host device

Claims (27)

[Claims] 1. An ink jet printing apparatus for performing printing on a print medium using a print head having a plurality of discharge ports for discharging ink, wherein ink is normally discharged from each of the plurality of discharge ports. Discharge detection means for detecting whether or not the discharge state is present, and storage means for storing information relating to the discharge state detected by at least one past detection operation of the discharge detection means. Inkjet printing apparatus. 2. An ink jet printing apparatus according to claim 1, further comprising means for presenting information relating to an ejection port whose ejection state cannot be recovered based on the information stored in said storage means. 3. A non-discharge countermeasure means for performing a process of replacing an ejection port whose ejection state cannot be recovered with another ejection port or a process of urging replacement of the print head based on the presented information. The ink-jet printing apparatus according to claim 2, wherein: 4. A recovery processing unit for performing a recovery process for obtaining a good ink discharge state from the plurality of discharge ports, and information newly stored by the discharge detection unit and information stored in the storage unit. Compare with the information indicating the status,
Comparison determining means for determining whether there is a predetermined change between these pieces of information; and control means for determining whether to activate the recovery processing means based on a result of the determination. The inkjet printing apparatus according to any one of claims 1 to 3, wherein: 5. The control means activates the recovery processing means when it is determined that there is the predetermined change, and causes the ejection detection means to perform the detection operation after the recovery processing, whereby the detection operation is performed. The inkjet printing apparatus according to claim 4, wherein information indicating the detected ejection state is stored in the storage unit. 6. The comparison determining means, as a result of the comparison,
6. The ink jet printing apparatus according to claim 4, wherein when it is recognized that the number of ejection ports in which non-ejections have occurred has increased, the predetermined change is determined. 7. The comparison determining means, as a result of the comparison,
When it is recognized that the number of ejection ports in which non-ejection has occurred has increased by a predetermined number or more, or that the ratio of the number of ejection ports in which non-ejection has occurred to the total number of ejection ports is equal to or more than a predetermined ratio. 6. The ink jet printing apparatus according to claim 4, wherein it is determined that the predetermined change occurs in such a case. 8. The method according to claim 1, wherein the comparing and judging means judges that the predetermined change has occurred when recognizing that the information indicating the position of the ejection port where the non-ejection has occurred has changed. Item 6. The inkjet printing apparatus according to item 4 or 5. 9. The comparison / determination means, as a result of the comparison,
When it is recognized that the information indicating the position of the discharge port where the non-discharge has occurred has changed, and that the number of discharge ports in which the non-discharge has been newly detected by the current detection operation is equal to or more than a predetermined number. Or when it is recognized that the ratio of the number of discharge ports in which non-discharge is newly detected by the current detection operation to the total number of discharge ports is equal to or more than a predetermined ratio, it is determined that the predetermined change is present. The inkjet printing apparatus according to claim 4 or 5, wherein 10. The ink-jet printing apparatus according to claim 4, wherein said recovery means has means for forcibly discharging ink from said plurality of discharge ports. 11. The means for forcibly discharging the ink,
The ink-jet printing apparatus according to claim 10, further comprising a unit that sucks ink from the plurality of discharge ports or a unit that pressurizes an ink supply system that reaches the print head. 12. An ink jet printing apparatus according to claim 1, wherein said discharge detecting means includes means for optically or electrically detecting a discharge state of said discharge port. 13. An ink jet printing apparatus according to claim 1, wherein said storage means has a nonvolatile memory. 14. The print head according to claim 1, wherein the print head includes a heating element for generating heat energy for causing film boiling of the ink as energy used for discharging the ink. An inkjet printing apparatus according to any one of the above. 15. A non-discharge determination method for a print head used in an ink jet printing apparatus and having a plurality of discharge ports for discharging ink, wherein ink is normally discharged from each of the plurality of discharge ports. A discharge detection step of detecting whether or not the discharge state is determined, and a discharge state is determined based on information stored in storage means for storing information on the discharge state detected in at least one previous discharge detection step. 2. The non-ejection determination method for a print head for an ink jet printing apparatus according to claim 1, further comprising a step of presenting information relating to an ejection port that cannot be recovered. 16. A non-discharge countermeasure step for performing a process of replacing an ejection port whose ejection state cannot be recovered with another ejection port or a process of prompting replacement of the print head based on the presented information. The non-discharge determination method for a print head for an inkjet printing apparatus according to claim 15, wherein 17. The inkjet printing apparatus according to claim 17,
A recovery processing unit that performs recovery processing for obtaining a good ink discharge state from the plurality of discharge ports, and indicates information stored in the storage unit and a discharge state newly detected by the discharge detection step. Compare with the information,
A comparison determination step of determining whether there is a predetermined change between these pieces of information; and a control step of determining whether to activate the recovery processing means based on a result of the determination. 17. The method of determining non-ejection of a print head for an ink jet printing apparatus according to claim 15, wherein: 18. The control step, when it is determined that the predetermined change is present, activates the recovery processing means, and causes the ejection detection step to be performed after the recovery processing. 18. The method according to claim 17, wherein information indicating a discharge state is stored in the storage unit. 19. The comparison determining step is characterized in that, when it is recognized as a result of the comparison that the number of ejection ports in which non-ejection has occurred has increased, it is determined that the predetermined change has occurred. 19. The non-ejection determination method for a print head for an inkjet printing apparatus according to claim 17, wherein 20. The comparing and judging step, as a result of the comparison, when it is recognized that the number of ejection ports in which non-ejection has occurred has increased by a predetermined number or more, or in the case of ejection ports in which non-ejection has occurred. 19. The non-ejection of the print head for an ink jet printing apparatus according to claim 17, wherein when it is recognized that the ratio of the number to the total number of ejection ports is equal to or more than a predetermined ratio, the predetermined change is determined. Judgment method. 21. The method according to claim 21, wherein the comparing and judging step judges that the predetermined change has occurred when it is recognized that the information indicating the position of the ejection port where the non-ejection has occurred has changed. Item 19. The non-ejection determination method for a print head for an inkjet printing apparatus according to Item 17 or 18. 22. The comparison determining step, as a result of the comparison, recognizing that the information indicating the position of the discharge port where the non-discharge has occurred has changed, and newly detecting the non-discharge by the current detection operation. When it is recognized that the number of ejected outlets is equal to or greater than a predetermined number, or that the ratio of the number of orifices in which non-ejection is newly detected by the current detection operation to the total number of outlets is equal to or greater than a predetermined ratio. 19. The non-discharge determination method for a print head for an ink-jet printing apparatus according to claim 17, wherein it is determined that the predetermined change occurs in the case of the change. 23. A method according to claim 17, wherein said recovery means includes means for forcibly discharging ink from said plurality of discharge ports. . 24. The means for forcibly discharging the ink,
24. The method according to claim 23, further comprising: a unit that sucks ink from the plurality of discharge ports or a unit that pressurizes an ink supply system that reaches the print head. 25. A print for an ink jet printing apparatus according to claim 15, wherein said discharge detecting step uses a means for optically or electrically detecting a discharge state of said discharge port. Head ejection failure determination method. 26. The method according to claim 15, wherein the storage unit includes a nonvolatile memory. 27. The print head according to claim 15, wherein the print head has a heating element for generating heat energy for causing film boiling of the ink as energy used for discharging the ink. A non-discharge determination method for a print head for an inkjet printing apparatus according to any one of the above.