JP2005088307A - Inkjet recording apparatus and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording apparatus which prevents the discharge operation of normal nozzles from being obstructed by a state of the other nozzles in the discharge operation at the spare discharge time or at the recording time, and to provide an inkjet recording method. <P>SOLUTION: Non discharge nozzle information detected at a shipment inspection is held in a ROM. When a recording operation is started and each kind of the discharge operation such as the spare discharge is carried out, mask processing is executed to discharge data corresponding to non discharge nozzles, so that the non discharge nozzles are refrained from executing the discharge operation. The mask processing is executed also to the non discharge nozzles of spare nozzles and dummy nozzles. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an ink jet recording method and an ink jet recording apparatus of the present invention, and more particularly to an ink jet recording method in the case where there are non-ejection nozzles among a plurality of nozzles constituting a recording head, and an ink jet recording apparatus using this method.

  Recording apparatuses that output image information from word processors, personal computers, facsimiles, and the like to recording media such as paper and film-like sheets have become widespread with the spread of various information processing apparatuses.

  Such recording apparatuses are roughly classified according to recording methods such as an ink jet method, a wire dot method, a thermal method, and a laser beam method. Among them, an ink jet type ink jet recording apparatus has attracted particular attention in recent years because it performs recording in a non-contact manner on a recording medium, has high quietness, and can realize color recording relatively easily.

  An ink jet recording apparatus performs recording by providing a recording head in which a plurality of nozzles for discharging ink are arranged for each ink color, ejecting ink from each recording head to a recording medium, and forming ink dots on the recording medium. Is. With the recent demand for higher resolution and higher image quality, there are many recording heads in which a large number of small-diameter nozzles that form small ink dots with a small ink discharge amount are arranged. Such small-diameter nozzles are more likely to cause ejection defects due to dust clogging than the large-diameter nozzles. Therefore, when a non-ejection nozzle is generated, there is a recording head provided with a spare nozzle for complementing the printing amount of the non-ejection nozzle. By using such a non-ejection complementary spare nozzle, a stable image can be always supplied even if a non-ejection nozzle is generated.

  Complementation with a spare nozzle is performed as follows. For example, using the nozzle check pattern data that inspects the state of each nozzle of the print head during the shipping inspection, all the nozzles including the spare nozzles are caused to perform the discharge operation, and the non-discharge nozzles are detected from the recorded pattern data. Then, information on the non-ejection nozzles is registered in advance in the image processing unit, and when recording data is formed, the recording data is not sent to the registered non-ejection nozzles, and the recording data is complemented by the spare nozzles. Make things. Then, a recording operation for complementing the non-ejection nozzles with the spare nozzles is performed.

  Further, in a recording head in which ink is supplied from a common liquid chamber to a plurality of nozzles, there is a risk that the nozzles located at the end of the nozzle array may be insufficiently filled with ink, so that the recording is performed at the end of the nozzle row. In many cases, dummy nozzles that are not used are arranged so that the nozzles used for recording are sufficiently filled with ink. The dummy nozzle is also referred to as a non-use nozzle because it is not used in the recording operation.

  FIG. 2 is a schematic diagram of a recording head having such a non-ejection complementary spare nozzle and a dummy nozzle.

  As shown in the figure, dummy nozzles 23 are arranged at both ends, a non-ejection complementary spare nozzle 22 is arranged adjacent to the dummy nozzle 23, and a recording nozzle 21 is arranged.

  In order to prevent ejection failure of the recording head, a preliminary ejection process is periodically performed to eject thickened ink in the nozzles by ejecting a predetermined amount of ink to a cap provided outside the recording area. Yes. Conventionally, both preliminary ejection related to dummy nozzles not used for recording and preliminary nozzles for non-ejection complementation are ejected simultaneously. In some cases, preliminary ejection is performed regardless of the nozzle state of the dummy nozzle and the preliminary nozzle, that is, whether or not the nozzle is a non-ejection nozzle.

  As described above, in the preliminary ejection related to the conventional dummy nozzle and the non-ejection complementary preliminary nozzle, both are ejected simultaneously, and all the nozzles are uniformly preliminarily ejected regardless of the state of the nozzles. Therefore, even if there are non-ejection nozzles in the preliminary nozzles and the dummy nozzles, preliminary ejection signals are sent to these non-ejection nozzles, and the ejection operation is performed. If dust or the like is present in the ink flow path of the non-ejection nozzle, an ink flow is generated in the ink flow path due to the ejection operation of the non-ejection nozzle, and the dust is originally in a good state due to the ink flow. It may move to the ink flow path of other nozzles, and the good nozzles may not discharge.

  The present invention has been made in view of such a conventional problem, and an inkjet recording apparatus in which normal nozzle ejection operation is not hindered by the state of other nozzles during ejection operation during preliminary ejection or recording, and An object is to provide an ink jet recording method.

  The ink jet recording apparatus of the present invention is a recording head in which a plurality of nozzles that eject ink to a recording medium are arranged, and the recording nozzle used for recording an image and the recording nozzle become non-ejection. In an ink jet recording apparatus for forming an image on a recording medium using a recording head having a spare nozzle used when the non-ejection nozzle supplements image data to be originally recorded and a dummy nozzle not used for recording , Non-ejection nozzle information holding means for holding non-ejection nozzle information for specifying non-ejection nozzles among the nozzles arranged in the recording head, and non-ejection nozzle information held by the non-ejection nozzle information holding means And mask means for applying a mask process to the ejection data corresponding to the non-ejection nozzle so that the non-ejection nozzle does not perform the ejection operation. The non-ejection nozzles to the mask process is applied, characterized in that includes the preliminary nozzles and non-discharge nozzles of the dummy nozzle.

  The inkjet recording method of the present invention is a recording head in which a plurality of nozzles for ejecting ink are arranged on a recording medium, and the recording nozzle used for recording an image and the recording nozzle become non-ejecting. In the ink jet recording method, an image is formed on a recording medium by using a recording head having a spare nozzle used when the non-ejection nozzle originally supplements image data to be recorded and a dummy nozzle not used for recording. A non-ejection nozzle detection step for detecting the ejection state of each nozzle and specifying a non-ejection nozzle; a non-ejection nozzle information holding step for retaining non-ejection nozzle information detected by the non-ejection nozzle detection step; Based on the non-ejection nozzle information held in the non-ejection nozzle information holding process, the ejection data corresponding to the non-ejection nozzle is subjected to mask processing, and the non-ejection nozzle information Comprising a mask process Le is not to perform the discharge operation, the faulty nozzle in which the mask processing is performed is characterized to include the pre-nozzle and the faulty nozzle of the dummy nozzle.

  In this way, the non-ejection nozzle is detected, the non-ejection nozzle information is held in the ink jet recording apparatus, and the ejection data of the non-ejection nozzle is masked based on the non-ejection nozzle information. Even in various discharge operations such as preliminary discharge, the non-discharge nozzles are not allowed to always perform the discharge operation. In addition, the non-ejection nozzle information is information that can identify the non-ejection nozzles individually, and furthermore, since the mask process is performed for each nozzle, the difference in ejection modes such as recording operation and preliminary ejection Even when the nozzles to be used are different, it is possible to appropriately perform mask processing on each of the spare nozzle and the dummy nozzle.

  By using the present invention, it is possible not to execute the ejection operation of the non-ejection nozzle not only during the recording operation but also in the ejection operation that is not directly related to the recording such as preliminary ejection. It is possible to sufficiently prevent dust or the like in the ink flow path from moving to other nozzles through the ink flow path and causing other normal nozzles to be in a non-ejection state.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic perspective view showing an ink jet recording apparatus according to an embodiment of the present invention.

  Reference numeral 101 denotes an ink cartridge. The ink cartridge 101 includes an ink tank filled with four color inks, black, cyan, magenta, and yellow, and a recording head 102. A plurality of ejection openings are arranged in the recording head 102, and recording is performed by ejecting ink droplets from the ejection openings. The arrangement of the nozzles of the recording head 102 will be described later.

  Reference numeral 103 denotes a paper feed roller which rotates in the direction of the arrow while holding the recording medium P together with the auxiliary roller 104 and feeds the recording medium P in the y direction as needed. Reference numeral 105 denotes a paper feed roller that feeds the recording medium and plays the role of holding the recording medium P as in 103 and 104. Reference numeral 106 denotes a carriage that supports the four ink cartridges 101 and moves them in the direction of the arrow x during recording. The carriage 106 waits at a home position (h) indicated by a dotted line in the drawing when recording is not being performed or when a recovery operation of the recording head is performed. That is, before the start of recording, when the recording start command is received, the carriage 106 at the home position performs recording by ejecting ink droplets from a plurality of ejection ports on the recording head 102 while moving in the x direction. When the data recording to the end of the paper surface is completed, the carriage returns to the original home position, and the paper feed roller 103 feeds the recording medium by a predetermined amount. By repeating such recording and paper feeding alternately, recording is performed on the entire surface of the recording medium.

FIG. 2 is a schematic diagram illustrating the nozzle surface of the recording head.
The nozzle rows of the recording head are configured to form a row for each ink color, and the nozzles in the same row eject ink of the same color. A plurality of dummy nozzles 23 that are not used for printing are arranged at both ends of each nozzle row, and a plurality of non-ejection complementary preliminary nozzles 22 are arranged adjacent to the dummy nozzles 23 that are not used. A plurality of recording nozzles 21 used for recording are arranged. In the figure, the number of spare nozzles and dummy nozzles is two at each end, but it goes without saying that the number is not limited to this. In this embodiment, different nozzle rows are provided for each ink color. However, the present invention is not limited to this, and a recording head in which a plurality of colors are arranged in a row may be used.

  The ink ejection method of the recording head of this embodiment is a thermal ink jet method as described below. That is, a heating heater is provided in the ink flow path corresponding to each nozzle of the recording head. The heating heater generates heat, and bubbles are instantaneously generated in the ink. A predetermined amount of bubbles is generated by the generation pressure of the bubbles. Ink is ejected. In the present embodiment, an example using such a discharge method is given, but it is needless to say that the present invention is not limited to this, and other discharge methods such as a piezo method may be used.

FIG. 3 is a block diagram showing an electrical configuration of the ink jet recording apparatus.
A control board 301 is a part that controls various operations by outputting drive signals to the recording head 307 and other drive units based on print data transmitted from a host computer or the like. The control board 301 includes the following components.

  Reference numeral 302 denotes an interface for inputting various information from the host computer. Reference numeral 303 denotes a CPU that controls the entire inkjet recording apparatus in an integrated manner using various programs stored in the ROM 304. A ROM 304 stores various control programs. The information 312 for specifying the non-ejection nozzles detected in the shipping inspection and the recording command program 313 are stored therein. The detection of the non-ejection nozzle in the shipping inspection will be described later. Reference numeral 305 denotes a DRAM which stores information necessary for the control circuit as needed. Reference numeral 306 denotes a logic circuit (ASIC), which holds control circuits for various drive units, and drives various control circuits in accordance with instructions from the CPU 303. For example, reference numeral 311 denotes a head control circuit that transmits a drive signal to the recording head 307 in accordance with a command from the CPU 303. Reference numeral 308 denotes a recording nozzle mask circuit, which executes recording nozzle mask processing. Reference numeral 309 denotes a spare nozzle mask circuit, which executes a mask process for the spare nozzle. A dummy nozzle mask circuit 310 performs dummy nozzle mask processing. Based on the recording data masked by these mask circuits, the head control circuit 311 determines a drive signal for each nozzle.

Next, the relationship between non-ejection nozzle information and the nozzle mask circuit will be described.
In the shipping inspection, as in the past, a nozzle check test pattern that can check the discharge state of each nozzle is recorded, and the test pattern is checked visually by an inspector or by a check device. Specify the discharge nozzle. A list of identified non-ejection nozzles is stored in the ROM as non-ejection nozzle information. This nozzle check is performed not only for the recording nozzles used for recording, but also for the spare nozzles and dummy nozzles, and the non-ejection nozzles in the spare nozzles and dummy nozzles are also specified.

  The recording nozzle mask circuit 308, the spare nozzle mask circuit 309, and the dummy nozzle mask circuit 310 check whether there is a non-ejection nozzle among the recording nozzle, the spare nozzle, and the dummy nozzle, respectively. When there is a discharge nozzle, in order to prevent the non-discharge nozzle from discharging, mask processing is performed on the discharge data such as recording data and preliminary discharge data corresponding to the nozzle. Therefore, the discharge operation is not executed for the non-discharge nozzle. Specifically, such processing is executed in the preliminary ejection operation and the recording operation. Details of the processing routine at that time will be described below.

FIG. 4 is a flowchart showing a preliminary discharge process regarding the dummy nozzle and the preliminary nozzle.
Upon receiving the preliminary discharge execution command, the CPU reads the preliminary discharge control program from the ROM (step 401). Further, non-ejection nozzle information is read from the ROM (step 402). When a non-ejection nozzle exists in the dummy nozzle or the spare nozzle (step 403), the spare nozzle mask circuit and the dummy nozzle mask circuit of the ASIC perform mask processing on the ejection data so that the non-ejection nozzle is not preliminarily ejected. (Step 404). On the other hand, when there is no non-ejection nozzle, the mask process by the mask circuit is not executed.

  After the non-ejection nozzle is masked, the recording nozzle is masked by the recording nozzle mask circuit (step 405), and the ejection signal is output according to the ejection data subjected to the mask processing. Is output. Then, according to the ejection signal, preliminary ejection of the dummy nozzle and the spare nozzle is executed (step 406).

  In this way, by performing mask processing on the non-ejection nozzles in advance so that the ejection operation is not performed, dust in the non-ejection nozzles travels along the ink flow path during preliminary ejection, and other normal Prevents movement to spare nozzles or dummy nozzles.

  Needless to say, the mask process for the non-ejection nozzles is similarly performed during the preliminary ejection of the recording nozzles.

FIG. 5 is a flowchart showing the ejection data processing during printing.
When a recording command and recording data are transmitted from the host computer side, the CPU reads a recording control program from the ROM (step 501). Further, non-ejection nozzle information is read (step 502). Then, it is checked whether there are any non-ejection nozzles in the spare nozzle and the recording nozzle (step 503). If there is a non-ejection nozzle, the ejection data corresponding to the non-ejection nozzle is masked so that the non-ejection nozzle does not perform the ejection operation (step 504). Since dummy nozzles are not used for recording, mask processing is performed on all dummy nozzles (step 505). If there is a non-ejection nozzle among the recording nozzles, a complementary process is performed using a normal spare nozzle (step 506). The complementing process is performed, for example, by shifting the ejection data corresponding to the recording nozzles existing between the non-ejection nozzle and the spare nozzle one by one to the spare nozzle side. That is, the ejection data of the non-ejection nozzle is executed by the nozzle adjacent thereto. In addition, although this embodiment demonstrated such a complementation process, this invention is not limited to this, Complementary process of any well-known method may be performed.

  The ejection signal that has been subjected to the above-described mask processing and complement processing is transmitted to the recording head, and the recording operation is executed.

  As described above, when there are non-ejection nozzles not only in the recording nozzles but also in the spare nozzles and the dummy nozzles, the non-ejection nozzles perform the pre-ejection and recording operations after performing mask processing on the non-ejection nozzles. It is possible to sufficiently prevent dust or the like in the nozzle from moving to another nozzle along the ink flow path. Therefore, the recording head can appropriately obtain the effect of the preliminary ejection and can always form a high-quality image.

It is a typical perspective view of an inkjet recording device. FIG. 3 is a schematic diagram illustrating an example of a nozzle row of a recording head. It is a block diagram which shows the electric constitution of an inkjet recording device. It is a flowchart which shows a preliminary discharge process. 6 is a flowchart illustrating discharge data processing in printing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Ink cartridge 102 Recording head 103 Paper feed roller 104 Auxiliary roller 105 Paper feed roller 106 Carriage 21 Recording nozzle 22 Non-ejection complement spare nozzle 23 Dummy nozzle 301 Control board 302 Interface 303 CPU
304 ROM
305 DRAM
306 ASIC
307 Recording head 308 Recording nozzle mask circuit 309 Preliminary nozzle mask circuit 310 Dummy nozzle mask circuit 311 Head control circuit 312 Non-ejection nozzle information 313 Recording control program

Claims (8)

A recording head in which a plurality of nozzles that discharge ink to a recording medium are arranged, the recording nozzle used when recording an image, and the non-ejecting nozzle when the recording nozzle fails In an ink jet recording apparatus that forms an image on a recording medium using a recording head that includes a spare nozzle that is used when complementing image data to be originally recorded and an unused nozzle that is not used for recording.
Non-ejection nozzle information holding means for holding non-ejection nozzle information for specifying non-ejection nozzles among the nozzles arranged in the recording head;
Masking means for performing a mask process on the ejection data corresponding to the non-ejection nozzle based on the non-ejection nozzle information held by the non-ejection nozzle information holding unit, and preventing the non-ejection nozzle from performing the ejection operation,
The non-ejection nozzle to which the mask process is applied includes the preliminary nozzle and the non-ejection nozzle of the non-use nozzle.   In preliminary ejection for causing the recording head to perform an ejection operation not involved in image formation, the mask unit performs mask processing on ejection data corresponding to non-ejection nozzles in the preliminary nozzle and the non-use nozzle. The ink jet recording apparatus according to claim 1.   The ink jet recording apparatus according to claim 1, wherein the non-ejection nozzle is determined by detecting an ejection state of each nozzle arranged in the recording head.   4. The ink jet recording apparatus according to claim 1, wherein the preliminary nozzle is disposed adjacent to a recording nozzle located at both ends of a nozzle row of the recording nozzle.   The non-use nozzles are disposed at both ends of the nozzle array of the recording head, and ink is filled in the recording nozzles and the spare nozzles positioned at both ends of the nozzle array of the recording nozzles. The ink jet recording apparatus according to claim 4.   2. The recording head according to claim 1, wherein bubbles are generated in the ink by applying thermal energy to the ink, and a predetermined amount of ink is ejected as droplets from the nozzles by the generation pressure of the bubbles. Or an ink jet recording apparatus described in item 5; A recording head in which a plurality of nozzles that discharge ink to a recording medium are arranged, the recording nozzle used when recording an image, and the non-ejecting nozzle when the recording nozzle fails In an ink jet recording method in which an image is formed on a recording medium using a recording head having a spare nozzle used when complementing image data to be originally recorded and an unused nozzle not used for recording,
A non-ejection nozzle detection step for detecting the ejection state of each nozzle and identifying a non-ejection nozzle;
A non-discharge nozzle information holding step for holding non-discharge nozzle information detected by the non-discharge nozzle detection step;
A mask process for performing a mask process on ejection data corresponding to the non-ejection nozzle based on the non-ejection nozzle information held in the non-ejection nozzle information holding process, and preventing the non-ejection nozzle from performing a ejection operation,
The non-ejection nozzle subjected to the mask processing includes the non-ejection nozzle of the preliminary nozzle and the non-use nozzle. In preliminary ejection for causing the recording head to perform an ejection operation not involved in image formation, the masking step performs mask processing on ejection data corresponding to non-ejection nozzles in the preliminary nozzle and the non-use nozzle. The ink jet recording apparatus according to claim 7.

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