JP2006150938A - Inkjet recorder, inkjet recording method, information processor, recording medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder excellent in throughput, which continues to make recording without stopping recording even if a failure of recording occurs in a part of line heads, when recording an image of the same color with a plurality of line heads. <P>SOLUTION: An image data for forming an image of the same color is divided and supplied to ink dischargeable line heads 101, 103 and 104 to properly discharge ink out of a plurality of line heads 101 to 104 to form the image of the same color, so that the respective ink dischargeable heads makes printing according to the supplied image data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus, a recording method, a storage medium, and a program. In particular, the image of the same color is divided by a plurality of line heads arranged along the conveyance direction while conveying the recording medium. The present invention relates to an inkjet recording apparatus, a recording method, a storage medium, and a program.

  Conventionally, a dry electrophotographic printer has been used to repeatedly print a certain number of images such as form paper, but recently, an ink jet recording apparatus has been used as a printer to replace the dry electrophotographic method. Has attracted attention. In general, inkjet recording devices can record a large amount of data because they are recorded directly on a web, and the running cost is low. Therefore, various forms such as insurance application forms, notification forms for utility charges, mail order application forms, etc. Suitable for paper recording.

  In particular, the line-type ink jet recording apparatus performs recording using a line head in which a plurality of ink discharge nozzles are arranged in a direction orthogonal to the conveyance direction of the recording medium. For example, it is known to be particularly suitable for recording of a mount, a label or tag sheet, a form sheet, and the like. Further, a line-type inkjet recording apparatus for color image formation that is currently used generally has a plurality of line-type inkjet recording heads (hereinafter also simply referred to as line heads) arranged along the conveyance direction of the recording medium. Color images are recorded by ejecting different color inks from the line head. That is, one color image is formed by one line head. Therefore, in this general line type recording apparatus, the maximum recording speed is determined by the maximum driving frequency of one line head.

  In other words, in the case of a general ink jet recording apparatus, a recording speed exceeding the maximum drive frequency of the line head alone (maximum nominal value capable of repeatedly ejecting ink per second: Hz) while maintaining stable image quality is realized. I can't. For this reason, a general line type recording apparatus has a problem that it cannot sufficiently meet the market demand for an improvement in recording speed.

  On the other hand, a line type ink jet recording apparatus that divides and records an image of the same color by a plurality of recording heads is also proposed for such a general line type ink jet recording apparatus. In this recording apparatus, raster development is performed on image data of the same color, and the generated raster data is divided, and then the divided raster data is assigned to a plurality of line heads, and divided by each line head to record an image. Do. For this reason, it is possible to perform recording exceeding the maximum drive frequency of a single line head as compared with a general line-type ink jet recording apparatus that forms an image of one color with a single recording head. As a result, the recording operation can be speeded up (for example, see Patent Document 1 below).

Japanese Patent Application No. 2004-049447

  However, in the high-speed line-type ink jet recording apparatus as described above, if even one of the plurality of line heads that discharge ink of the same color deteriorates the ink discharge performance, it is appropriate. The problem arises that the image cannot be continued. In the line head, ink ejection performance is deteriorated due to the influence of heat, pressure, chemical reaction with ink, and the like during ink ejection. The degree of performance degradation is not necessarily uniform among the line heads, and only one of the plurality of line heads often reaches the end of its life. In the conventional apparatus, when it is determined that only one of the plurality of line heads has reached the end of its life during the recording operation, it is necessary to take measures to interrupt the recording and replace the recording head. Absent.

Further, when a sub tank is provided for each line head, the ink in each sub tank is not necessarily consumed uniformly. For this reason, for example, when there is a shortage of ink remaining in only one ink tank, and only one recording head is in an unrecordable state, as described above, recording is performed in a state where the recording quality cannot be guaranteed. There is no choice but to continue or interrupt the printing operation to supply ink.
However, since a line-type ink jet recording apparatus is usually required to have a high throughput, it is desirable to continue the recording operation as much as possible. However, if the above-described ejection failure occurs, if the recording operation is continued, there is a disadvantage that the recording quality is deteriorated. Therefore, the continuation of the recording operation and the maintenance of the recording quality may be in a trade-off relationship. There is sex.

  As a solution to these problems, it is conceivable to increase the life of the line head and increase the capacity of the sub tank. However, in order to increase the life of the line head, a lot of development time and cost are required. When the capacity of the sub-tank is increased, there is a problem that the entire apparatus is increased in size and cost is increased, and it is necessary to solve many problems to realize it.

  Further, when recording a standard form such as a form, it is conceivable that the same ruled line 102 is repeatedly recorded on each page of a recording medium 101 such as paper as shown in FIG. In such a case, when the raster data obtained by raster development of the image data is divided and assigned to a plurality of line heads to record the image data, only a specific line head is used intensively, There also arises a problem that the replacement frequency of a specific line head is increased.

  The present invention has been made paying attention to the problems of the prior art described above, and when recording an image of the same color using a plurality of line heads, even if an unrecordable state occurs in some line heads, An object of the present invention is to provide an ink jet recording apparatus excellent in throughput that can continuously perform a recording operation without stopping the recording operation.

  Another object of the present invention is to avoid intensive use of a specific recording head and to suppress the frequency of replacement of the recording head.

In order to achieve the above object, the present invention has the following configuration.
That is, the first aspect of the present invention is the same in an inkjet recording apparatus that uses a plurality of line heads arranged along the recording medium conveyance direction by the recording medium conveyance means to divide and record images of the same color. Image data that divides and supplies image data for forming the same color image to a dischargeable head that enables proper ink discharge among a plurality of line heads for forming a color image Supply means, and control means for controlling recording by each of the ejectable heads according to the image data supplied by the image data supply means.

  According to a second aspect of the present invention, in an inkjet recording apparatus that divides and records an image of the same color using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport unit, the same color Among the plurality of line heads for forming an image, a dischargeable head detection unit that detects a dischargeable head that enables proper ink discharge, and a dischargeable head detected by the dischargeable head detection unit. The image data for forming the image of the same color is divided into a plurality of image data supply means for supplying the divided image data to each of the ejectable heads, and the divided image data supplied by the image data supply means. And a control means for controlling a recording operation by each of the ejectable heads.

  According to a third aspect of the present invention, there is provided an inkjet recording method for dividing and recording an image of the same color using a plurality of line heads arranged along a recording medium transport direction by a recording medium transport unit. Among the plurality of line heads for forming an image, a dischargeable head detection step for detecting a dischargeable head that enables proper ink discharge, and the dischargeable head detected by the dischargeable head detection means. An image data dividing step for dividing image data for forming the same color image in number, and an image data supplying step for supplying the divided image data divided in the image data dividing step to each of the ejectable heads; And a step of controlling a recording operation by each of the ejectable heads according to the divided image data supplied by the image data supply means. And wherein the Rukoto.

  According to a fourth aspect of the present invention, an image of the same color is used for an inkjet recording apparatus that records an image of the same color using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport means. An image processing apparatus capable of transmitting image data for forming an image, and detecting a dischargeable head that enables proper ink discharge among the plurality of line heads for forming an image of the same color A dischargeable head detection unit that performs the image data division for dividing the image data for forming the image of the same color by the number of the dischargeable heads detected by the dischargeable head detection unit, and the image data division Image data transmission means for enabling transmission of the divided image data divided by the means to the ink jet recording apparatus.

  According to a fifth aspect of the present invention, there is provided an inkjet recording apparatus that divides and records an image of the same color using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport unit. The raster data obtained by raster development of the image data is divided, the data supply means for assigning the divided raster data to a plurality of line heads, and each discharge is possible according to the raster data assigned by the data supply means Control means for controlling recording by the head, wherein the data supply means is adapted to record the divided raster data so that the number of dots recorded by the line heads is equal to each other in recording the image data. Is assigned to the plurality of line heads.

  According to a sixth aspect of the present invention, there is provided an inkjet recording apparatus that divides and records an image of the same color using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport unit. The raster data obtained by raster development of the image data is divided, the data supply means for assigning the divided raster data to a plurality of line heads, and each discharge is possible according to the raster data assigned by the data supply means Control means for controlling recording by a head, and the image data is composed of a plurality of pages, and the data supply means assigns the divided raster data to the line head in recording the image data. The assignment is switched for each page.

  According to a seventh aspect of the present invention, there is provided an inkjet recording method in which images of the same color are divided and recorded using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport means. Data supply for dividing raster data obtained by raster development of image data and assigning the divided raster data to the plurality of line heads so that the number of dots recorded by each line head is equal to each other And a control step of controlling printing by each of the ejectable heads according to the raster data assigned by the data supply means.

  According to a ninth aspect of the present invention, a first recording mode for recording the image data by the plurality of line heads and a second recording mode for recording the image data of the same color by a single line head are provided. And the first and second recording modes can be selectively switched and executed.

  According to a tenth aspect of the present invention, there is provided an inkjet recording method in which images of the same color are divided and recorded using a plurality of line heads arranged along the recording medium transport direction by the recording medium transport means. Raster data obtained by raster development of image data is divided, a data supply step for assigning to a plurality of print heads, and printing by each dischargeable head is controlled according to the raster data assigned by the data supply means A control step, wherein the image data consists of a plurality of pages, and the data supply step assigns the divided raster data to each of the plurality of recording heads in the recording of the image data. It is characterized by switching.

  An eleventh aspect of the present invention is a storage medium that stores a control program for realizing the ink jet recording method by a computer.

  A twelfth aspect of the present invention is a control program for realizing the ink jet recording method by a computer.

  According to the present invention, when a line head in a state where ink cannot be properly ejected is present in a part of a plurality of line heads for forming the same color image, the line head is excluded. The image data is divided and supplied to the line head. For this reason, it is possible to execute an appropriate recording operation using a line head capable of properly discharging ink without stopping the recording operation. Therefore, for example, when there is a line head with a little endurance life or when there is a shortage of ink in the sub-tank that supplies ink to each line head, the line head having a sufficient life expectancy or sufficient ink is stored. Appropriate image formation can be continuously performed using the sub-tank. For this reason, throughput can be improved. Further, since the recording can be continuously performed, it is possible to suppress the generation of useless paper that is generated when the recording operation is stopped.

  Furthermore, according to the present invention, it is possible to avoid a specific recording head from being intensively used, and to suppress the replacement frequency of the recording head.

[First Embodiment]
FIG. 1 is a diagram showing a main configuration of an ink jet recording system according to an embodiment of the present invention.
The ink jet recording system in this embodiment includes an ink jet recording apparatus 107 that performs a recording operation on a recording medium, and a host computer 106 that exchanges various data with the ink jet recording apparatus 107. The host computer 106 and the ink jet recording apparatus 107 are connected by a printer cable 108. Various data including image data and cleaning commands processed by the host computer 106 are transmitted to the ink jet recording apparatus 107. As a result, a recording operation is performed in the inkjet recording apparatus 107. Also, printer status such as error information of the ink jet recording apparatus 107 is transmitted to the host computer (106). Therefore, the state of the ink jet recording apparatus can be recognized by the host computer.

  Further, the ink jet recording apparatus according to the present embodiment forms a monochrome image using four long line heads that eject ink by the ink jet recording method.

  That is, the inkjet recording apparatus 107 has four line heads 101 to 104 arranged as recording means in parallel in the conveyance direction of the recording medium P. In each line head, a plurality of ink ejection nozzles that eject black ink by an inkjet recording method are arranged. An electrothermal conversion element is disposed in each ink ejection nozzle of the line head used in this embodiment. The ink in each nozzle is ejected from the ejection port by the thermal energy generated by each electrothermal conversion element.

  Each of the four line heads is provided with four sub-tanks 121 to 124 that are detachable from each other. The black ink stored in each sub tank 121-124 is supplied to each line head 101-104. When the ink remaining amount in each of the sub tanks 121 to 124 becomes a predetermined value or less, the black ink stored in the common main tank 125 is supplied to each of the sub tanks 121 to 124.

  In the common main tank 125 and each of the sub tanks 121 to 124, a pair of electrodes facing each other with a predetermined gap are arranged from the position spaced apart from the bottom of each tank by a predetermined distance from the top to the top. Yes. When ink is present between the pair of electrodes, both electrodes are in a conductive state, and a state where ink can be supplied is detected. Conversely, when there is no ink between the pair of electrodes, both electrodes are in a non-conductive state, and a shortage of ink is detected.

  The recording medium P is transported along a transport path below each of the line heads 101 to 104 by a transport unit 110 including an endless transport belt or a transport roller driven by a motor. In this transport operation, when the front end of the recording medium P is detected by the recording medium sensor 111 disposed on the upstream side in the transport direction from the line head 101, recording on the recording medium P is performed at a predetermined timing with reference to the detection time. Operation starts. FIG. 1 shows a case where continuous paper is used as the recording medium P.

FIG. 2 is a block diagram showing a schematic configuration of the control unit 201 of the line type ink jet recording apparatus used in the present embodiment.
The control unit 201 includes a CPU 202, a ROM 203, a RAM 203, an image memory 205, and the like. The CPU 202 performs processing such as various calculations, discrimination, and control. The ROM 203 stores a control program and the like. The RAM 204 is used as a work area or reception buffer for various data processing by the CPU 202. The image memory 205 is used as an image development unit.

  The control unit 201 is provided with a head drive circuit 209, a motor driver 210, an interface control unit 207, a control circuit 212, and the like. Among these, the head drive circuit 209 drives the electrothermal conversion elements of the line heads 101 to 104. The motor driver 210 drives various motors 206 that control a cleaning operation and a recording operation for keeping the recording heads 101 to 104 in an optimum state for recording. The control circuit 212 controls the head driving circuit 209, the motor driver 210, the I / O 211, and the like according to a control signal from the CPU 202. The interface control unit 207 is connected between the transport unit 110 and the I / O.

  The recording apparatus basically receives image data, a cleaning command, and the like transmitted from the host computer (information processing apparatus) 106 via the printer cable 108 and the USB controller 208, and operates according to the data and various commands.

Next, the divided recording operation of the ink jet recording apparatus having the above configuration will be described below with reference to FIG.
Recording on the recording medium P is performed based on a recording horizontal synchronization signal synchronized with the conveyance of the recording medium P. When the horizontal synchronization signal is detected, the data for one raster stored in the black image memory 205 is transferred to the line head 101 located on the most downstream side in the recording medium conveyance direction (Y direction), and one raster image is obtained. 301 is recorded. Next, when a horizontal synchronization signal is detected, the next raster image data read from the black image memory 205 is transferred to the line head 101 to form a raster recording 302. When the next horizontal synchronization signal is detected, the image data in the black image memory 205 is transferred to the line head 103 to form a raster recording 303. Thereafter, when the next horizontal synchronization signal is further detected, the image data in the black image memory 205 is transferred to the black head 103 to form a raster recording 304. Thereafter, similarly, the black heads 101 to 104 are sequentially used to share an image in units of one raster.

  As described above, in the first embodiment, when the four line heads that eject black ink are in a state where ink can be ejected properly, monochrome image data developed in a continuous area is converted into one raster unit. Are sequentially supplied to the four black recording heads. As a result, the monochrome image is recorded by being shared by the four linear heads. This makes it possible to record a monochrome image at a maximum recordable frequency that is four times the maximum drive frequency of a single recording head. As a result, when a recording operation is performed using a single recording head. Four times the recording throughput can be obtained.

Hereinafter, a control operation procedure when changing the number of divisions in the first embodiment will be described with reference to FIG.
FIG. 4 is a flowchart showing recording operation control performed according to the life expectancy of the recording head.
The control unit 201 of the ink jet recording apparatus cumulatively counts the number of ink droplet ejections performed from the start of use of each line head to the present, and based on the count value, the life expectancy of each line head. Is detected (S401). That is, based on the count value cumulatively counted by the control unit 201 and the endurance life of each line head, it is detected whether or not the endurance life of each line head has reached a preset threshold value. For a line head whose life expectancy has reached the threshold value, it is determined that the life expectancy of the line head is small and insufficient to continue the recording operation. The endurance life of the line head depends on the cumulative number of ejections per nozzle, and the endurance life is, for example, a nominal value of 5 × 10 ⁸ [dot / Nozzle]. This value is statistically obtained data and can be said to be almost guaranteed, but it also depends on the environmental conditions in which the recording apparatus is used. Since the cumulative number of discharges for each nozzle is determined by the input recording data, even if all line heads have the same endurance life in the initial state, even if they start to be used at the same time, they will have a longevity due to long-term use. There will be a difference. For this reason, it is necessary to detect the life expectancy of each line head to be used.

  In this manner, when a line head having a short life expectancy is detected, a recordable head capable of continuing the remaining recording operation is specified and the number of the heads is confirmed (S402). Here, when the number of recordable heads is one or more, when the recording operation is performed by dividing the remaining recordable heads, it is necessary to reduce the currently set recording medium conveyance speed. It is determined whether or not there is (S404). That is, when the number of recordable heads decreases in the confirmation operation of S402, the maximum recordable frequency that can be recorded by the remaining recordable heads, that is, the maximum recording speed is reduced. Therefore, it is determined whether or not the recording operation can be continued with the currently set conveyance speed.

  Here, if it is judged that it is necessary to decelerate, it decelerates and performs the conveyance speed (S405), and if it is not necessary to decelerate, the current conveyance speed is maintained. Thereafter, image data is sequentially supplied to each recordable head for each raster, and a monochrome image is divided and recorded using each recordable head (S406). When the number of remaining recording heads is zero, the recording operation is stopped and the display unit of the ink jet recording apparatus is driven to display an error. Further, an error signal is transmitted to the host computer 106 side and an error is displayed on the display of the host computer 106 side (S403). Note that the line head determined to have a short life expectancy may be replaced when a series of recording operations are stopped.

  As described above, the recording apparatus can continue to operate even when a plurality of recording heads in the recording apparatus reach the end of their lives almost simultaneously, but such a case seems to be extremely rare.

  In this way, if there is a line head that is expected to have a short life expectancy to continue a series of recording operations among a plurality of line heads, the remaining heads before the line head becomes unrecordable. An image is formed by switching to a recording operation using only a recordable head. For this reason, it is possible to continue recording without degrading the recording quality.

  FIG. 5 is a flowchart showing the recording operation control performed in accordance with the remaining amount of ink in the sub tanks 104 to 101 provided for each line head.

  As described above, each of the sub tanks 104 to 101 is provided with ink remaining amount detecting means having a pair of electrodes. This ink remaining amount detecting means detects whether or not the amount of ink remaining in each sub-tank has become smaller than a certain amount (whether or not ink shortage has occurred), and the detection result is the control of the ink jet recording apparatus. Is transmitted to the unit 201. When ink shortage is detected in at least one of the subtanks 104 to 101 (S501), the control unit 201 determines whether there is a subtank in which ink shortage has not occurred (S502). When there is a sub-tank where ink shortage does not occur, the position and number of sub-tanks where ink shortage does not occur are detected. Thereafter, when performing a recording operation using a line head (recordable head) connected to a sub-tank where ink shortage has not occurred, the currently set recording medium conveyance speed is reduced. It is determined whether or not it is necessary (S504). If it is determined that it is necessary to decelerate, the conveying operation is performed after decelerating (S505). If it is not necessary to decelerate, the current conveying speed is maintained. Thereafter, image data is sequentially supplied for each raster to a line head (recordable head) connected to a sub tank in which ink shortage has not occurred, and a monochrome image is divided and recorded using each recordable head. (S506).

  If the number of remaining line heads is zero, the recording operation is stopped, and an error is notified in the ink jet recording apparatus 107 and the host computer 106 as described above (S503).

  As described above, in the first embodiment, when there is a subtank that is expected to run out of the remaining amount of ink in a series of printing operations among a plurality of subtanks, the ink in the subtank is completely consumed. Before, an image is formed by switching to a recording operation using only the line head connected to the remaining sub-tanks. For this reason, it becomes possible to continue recording without degrading the recording quality.

Next, the recording operation when one of the four line heads 101 to 104 becomes unusable will be described more specifically.
When the life expectancy of the line head 104 becomes a certain value or less or the remaining amount of ink in the sub tank 202 becomes a certain amount or less, the control unit 201 determines that the line head 104 is not suitable for continuous recording. . In this case, it is determined from the period of the horizontal synchronization signal whether the current conveyance speed of the recording medium P can be recorded by the remaining three line heads. If the recording speed cannot be recorded, the conveyance speed is recorded. Control to drop to a possible speed. Since the maximum transportable recording speed is proportional to the number of recording heads, the maximum recordable speed corresponding to the number of recording heads is set in advance in the control program. After the recordable speed is set, the division number of the image data is changed from 4 to 3.

  Thereafter, for example, a recording operation as shown in FIG. 6 is performed by the three recordable line heads 101 to 104. That is, when a horizontal synchronization signal is detected, data for one raster stored in the black image memory 205 is transferred to the line head 101 (recordable head) located on the most downstream side in the recording medium conveyance direction (Y direction). Is done. As a result, one raster image 701 is recorded. Next, when a horizontal synchronization signal is detected, the data for one raster read from the black image memory 205 is not transferred to the line head 102, but is transferred to the line head 103 which is a recordable head to be a raster image. 702 is formed. When the next horizontal synchronization signal is detected, the image data for the next one raster read from the black image memory 205 is transferred to the line head 104 to form a raster image 703. Thereafter, the black heads 101, 103, and 104 are similarly assigned to one raster unit to form an image.

  As described above, according to the first embodiment, as long as there is a recordable line head among the plurality of line heads, the image data is stored even if another line head falls into a recording impossible state. Switch to supply only to the recordable head. Accordingly, a series of recording operations can be continuously performed without stopping the recording operation. Therefore, according to the first embodiment, the throughput can be greatly improved as compared with the case where the recording operation is temporarily stopped and the head is replaced or the ink is supplied.

  In addition, even if a line head that cannot be recorded is generated, a series of recording can be continuously performed without degrading the image quality, so that waste of the recording medium and ink can be prevented.

  In the first embodiment, the case where the life expectancy of the line head and the ink remaining amount are detected and the image data supply operation is switched based on the detection result has been described as an example. However, the present invention is not limited to the above-described embodiment, and it is possible to detect other than the remaining life expectancy or the remaining amount of ink and switch the image data supply operation based on the detection result. For example, non-ejection detection means for detecting ejection failure from the recording head is provided, and the image data is divided and supplied only to the line head excluding the ejection failure head detected by the non-ejection detection means. good. Further, the image data may be divided and supplied to the other line heads except for the line head in which the abnormal temperature is detected by the temperature detection means of the recording head. That is, any detection means may be applied as long as it is a means for specifying a line head capable of proper ink ejection, and the present invention is not limited to the above embodiment.

  In the first embodiment, the case where the remaining ink amount is detected by using a pair of electrodes arranged in each tank as the remaining ink amount detecting means has been described as an example. However, the ink remaining amount detecting means can detect the ink remaining amount by detecting the number of ink ejected from each line head. In this case, the configuration of each tank can be simplified, the manufacturing cost can be reduced, and the remaining amount of ink can be determined in advance based on the image data on the host computer side.

  In the first embodiment, the control unit provided in the ink jet recording apparatus serves as a dischargeable head detection unit that detects a dischargeable head that enables proper ink discharge among a plurality of line heads. A function as an image data dividing unit that divides image data for forming the same color image by the number of dischargeable heads detected by the dischargeable head detection unit is provided in the inkjet recording apparatus. The case where it is realized by the control unit being described has been described as an example. However, it is also possible to give each function to the host computer. In other words, the divided image data and control data for specifying the line head to which the divided image data should be supplied can be transmitted from the host computer to the inkjet recording apparatus. In this case, on the ink jet recording apparatus side, it is also possible to supply the received divided image data to the line head instructed by the control data. According to this, it is possible to obtain the same effect as in the above embodiment, and it is possible to further simplify the control operation in the ink jet recording apparatus.

  In the first embodiment, a case where a monochrome image is recorded using only black ink has been described. However, the present invention can also be applied to a case where an ink image other than black ink is divided and recorded. is there.

Next, another embodiment of the present invention will be described with reference to the accompanying drawings.
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
Note that the second embodiment also has the configuration shown in FIGS. 1 and 2 as in the first embodiment. Therefore, in the following description, an image forming operation executed mainly by the ink jet recording apparatus 107 according to the present embodiment will be described.
In the ink jet recording apparatus according to the second embodiment, raster data obtained by raster development of image data of the same color is divided, and when the divided raster data is allocated to a plurality of recording heads, an allocation method for each page It is characterized by changing. Hereinafter, this will be described in detail with reference to FIG.

  In FIG. 7, reference numeral 400 denotes raster data obtained by raster development of image data recorded on each page of the recording medium P. 400A (8 dots), 400B (2 dots), 400C (2 dots), 400D (2 dots) and 400E (8 dots) are the divided raster data.

  In the processing of the first page, raster recording (401) is obtained by assigning raster data 400A (8 dots) to the line head (101) in accordance with a conveyance position detection signal of the recording medium P by an encoder (not shown). It is done. Similarly, at the next timing, raster data 400B (2 dots) is transferred to the line head (102), raster data 400C (2 dots) is transferred to the line head (103), and raster data 400D (2 dots) is transferred to the line head (104). ), Raster data 400E (8 dots) is assigned to the line head (101), and raster recording (401 to 405) is performed, whereby an output image 406 is obtained.

  When the processing for the first page is completed, the number of pixels recorded by the line head (101) is 16 dots, the line head (102) is 2 dots, the line head (103) is 2 dots, and the line head (104) is 2 dots. It becomes.

  The processing for the second page differs from the first page for the divided raster data 400A (8 dots), 400B (2 dots), 400C (2 dots), 400D (2 dots), and 400E (8 dots). Assign to line head.

  For example, raster data 400A (8 dots) is assigned to the line head (102), raster data 400B (2 dots) is assigned to the line head (103), raster data 400C (2 dots) is assigned to the line head (104), and raster data 400D. (2 dots) is assigned to the line head (101), raster data 400E (8 dots) is assigned to the line head (102), and raster recording (401 ′ to 405 ′) is performed to obtain an output image 406 ′.

  In the processing of the third page, raster data 400A (8 dots) is applied to the line head (103), raster data 400B (2 dots) is applied to the line head (104), and raster data 400C (2 dots) is applied to the line head (102). The raster data 400D (2 dots) is assigned to the line head (101), the raster data 400E (8 dots) is assigned to the line head (103), and raster recording (401 ″ to 405 ″) is performed to output an output image 406 ′. 'Is obtained.

  Similarly, in the processing of the fourth page, the raster data 400A (8 dots) is used for the line head (104), the raster data 400B (2 dots) is used for the line head (101), and the raster data 400C (2 dots) is used for the line head (104). 102), raster data 400D (2 dots) is assigned to the line head (103), raster data 400E (8 dots) is assigned to the line head (104), and raster recording (401 ′ ″ to 405 ′ ″) is performed. As a result, an output image 406 ′ ″ is obtained. Reference numeral 407 denotes a correspondence relationship between each line head (101 to 104) and each raster recording (401 to 405, 401 ′ to 405 ′, 401 ″ to 405 ″, 401 ′ ″ to 405 ′ ″). It is shown.

  As a result of the processing by the divided image forming means, when the processing for the fourth page is completed, the accumulated recording pixel number of the line head (101) is 22 dots, the line head (102) is 22 dots, and the line head (103). Is 22 dots, and the cumulative recording pixel number of the line head (104) is 22 dots, and the cumulative recording pixel number of each line head is equalized.

  As described above, in the second embodiment, when forming the same image data of the same color over a plurality of pages, for example, a ruled line of a form, the image data is raster-developed, and the generated raster data Is divided and the divided raster data is assigned to a plurality of line heads for recording. When assigning this data, the line head assigned to each page is changed. Thereby, it is possible to avoid that only a specific line head is used intensively, and it is possible to avoid the problem that the replacement rate of the specific line head is increased.

  In the above description, the line heads to which the divided raster data are assigned are shifted one by one for each page. However, if a plurality of line heads are used at the same rate, However, the present invention is not particularly limited, and the line head to which the divided raster data is allocated may be randomly changed.

[Third Embodiment]
In the second embodiment, by changing the line head to which the divided raster data is assigned for each page, it is avoided that only a specific line head is used. However, in the third embodiment, when raster data obtained by raster development of the same image data of the same color is divided and assigned to a plurality of line heads, the assignment is made according to the number of recording pixels of each line head. The previous line head is changed. Hereinafter, a divided image forming unit that determines an allocation destination according to the number of recording pixels of each line head when the divided raster data is allocated to each recording head will be described with reference to FIG.

  In FIG. 8, 500 is raster data obtained by raster development of image data, and 500A (1 dot), 500B (2 dots), 500C (3 dots), and 500D (4 dots) are divided rasters. It is data.

  In the first page, raster recording (501) is performed by allocating raster data 500A (one dot) to the line head (101) in accordance with a conveyance position detection signal of the recording medium (P) by an encoder (not shown). Is obtained. Similarly, at the next timing, raster data 500B (2 dots) is transferred to the line head (102), raster data 500C (3 dots) is transferred to the line head (103), and raster data 500D (4 dots) is transferred to the line head (104). ) And raster recording (501 to 504), an output image 505 is obtained.

  When the processing of the first page is completed, the number of recording pixels of the line head (101) is 1 dot, the line head (102) is 2 dots, the line head (103) is 3 dots, and the line head (104) is recorded. The number of pixels is 4 dots.

  In the processing of the second page, the allocation destination is changed according to the number of recording pixels of each line head. That is, raster data with a small number of recording pixels is assigned to a line head with a large number of recording pixels on the previous page, and raster data with a large number of recording pixels is assigned to a line head with a small number of recording pixels on the previous page. For example, raster recording (501 ') is obtained by assigning raster data 500A (1 dot) to the line head (104) in accordance with a conveyance position detection signal of the recording medium (P) by an encoder (not shown). Similarly, at the next timing, raster data 500B (2 dots) is transferred to the line head (103), raster data 500C (3 dots) is transferred to the line head (102), and raster data 500D (4 dots) is transferred to the line head (101). ) And raster recording (501 ′ to 504 ′), an output image 505 ′ is obtained. Reference numeral 506 denotes a correspondence relationship between each line head (101 to 104) and each raster recording (501 to 504, 501 'to 504').

  When the processing for the second page is completed, the accumulated recording pixel number of the line head (101) is 5 dots, the line head (102) is 5 dots, the line head (103) is 5 dots, and the line head (104) The cumulative number of recording pixels is 5 dots, and each line head is used at the same rate.

  In the above description, the line head to which the divided raster data is assigned is sequentially changed for each page according to the number of recording pixels. However, the line head to which the raster data is assigned is changed to the cumulative number of recording pixels. Accordingly, there is no problem even if it is sequentially changed every several pages.

  In addition, when changing the line head to be allocated according to the number of recording pixels of each line head, the line head to be allocated after calculating the total number of dots of raster data in advance so that the frequency of use of each line head is uniform. May be determined. This will be described below with reference to FIG.

  Reference numerals 620, 621, and 622 in FIG. 9 are variable data. 620 is raster data obtained by raster development of the image data of the first page, and 600A (1 dot), 600B (2 dots), 600C (3 dots), and 600D (4 dots) are divided raster data. It is. 621 is raster data obtained by raster development of the image data of the second page, and 601A (4 dots), 601B (2 dots), 601C (2 dots), and 601D (4 dots) are divided raster data. It is. 622 is raster data obtained by raster development of the image data of the third page, and 602A (1 dot) and 602B (1 dot) are divided raster data.

  The total number of recorded pixels for three pages is 24 dots. When this is divided so that the number of accumulated recording pixels of each line head is the same, when dividing into four line heads, raster data of 6 dots is assigned to each line head.

  For example, raster data of 600A (1 dot), 601A (4 dots), and 602A (1 dot) is used as the line head (101), and raster data of 600B (2 dots) and 601D (4 dots) is used as the line head (102). In addition, 600C (3 dots), 601B (2 dots), and 602B (1 dot) raster data are transferred to the line head (103), and 600D (4 dots) and 601C (2 dots) raster data are transferred to the line head (104). And output images (611 to 613) are obtained by raster recording (601 to 610). When the processing for the third page is completed, the cumulative recording pixel number of each line head is 6 dots.

  In another embodiment, the line head to which the divided raster data is allocated may be determined according to the history of the number of recorded pixels of the line head. That is, raster data with a small number of recording pixels may be allocated to a line head with a large cumulative recording pixel number, and raster data with a large number of recording pixels may be allocated to a line head with a small cumulative recording pixel number.

[Fourth Embodiment]
In the second and third embodiments, the case where four black heads are used as the line head has been described. However, the present invention can be applied to a configuration in which two or more line heads in charge of recording of the same color exist. Needless to say. For example, if six black heads are used as the line head, the effect of 1.5 times that of the first embodiment can be obtained (the replacement frequency becomes 2/3 times).

  In this embodiment, a monochrome recording apparatus has been described as an example. However, for example, a configuration of three black heads, one cyan head, one magenta head, and one yellow head is applied to a full color recording apparatus. Also good. In this case, for example, high-speed recording is performed by applying the divided image forming unit using three black heads in the monochrome recording mode, and high-quality recording is performed without applying the divided image forming unit in the full-color recording mode. A recording apparatus having a number of options (recording modes) can be configured.

  The recording apparatus used in the present invention uses a charge control type, a continuous type using a spray system, a bubble jet (registered trademark) system using thermal energy, or a piezo system using a piezoelectric vibration plate. It may be an on-demand type. However, in terms of throughput, a full line type inkjet line head configured by arranging a number of printing elements corresponding to the printing width is preferable in that printing can be performed at extremely high speed.

[Other Embodiments]
Note that the present invention can be applied to a system (for example, a copier, a facsimile machine, etc.) consisting of a single device even when applied to a system composed of a plurality of devices (for example, a host computer, interface device, reader, printer, etc.). It may be applied.

  Another object of the present invention is to supply a storage medium storing software program codes for implementing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. Needless to say, this can also be achieved by reading and executing the program code stored in the.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. be able to.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a figure which shows the main structures of the inkjet recording system in embodiment of this invention. It is a block diagram which shows schematic structure of the control part of the line type inkjet recording device used by embodiment of this invention. It is explanatory drawing which shows the recording operation of the inkjet recording device in embodiment of this invention, and has shown the case where each line head is in the state which can discharge an ink appropriately. 6 is a flowchart illustrating recording operation control performed according to the endurance life of the line head in the embodiment of the present invention. 6 is a flowchart illustrating recording operation control performed in accordance with the remaining amount of ink in a sub tank provided for each line head in the embodiment of the present invention. It is explanatory drawing which shows the recording operation of the inkjet recording device in embodiment of this invention, and has shown the case where one line head becomes an unusable state among four line heads. FIG. 3 is a diagram for explaining divided image forming means in the recording apparatus according to the first embodiment of the present invention. It is a figure for demonstrating the division | segmentation image formation means in the recording device concerning the 2nd Embodiment of this invention. It is a figure for demonstrating the division | segmentation image formation means in the recording device concerning the 3rd Embodiment of this invention. It is a figure which shows an example of the image data used by printing of form paper.

Explanation of symbols

101 Line head (Black 1)
102 Line head (Black 2)
103 Line head (Black 3)
104 line head (black 4)
105 Black Image Memory 107 Inkjet Recording Device 110 Conveyance Unit 111 Recording Medium Detection Sensor 201 Control Unit 202 CPU
203 Program storage memory 203 ROM
205 Image Memory 206 Various Motors 207 Transport Control Interface 208 USB Controller 301 Raster Image Formed by Line Head 101 302 Raster Image Formed by Line Head 102 303 Raster Image Formed by Line Head 103 304 Formed by Line Head 104 Raster image 701 Raster image formed by the line head 104 702 Raster image formed by the line head 104 703 Raster image formed by the line head 104 400A to 400B Divided raster data 401 to 405 Raster recording on the first page 401 ′ to 405 ′ Raster recording on the second page 401 ″ to 405 ″ Raster recording on the third page 401 ′ ″ to 405 ′ ″ Raster recording on the fourth page 500A to 500 Divided raster data 501 to 504 Raster recording on the first page 501 'to 504' Raster recording on the first page 600A to 600D Divided raster data 601A to 601D Divided raster data 602A to 602B Divided raster data 601 -604 Raster recording on the first page 605-608 Raster recording on the second page 609-610 Raster recording on the third page P Recording medium L Ruled line

Claims (19)

In an ink jet recording apparatus that uses a plurality of line heads arranged along a recording medium conveyance direction by a recording medium conveyance unit to divide and record an image of the same color,
Among the plurality of line heads for forming an image of the same color, an image that divides and supplies the image data for forming the image of the same color to an ejectable head that enables proper ink ejection Data supply means;
An ink jet recording apparatus comprising: control means for controlling recording by each of the ejectable heads in accordance with image data supplied by the image data supply means. In an ink jet recording apparatus that uses a plurality of line heads arranged along a recording medium conveyance direction by a recording medium conveyance unit to divide and record an image of the same color,
Among the plurality of line heads for forming an image of the same color, a dischargeable head detection unit that detects a dischargeable head that enables proper ink discharge; and
Image data supply means for dividing the image data for forming the image of the same color by the number of the dischargeable heads detected by the dischargeable head detection means, and supplying the divided image data to each dischargeable head When,
An ink jet recording apparatus comprising: control means for controlling a recording operation by each of the ejectable heads according to the divided image data supplied by the image data supply means.   The dischargeable head detection means includes a life expectancy detection means for detecting a life expectancy of the line head, and a discrimination means for setting a line head having a life expectancy detected by the life expectancy detection means to be a dischargeable head. The inkjet recording apparatus according to claim 2, wherein:   4. The ink jet recording apparatus according to claim 3, wherein the endurance life detection unit detects the endurance life of the line head by detecting the number of ink ejected from each line head.   The ejectable head detection means detects the remaining amount of ink in each ink tank that supplies ink independently to each of the plurality of line heads, and the remaining ink detection means detects the remaining amount of ink. The inkjet recording apparatus according to claim 2, further comprising: a discriminating unit that uses a line head in which the remaining amount of ink in each of the ink tanks is equal to or greater than a predetermined amount as an ejectable head.   The ink remaining amount detecting means has a pair of electrodes disposed in each ink tank via a predetermined gap, and detects whether or not the pair of electrodes is in a conductive state via ink. The ink jet recording apparatus according to claim 5, wherein whether or not the remaining amount of ink is equal to or greater than a certain amount is detected.   The control means includes control means for controlling a recording medium conveyance speed by the conveyance means and a recording frequency by each dischargeable head according to the number of the dischargeable heads detected by the dischargeable head detection means. The ink jet recording apparatus according to claim 2, wherein In an inkjet recording method for dividing and recording an image of the same color using a plurality of line heads arranged along the recording medium conveyance direction by the recording medium conveyance means,
A dischargeable head detection process for detecting a dischargeable head that enables proper ink discharge among a plurality of line heads for forming an image of the same color;
An image data dividing step of dividing image data for forming the image of the same color by the number of dischargeable heads detected by the dischargeable head detection means;
An image data supply step of supplying the divided image data divided in the image data division step to each of the dischargeable heads;
And a step of controlling a recording operation by each of the ejectable heads in accordance with the divided image data supplied by the image data supply means. Image data for forming the same color image is transmitted to an ink jet recording apparatus that records the same color image using a plurality of line heads arranged along the recording medium conveyance direction by the recording medium conveyance means. An information processing apparatus that enables
Among the plurality of line heads for forming an image of the same color, a dischargeable head detection unit that detects a dischargeable head that enables proper ink discharge; and
Image data dividing means for dividing image data for forming the image of the same color by the number of dischargeable heads detected by the dischargeable head detection means;
An information processing apparatus comprising: image data transmission means capable of transmitting the divided image data divided by the image data dividing means to the inkjet recording apparatus. In an ink jet recording apparatus that uses a plurality of line heads arranged along a recording medium conveyance direction by a recording medium conveyance unit to divide and record an image of the same color,
Data supply means for dividing raster data obtained by raster development of image data of the same color, and assigning the divided raster data to a plurality of line heads;
Control means for controlling printing by each of the ejectable heads according to the raster data assigned by the data supply means,
The data supply means assigns the divided raster data to the plurality of line heads so that the number of dots recorded by the line heads is equal to each other in the recording of the image data. Inkjet recording device. In an ink jet recording apparatus that uses a plurality of line heads arranged along a recording medium conveyance direction by a recording medium conveyance unit to divide and record an image of the same color,
Data supply means for dividing raster data obtained by raster development of image data of the same color, and assigning the divided raster data to a plurality of line heads;
Control means for controlling printing by each of the ejectable heads according to the raster data assigned by the data supply means,
The image data is composed of a plurality of pages, and the data supply means switches the allocation for each page when allocating the divided raster data to the plurality of line heads in the recording of the image data. Inkjet recording device. A first recording mode for recording the image data by the plurality of line heads;
A second recording mode for recording the image data of the same color with one line head,
The inkjet recording apparatus according to claim 10 or 11, wherein the first and second recording modes can be selectively switched and executed. In an inkjet recording method for dividing and recording an image of the same color using a plurality of line heads arranged along the recording medium conveyance direction by the recording medium conveyance means,
Raster data obtained by raster development of image data of the same color is divided, and the divided raster data is divided into the plurality of line heads so that the number of dots recorded by each line head is equal to each other. The data supply process to be assigned,
And a control step of controlling printing by each of the ejectable heads according to raster data assigned by the data supply means. In an inkjet recording method for dividing and recording an image of the same color using a plurality of line heads arranged along the recording medium conveyance direction by the recording medium conveyance means,
A data supply step of dividing raster data obtained by raster development of image data of the same color and allocating them to a plurality of recording heads;
A control step of controlling printing by each of the ejectable heads according to the raster data assigned by the data supply means,
The image data is composed of a plurality of pages, and the data supply step switches the allocation for each page when allocating the divided raster data to the plurality of recording heads in the recording of the image data. Inkjet recording method.   A first recording mode for recording the image data by the plurality of recording heads; and a second recording mode for recording the image data of the same color by a single recording head. 15. The ink jet recording method according to claim 13, wherein the ink jet recording method can be used by switching modes.   The image data supply means divides the image data for forming the image of the same color, and the divided image data so that the numbers of dots recorded by the line heads are equal to each other. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is allocated and supplied to an ejection head that enables the proper ink ejection.   The image data supply means sequentially divides raster data obtained by raster development of image data of the same color consisting of a plurality of pages, and assigns and supplies the divided raster data to the plurality of line heads. 9. The ink jet recording apparatus according to claim 1, wherein the allocation of each raster data to each line head is switched at least for each page.   A storage medium storing a control program for realizing the recording method according to claim 8 by a computer. A control program for realizing a recording method according to any one of claims 8, 13 to 17 by a computer.

Images