JP5271102B2 - Recording apparatus and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus capable of suppressing deterioration in image quality when a poor delivery of a nozzle is generated in a multi-drops type recording apparatus, and to provide a recording method. <P>SOLUTION: The recording apparatus is equipped with an inkjet head 4 having a nozzle 11, and forms an image by delivering ink on a recording medium P from recording data. The multi-drops type recording apparatus which can change the size of a dot formed on the recording medium in accordance with the number of drops of ink drops delivered from one nozzle to one pixel includes: a storing means for storing the position of a poor delivering nozzle, the number of drops of poor delivery, a plurality of alternative patterns including the number of drops of alternative delivery to the number of drops of poor delivery, and an alternative condition for selecting either one pattern from a plurality of the alternative patterns; and a controlling means for controlling to select an alternative pattern on the basis of the alternative condition in alternative to the number of the drops of poor delivery delivered from the nozzle of poor delivery and to deliver ink with the number of drops other than the number of drops of poor delivery from the nozzle of poor delivery. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a recording apparatus and a recording method.

  2. Description of the Related Art Conventionally, there are recording apparatuses that record characters, images, and the like by ejecting ink onto a recording medium such as a resin sheet in a banner advertisement or a signboard, for example, a large-sized ink jet printer. In such an ink jet printer, for example, as in the ink jet printer described in Patent Document 1, a so-called multi-dot is formed in which one large dot is formed by continuously ejecting ink to a pixel a plurality of times. A drop type ink jet printer is known.

  Here, in the conventional multi-drop type ink jet printer, when a defect (operation failure, shape defect, etc.) occurs in a part of the nozzle that discharges ink, if one drop is generated from the nozzle, ink is normally discharged. In such a case, there may be a discharge failure such that ink cannot be discharged normally.

  In order to solve such a problem, Patent Document 1 discloses a technique for forcibly changing the number of ink droplets when an ink discharge condition becomes a specific condition.

JP 2007-210245 A

  By the way, in the technique of Patent Document 1, when there is a problem with nozzle ejection itself, it is not possible to suppress ink ejection failure. For example, when it is impossible to eject two drops, it is not possible to substitute ejection with two drops.

  Also, as an alternative method when a nozzle failure occurs, a proposal has been proposed in which ink is discharged from a discharge hole near the discharge hole where the discharge failure occurs, but the ink discharge position is different. There's a problem. In addition, as an alternative method when a nozzle failure occurs, an alternative method by ejecting ink of a different color has been proposed, but there is a problem that the color of the ink is different. That is, there is a problem that the positions and colors of the dots to be formed are different from the original ones.

  Accordingly, the present invention has been made in view of the above circumstances, and provides a recording apparatus and a recording method capable of suppressing deterioration in image quality when a nozzle ejection defect occurs in a multidrop recording apparatus. It is to provide.

  The present invention provides the following means in order to solve the above problems.

The recording apparatus of the present invention includes an inkjet head having a plurality of nozzles, a conveyance unit that conveys a recording medium, and a carriage that carries the inkjet head and moves reciprocally along a direction perpendicular to the conveyance direction of the recording medium. When, wherein the a recording apparatus for forming an image by ejecting ink from the inkjet head onto the recording medium based on the recording data while moving the carriage, from one nozzle for one pixel The size of the dot formed on the recording medium is determined according to the number of ink droplets ejected within the period from the start of recording at the position of the one pixel to the start of recording at the position of the next pixel. in multi-drop type recording apparatus for variably, the position of the discharge-defective nozzle in which the pixels to be recorded becomes defective in a specific discharge droplet number, a said discharge Deshizuku number discharge Good and number of drops, said discharge out a plurality of alternate patterns of different droplet number defective droplet number, the plurality of alternative for selecting one pattern from the alternate pattern alternate discharge against said discharge out defective droplet number storage means for storing a condition, and to substitute the defective discharge number of drops ejected from the ejection failure nozzle stored in the storage means, on the basis of the said alternative condition stored in said storage means Control means for selecting an alternative pattern and performing control to eject ink of a number of drops other than the number of defective ejections from the ejection failure nozzle;
An operation panel, and an interface circuit connected to the control unit and connected to a host computer outside the recording apparatus, and the control unit receives an input from at least one of the operation panel and the host computer. The storage means controls to store the position of the defective ejection nozzle and the number of defective ejection droplets .

In the recording apparatus according to the present invention, when there is a nozzle that cannot eject a specific number of ink droplets in the multi-drop type recording apparatus, the position of the nozzle and the number of defective ejection droplets are stored in the storage means, and the control means In this case, the number of alternative ink droplets before and after the number of defective ink droplets is selected from the alternative pattern and alternative conditions, and the ink can be ejected with a number of droplets other than the number of defective ink droplets. You can record without waking up. Therefore, when a nozzle ejection failure occurs, recording can be performed while suppressing deterioration in image quality. After detecting the position of the ejection failure nozzle and the number of ink droplets with ejection failure by visual observation or the like, it can be manually input from the operation panel or the host computer, and the control means 51 stores the location of the ejection failure nozzle and the number of ejection failure droplets. Thus, the number of ink droplets to be replaced can be selected reliably based on the information on the position of the defective ejection nozzle and the number of defective ejection droplets, and recording can be performed without causing pixel omission. Therefore, when a nozzle ejection failure occurs, recording can be performed while suppressing deterioration in image quality.

  The recording apparatus of the present invention further includes a defective discharge nozzle detection unit that detects the position of the defective discharge nozzle and the number of defective discharge droplets, and the control unit stores the discharge in the storage unit based on the detection result. The position of the defective nozzle and the number of defective ejection droplets are stored.

  In the recording apparatus according to the present invention, the position of the ejection failure nozzle and the number of ejection failure droplets are automatically detected by the ejection failure nozzle detection means, and the position of the ejection failure nozzle and the number of ejection failure droplets are stored by the control means 51. Thus, the number of ink droplets to be replaced can be selected reliably based on the information on the position of the defective ejection nozzle and the number of defective ejection droplets, and recording can be performed without causing pixel omission. Therefore, when a nozzle ejection failure occurs, recording can be performed while suppressing deterioration in image quality.

The recording apparatus of the present invention, a temperature sensor for detecting the temperature of the ink, the droplet number to replace in case of non ejection number that can eject droplets with respect to the temperature of the ink to a temperature of the ink An alternative temperature information storage unit for storing the temperature, and the control means determines whether or not the number of ink droplets substituted for the temperature detected by the temperature sensor is undischargeable, and is undischargeable. is characterized in the alternative temperature information number of drops alternative to stored in the storage unit to the control for discharging the ink in the case.

  In the recording apparatus according to the present invention, the viscosity of the ink changes according to the temperature. For example, when the temperature is low, the viscosity of the ink generally increases. As a result, when ink droplets are ejected a plurality of times, there is a risk that the drive will not be in time and ejection failure will occur. When the temperature is low as described above, it is possible to suppress the occurrence of ejection failure by selecting the number of ink droplets to be replaced by the control unit based on the information in the replacement temperature information storage unit. Therefore, by selecting the number of ink droplets according to the temperature, it is possible to prevent the occurrence of ink ejection failure in advance.

The recording method of the present invention includes an inkjet head having a plurality of nozzles, a conveyance unit that conveys a recording medium, and a carriage that is mounted with the inkjet head and reciprocates along a direction perpendicular to the conveyance direction of the recording medium. When provided with, a recording method in which ink from the ink jet head based on the recording data while moving the carriage to form an image by ejecting onto the recording medium, one of the nozzles with respect to one pixel The size of dots formed on the recording medium in accordance with the number of ink droplets ejected within a period from the start of recording at the position of the one pixel to the start of recording at the position of the next pixel in multi-drop type recording method for varying a position of the defective discharge nozzle, wherein the pixels to be recorded becomes defective in a specific discharge droplet number, it is said discharge Deshizuku number And bad number of drops out, a plurality of alternative patterns of different droplet number and said discharge out defective droplet number replacing discharged against said discharge out defective number of drops, for selecting one pattern from the alternate pattern of the plurality of A storage means for storing alternative conditions ; an operation panel; and an interface circuit connected to the control means and connected to a host computer outside the recording apparatus, and at least one of the operation panel and the host computer Instead of the step of storing the position of the ejection failure nozzle and the number of ejection failure droplets in the storage means by the input from either one of the above, the substitution condition is replaced with the number of ejection failure droplets ejected from the ejection failure nozzle. A step of selecting the alternative pattern based on the step, and a step of ejecting ink with a number of drops other than the number of defective ejection from the ejection failure nozzle. It is characterized in that it is.

  In the recording method according to the present invention, in a multi-drop type recording apparatus, when there is a nozzle that cannot eject a specific number of ink droplets, the position of the nozzle and the number of defective ejection droplets are stored in a storage means, and the ejection is performed. Since the number of alternative ink droplets before and after the defective ink droplet number is selected from the alternative pattern and alternative conditions and ink is ejected with a droplet number other than the defective ejection ink droplet number, recording is performed without causing pixel omission. be able to. Therefore, when a nozzle ejection failure occurs, recording can be performed while suppressing deterioration in image quality.

The recording method of the present invention, a temperature sensor for detecting the temperature of the ink, the droplet number to replace in case of non ejection number that can eject droplets with respect to the temperature of the ink to a temperature of the ink An alternative temperature information storage unit for storing, a step of detecting the temperature of the ink, and a step of determining whether or not the number of ink droplets substituted for the temperature detected by the temperature sensor cannot be ejected. is characterized in that at the alternative temperature information number of drops alternative to stored in the storage unit when was impossible the discharge has a step of ejecting the ink.

  In the recording method according to the present invention, the viscosity of the ink changes depending on the temperature. For example, when the temperature is low, the viscosity of the ink generally increases. As a result, when ink droplets are ejected a plurality of times, there is a risk that the drive will not be in time and ejection failure will occur. When the temperature is low as described above, the occurrence of ejection failure can be suppressed by selecting the number of ink droplets to be replaced based on the information in the replacement temperature information storage unit. Therefore, by selecting the number of ink droplets according to the temperature, it is possible to prevent the occurrence of ink ejection failure in advance.

  According to the recording apparatus of the present invention, in the multi-drop type recording apparatus, when there is a nozzle that cannot eject a specific number of ink droplets, the position of the nozzle and the number of defective ejection droplets are stored in the storage unit, and control is performed. In the means, the number of alternative ink droplets before and after the number of defective ink droplets is selected from the alternative pattern and alternative condition, and the ink can be ejected with a number of droplets other than the number of defective ink droplets. It is possible to record without causing omission. Therefore, when a nozzle ejection failure occurs, recording can be performed while suppressing deterioration in image quality.

1 is a schematic configuration diagram of an inkjet printer according to an embodiment of the present invention. It is a top view which shows the structure of the surface of the inkjet head in embodiment of this invention. It is explanatory drawing which shows the multidrop-type recording method in embodiment of this invention. 1 is a block diagram of an ink jet printer according to an embodiment of the present invention. It is explanatory drawing which shows the recording method of the inkjet printer in embodiment of this invention. It is explanatory drawing which shows the example of the recording result of the inkjet printer in embodiment of this invention. It is explanatory drawing which shows the recording method of the inkjet printer in embodiment of this invention (when a small dot is ejection failure). It is explanatory drawing (when a middle dot is ejection failure) which shows the recording method of the inkjet printer in embodiment of this invention. It is explanatory drawing which shows the recording method of the inkjet printer in embodiment of this invention (when a large dot is ejection failure). It is a schematic block diagram of the discharge failure nozzle detection means in embodiment of this invention. It is explanatory drawing which shows the recording method of the inkjet printer in embodiment of this invention (when adjusting the number of dots with temperature).

  Next, an embodiment of a recording apparatus according to the present invention will be described with reference to FIGS. In the present embodiment, the case of an ink jet printer will be described.

  As shown in FIG. 1, an inkjet printer 1 according to the present embodiment includes a plurality of ink cartridges 2 each having ink of different colors, an inkjet head 4 that performs recording by ejecting ink droplets onto a recording medium P, and an ink cartridge. 2, an ink supply pipe (not shown) that supplies ink to the inkjet head 4, a carriage unit 6 that houses the inkjet head 4 and slides along the scanning direction on the recording medium P, and transports the recording medium P. A recording paper transport mechanism 7 and a base 8 on which these components are installed are provided. The sliding direction of the carriage unit 6 is indicated by a double arrow in FIG.

  The carriage unit 6 is connected to a conveyance belt 28 wound around a pair of pulleys 27. The pair of pulleys 27 are rotated by receiving a rotational driving force from a driving motor (not shown). The base 8 is provided with a guide rail 29 that guides the slide movement of the carriage unit 6. The guide rail 29 and the conveyance belt 28 are provided on the base 8 so as to extend in a direction orthogonal to the direction in which the recording medium P is conveyed. Accordingly, the carriage unit 6 slides in a direction orthogonal to the conveyance direction of the recording medium P.

  The ink jet head 4, the carriage unit 6, the conveyance belt 28, the pair of pulleys 27, the drive motor (not shown), and the guide rail 29 described above are print recording mechanisms that print and record characters and figures on the recording medium P. 30.

  The recording paper transport mechanism 7 includes a transport roller 31 that transports the recording medium P, a platen 32 that supports the recording medium P, and a pressing member 33 that presses the recording medium P against the transport roller 31. The platen 32 is provided on the base 8 so as to extend in a direction orthogonal to the direction in which the recording medium P is conveyed, similarly to the moving direction of the carriage unit 6.

  Here, as shown in FIG. 2, a plurality of nozzles 11 from which ink droplets are ejected are formed on the surface 4 a of the inkjet head 4 facing the recording medium P. A plurality of nozzles 11 are formed at substantially equal intervals in a row that intersects the scanning direction of the inkjet head 4 (the direction orthogonal to the conveyance direction of the recording medium P). Further, the nozzle 11 is configured to eject a plurality of ink droplets (up to three droplets in this embodiment) to one pixel (details will be described later). That is, as shown in FIG. 3, when one drop is ejected from one nozzle 11 to one pixel, a small dot 12 is formed (FIG. 3A), and when two drops are ejected, a medium dot 13 is formed (FIG. 3). 3 (b)) When three drops are ejected, a large dot 14 is formed (FIG. 3C). As described above, the ink jet printer 1 of the present embodiment is a so-called multidrop type ink jet printer.

  Next, a block diagram of the ink jet printer 1 in the present embodiment will be described.

  As shown in FIG. 4, the inkjet printer 1 is provided with a control device 50. The control device 50 includes a CPU and includes a control unit 51 that executes various controls, and a ROM 52. The control unit 51 is configured to control the entire device according to a program recorded in the ROM 52. The control device 50 has an interface that can be connected to a RAM 53 that is used as a primary storage location for various data or as a work area for the control means 51, and a host PC 54 that is a host computer outside the inkjet printer 1. And a circuit (I / F circuit) 55.

  The control unit 51 includes a recording image memory 56 for storing image data to be recorded on the recording medium P, an operation panel 57 for performing various settings, a conveyance roller driving circuit 58 for driving the conveyance roller 31, and a carriage unit. 6, a temperature sensor 61 for detecting the temperature of ink, preferably the temperature of ink in the head, and the position of the defectively ejected nozzle 11 when there is a defectively ejected nozzle 11 as storage means. And a plurality of alternative patterns including the number of defective ejection droplets, the number of alternative droplets ejected with respect to the number of defective ejection droplets, and an alternative condition for selecting any one pattern from the plurality of alternative patterns Non-ejection nozzle information memory 63, a drive waveform memory 65 for storing the number of ink droplets to be recorded on the nozzle 11, and a recorded image memory A drive waveform generating circuit 66 for generating a driving waveform based on the number of ink droplets to be actually recorded on the nozzle 11 based on information from the 6 and ejection failure nozzle information memory 63, are connected.

  In addition, a drive waveform generation circuit 66 is connected to the drive waveform memory 65. Further, an output circuit 67 that converts the drive waveform generated by the drive waveform generation circuit 66 into an electric signal is connected to the drive waveform generation circuit 66, and a predetermined number of ink droplets is recorded from the nozzle 11 connected to the output circuit 67. It is comprised so that it may be dripped at P.

  In addition, the non-ejection nozzle information memory 63 includes a non-ejection nozzle position storage unit 71 for storing the position of the nozzle 11 causing the ejection failure, and which number of ink droplets (dots) becomes the ejection failure in the ejection failure nozzle 11. A non-ejection ink droplet number storage unit 72 that stores whether or not, and an alternative temperature information storage unit 73 that stores information that associates the temperature of the ink, preferably the temperature of the ink in the head, with the number of ink droplets to be ejected. A plurality of alternative patterns including the number of ink droplets to be discharged in an alternative to the number of defective ink droplets discharged from the nozzle 11 having a defective discharge, and an alternative condition for selecting any one pattern from the plurality of alternative patterns; And an alternative method storage unit 74 for storing.

  In the control device 50 configured as described above, the control unit 51 generates an alternative pattern based on the alternative condition stored in the alternative method storage unit 74 in order to replace the number of defective ink droplets ejected from the defective ejection nozzle 11. The selected number is determined so that the number of droplets other than the number of defective ejection ink droplets is ejected from the ejection failure nozzle 11. The drive waveform generation circuit 66 generates a drive waveform from the image data in the recording image memory 56, the number of alternative ink droplets determined for the ejection failure nozzle 11, and the drive waveform in the drive waveform memory 65. The output circuit 67 generates a signal to be output to each nozzle 11 from the drive waveform.

  The ink ejection method will be described with reference to FIG. The top rectangular wave 110 in FIG. 5 represents the regular ejection timing generated by the drive waveform generation circuit 66. During recording, the carriage unit 6 moves in the scanning direction at a constant speed, and ink is ejected from the nozzles 11 at a predetermined interval. Therefore, the ejection timing is regular. The second rectangular wave 120 from the top represents the nozzle drive timing. When there is one convex portion for one discharge timing, one drop of ink is discharged. Similarly, when there are two convex portions, two drops of ink are ejected, and when there are three convex portions, three drops of ink are ejected. At this timing, an electric signal corresponding to a predetermined driving waveform is generated by the output circuit 67, and the electric signal is applied to an electrode formed in an ink supply groove (not shown) formed corresponding to the nozzle 11, Ink droplets are ejected from the nozzles 11 as the grooves expand and contract.

  Next, a recording method of the ink jet printer 1 of the present embodiment will be described.

  The recording medium P sent out from a paper feeding device (not shown) on which a roll body around which the recording medium P before recording is set is recorded on the platen 32, and then is wound on a winding device (not shown). It is wound up into a roll.

  Here, when recording on the recording medium P, the ink jet head 4 accommodated in the carriage unit 6 ejects a desired number of ink droplets from the nozzle 11 while moving along the guide rail 29. Record with.

  Next, the ink ejection method of the present embodiment will be described using examples.

  As shown in FIG. 6, for example, the small dots 12 are recorded on the recording row A, the medium dots are recorded on the recording row B, and the large dots are recorded on the recording row C by seven nozzles 11a to 11g. Is instructed from the control device 50. This instruction is executed in accordance with the ink droplet ejection method described above by operating the control means 51 based on a program stored in the ROM 52.

  Then, although the nozzle 11a and the nozzle 11d are able to eject ink normally, some ejection failure may occur like other nozzles. Specifically, the nozzle 11b is recorded at a position where the medium dot 13 is shifted from the desired position due to the ejection failure of the two ink droplets, and the nozzle 11c has the small dot 12 from the desired position due to the ejection failure of the one ink droplet. This is the case where it is recorded at a shifted position. In addition, the nozzle 11e does not record only the small dot 12 due to defective ejection of one drop of ink, the nozzle 11f does not record only the medium dot 13 due to defective ejection of two drops of ink, and the nozzle 11g does not record due to defective ejection of three drops of ink. This is a case where only the large dots 13 are not recorded.

  In this embodiment, as described above, an alternative means is provided when a discharge failure occurs during recording.

  As shown in FIG. 7, for example, when the position of the small dot 12 is shifted (nozzle 11c) or cannot be recorded (nozzle 11e), the medium dot 13 is recorded at the position where the small dot 12 is originally recorded. Configure.

  Specifically, when such a discharge failure occurs, the position and the number of ink droplets of the discharge failure nozzle 11 are first stored in the non-discharge nozzle position storage unit 71 of the non-discharge nozzle information memory 63 and the number of non-discharge ink droplets. Each of them is stored in the unit 72. As a method for storing the position of the ejection failure nozzle 11 and the number of ink droplets in the non-ejection nozzle information memory 63, a method using a ejection failure nozzle detection means stored in the non-ejection nozzle information memory 63 by automatic detection, or a test pattern There is a method in which the nozzle position and the number of ink droplets with ejection failure are visually determined, input from the operation panel 57 or the host PC 54, and manually stored in the non-ejection nozzle information memory 63 (described in detail later). ). Based on the information stored in the non-ejection nozzle information memory 63, the number of alternative ink droplets is determined. How to replace the defective portion is input from a method automatically selected by the control means 51 based on the alternative pattern and the alternative condition stored in the alternative method storage unit 74 or from the operation panel 57. There is a method to select manually. In the case of FIG. 7, since the ejection of the small dots 12 is defective, the number of alternative ink drops is set to 2 and a desired drive waveform is generated by the drive waveform generation circuit 66 and the medium dot 13 is recorded. ing.

  Further, as shown in FIG. 8, for example, when the position of the medium dot 13 is shifted (nozzle 11b) or when recording is not possible (nozzle 11f), the small dot 12 or large dot is printed at the position where the medium dot 13 is originally recorded. The dot 14 is configured to be recorded. Here, instead of the medium dot 13, all are set to small dots 12 (FIG. 8A), all are set to large dots 14 (FIG. 8B), small dots 12 and large dots 14 are Can be set so as to be alternately recorded (FIG. 8C), or the setting can be changed.

  In other words, in the case of the ejection failure of the medium dot 13, in the alternative method storage unit 74, (1) when it is desired to substitute for a lighter overall tone, (2) when it is desired to substitute for a darker overall tone, (3 ) When it is desired to substitute the density so as to approximate the original image, the respective substitute patterns are stored and can be determined by the operation panel 57 or the host PC 54 so that one of them can be selected. . According to the selection result, the number of alternative ink droplets is determined, and a drive waveform generation circuit 66 generates a desired drive waveform.

  Further, as shown in FIG. 9, for example, when the large dot 14 cannot be recorded (nozzle 11g), the medium dot 13 is recorded at the position where the large dot 14 is originally recorded.

  That is, since the large dots 14 are ejected poorly, the number of alternative ink droplets is set to two, the drive waveform generation circuit 66 generates a desired drive waveform, and the medium dot 13 is recorded.

  With this configuration, when there is a nozzle 11 that cannot eject a specific number of ink droplets, ink can be ejected with the number of ink droplets before and after that, and recording can be performed without causing pixel omission. it can. Therefore, when ink ejection failure occurs, recording can be performed while suppressing deterioration in image quality.

  As a method for detecting the position of ink ejection failure, there are a manual detection method and an automatic detection method.

  In the case of manual detection, a test pattern is recorded before starting recording on the recording medium P, and by visually checking the test pattern, it is detected whether there is a nozzle 11 with defective discharge. If present, information on the position of the defective nozzle 11 and the number of defective ink droplets is manually input from the host PC 54 or the operation panel 57, and the non-ejection nozzle position storage unit 71 of the non-ejection nozzle information memory 63 and Each of them is stored in the non-ejection ink droplet number storage unit 72.

  On the other hand, as shown in FIG. 10, the ejection failure nozzle detection means that automatically detects causes the light emitting element 81 to emit light under the control of the control means 51 for the ink F ejected from the inkjet head 4, and receives the light. Light is received by the element 82. At this time, a signal photoelectrically converted by the light receiving element 82 is input to the sensor control circuit 83. The sensor control circuit 83 AD converts the signal and outputs the AD converted signal to the control means 51. The control means 51 ejects ink while changing the nozzle 11 ejected by the inkjet head 4 and the number of ink droplets, and detects the ejected ink as described above. In the control means 51, it is determined based on a signal from the sensor control circuit 83 whether the nozzle 11 and the nozzle 11 are normal or abnormal. As the determination method, when the light emitting element 81 emits light, the amount of light (output signal) received by the light receiving element 82 differs depending on the presence or absence of the ink F. Can do. When the control unit 51 detects the defective nozzle 11, control is performed to store the position of the nozzle in the non-ejecting nozzle position storage unit 71, and the number of defective ejection ink droplets is stored. The control stored in the unit 72 is performed. That is, the control unit 51 automatically stores the position of the defective nozzle and the number of defective ejection droplets in the inkjet head 4 in the non-ejection nozzle information memory 63.

  Further, the alternative temperature information storage unit 73 stores a table as shown in FIG. This table associates the number of ink droplets that can be ejected with respect to the ink temperature with the number of ink droplets that are substituted when the ink temperature cannot be ejected. When recording on the recording medium P, the temperature of the ink F, preferably the temperature of the ink F in the head, is measured by the temperature sensor 61 by the control means 51. For example, the temperature of the ink is less than T3 ° C. In this case, the large dot 14 is not recorded, but the medium dot 13 or the small dot 12 is recorded. If the ink temperature is lower than T2 ° C., the medium dot 13 and the large dot 14 are not recorded. , Recording is performed with small dots 12. That is, the control means 51 determines whether or not the number of ink droplets to be ejected can be ejected with respect to the temperature of the ink detected by the temperature sensor 61, and stores the information in the alternative temperature information storage unit 73 if it cannot be ejected. The number of ink droplets to be replaced is selected based on the determined table. In addition, the temperature sensor 61 is attached to the board | substrate distribute | arranged to the inkjet head 4, for example.

  With this configuration, the viscosity of the ink F generally increases when the temperature is low, but when the temperature is low, the occurrence of ejection failure can be suppressed by reducing the number of ink droplets. . Therefore, by selecting the number of ink droplets according to the temperature, it is possible to prevent the occurrence of defective ejection of the ink F in advance.

  According to the present embodiment, in the multi-drop type ink jet printer 1, a non-ejection nozzle position storage unit 71 that stores the positions of defective ejection nozzles and a non-ejection ink droplet number storage unit 72 that stores the number of defective ejection ink droplets. And an alternative method storage unit for storing a plurality of alternative patterns including the number of ink droplets to be alternative discharged with respect to the number of defective ink droplets, and an alternative condition for selecting any one pattern from the plurality of alternative patterns 74, the non-ejection nozzle information memory 63, and the number of ejection failure ink droplets ejected from the ejection failure nozzle, the alternative pattern is selected based on the alternative condition, and the ejection failure ink droplet from the ejection failure nozzle Control means 51 for controlling the ejection of ink with a number of ink droplets other than the number, so that there is a nozzle 11 that cannot eject a specific number of ink droplets. Case, it is possible to eject ink in ink droplet number before and after, can be recorded without causing missing pixels. Therefore, when ejection failure of the nozzle 11 occurs, recording can be performed while suppressing deterioration in image quality.

  Further, the position of the ejection failure nozzle and the number of ink droplets with ejection failure are detected automatically or manually, and the position of the ejection failure nozzle and the number of ejection failure ink droplets are detected by the control means 51 in the non-ejection nozzle of the non-ejection nozzle information memory 63. Since the position storage unit 71 and the non-ejection ink droplet number storage unit 72 are respectively stored, it is possible to reliably select the number of ink droplets to be replaced based on the information on the position of the ejection failure nozzle and the number of ejection failure ink droplets. Recording can be performed without causing pixel omission. Therefore, when ejection failure of the nozzle 11 occurs, recording can be performed while suppressing deterioration in image quality.

  Further, since the temperature sensor 61 for detecting the temperature of the ink F, preferably the temperature of the ink F in the head, is provided so that the number of ink droplets to be ejected can be selected according to the temperature by the control means 51. If the ink viscosity is low, the viscosity of the ink generally increases, and there is a risk of ejection failure due to inadequate drive when ejecting ink droplets multiple times, but reducing the number of ink droplets may cause ejection failure. Can be suppressed. Therefore, by selecting the number of ink droplets according to the temperature, it is possible to prevent the occurrence of ink ejection failure in advance.

  Note that the present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific structure and configuration described in the embodiment are merely examples, and can be changed as appropriate.

  For example, in the present embodiment, a case has been described in which a small dot recording failure occurs, but a medium dot is substituted, but the recording may not be performed. Further, for example, when recording defects of small dots and large dots occur, all may be replaced with medium dots.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer 11 ... Nozzle 12 ... Small dot 13 ... Medium dot 14 ... Large dot 50 ... Control device 54 ... Host PC 57 ... Operation panel 61 ... Temperature sensor 71 ... Non-ejection nozzle position detection part 72 ... Non-ejection ink droplet number Detection unit 73 ... Alternative temperature information storage unit 74 ... Alternative method selection unit

Claims (5)

Comprising an inkjet head having a plurality of nozzles, and transporting means for transporting the recording medium, and a carriage that reciprocates along a direction perpendicular to the conveying direction of the recording medium by mounting the ink jet head, the carriage a recording apparatus for forming an image by ejecting ink from the inkjet head onto the recording medium based on the recording data while moving the, from one nozzle for one pixel to the position of the pixel the one Multi-drop recording that varies the size of dots formed on the recording medium in accordance with the number of ink droplets ejected within a period from the start of recording to the start of recording at the position of the next pixel In the device
The position of the defective ejection nozzle where the recorded pixel becomes defective with a specific number of ejection droplets, the number of ejection failure droplets that is the number of ejection droplets, and the number of ejection failure droplets that are discharged in substitution for the number of ejection failure droplets and a plurality of alternative patterns of different droplet number, memory means for storing the alternative conditions for selecting one pattern from the alternate pattern of the plurality of the,
Instead of the number of defective ejection droplets ejected from the ejection failure nozzle stored in the storage means, the alternative pattern is selected based on the alternative condition stored in the storage means, and the ejection failure nozzle and control means for performing control for discharging the ink in the number of droplets other than the defective discharge number of droplets from
An operation panel, and an interface circuit connected to the control means and connected to a host computer outside the recording apparatus,
The control means performs control to store the position of the defective ejection nozzle and the number of defective ejection droplets in the storage means in response to an input from at least one of the operation panel and the host computer. apparatus.   The apparatus further includes a discharge failure nozzle detection unit that detects the position of the discharge failure nozzle and the number of discharge failure droplets, and the control unit stores the position of the discharge failure nozzle and the discharge failure droplet in the storage unit based on the detection result. The recording apparatus according to claim 1, wherein a number is stored.   A temperature sensor for detecting the temperature of the ink;
  An alternative temperature information storage unit that stores the number of drops that can be ejected with respect to the temperature of the ink and the number of drops that are substituted when the ink cannot be ejected with respect to the temperature of the ink;
  The control means determines whether or not the number of ink droplets substituted for the temperature detected by the temperature sensor cannot be ejected, and when it is determined that ejection is impossible, the substitute droplet stored in the alternate temperature information storage unit The recording apparatus according to claim 1, wherein control is performed to discharge the ink by a number.   An ink jet head having a plurality of nozzles, a transport means for transporting a recording medium, and a carriage mounted with the ink jet head and reciprocating along a direction perpendicular to the transport direction of the recording medium. A recording method of forming an image by ejecting ink from the inkjet head onto the recording medium based on recording data while moving the position of the one pixel from one nozzle to one pixel. A multi-drop type that varies the size of dots formed on the recording medium in accordance with the number of ink droplets ejected within a period from the start of recording to the start of recording at the position of the next pixel. In the recording method,
  The position of the defective ejection nozzle where the recorded pixel becomes defective with a specific number of ejection droplets, the number of ejection failure droplets that is the number of ejection droplets, and the number of ejection failure droplets that are discharged in substitution for the number of ejection failure droplets A storage means for storing a plurality of alternative patterns having different droplet numbers, and an alternative condition for selecting any one of the plurality of alternative patterns, an operation panel, and connected to the control means. An interface circuit connected to a host computer outside the recording apparatus,
  Storing the position of the ejection failure nozzle and the number of ejection failure droplets in the storage means by an input from at least one of the operation panel and the host computer;
  A step of selecting the substitute pattern based on the substitute condition stored in the storage means instead of the number of defective discharge discharged from the discharge failure nozzle stored in the storage means;
  And a step of ejecting ink of a number of drops other than the number of defective ejections from the ejection failure nozzle.   A temperature sensor for detecting the temperature of the ink;
  An alternative temperature information storage unit that stores the number of drops that can be ejected with respect to the temperature of the ink and the number of drops that are substituted when the ink cannot be ejected with respect to the temperature of the ink;
  Detecting the temperature of the ink;
  Determining whether or not the number of ink droplets substituted for the temperature detected by the temperature sensor cannot be ejected;
  5. The recording method according to claim 4, further comprising a step of ejecting the ink with an alternative number of drops stored in the alternative temperature information storage unit when it is determined that ejection is impossible.

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