JP2000272116A - INK JET PRINTER WITH IMAGE READING DEVICE AND METHOD OF PROCESSING PRINT NOZZLE - Google Patents

Abstract

(57) [Summary] [Problem] When a print nozzle is clogged, a defective portion is correctly detected, a warning is displayed to a user, and maintenance of the nozzle clogging is automatically performed in some cases. Accordingly, it is possible to provide an apparatus and a method which can perform printing in a regular nozzle state without clogging and always obtain a stable and high-quality print sample. An ink nozzle of an inkjet printer A functions properly. An image data image processing unit 13 which prints a test pattern, reads image data of the print sample by the image reading device 1 and detects a defect of the ink nozzle 24 from the result.
If it is determined that there is a defective nozzle, a message is displayed to the user, or a cleaning operation is automatically performed. If the test print does not become good even after the cleaning operation, a message to replace the ink is sent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to detection and maintenance of a print nozzle function in an ink jet printer with an image reading device.

[0002]

2. Description of the Related Art Conventionally, a test pattern has been printed to check the print nozzles of ink jet printing, and a user has visually inspected a printed sample to determine whether or not a nozzle failure has occurred.

Further, a method is known in which a test pattern is read by an optical sensor installed on an ink jet printer carriage and a non-ejection nozzle is detected, as described in JP-A-10-258503.

[0004]

However, when visually judging a print sample, there is a difference depending on the user's subjectivity, and it is erroneously judged to be good despite nozzle clogging. There was a case.

In the case of the means described in Japanese Patent Application Laid-Open No. H10-258503, clogging occurs because it is vaguely detected whether nozzle clogging has occurred (ON / OFF). If it is detected that the nozzles are present (ON), all nozzles are cleaned. That is, since cleaning is also performed on portions that do not require cleaning, the ink is wastefully consumed, which is a problem because it is uneconomical. . In addition, it is necessary to newly provide an optical sensor which is not normally used and is used only when the user feels clogging of the print nozzles, which is a very inefficient device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. In the case where clogging of a print nozzle has occurred, a defective portion is detected correctly and a warning is displayed to a user. Provide an apparatus that automatically performs maintenance of nozzle clogging, enables printing in a nozzle state without clogging, and always obtains a stable, high-quality print sample, and a method of processing the nozzle. With the goal.

Further, it is possible to check for print nozzle defects even in the case of an ink head capable of expressing gradation for 1 dot printing, or in the case of an ink head using low-saturation ink. Also aim. .

It is another object of the present invention to complete the cleaning operation with a minimum required amount of ink and time.

It is another object of the present invention to provide a user with a message for replacing an ink head when a nozzle failure cannot be cleaned.

[0010]

The present invention has the following configuration to achieve the above object. The invention of claim 1 is
An image reading device that reads a document image by reflected light of light irradiated on a document placed on a document table and processes the image data, and discharges ink from print nozzles based on the image data to form an image on a recording medium. A first storage area for storing test image data for test printing, and a test printing of the test image data by the inkjet printer, wherein the test printing image A second storage area for storing test print image data read by the image reading device in association with a print nozzle or a nozzle group of the inkjet printer, and test print image data stored in the second storage area. Detection means for detecting a defective print nozzle or a nozzle group based on An image reading apparatus with an ink jet printer, characterized and.

According to a second aspect of the present invention, there is provided the ink jet printer with the image reading device according to the first aspect, further comprising a cleaning unit for cleaning a defective print nozzle or a nozzle group detected by the detection unit. .

According to a third aspect of the present invention, there is provided an image reading apparatus which reads a document image by reflected light of light radiated on a document placed on a document table and processes the image data, and a print nozzle based on the image data. A print nozzle processing method of an inkjet printer with an image reading device having an inkjet printer that ejects ink from the ink and prints an image on a recording medium, wherein a test printing step of printing a test pattern on a recording medium by the inkjet printer,
A test pattern reading step of reading the test pattern printed in the test printing step by the image reading device and processing the image data; and an image data of the test pattern reading step by a print nozzle of the inkjet printer. Alternatively, there is provided a storage step of storing the data in the storage unit in association with the nozzle group, and a failure detection step of detecting a defective print nozzle or a nozzle group by performing threshold processing on the image data stored in the storage unit. 1 is a print nozzle processing method for an inkjet printer with an image reading device.

According to a fourth aspect of the present invention, there is provided the print nozzle processing method for an ink jet printer with an image reading device according to the third aspect, wherein the test printing step is automatically performed based on a predetermined rule.

According to a fifth aspect of the present invention, the test printing step and / or the test pattern reading step are performed a plurality of times before the defect detecting step. This is a print nozzle processing method of the printer.

According to a sixth aspect of the present invention, the defect detecting step includes:
4. The print nozzle processing method for an ink jet printer with an image reading device according to claim 3, wherein the threshold value is changed according to the type of the test pattern to be printed.

The image reading apparatus according to claim 3, wherein the test printing step is performed only for a print nozzle or a nozzle group used for printing or used for printing. 1 is a method of processing a print nozzle of an inkjet printer provided with a print nozzle.

According to a further aspect of the present invention, there is provided a print nozzle process for an ink jet printer with an image reading device according to claim 3, further comprising a cleaning step of cleaning a defective print nozzle or a nozzle group detected in the detection step. Is the way.

According to a ninth aspect of the present invention, after the cleaning step, the test printing step is performed again, and if there is a defective print nozzle or nozzle group, a warning is issued to the user to replace the print nozzle or nozzle group. Claim 3
3. A print nozzle processing method for an ink jet printer with an image reading device according to (1).

According to the first aspect of the present invention, based on the test image data for test printing stored in the first storage area, the test image data is test printed by the ink jet printer. Then, the test print image is read by an image reading device attached to the ink jet printer, and the test print image data as a result of the reading is read.
The information is stored in the second storage area in association with the print nozzle or nozzle group of the inkjet printer used for the test printing. Therefore, the detecting unit can detect a defective print nozzle or nozzle group such as clogging from the relationship between the test print image data stored in the second storage area and the corresponding print nozzle or nozzle group. Therefore, by effectively utilizing the image reading device used for normal facsimile and copying attached to the ink jet printer, the failure of the print nozzle or nozzle group is detected,
Since maintenance can be performed based thereon, an ink jet printer with an image reading device that can always print in a good state can be obtained.

According to the second aspect of the present invention, in addition to the functions and effects of the first aspect of the present invention, a print nozzle or a nozzle group is provided by cleaning means for cleaning a defective print nozzle or nozzle group detected by the detection means. When the group is defective, such as clogging, the clogging can be avoided by cleaning.

According to the third aspect of the present invention, a test pattern is printed on a storage medium by an ink jet printer in a test printing step, and the printed test pattern is processed into image data through a test pattern reading step, and the image data is printed. The data is stored in the storage means in association with the print nozzle or nozzle group of the ink jet printer, and the stored image data is subjected to threshold processing in a defect detection step to detect a defective print nozzle or nozzle group. . Therefore, since the image reading apparatus used for facsimile and copying is provided, it is possible to detect a defective print nozzle or nozzle group by simple means.

According to the fourth aspect of the present invention, in addition to the functions and effects of the third aspect of the present invention, a test printing process is automatically performed based on a predetermined rule, so that defects such as clogging of print nozzles are appropriately detected. It is possible to perform maintenance at an appropriate time. Therefore, printing can always be performed in a good state.

According to the fifth aspect of the present invention, in addition to the functions and effects of the third aspect of the present invention, the test printing step and the test pattern reading step are performed a plurality of times before the defect detecting step, so that accurate test printing and test pattern Reading becomes possible, and erroneous detection in the defect detection process can be reduced by improving the detection accuracy in the defect detection process.

According to the sixth aspect of the invention, in addition to the functions and effects of the third aspect of the invention, the threshold value in the failure detection step is changed according to the type of the test pattern to be printed. By changing the threshold value for a certain test pattern, a pale color or the like can be accurately detected, and erroneous detection in the defect detection step can be reduced.

According to the seventh aspect of the present invention, in addition to the effects of the third aspect of the present invention, the test printing process is performed only on the print nozzles or nozzle groups used for printing or used for printing. Unnecessary consumption of the amount of ink used in the test printing process and the processing time can be reduced. Therefore, effective print nozzle processing can be performed.

According to the eighth aspect of the present invention, in addition to the function and effect of the third aspect of the present invention, a cleaning step of cleaning a defective print nozzle or a nozzle group detected in the detection step is provided. What is clogged and can be avoided by performing washing or the like is automatically maintained, so that an inkjet printer with an image reading device that is more user-friendly and easy to use is provided.

According to the ninth aspect of the present invention, in addition to the effect of the third aspect of the present invention, after the cleaning step, the test printing step is performed again. The user is warned of the replacement of the print nozzle or the nozzle group, so that the user can replace the print nozzle at an appropriate timing. Therefore, the user can use the print nozzle without being conscious of replacement of the print nozzle, and can always perform printing in a good state.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a block diagram of the entire system of an ink jet printer A with an image reading scanner device of the present invention. In FIG. 1, reference numeral 1 denotes an image reading apparatus used for a scanner or a copy, etc., 2 denotes a color system conversion processing system, 3 denotes a CPU, 4 denotes a program RAM, 5 denotes an image data RAM, 6 denotes a program ROM, and 7 denotes a program ROM. Test pattern image data, 8 is a computer, 9 is a replacement panel unit, 10 is a display unit, 11 is a paper feed / discharge control unit, 12 is a greenhouse sensor, 13 is an image data image processing unit, and 14 is a head control. And 15, a print head unit, and 16 a nozzle cleaning device.

The scanner which is the image reading apparatus 1 copies a document image to be copied or taken in by a CCD (Charge C).
Oupled Device), scan line by line and convert to digital signal according to image density, R (red) / G (green)
/ B (blue) image data is a device that executes and outputs shading processing as correction of sensitivity variation and illumination unevenness of each pixel of image data.

The color system conversion processing system 2 converts the R / G / B image data sent from the scanner 1 into C (cyan) /
A process for converting the image data into M (magenta) / Y (yellow) / K (black) image data and sending it to the CPU 3 is performed.

The CPU 3 includes a program RAM 4, an image data RAM 5, a program ROM 6, a test pattern image data ROM 7, a replacement panel 9, a display unit 10,
Paper feed / transport control unit 11, temperature / humidity sensor 1
2. Connected to the image processing unit 13, the program RO
It operates according to the program stored in M6.

The RAMs 4 and 5 are used as work storage areas for the CPU 3, and are also used for storing information and image data in various systems. Each ROM6,7 is C
Contents that must be retained even when the power is turned off, such as an operation program of the PU 3, a program for operating each system module, and image data for printing a test pattern, are stored.

The operation panel section 9 is an operation section which receives various inputs from the user and sends the information to the CPU 3, and the display section 10 is a display section which displays the status of various systems to the user and gives a message. The paper feed / discharge control unit 11 feeds / prints a print medium to the information from the CPU 3.
Controls transport.

The temperature and humidity sensors 12 are various sensors for monitoring the operating environment of each part of the ink jet printer A with the scanner device.
Is a process for temporarily storing image data sent from the image reading device 1 (scanner) and determining whether the image data is a character image or a photographic image, performing a filtering process on the image, performing a halftone process, and the like. The apparatus also performs a nozzle test pattern comparison process.

The head control unit 14 controls the image data sent from the image data image processing unit 13 so that it can be processed by the print head unit 15, and controls the carriage 34 (see FIG. 4). The print head unit 15 is an ejection device that prints ink of each color on a print medium based on information from the head processing unit 14.
The nozzle cleaning device 16 includes a print head unit 15.
The cleaning of defective nozzles is performed when a defective printing nozzle for ejecting ink occurs.

FIG. 2 is a schematic perspective view of the entire ink jet printer A with a scanner device, which is composed of a scanner unit 1 as an image reading device and a printer unit 18 for printing. The scanner unit 1 includes a document table 19 on which a document is placed and a document cover 20 for holding the document table 19 and preventing light emitted from a lamp 28 described later and reflected light from leaking.
And a schematic configuration inside the scanner unit 1 will be described with reference to FIG.

FIG. 3 is a schematic sectional view operatively showing the optical system inside the scanner 17. When an original 26 is set on a platen glass 25 which is a colorless and transparent plate glass and an image reading command is issued, the original 26 is positioned below the platen glass 25 and arranged so as to emit light toward the platen glass 25. The illumination light source lamp 28 is turned on, and this irradiation light is radiated onto the document 26, and the illuminated light is
It reflects light of a certain wavelength according to the color drawn above. The light of the reflected wavelength is reflected by mirrors 29, 30, and 31,
The light enters the CCD 33 via the through lens 32. C
The light incident on the CD 33 is converted into an electric signal according to the amount of light. At this time, when reading a color image, RG
B is converted into an electric signal for each wavelength range. Note that the standard white plate 27 is a white plate used to execute a shading process for correcting variations in sensitivity and illumination unevenness for each pixel before reading the document 26.

The printer section 18 shown in FIG. 2 includes a printer main body, a paper feed section 21 for storing a set of print media such as paper and OHP paper, and a discharge section for discharging the printed print medium. An operation panel 9 and a display unit 10 for a user to give an instruction to the paper unit 22 and the entire apparatus A are provided. Details of the inside of the printer main body will be described with reference to FIG.

FIG. 4 shows a printer unit 18 for performing printing.
1 is operatively shown in a perspective view. The ink jet printer A itself has a carriage 34 on which cartridges of respective colors in which an ink head 40 and an ink tank 41 are integrated as shown in FIG. 5, and the carriage 34 scans to keep the gap between the print medium P constant. Shaft 35, a carriage motor 36 for scanning the carriage 34, a rotor 36A rotating in synchronization with the rotation of the carriage motor 36, a carriage belt 37 wound around a driven roller 36B, and a print medium. A transport roller 38 for guiding P, and a head cleaning unit 39 for cleaning an ink nozzle 42 of an ink head 40 provided near an end of the carriage shaft 35 are schematically configured.

A carriage shaft 35 is slidably and penetratingly engaged with the lower portion of the carriage 34, and a carriage belt 37 is fixed to the upper surface. Therefore,
When the carriage motor 36 rotates, the rotation is transmitted to the carriage belt 37, and the carriage 34 is synchronized with the carriage belt 37 to move the carriage shaft 35 and the carriage belt 3 together.
7, and reciprocate. Further, since the transport roller 38 for guiding the print medium P is provided below the position where the carriage 34 reciprocates, the print medium P passes between the transport roller 38 and the carriage 34, and matches the print command. The ink head 40 while controlling the rotation of the transport roller 38 and the carriage motor 36
By ejecting ink from the ink nozzles 42 formed in an array on the surface, printing of a document image on the print medium P becomes possible. The carriage motor 36 and the like are driven by a position-controllable servomotor or the like in order to perform more accurate printing.

An outline of a printing process of the ink jet printer A having the above configuration will be described. First, the paper P is placed on the paper feed unit 21 connected to the printer unit 18, and a printing request based on image information from a computer or the like, or a document 26 is placed on the platen glass 25 and the user copies on the operation panel unit 9. When the button is pressed, the paper P is transported from the paper supply unit 21 and reaches the printer unit 18.

The printer section 18 scans the ink carriage 34 supported by the ink carriage shaft 35,
Accordingly, the necessary ink head 4 corresponding to the image information
By ejecting ink from 0, image information is printed on the paper P. At this time, the sheet is temporarily stopped, and when the ink carriage 34 completes scanning of one line (one direction), the sheet P corresponding to a plurality of ink nozzles of the ink head 40 is conveyed. As described above, the above-described processing is continuously performed in the printer unit 18 in accordance with the image information, so that the image information using ink is written on the paper P. The recorded paper P is discharged to a tray serving as the paper discharge unit 22 and provided to the user as a printed matter.

FIG. 6 is a perspective view of the ink head 40 of the ink jet printer A, which usually includes black ink (K), cyan ink (C), magenta ink (M),
Ink nozzles 4 each having a head of yellow ink (Y), each head being a fine hole arranged with a phase shift
2 is given. In the present embodiment, 3 constituting each row
The nozzles shifted in position are formed as n blocks in parallel as one block, and a cyan head CH, a magenta head MH, and a yellow head YH are arranged in parallel in this order with n rows and 3 columns as a unit. Further, the three heads CH, M
The three heads CH, MH,
A black head KH having the same configuration as that of YH is provided. In this embodiment, the arrangement of the heads is described in n rows and 3 columns, but the present invention is not limited to this. The diameter of one of the ink nozzles 42 is several tens of μm, and is made by ultra-fine processing technology.

FIG. 7 is an enlarged view of the ink head 40. The ink nozzle 42 is the part that most affects the image quality in image formation, and if clogging of the ink nozzle 42 with ink, dust, or the like occurs, the image quality deteriorates immediately. At present, there are roughly two types of methods for discharging ink from the ink nozzles 42, and the principle of discharging is shown in FIG. The first is a piezo system in which the ink in the ink chamber 44 is discharged by deformation of the piezo element 43 in FIG. 8A, and the second is a bubble generated by heat provided with a ceramic heater 45 in the nozzle of FIG. There is a bubble jet method or a thermal method in which the ink in the ink chamber (nozzle) 46 is ejected.

An important element of the ink jet printer is an ink technology. Ink affects the reliability of hardware and greatly contributes to print quality, which is the final output. Inks are composed of a number of chemicals, such as dyes that are colorants, wetting agents that prevent solid analysis in the ink and dryness of the ink, additives for adjusting the pH and physical properties of the ink, and penetrants.

Next, a test print mode for diagnosing whether the ink nozzles 42 of the above-described inkjet printer A with a scanner device is functioning properly will be described with reference to the flowcharts of FIGS. When entering the test print mode, the CPU 3 loads the image data of the test pattern stored in the ROM 7 and transfers it to the image processing section 13 (S1, S2). Upon receiving the data, the image processing unit 13 sends the transferred image data of the test pattern to the head control unit 14, and the image data sent to the head control unit 14 is sent to the print head unit 15 so that the test pattern is It is printed on the paper P (test pattern print sample) (S3).

FIG. 10 shows an example of the test pattern print sample. The test pattern of the present embodiment discharges ink from all nozzles in order from the first nozzle of the cyan head CH, the magenta head MH, the yellow head YH, and the black head KH one dot at a time, and is ejected on the paper. As shown in FIG. 10, pattern printing is performed on each color sample in a diagonal line state. By reading the dashed line portion of the linear test pattern, the number of the ink nozzle 42 that is clogged is detected.

Next, the test pattern print output sample is read by the scanner which is the image reading device 1 (S4). It is desired that the reading resolution of this scanner is equal to or higher than the resolution of the ink nozzles 42. If the image is read by a scanner having a resolution lower than that of the ink nozzle 42, only about half of the printed 1 dot can be read and cannot be recognized as one pixel on the scanner side, or 2 dots may be read as one pixel. This is because there is a possibility that an erroneous determination may be made for the detection of clogging.

Next, the image data of the test print pattern read by the scanner 1 is converted into cyan, magenta, yellow, and black data by the color system conversion system 2 and sent to the image data image processing unit 13 via the CPU 3. Is entered. Here, the recognition result for each pixel is compared with the threshold value, and when the recognition result is larger than the threshold value, it is determined that there is no nozzle failure. Ends the nozzle test print mode (S5, 6, 7, 8 and 10). However, if even one pixel has a pixel smaller than the threshold value in the comparison result, it is determined that the nozzle is defective, and the CPU 3 displays a nozzle cleaning instruction on the display unit 10 (S9, 10).

FIG. 11 is a block diagram showing conditions for shifting to the test printing mode described above.
FIG. 2 shows an example of the operation panel 9 and the display unit 10. When the power supply 72 of the device A is turned on (S20), the ROM 6
Is set so as to enter the test print mode (S33) of the ink nozzle 42 according to the program stored in the printer. This may cause nozzle clogging while the apparatus A has been left for a long period of time, but always enables stable high-quality printing during use. Conversely, when the power supply 72 of the device A is turned off (S21),
A program stored in the ROM 6 in advance may be set to enter the test print mode (S33) of the ink nozzle 42. As a result, even if the apparatus is left for a long time before the next use, the occurrence of nozzle clogging is prevented in advance, and stable high-quality printing can be always performed.

The idle time is monitored by a timer (not shown) provided in the CPU 3 of the apparatus A. If the idle time is longer than a predetermined time (S22), a test print of the nozzle 42 is executed by the stored program. It is set to enter the mode (S33). It is very difficult to distinguish between those who frequently use the apparatus A and those who have not used it for a long period of time, but if the relationship between the idle period and the occurrence of nozzle clogging is empirically known, By storing the period in advance, even if the apparatus has been left for a long period of time, measures against nozzle clogging are taken, and stable high-quality printing can be always performed.

Further, when the value reaches a certain value or more through a print number counter (not shown) provided in the CPU 3 of the apparatus A (S23), the nozzle test print mode (S33) is set. . Since there is a high possibility that ink residue and dust are clogged in the nozzles due to an increase in the number of times of printing, monitoring with a print number counter always enables stable high-quality printing. For the same reason, when the value reaches a certain value or more via a print time timer (not shown) provided in the CPU 3 of the apparatus A (S24), the nozzle test print mode (S3
3) It is set to enter. As a result, countermeasures are taken against nozzle clogging due to an increase in the number of times of printing, and stable high-quality printing can be always performed.

Further, a not-shown “do” provided in the CPU 3 is provided.
When the print value reaches a certain value or more via the t print counter (S25), there is a high probability that the ink residue or dust is clogged in the nozzle 42, so the test print mode (S3
It is set to automatically enter 3). As a result, countermeasures are taken against nozzle clogging due to an increase in the number of times of printing, and stable high-quality printing is always possible. Similarly, when a certain printing time or more is reached via a dot printing timer (not shown) provided in the CPU 3 (S26), a setting is made to enter the nozzle test printing mode (S33). Countermeasures are taken against nozzle clogging due to the increase, and stable high-quality printing is always possible.

When a print instruction is issued from the operation unit 9 of the apparatus A or the computer 8 (S27),
It is set to enter the test print mode (S33) of the ink nozzle 42 before executing the printing. As a result, measures are taken against nozzle clogging before printing operation with respect to nozzle clogging due to long-term storage, and stable high-quality printing is always possible.

When a high-quality print medium is selected in the paper selection of the print instruction command from the operation unit 9 or the computer 8 (S28), a test print mode for the nozzles (S33) before executing the print. Can be set to enter. This reduces wasteful use of expensive printing media due to nozzle clogging due to long-term storage, and enables stable high-quality printing at all times.

Further, when a print end command is issued from the printer section 18 of the apparatus A (S29), it can be set to enter the test print mode (S33) of the nozzle 42. This makes it possible to take measures against nozzle clogging due to paper dust or the like at the time of printing, so that stable high-quality printing is always possible.

Also, when a print end command is issued from the printer unit 18 of the apparatus A, and the paper used at that time is a plain paper or a print medium less than or equal to the selected paper (S
30), it can be set to enter the nozzle test print mode (S33) after executing the print. This prevents waste and clogging of the expensive ink head 42 due to nozzle clogging due to paper dust or the like at the time of printing, and enables stable high-quality printing at all times.

Further, a change in the installation environment of the device A is monitored via the temperature / humidity sensor 12 of the device A, and when the environment change is large (S31), the test print mode (S33) is set. . As a result, unnecessary clogging of the expensive ink head 42 due to nozzle clogging due to drying or the like is prevented, and stable high-quality printing is always possible.

When the user desires via the test pattern print mode selection button 74 provided on the operation section 9 of the apparatus A (S32), the test print mode (S3) is selected.
3) It is set to enter. This prevents image deterioration due to clogging even at special occasions when an unusual user uses it, and enables stable high-quality printing at all times.

The cleaning of the ink head 42 can be selected by pressing the cleaning mode button 73 on the operation unit 9.

Next, the test print mode (S3) is performed under the nozzle test print conditions (S20 to S32) described above.
When 3) is set, the CPU 3 loads the test pattern image data in accordance with the instructions of the program stored in the program ROM 6, and causes the printer 18 to execute the test pattern image data.
This test pattern is a test pattern in which ink is sequentially ejected in a single color pixel by pixel from the ink nozzles of the cyan head CH, the magenta head MH, the yellow head YH, and the black head BH.

FIG. 13 shows a predetermined ink nozzle 4 having no defect.
2 shows an experimental result on the print state of the test pattern when the number of times of printing the test pattern is not a single time but a plurality of times. FIG. 13 is a graph in which the horizontal axis represents the number of test pattern prints, and the vertical axis represents the nozzle defect determination result correct answer rate. As can be seen from the graph, when the number of print executions (the number of prints) of the test pattern is one or a plurality of times, the correct answer rate at which correct printing is performed is better when the printing is performed a plurality of times.

Next, means for detecting a clogged portion of the ink nozzle 42 from a test pattern printed under the above conditions will be described. In the present embodiment, the printed test pattern is read by effectively utilizing the image reading device (scanner) 1, and pixels in which pixels that should be read are not read are detected to identify a defective nozzle portion.

More specifically, a test pattern sample is first set on a platen glass 25 which is a colorless and transparent plate glass, and light is irradiated on the original by a lamp 28 to reflect light having a wavelength corresponding to the color drawn on the original. Light is applied to each mirror 29,3
The light enters the CCD 33 via 0, 31, and the through lens 32. The light incident on the CCD 33 is converted into an electric signal according to the amount of light. At this time, in the case of reading a color image, the light is converted into an electric signal for each of the RGB wavelength ranges. The R / G / B image data is stored in the main scanning direction 1
Shading processing is performed to correct individual variations of the CCDs arranged in rows and the light emission distribution characteristics of the illumination light source lamps, and cyan / magenta / yellow is converted from the R / G / B signal by the following color system conversion processing. / Black signal. At this time, when a resolution of 300 dpi is used, the dot diameter of one pixel is about 80 to 85 μm, and
At the time of 00 dpi, the thickness is 40 to 45 μm. Here, there is no problem if the resolution of the nozzle 42 that has performed the test pattern printing is 300 dpi and is the same as the resolution of the scanner 1, but if it is different, the resolution conversion processing must be performed so as to have the same resolution.

Since the read data of the input system includes a processing system error and varies slightly, the number of times the check print pattern can be read is freely selectable. It is shown in FIG. In FIG. 14, the horizontal axis indicates the number of times of reading, and the vertical axis indicates the accuracy rate of the nozzle clogging state determination result. When the number of times of reading the print pattern is one or more, the nozzle clogging state is correctly determined. It turned out that the correct answer rate improved when read multiple times. Therefore, in this embodiment, a plurality of reading processes are performed to improve the reading accuracy.

Next, a method for detecting nozzle clogging will be described with reference to the flowcharts of FIGS. The ink head 40 used in this embodiment has 99 nozzles each for cyan, magenta, and yellow nozzles, and has a nozzle resolution of 300 dpi.

First, when there is a nozzle print mode command based on the above conditions (S40), a test pattern is printed (S41 and S42), and the sample is read by the image reading device (scanner) 1 (S43). The image data output from the reading device (scanner) 1 is subjected to color system conversion processing in the image processing system 2 (S
44) Then, the resolution is converted so as to have the same resolution as that of the print nozzle (S45). This time the scanner 1 is also 300d
No resolution conversion was required because the pi's were used.

Next, the input values of the first to Nth image data are prepared in the image processing unit 13 through the detecting means (S46) for detecting the dot start position of the first nozzle (not shown) in FIG. The data is sequentially input to the image data box (memory) IB as shown in a) in association with the nozzles (S47), and each input image data is compared with a certain threshold to make a judgment (S48, 4
9). The image data box IB is initially in the state shown in FIG.
By inputting the image data (7) of (7), FIG.
The data is changed to each data of (b), and further the step (S51)
Through the predetermined threshold processing, the presence / absence data of clogging shown in FIG. 16C is created. When it is detected that the second and third yellow nozzles and the ninth and 98th magenta nozzles are defective based on the image data box IB of FIG. Is displayed, and the user can take actions such as cleaning and replacement based on the warning (S53, S53).
4).

FIG. 16 shows the measurement results in the case of binary print data. Some types of ink heads can print light colors with multi-value gradation. A method for detecting nozzle clogging using a nozzle capable of multi-level gradation printing will be described. In such a case, as shown in FIGS. 17, 18, 19, and 20, (a) of FIG. 17, an image data box IB in which memory data is input stepwise in advance in accordance with a change in gradation is used as a test print pattern. prepare. As a result of printing and reading the test print pattern, data shown in (b) of FIGS. 17, 18, 19, and 20 is obtained. FIGS. 17, 18, 1
By obtaining the results (c) of Nos. 9 and 20, the nozzle clogging state is determined. Note that the threshold value according to each stage in the present embodiment is 21 in FIG. 17, 18, 19 and 20 in order.
4, 150, 96 and 32. By this processing, it is possible to appropriately determine the clogged state of the nozzle even for a light test print sample having a gradation property.

Further, since printing with gradation is possible depending on the type of ink used, such a case will be described. A case in which gradation ink or photo ink is used instead of ordinary ink will be described with reference to FIG. Before inputting the image data, the test pattern stored in the memory as shown in FIG. 21A is the same as that when the ordinary ink is used. Fig. 2 Despite the maximum print gradation expression ability
As shown in FIG. 1 (b), it was found that the printing gradation expressing ability when using the normal ink showed almost the same value as that when the printing ink was half (FIG. 19). Therefore, when the saturation of the ink is low, etc., the clogging state is correctly detected even for the ink head of the light-colored photo ink, etc. by changing the threshold value according to the condition according to the photo ink and making a comparison judgment. It is possible to do.

In the method for detecting clogging of the nozzles 42 described above, a case has been described in which ink is always ejected from all nozzles to detect a defective nozzle. However, the detection of clogging can be performed more efficiently and effectively. In order to perform this, a method of detecting with fewer nozzles will be described. The first means is a nozzle used by a laser printer for printing, such as a black head KH for monochrome printing, a cyan head CH, a magenta head MH, and a yellow head YH for color printing. As described above, the nozzle head 40 used for later printing is detected in advance for clogging. Details will be described with reference to the flowchart of FIG.

First, when a print command is transmitted from the CPU 3, the ink head (all nozzles, black,
Only the color and only the photo color nozzle are selected (S61 to S64), and at the same time, the type of print gradation (two gradations, multi-valued gradation) is selected (S65 to S67). Then, a nozzle check of the nozzle 42 for performing clogging detection is performed in accordance with the selected ink head 40 and the type of print gradation (S68 to S87). In this manner, by detecting clogging in advance only for the ink head 40 and the ink nozzles 42 to be used later, ink required for printing a test pattern, processing time, and the like can be reduced, and nozzle clogging can be efficiently performed. Maintenance can be performed.

The second means, contrary to the first means, enables efficient processing even after the fact that clogging is detected only for the nozzles used for printing. In this case,
A flag area indicating the use history of the nozzle is provided in any of the memories, a flag corresponding to the nozzle head 40 used in the previous printing is searched, and only the used head 40 or the nozzle 42 corresponding to the searched flag is searched. Is checked for clogging. For example, if the previous printing was printing using only black ink, clogging detection would be performed only for the black head KH. Therefore, also in this case, the required processing time can be shortened with the minimum necessary ink consumption.

The clogged portion of the nozzle 42 whose clogging is detected by the above-described clogging detecting means is cleaned by the nozzle head cleaning device 16 (cleaning mode). Note that the transition to the cleaning mode is performed by a user command or by automatic setting.
Can be done on the street. In the case of user instruction,
When a clogged nozzle is detected, the user is warned by displaying a nozzle cleaning command on the display unit 10 (see FIG. 12) based on the test printout result of the nozzle clogging, and operated according to the user's desire to perform a cleaning operation. The nozzle cleaning operation of the ink head 40 is started via the cleaning mode button 73 on the panel unit 9. On the other hand, in a case where the mode is automatically shifted to the cleaning mode, when the clogged nozzle is detected, the ink head 40 is cleaned by the head cleaning unit 39 of the nozzle head cleaning device 16 without waiting for a user command.

FIG. 23 shows the cleaning operation of the ink head unit 40. Normally, carriage 3 after printing is stopped
4 is located at the home position P1 or P2 on the overrun (running portion) area W2 outward from the sheet width W1, but when the nozzle cleaning operation is selected, the carriage 34 is moved to the position of the nozzle head cleaning device 16. The head is moved to the head cleaning unit 39 to clean the ink head 40. After the cleaning is completed, it returns to the normal home position 1 or 2.

In the cleaning operation of the ink head 40, the entire surface of the ink head 40 is cleaned. Means for cleaning more effectively will be described with reference to the flowchart shown in FIG. As described above, the clogged nozzle can be accurately detected for each nozzle block or nozzle unit from the use conditions and the image data box IB shown in each (c) of FIGS. 16 to 21 (S90 to S98). By performing the cleaning, an efficient cleaning operation can be realized (S99 to S101).

Next, a schematic diagram of the head cleaning section 39 will be described with reference to FIGS. For example, if the result of the nozzle check is the image data box I shown in FIG.
If B, the ink head 40 that needs cleaning
Are magenta and yellow, so that the cleaner pad 100 for cleaning the nozzle operates only the portion corresponding to magenta and yellow to clean the nozzle 42. This can reduce the amount of ink more than necessary for the cleaning operation and the time required for the cleaning operation. In the case of a user command, a message indicating the completion of cleaning is displayed on the display unit 10 upon completion of cleaning.

In the case of FIG. 25, the unit of the ink nozzle 42 to be cleaned is shown in units of each color ink head. More preferably, the unit is performed in a predetermined block constituting each color nozzle, for example, in units of one row (three nozzles). It is. FIG. 26 is a schematic diagram of the head cleaning unit 39 that cleans only the ink nozzle blocks that need cleaning. For example, the image data box I shown in FIG.
In the case of cleaning based on the result B, the ink head 40 requiring cleaning is the third magenta head.
Block, the 33rd block, and the first block of the yellow head. At that time, the cleaner pad 101 is the third and 33rd blocks of the magenta head and the first block of the yellow head.
The nozzle 42 is cleaned by operating only the block. This cleaning operation can reduce the amount of ink more than necessary and the time required for the cleaning operation.

More preferably, the cleaning of the ink nozzles 42 is performed for each nozzle, and a schematic diagram of the head cleaning unit 39 is shown in FIG. For example, FIG.
In the case of result 6 (c), the ink heads requiring cleaning are the ninth and 98th magenta heads MH, the second and third yellow heads YH, and the ninth and 98th magenta heads of the cleaner pad 102. Only the second and third portions of the yellow head operate to clean the nozzle 42. This cleaning operation can reduce the amount of ink more than necessary and the time required for the cleaning operation.

In the above description, a case has been described in which a message is given to the user on the display unit 10 when it is determined that there is a nozzle defect. However, the cleaning operation may be automatically started as described above. . When the cleaning operation starts automatically, after cleaning the nozzle,
It is possible to perform the test pattern printing again, perform the nozzle check again from the print data, and if the clogging still exists, it is possible to effectively repeat the cleaning of the clogged nozzle or the nozzle group automatically. . And
If the clogging is not resolved even if the nozzles 42 are repeatedly cleaned a plurality of times, proper printing cannot be performed, so a message for replacing the ink head 40 is displayed to the user to warn the user that it is time to replace the ink head 40. By doing so, the ink head 40 can be replaced at an appropriate timing, and good printing is always ensured. FIG. 28 is a flowchart showing a process of warning the replacement of the ink head 40 described above. The process from the test printing mode (S110) to the display of the warning message on the display unit (S120) is the same as the so-called test pattern printing process and the nozzle clogging test check process, and the description is omitted.

First, a reading nozzle defect detection step is performed (S110 to S117). When a defective nozzle portion is detected, a warning message is displayed on the display unit 10 (S119, 120), and at the same time, the CPU 3 counts the number N of times a defective nozzle has occurred (S12).
1). If the number N of consecutive nozzle failures is, for example, less than three, the process proceeds to the cleaning mode of the ink head 40 (S122) to clean the ink head 40. After the cleaning is completed, the test print mode (S11) is performed again.
Go to 0). On the other hand, when the number of consecutive times N at which the nozzle failure has occurred becomes three, it is determined that the abnormality is irreparable due to the scorching of the ink in the heater (not shown),
A message for replacing the ink head 40 is displayed to the user (S124), and the nozzle diagnostic mode ends (S123). In this case, it is abnormal (ink head replacement)
Is displayed on the display unit 10 via the CPU 3.

As described above, if clogging is not resolved even if nozzle cleaning is performed a plurality of times, the user is warned that it is time to replace the ink head 40, so that the ink head 40 can be replaced at an appropriate timing. And good printing is always ensured. The test print mode (S110) is automatically changed to the nozzle cleaning mode (S12).
In the case of performing the above steps 2), it is necessary to provide a device for guiding the test pattern print sample sent to the paper discharge unit 22 onto the document table 19.

[0083]

As described above, according to the present invention, the nozzle function of an ink jet printer with an image reading device is diagnosed, and if a defective portion is detected, the maintenance of the print nozzle is carried out. Can always supply a stable and high-quality image as an image output on a print medium.

According to the present invention, an image can be mechanically determined by reading a test pattern by effectively utilizing an image reading apparatus (scanner) provided for performing a scanner or a copy. There is no need to attach a reader again for diagnosing the nozzle function. Also,
There is no subjective judgment of test pattern printing, and a highly accurate result can be obtained, and no error judgment is made.

In addition, since the nozzle failure is automatically determined, the time required for the determination is reduced, and when there is a nozzle failure, the cleaning operation is automatically started, thereby eliminating troublesome operations.

If the printer nozzle is clogged, the location of the nozzle failure is examined based on the result of the judgment and the printer nozzle is cleaned by the minimum necessary cleaning operation. Saves time.

Further, by performing the detection while changing the threshold value in accordance with the type of the test pattern to be printed in the detection step, it is possible to appropriately detect a defective nozzle even in light color printing.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system of an inkjet printer A with a reading image capturing device according to an embodiment of the present invention.

FIG. 2 is a perspective view of an inkjet printer A with a reading image capturing device according to the embodiment of the present invention.

FIG. 3 is an operational explanatory view of an optical system of the image capturing apparatus 1.

FIG. 4 is an operational explanatory diagram of the printer unit 18 according to the embodiment of the present invention.

FIG. 5 is a perspective view of a print ink head 40 of the printer unit 18 according to the embodiment of the present invention.

FIG. 6 is a bottom view of the print ink head 40 according to the embodiment of the present invention.

FIG. 7 is an enlarged view of a bottom surface of the print ink head 40 according to the embodiment of the present invention.

FIG. 8 is an operational explanatory view of the principle of ink ejection from a head nozzle of an ink jet printer (a: piezo system, b: bubble jet system).

FIG. 9 is a flowchart of a test print mode according to the embodiment of the present invention.

FIG. 10 is an explanatory diagram of a test print pattern.

FIG. 11 is a block diagram showing conditions for shifting to a test print mode according to the embodiment of the present invention.

FIG. 12 is a schematic diagram of an operation panel of the inkjet printer A with the image capturing device according to the embodiment of the present invention.

FIG. 13 is a graph showing a nozzle defect determination result correct answer rate with respect to the number of test pattern prints using the inkjet printer A with the image capturing device according to the embodiment of the present invention.

FIG. 14 is a graph illustrating a nozzle failure determination result correct answer rate with respect to the number of times a test print pattern is read, using the inkjet printer A with an image capture device according to the embodiment of the present invention.

FIG. 15 is a flowchart of a nozzle defect detection process using a nozzle check pattern of the inkjet printer A with an image capturing device according to the embodiment of the present invention.

FIG. 16 is an explanatory diagram of the contents of an image data box IB when a nozzle check pattern uses binary print data according to the embodiment of the present invention.

FIG. 17 is an explanatory diagram of the contents of an image data box IB when a multi-value gradation nozzle check pattern according to an embodiment of the present invention is used.

FIG. 18 is an explanatory diagram of the contents of an image data box IB when a multi-value gradation nozzle check pattern according to the embodiment of the present invention is used.

FIG. 19 is an explanatory diagram of the contents of an image data box IB when a multi-value gradation nozzle check pattern according to an embodiment of the present invention is used.

FIG. 20 is an explanatory diagram of the contents of an image data box IB when a multi-value gradation nozzle check pattern according to the embodiment of the present invention is used.

FIG. 21 is a diagram illustrating the contents of an image data box IB when using binary tone print data when using photo ink. It is.

FIG. 22 is a flowchart of a nozzle check mode according to the embodiment of the present invention.

FIG. 23 is an ink carriage 3 according to the embodiment of the invention.
4 is an operation explanatory view of FIG.

FIG. 24 is a flowchart of a nozzle cleaning mode according to the embodiment of the present invention.

FIG. 25 is a perspective view for explaining the operation of the cleaner pad 100 for cleaning each color nozzle according to the embodiment of the present invention.

FIG. 26 is a perspective view for explaining the operation of the cleaner pad 101 for cleaning each color nozzle according to the embodiment of the present invention.

FIG. 27 is a perspective view for explaining the operation of the cleaner pad 102 for cleaning each color nozzle according to the embodiment of the present invention.

FIG. 28 is a flowchart of an ink head nozzle diagnostic mode of the inkjet printer A with an image capturing device according to the embodiment of the present invention.

[Explanation of symbols]

 A Inkjet printer with scanner device 1 Image reading device (scanner) 2 Color conversion system 3 CPU 7 Test pattern image data ROM 10 Display unit 13 Image data image processing unit 14 Head control unit 15 Print head unit 17 Scanner unit 18 Printer unit 39 Nozzle cleaning unit 40 Ink head 41 Ink nozzle IB Image data box CH Cyan head MH Magenta head YH Yellow head BH Black head 100, 101, 102 Cleaner pad

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Yoshio Mizuyama Inventor F-term (reference) in 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka, Japan 2C056 EA16 EB27 EB40 EB42 EC23 EC26 JB03 2C061 AQ05 AR01 AS02 KK04 KK13 KK14 KK18 KK25 KK26 KK28 KK34 KK35

Claims (9)

[Claims] An image reading apparatus reads a document image by reflected light of a light radiated on a document placed on a document table and processes the image data, and discharges ink from a print nozzle based on the image data. A first storage area for storing test image data for test printing, and a test printing of the test image data by the ink jet printer. A second storage area for storing test print image data obtained by reading the test print image by the image reading device in association with a print nozzle or a nozzle group of the inkjet printer; and a second storage area for storing the test print image data. Detection of defective print nozzles or nozzle groups based on test print image data And an ink jet printer with an image reading device. 2. An ink jet printer with an image reading device according to claim 1, further comprising cleaning means for cleaning a defective print nozzle or a nozzle group detected by said detection means. 3. An image reading apparatus for reading a document image by reflected light of light radiated on a document placed on a document table and processing the image data, and ejecting ink from print nozzles based on the image data. A print nozzle processing method of an ink jet printer with an image reading device having an ink jet printer that prints an image on a recording medium by printing a test pattern on a recording medium by the ink jet printer. A test pattern reading step in which the printed test pattern is read by the image reading device and processed into image data; and the image data in the test pattern reading step corresponds to a print nozzle or nozzle group of the ink jet printer. And a storage step of storing the image in the storage means, and an image stored in the storage means. - an image reading print nozzles processing method of the apparatus with an ink jet printer characterized by having a defect detection step of detecting a defective print nozzles or nozzle groups and a data thresholded. 4. The method according to claim 3, wherein the test printing step is automatically performed based on a predetermined rule. 5. The print nozzle process for an ink jet printer with an image reading device according to claim 3, wherein the test printing process and / or the test pattern reading process are performed a plurality of times before the defect detecting process. Method. 6. The print nozzle processing method for an ink jet printer with an image reading device according to claim 3, wherein in the defect detecting step, a threshold value is changed according to a type of a test pattern to be printed. 7. The printing of an ink jet printer with an image reading device according to claim 3, wherein the test printing step is performed only for print nozzles or nozzle groups used for printing or used for printing. Nozzle processing method. 8. The method according to claim 3, further comprising a cleaning step of cleaning a defective print nozzle or a nozzle group detected in the detection step. 9. The test printing step is performed again after the cleaning step, and if there is a clogged print nozzle or nozzle group, a user is warned of replacement of the print nozzle or nozzle group. Item 4. A print nozzle processing method for an ink jet printer with an image reading device according to Item 3.