JP2011042054A - Recording apparatus, control method, and program - Google Patents

Abstract

A recording apparatus capable of preventing the occurrence of unused nozzles is provided.
Based on the usage rate of each nozzle used for recording an image on a recording medium, a nozzle including a nozzle having a usage rate smaller than a predetermined value is used when a new image is recorded. It selects as a use nozzle (step A1). Then, an image is recorded on the recording medium using the selected use nozzle (step A3). Next, the transport amount for transporting the recording medium is determined based on the use nozzle selected in Step A1, and the recording medium is transported in the transport direction by the determined transport amount (Step A4).
[Selection] Figure 8

Description

  The present invention relates to an ink jet recording apparatus.

  In recent years, OA (Office Automation) devices such as personal computers, copiers, and word processors have become widespread. In addition, as one type of image forming (recording) apparatus of the OA equipment, an ink jet recording apparatus that performs digital image recording by an ink jet method is rapidly spreading.

  In recent years, since colorization has progressed along with higher functionality of OA equipment, various color ink jet recording apparatuses have been developed.

  In general, in an ink jet recording apparatus, it is necessary to perform a colorant drying prevention process for a nozzle. Examples of the colorant drying prevention process include a process of consuming ink, such as a blanking process. If this colorant drying prevention process is not performed, ink ejection defects (ink ejection failure, ink landing position deviation, satellites, etc.) occur, and as a result image quality is degraded.

  For this reason, as a technical document filed prior to the present invention, there is a document that discloses a technique for avoiding white spots caused by non-ejection of ink and avoiding deterioration in image quality (for example, patents). Reference 1).

  In the above-mentioned Patent Document 1, the ejection failure information of the ejection part of the recording head is acquired, and based on the acquired ejection failure information, the dot formation of the pixel value corresponding to the specific area where ejection is defective is controlled. (N is an integer equal to or greater than 2) is quantized to a value, and dots are formed by a plurality of ejection units based on the quantized value.

  Further, there is a document that discloses a technique that can reproduce a desired color for each printing apparatus (see, for example, Patent Document 2).

  In the above-mentioned Patent Document 2, variation information representing variation for each of the plurality of nozzles is obtained, and based on the obtained variation information, a nozzle to be used for printing is selected from among the plurality of nozzles. Printing control is performed using only selected nozzles. Since the nozzles used for printing are nozzles selected by reflecting the variation information for each nozzle, the variation of each nozzle is taken into consideration and the desired color for each printing device is reproduced. Can do.

  However, the methods disclosed in Patent Documents 1 and 2 are methods based on the premise that deterioration of image quality is avoided even when ink ejection failure occurs, and the generation of unused nozzles is prevented. Is not considered at all.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a recording apparatus, a control method, and a program capable of preventing the occurrence of unused nozzles.

  In order to achieve this object, the present invention has the following features.

<Recording device>
The recording apparatus according to the present invention includes:
A recording apparatus for recording an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. Nozzle selection means to select;
Recording means for recording an image on the recording medium using the use nozzle;
A transport unit that transports the recording medium based on the use nozzle, and transports the recording medium in the transport direction by the determined transport amount;
It is characterized by having.

<Control method>
The control method according to the present invention includes:
A control method performed by a recording apparatus that records an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. A nozzle selection process to select;
A recording step of recording an image on the recording medium using the use nozzle;
A conveyance step of determining a conveyance amount for conveying the recording medium based on the use nozzle, and conveying the recording medium in a conveyance direction by the determined conveyance amount;
It is characterized by having.

<Program>
The program according to the present invention is:
A program to be executed by a recording apparatus that records an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. Nozzle selection process to select,
A recording process for recording an image on the recording medium using the use nozzle;
A transport amount for transporting the recording medium is determined based on the use nozzle, and a transport process for transporting the recording medium in the transport direction by the determined transport amount;
Is executed by a computer.

  According to the present invention, it is possible to prevent the generation of unused nozzles.

1 is a diagram illustrating a schematic configuration example of a recording apparatus according to an embodiment. 2 is a diagram illustrating a schematic configuration example of a recording head. FIG. FIG. 3 is a diagram illustrating an exemplary configuration of a main part of a recording head 14. 3 is a diagram illustrating a schematic configuration example of a conveyance belt 33. FIG. FIG. 4 is a diagram illustrating an example of a recording operation of the recording head. It is a figure which shows the internal structural example of a recording device. 3 is a diagram illustrating a configuration example of a printer driver 91 on the host 90 side. FIG. It is a figure which shows the example of a printing process operation | movement in the recording device of this embodiment. FIG. 6 is a diagram for explaining an example of a printing processing operation. It is a figure which shows the example of a selection method of a use nozzle. It is a figure for demonstrating the case where a 600 dpi image is recorded with the nozzle density of 300 dpi. It is a figure which shows the example of a printing process operation | movement in the recording device of 3rd Embodiment. FIG. 6 is a diagram for explaining an example of a printing processing operation. FIG. 10 is a diagram for explaining an example of a print processing operation according to a fourth embodiment.

<Outline of Recording Apparatus of this Embodiment>
First, the outline of the recording apparatus of the present embodiment will be described with reference to FIGS.

  The recording apparatus of this embodiment is a recording apparatus that records an image on a recording medium using a plurality of nozzles mounted on a recording head.

  As shown in FIGS. 8 and 9, the recording apparatus of the present embodiment includes nozzles having a usage rate smaller than a predetermined value based on the usage rate of each nozzle used when recording an image on a recording medium. The nozzle to be included is selected as a nozzle to be used when a new image is recorded (step A1).

  Next, an image is recorded on the recording medium using the used nozzle selected in Step A1 (Step A3).

  Next, the transport amount for transporting the recording medium is determined based on the use nozzle selected in Step A1, and the recording medium is transported in the transport direction by the determined transport amount (Step A4).

  As a result, it is possible to prevent the occurrence of nozzles with low usage rates (unused nozzles) and to avoid the occurrence of ink ejection defects. Moreover, since generation | occurrence | production of the nozzle (unused nozzle) with a low usage rate is prevented beforehand, processing, such as a maintenance with respect to an unused nozzle, can be reduced. Hereinafter, the recording apparatus of the present embodiment will be described in detail with reference to the accompanying drawings.

<Configuration example of recording apparatus>
First, the recording apparatus of this embodiment will be described with reference to FIGS. FIG. 1 shows a schematic configuration example of a recording apparatus. FIG. 2 shows a schematic configuration example of the recording head 14 mounted on the recording apparatus. FIG. 3 shows a configuration example of a main part of the recording head 14. FIG. 4 shows a schematic configuration example of the conveyance belt 33 mounted on the recording apparatus. FIG. 5 shows an example of the recording operation of the recording head 14.

  As shown in FIG. 1, the recording apparatus according to the present embodiment includes an image forming unit 2 and the like inside an apparatus main body 1. In addition, a sheet feeding tray 4 on which a large number of recording media (hereinafter referred to as “sheets”) 3 can be stacked is configured below the apparatus main body 1.

  The recording apparatus of the present embodiment takes in the paper 3 fed from the paper feed tray 4 and records a required image on the paper 3 by the image forming unit 2 while transporting the captured paper 3 by the transport mechanism 5. Then, the paper 3 is discharged to a paper discharge tray 5 mounted on the side of the apparatus main body 1.

  The recording apparatus according to the present embodiment includes a duplex unit 7 that can be attached to and detached from the apparatus main body 1. When performing double-sided printing in the recording apparatus of the present embodiment, after printing one side (front side), the paper 3 is taken into the double-side unit 7 while the paper 3 is being conveyed in the reverse direction by the conveyance mechanism 5 and the paper 3 is reversed. Then, the other surface (back surface) is sent again to the transport mechanism 5 as a printable surface. Then, after printing the other side (back side), the sheet 3 is discharged to the discharge tray 5.

  The image forming unit 2 slidably holds the carriage 13 on the guide shafts 11 and 12, and moves the carriage 13 in a direction (main scanning direction) orthogonal to the conveyance direction of the sheet 3 by a main scanning motor (not shown). Let

  A recording head 14 is mounted on the carriage 13. An ink cartridge 15 for supplying ink to the recording head 14 is detachably mounted. The recording head 14 is configured by arranging nozzle holes 14n (see FIG. 3) shown in FIG. 3, and ejects ink from the nozzle holes 14n.

  Note that the recording apparatus of the present embodiment can be constructed so that a sub tank is mounted instead of the ink cartridge 15 and ink is replenished and supplied from the main tank to the sub tank.

  For example, as shown in FIGS. 2 and 3, the recording head 14 is an inkjet head 14y, 14m, 14c that ejects ink of each color of yellow (y), magenta (m), cyan (c), and black (k). , 14k. The recording head 14 can also be composed of one or a plurality of heads having a plurality of nozzle rows that eject ink of each color. Note that the number of colors and the arrangement order are not particularly limited, and any configuration can be applied.

  A known configuration such as a piezoelectric actuator such as a piezoelectric element, a thermal actuator, a shape memory alloy actuator, or an electrostatic actuator can be applied to the ink jet head constituting the recording head 14.

  The sheets 3 loaded on the sheet feeding tray 4 are separated one by one by a sheet feeding roller (half-moon roller) 21 and a separation pad (not shown), fed into the apparatus main body 1 and sent to the transport mechanism 5. It is.

  The transport mechanism 5 includes a transport guide portion 23, a transport roller 24, a pressure roller 25, guide members 26 and 27, and a pressing roller 28.

  The conveyance guide unit 23 guides the paper 3 fed from the paper feed tray 4 upward along the guide surface 23a, and guides the paper 3 fed from the duplex unit 7 along the guide surface 23b.

  The transport roller 24 transports the paper 3. The pressure roller 25 presses the paper 3 against the transport roller 24. The guide member 26 guides the sheet 3 to the conveyance roller 24 side. The guide member 27 guides the sheet 3 returned at the time of duplex printing to the duplex unit 7. The pressing roller 28 presses the paper 3 sent out from the transport roller 24 against the transport roller 24.

  Further, the transport mechanism 5 includes a transport belt 33, a charging roller 34, a guide roller 35, a guide member (platen plate) (not shown), and a cleaning roller (not shown). .

  The transport belt 33 is for transporting the paper 3 while maintaining the flatness of the paper 3. The conveying belt 33 of the present embodiment is an endless belt, is stretched between a driving roller 31 and a driven roller (tension roller) 32, and circulates in the direction indicated by an arrow in FIG. 1 (paper conveying direction). It is composed. The conveyor belt 33 has a single-layer configuration, or a two-layer configuration of a first layer (outermost layer) 33a and a second layer (back layer) 33b as shown in FIG. 4, or a configuration of three or more layers. Can do.

  For example, the transport belt 33 is a surface layer that is a sheet adsorbing surface formed of a resin material (for example, ETFE pure material) having a pure thickness of about 40 μm that is not subjected to resistance control, and resistance control by carbon using the same material as the surface layer. And a back layer (medium resistance layer, earth layer).

  The charging roller 34 is for charging the transport belt 33. The charging roller 34 is disposed so as to come into contact with the surface layer of the transport belt 33 and to be rotated by the rotation of the transport belt 33. A high voltage is applied to the charging roller 34 in a predetermined pattern from a high voltage circuit (high voltage power source; not shown).

  The guide roller 35 is opposed to the charging roller 34 and guides the conveyance belt 33. The guide member (plastic template) guides the conveyance belt 33 at a portion facing the image forming unit 2. The cleaning roller is for removing the recording liquid (ink) attached to the conveyance belt 33.

  Further, the recording apparatus of the present embodiment includes a paper discharge roller 30 on the downstream side from the transport mechanism 5. The paper discharge roller 30 is for sending the paper 3 on which an image is recorded to the paper discharge tray 5.

  In the recording apparatus of this embodiment, the conveyor belt 33 is rotated in the direction indicated by the arrow (paper conveyance direction) in FIG. To do. In this case, the charging roller 34 charges the transport belt 33 at a predetermined charging pitch by switching the polarity at predetermined time intervals.

  When the sheet 3 is fed onto the conveying belt 33 charged to a high potential, the inside of the sheet 3 is in a polarized state, and the charge having the opposite polarity to the charge on the conveying belt 33 is in contact with the belt 33 of the sheet 3. The charge that is dielectrically formed on the surface and electrostatically charged on the transported paper 3 and the transported paper 3 is electrostatically attracted to each other, and the paper 3 is electrostatically attracted to the transport belt 33. As a result, the paper 3 strongly adsorbed to the transport belt 33 is calibrated for warping and unevenness, and a highly flat surface is formed.

  In the recording apparatus of the present embodiment, the conveyance belt 33 is circulated in the direction indicated by the arrow in FIG. 1 (paper conveyance direction), the paper 3 is moved, and the carriage 13 is moved in one direction or both directions to generate an image signal. Accordingly, the recording head 14 is driven, and as shown in FIGS. 5A and 5B, the ink 14i is ejected (jetted) from the recording head 14, and the ink is landed on the paper 3 to form dots (images) Di. An image for one line (one scan) is recorded. Then, after the sheet 3 is conveyed by a predetermined amount, the next one line (one scan) is recorded.

  The recording apparatus ends the recording operation when receiving a recording end signal or a signal indicating that the trailing edge of the sheet 3 has reached the recording area. FIG. 5B is an enlarged view of the dot Di formation portion of FIG.

  The recording apparatus according to the present embodiment discharges the sheet 3 on which an image is recorded by the above-described control to the discharge tray 5 using the discharge roller 30.

<Internal configuration example of recording apparatus>
Next, an example of the internal configuration of the recording apparatus according to the present embodiment will be described with reference to FIG. FIG. 6 shows an internal configuration example of the recording apparatus.

  A control unit 100 installed in the recording apparatus according to the present embodiment includes a CPU 101 that controls the entire recording apparatus, a ROM 102 that stores programs executed by the CPU 101 and other fixed data, and a RAM 103 that temporarily stores image data and the like. , A non-volatile memory (NVRAM) 104 for holding data even while the power supply of the recording apparatus is shut off, and various input / output signals for controlling various image processing such as signal processing and rearrangement and other recording apparatuses And an ASIC 105 for processing.

  The control unit 100 also includes a host I / F 106 for exchanging data and signals with the host 90, which is an image processing apparatus such as a personal computer, a head drive control unit 107 for driving and controlling the recording head 14, and A head driver 108, a main scanning motor driving unit 111 for driving the main scanning motor 110, a sub scanning motor driving unit 113 for driving the sub scanning motor 112, an environmental sensor 118 for detecting environmental temperature and / or environmental humidity, An I / O 116 for receiving a detection signal from the environment sensor 118 is included.

  The control unit 100 is connected to an operation panel 117 for inputting and displaying information necessary for the recording apparatus. Further, the control unit 100 performs on / off switching and output polarity switching control of the high voltage circuit (high voltage power supply) 114 that applies a high voltage to the charging roller 34.

  Here, the control unit 100 receives image data from the host 90 side such as a data processing device such as a personal computer, an image reading device such as an image scanner, and an imaging device such as a digital camera via a cable or a network. Receive at / F106. Note that image data generation output to the control unit 100 is performed by the printer driver 91 on the host 90 side.

  The CPU 101 reads the image data in the reception buffer included in the host I / F 106 and analyzes the read image data. The ASIC 105 performs rearrangement processing of the image data. The head drive control unit 107 transfers the image data processed by the ASIC 105.

  The processing for converting the image data into bitmap data is performed by the printer driver 91 on the host 90 side, and is transferred to the recording apparatus or stored in the ROM 102 with font data.

  When the head drive control unit 107 receives image data (dot pattern data) corresponding to one row (one scan) of the recording head 14, the head drive control unit 107 converts the image data of one row (one scan) into the clock. In synchronization with the signal, serial data is sent to the head driver 108, and a latch signal is sent to the head driver 108 at a predetermined timing.

  The head drive control unit 107 includes a ROM that stores pattern data of a drive waveform (drive signal), a waveform generation circuit including a D / A converter that performs D / A conversion on drive waveform data read from the ROM, an amplifier, and the like Including a drive waveform generating circuit and the like.

  The head driver 108 is a shift register that receives a clock signal from the head drive control unit 107 and serial data that is image data, a latch circuit that latches the register value of the shift register using a latch signal from the head drive control unit 107, and It includes a level conversion circuit (level shifter) that changes the output value of the latch circuit, an analog switch array (switch means) that controls on / off of the level shifter, and the like. The head driver 108 controls on / off of the analog switch array and selectively applies a required driving waveform included in the driving waveform to the actuator means of the recording head 14 to drive the recording head 14.

<Example of Internal Configuration of Printer Driver 91 on Host 90>
Next, a configuration example of the printer driver 91 on the host 90 side will be described with reference to FIG. FIG. 7 shows a configuration example of the printer driver 91.

  The printer driver 91 performs CMM (Color Management) for performing processing (RGB color system → CMY color system) for converting image data 130 supplied from application software or the like from a color space for monitor display to a color space for a recording apparatus. Module) processing unit 131, BG (Black Generation) / UCR (Under Color Removal) processing unit 132 that performs black generation / under color removal from CMY values, and input / output correction that reflects the characteristics of the recording apparatus and user preferences A gamma correction unit 133, a zooming unit 134 that performs enlargement processing in accordance with the resolution of the recording apparatus, and a multi-value / low-value matrix that generates output data 136 by replacing image data with a pattern arrangement of dots ejected from the recording apparatus Including a halftone processing unit 135.

<Printing Process of Recording Device of Present Embodiment>
Next, the printing process of the recording apparatus of this embodiment will be described.

  Generally, a recording apparatus must perform a colorant drying prevention process for a nozzle. Examples of the colorant drying prevention process include a process of consuming ink, such as a blanking process. If this colorant drying prevention process is not performed, ink ejection failure (ink ejection failure, ink landing position misalignment, satellite, etc.) occurs, and as a result, image quality is degraded.

  Until now, as countermeasures against defective ink ejection, maintenance of unused nozzles and image processing that does not use defective ink ejection nozzles have been performed. However, with the above-described measures, it is necessary to ensure maintenance time, detect ink ejection failure nozzles, and the like.

  For this reason, the printing apparatus according to the present embodiment selects, based on the usage rate of each nozzle, a nozzle including a nozzle whose usage rate is smaller than a predetermined value as a usage nozzle that is used when a new image is recorded. . Then, an image is recorded on the paper 3 using the selected use nozzle. This prevents the occurrence of nozzles with low usage rates (unused nozzles) and avoids the occurrence of ink ejection defects. Moreover, since generation | occurrence | production of the nozzle (unused nozzle) with a low usage rate is prevented beforehand, processing, such as a maintenance with respect to an unused nozzle, can be reduced. Hereinafter, the printing process of the recording apparatus of the present embodiment will be described in detail with reference to FIGS.

  Based on the usage rate of each nozzle stored in the NVRAM 104, the CPU 101 selects a nozzle to be used when recording a new image (step A1).

  The NVRAM 104 manages the usage rate of each nozzle mounted on the recording head 14 for each inkjet head. As a result, the CPU 101 can grasp the past usage rate of each nozzle used when recording an image on the paper 3 for each inkjet head. Based on the usage rate of each nozzle stored in the NVRAM 104, the CPU 101 preferentially selects a nozzle whose usage rate is smaller than a predetermined value as a usage nozzle.

  In the example of FIG. 9, each inkjet head has four nozzles mounted thereon, and the recording head 14 has a total of 16 nozzles mounted thereon. Therefore, the NVRAM 104 manages the usage rate of the 16 nozzles mounted on the recording head 14 for each inkjet head. Then, the CPU 101 preferentially selects a nozzle having a usage rate smaller than a predetermined value as a usage nozzle based on the usage rates of the four nozzles constituting one inkjet head. In the example of FIG. 9, the CPU 101 shows a case where three of the four nozzles are selected as the use nozzles.

  In addition, the selection method of a use nozzle is not specifically limited, As long as a nozzle with a utilization rate smaller than a predetermined value can be preferentially selected as a use nozzle, any selection method is applicable.

  For example, there is a method in which a nozzle having a nozzle usage rate smaller than a predetermined value is specified, and a nozzle arranged in an area including the specified nozzle is selected as a used nozzle. Describing based on FIG. 10A, among the four nozzles (1st to 4th nozzles) constituting one inkjet head, the first and third nozzles from the top (the nozzles used in a dotted line). It is assumed that the usage rate of the nozzles constituting the upper and lower ends is determined to be smaller than a predetermined value. In this case, the first to third nozzles arranged in the area including the first and third nozzles are selected as the use nozzles. Then, the use nozzle selected by the one ink-jet head is also applied to other ink-jet heads, and the nozzle surrounded by the dotted line shown in FIG. 10A is selected as the use nozzle.

  It is also possible to select the nozzles to be used for each inkjet head and to select the nozzles to be used finally based on the nozzles selected for each inkjet head.

  For example, referring to FIG. 10B, the head 1 selects the first and second nozzles as the use nozzles, the head 2 selects the second and third nozzles as the use nozzles, and the head 3 It is assumed that the second to third nozzles are selected as the use nozzles, and the head 4 has selected the second to third nozzles as the use nozzles. In this case, based on the used nozzles selected by the heads 1 to 4, the first to third nozzles are finally selected as used nozzles so as to include the used nozzles selected by the heads 1 to 4. .

  Also, based on FIG. 10C, the head 1 selects the first and second nozzles as the use nozzles, the head 2 selects the second and third nozzles as the use nozzles, and the head 3 It is assumed that the second to third nozzles are selected as used nozzles, and the head 4 has selected the third to fourth nozzles as used nozzles. In this case, based on the used nozzles selected by the heads 1 to 4, the second to third used nozzles selected by the heads 2 and 3 where the areas selected as the used nozzles overlap most are finally used nozzles. Choose as.

  As described above, any selection method can be applied as long as it is possible to preferentially select a nozzle having a usage rate smaller than a predetermined value based on the usage rate of each nozzle stored in the NVRAM 104. It is.

  In addition, as shown in FIGS. 9 and 10, it is preferable that the finally used nozzles are such that the width of the nozzle used and the position of the nozzle used are the same among all the inkjet heads. In FIGS. 9, 10 </ b> A, and 10 </ b> B, since the first to third nozzles constituting each inkjet head are selected as the use nozzles, the width of the use nozzle and the position of the use nozzle are all It is the same between the inkjet heads. In FIG. 10C, since the second to third nozzles constituting each inkjet head are selected as the used nozzles, the width of the used nozzles and the positions of the used nozzles are between all the inkjet heads. It is the same. In this way, by making the width of the used nozzle and the position of the used nozzle the same among all the ink jet heads, an image can be recorded on the paper 3 with simple conveyance control.

  The CPU 101 notifies the head drive control unit 107 and the sub-scanning motor control unit 113 of information on the finally used nozzle.

  When the head drive control unit 107 receives image data (dot pattern data) corresponding to one scan that can be drawn using the used nozzle (step A2 / Yes), the head drive control unit 107 receives the received image data for one scan. The serial data is sent to the head driver 108 in synchronization with the clock signal. Further, the head drive control unit 107 sends a latch signal to the head driver 108 at a predetermined timing. As a result, the recording head 14 records an image on the paper 3 using the nozzles selected by the CPU 101 (step A3).

  In FIG. 9, since the number of nozzles used in the sub-scanning direction is three, an image is recorded on the paper 3 by the width corresponding to the three nozzles.

  The sub-scanning motor driving unit 113 determines the transport amount for transporting the paper 3 based on the nozzles used, and the sub-scan motor so as to transport the paper 3 in the transport direction (sub-scanning direction) by the determined transport amount. 112, the conveyance belt 33 is controlled, and the sheet 3 is conveyed in the conveyance direction by the conveyance amount corresponding to the used nozzle (step A4).

  In FIG. 9, since an image is recorded in the same area in one scan, the carry amount (line feed) is determined as the carry amount for the used nozzles (3 nozzles) in the sub-scanning direction, and only the decided carry amount. The paper 3 is transported in the transport direction (sub-scanning direction).

  The CPU 101 determines whether or not the recording process has ended (step A5). If the recording process has ended (step A5 / Yes), the recording process ends (End). If the recording process is not completed (step A5 / No), the recording process is continued, and the processes of steps A3 to A4 are repeated until the recording process is completed.

<Operation / Effect of Recording Apparatus of this Embodiment>
As described above, the recording apparatus according to the present embodiment selects, based on the usage rate of each nozzle, a nozzle including a nozzle whose usage rate is smaller than a predetermined value as a used nozzle to be used when newly recording an image. To do. Then, an image is recorded on the paper 3 using the selected use nozzle. As a result, it is possible to prevent the occurrence of nozzles with low usage rates (unused nozzles) and to avoid the occurrence of ink ejection defects. Moreover, since generation | occurrence | production of the nozzle (unused nozzle) with a low usage rate is prevented beforehand, processing, such as a maintenance with respect to an unused nozzle, can be reduced.

(Second Embodiment)
Next, a second embodiment will be described.

  In the first embodiment described above, as shown in FIGS. 8 and 9, the used nozzle selected in step A1 is not changed, and an image is recorded in one scan using the used nozzle in the same region. The carry amount (line feed) was determined as the carry amount for the used nozzles (3 nozzles) in the sub-scanning direction (paper carrying direction).

  However, there is a case where an image is recorded in the same region by scanning a plurality of times. For example, in serial inkjet recording, an image is recorded on the paper 3 while the recording head 14 is reciprocated in the main scanning direction. In this case, when an image (dot) is recorded at a higher density than the nozzle density (interval between nozzles mounted on the inkjet head), it is necessary to move (scan) the same region a plurality of times.

  For example, as shown in FIG. 11, when an image of 600 dpi is recorded at a nozzle density of 300 dpi, it is necessary to record an image between the nozzles, and therefore the same region must be scanned at least two times. That is, assuming that the nozzle density is Nd and the image density is LD, the number of scans N required for recording an image with the nozzle density; It becomes more than ND.

  Therefore, in the case where an image is recorded on the paper 3 by N (N is an integer of 1 or more) scanning in the same region using the used nozzle without changing the selected used nozzle selected in Step A1. Then, a value obtained by dividing a distance corresponding to the number of nozzles (for the used nozzles) in the sub-conveying direction (paper conveying direction) of the used nozzles by N is determined as a conveying amount, and the sheet 3 is conveyed by the determined conveying amount.

  For example, when the number of used nozzles in the sub-scanning direction is 3 and the number of scans N is 3, 3α ÷ 3 = α is determined as the transport amount. α means a distance corresponding to one nozzle. As a result, an image having a density higher than the nozzle density of the used nozzle can also be recorded on the paper 3.

(Third embodiment)
Next, a third embodiment will be described.

  In the first and second embodiments, the used nozzle selected in step A1 is not changed, and an image is recorded on the paper 3 using the used nozzle. However, the use nozzle can be changed for each transport operation. Hereinafter, a processing operation when selecting a use nozzle for each transport operation will be described.

  The CPU 101 determines whether or not drawing is possible (standby state) (step B1). The drawable state is a position where the recording head 14 can draw (the forward scan start position or the backward scan start position), the transport operation of the paper 3 is finished, and the paper 3 is in the stopped state. It means that it is in a standby state for scanning (drawing).

  If the CPU 101 determines that the drawing is possible (standby state) (step B1 / Yes), the CPU 101 uses the usage rate of each nozzle stored in the NVRAM 104 and the image data received by the head drive control unit 107. Then, a nozzle to be used when a new image is recorded is selected (step B2).

  The usage rate of each nozzle; Nusg is calculated by the following equation.

  Nusg = 1 / (Tn−Tl)

  Here, Tn indicates the current time. Tl indicates the time when the nozzle was used last (time when ink was ejected).

  Further, the number of nozzles that can be driven by the image data received by the head drive control unit 107 is Ndrv, the total number of nozzles mounted on one inkjet head is Nall, and the nozzle number i is 1 to Nall.

  At this time, the CPU 101 selects the use nozzle (nozzle number; i) as follows.

  Let Nusg [i] be the usage rate of nozzle number i.

  Assuming i is 1 to Nall-Ndrv + 1, the evaluation value of each nozzle number; i is calculated.

  Evaluation value = Nusg [i] + Nusg [i + 1] +... + Nusg [i + Ndrv-1]

At this time, the nozzle number i having the smallest evaluation value is set to the nozzle number m having the smallest usage rate. Thereby, the nozzle number m with the smallest usage rate can be determined. Based on the determined nozzle number m, a nozzle to be used for recording an image is selected.
The nozzles used are nozzle numbers m to m + Ndrv-1.

  In the case of FIG. 13, the nozzle number m = 1 with the smallest usage rate is obtained, and the number of nozzles that can be driven by the image data received by the head drive control unit 107; Ndrv = 3. For this reason, the nozzles used are nozzle numbers 1 to 1 + 3-1 = 3.

  The CPU 101 notifies the head drive control unit 107 and the sub-scanning motor control unit 113 of the information on the nozzles used.

  The head drive control unit 107 sends image data for one scan to the head driver 108 as serial data in synchronization with the clock signal based on the information on the used nozzles received from the CPU 101. Further, the head drive control unit 107 sends a latch signal to the head driver 108 at a predetermined timing. As a result, the recording head 14 records an image on the sheet 3 using the used nozzle selected by the CPU 101 (step B3).

  In the case of FIG. 13, since the number of nozzles in use in the sub-scanning direction is three, an image is recorded on the sheet 3 by the width corresponding to the three nozzles.

  The sub-scanning motor driving unit 113 determines the transport amount for transporting the paper 3 based on the nozzles used, and the sub-scan motor so as to transport the paper 3 in the transport direction (sub-scanning direction) by the determined transport amount. 112, the transport belt 33 is controlled, and the paper 3 is transported in the transport direction by the transport amount corresponding to the used nozzles (step B4).

  In the case of FIG. 13, since an image is recorded in the same area by one scan, the carry amount (line feed) is determined as the carry amount for the used nozzles (3 nozzles) in the sub-scanning direction, and the decided carry The sheet 3 is transported in the transport direction (sub-scanning direction) by the amount.

  The CPU 101 determines whether or not the recording process has ended (step B5). If the recording process has ended (step B5 / Yes), the recording process ends (End). If the recording process is not completed (step B5 / No), the recording process is continued, and the processes in steps B1 to B4 are repeated until the recording process is completed.

<Operation / Effect of Recording Apparatus of this Embodiment>
As described above, the recording apparatus according to the present embodiment selects the nozzles to be used for newly recording an image for each transport operation. Then, an image is recorded on the paper 3 using the use nozzle selected for each transport operation. As a result, it is possible to prevent the occurrence of nozzles with low usage rates (unused nozzles) and to avoid the occurrence of ink ejection defects. Moreover, since generation | occurrence | production of the nozzle (unused nozzle) with a low usage rate is prevented beforehand, processing, such as a maintenance with respect to an unused nozzle, can be reduced. In addition, since the nozzles to be used are selected for each transport operation, the nozzle usage rate can be made more uniform than in the first and second embodiments. In addition, since the image forming process can be started using the image data that has been received by the head drive control unit 107 at the time when the conveyance is enabled, it is possible to avoid interruption of image formation.

(Fourth embodiment)
Next, a fourth embodiment will be described.

  In the third embodiment described above, as shown in FIGS. 12 and 13, an image is recorded in one scan using the used nozzle selected for each transport operation in the same region. The used nozzles in the sub-scanning direction (paper transport direction) of the used nozzles selected for each transport operation are determined as the transport amount.

  However, there is a case where an image is recorded in the same region by scanning a plurality of times. For this reason, when an image is recorded on the sheet 3 by scanning N (N is an integer of 2 or more) times in the same region using the used nozzle selected for each transport operation, the transport amount is determined by the following method. .

  As shown in FIG. 14, in the step B4, the sub-scanning motor driving unit 113 sets the upper end position in the transport direction of the used nozzle selected in step B2 when the image of the area scanned N-1 times is recorded; Pa And the difference between the upper end position in the transport direction of the nozzle used when the image of the area that has been scanned N-1 times; Pb; ΔP is calculated (S1).

  ΔP = | Pa−Pb |

  Next, the sub-scanning motor drive unit 113 determines the calculated difference; ΔP as the transport amount, controls the sub-scanning motor 112 and the transport belt 33 based on the determined transport amount, and determines the determined transport amount. Only the sheet 3 is conveyed in the conveying direction (S2). As a result, the sheet 3 can be transported to the position of the recording head 14 necessary for completing the image of the area scanned N−1 times.

  Note that the upper end position of the used nozzle; Pa is automatically determined by selecting the used nozzle. However, the upper end position of the nozzle used when the image of the area scanned N-1 times is recorded; Pb cannot be determined unless the position where the image of the area scanned N-1 times is formed is known. .

  For this reason, the position of the nozzles used when forming the image of the scanned area N-1 times (the upper end position of the nozzle and the lower end position of the nozzle) is managed by the NVRAM 104, and the sub-scanning motor driving unit 113 is controlled by the NVRAM 104. Based on the managed nozzle position information (the upper end position of the nozzle, the lower end position of the nozzle), the upper end position of the nozzle used when the image of the scanned area N-1 times is recorded; Pb is specified Become.

  Further, the position information (nozzle upper end position, nozzle lower end position) of the nozzles used when the image of the scanned area is recorded each time (1 to N-1 times) is managed by the NVRAM 104, and the sub-scanning motor drive unit 113 is the upper end position of the nozzle used when the image of the area scanned N−1 times is recorded based on the position information of the nozzle managed by the NVRAM 104 (the upper end position of the nozzle and the lower end position of the nozzle); Pb is specified. Accordingly, the sub-scanning motor driving unit 113 can calculate the difference; ΔP.

(Fifth embodiment)
Next, a fifth embodiment will be described.

  In the first to fourth embodiments described above, based on the usage rate of each nozzle, a used nozzle is selected from a plurality of nozzles mounted on the recording head 14, and a nozzle with a low usage rate (unused nozzle). It is decided to prevent the occurrence of this. For this reason, since the number of nozzles is smaller than when printing is performed using all the nozzles mounted on the recording head 14, the number of scans increases. As a result, the time until the recording operation ends may be delayed.

  For this reason, the recording apparatus of the present embodiment selects which print process to use, the print process using the nozzles used, or the print process using a plurality of nozzles, and performs the selected print process. To control.

  As a result, when it takes time to complete the recording operation when performing printing processing using the nozzles in use, the printing processing using a plurality of nozzles is selected, and the time until the recording operation is completed It can be shortened.

  In the case where an image is recorded on the paper 3 using the use nozzle as in the first to fourth embodiments described above, the carry amount is determined based on the use nozzle, and the paper is fed by the decided carry amount. 3 is controlled to be conveyed in the conveying direction (sub-scanning direction).

  Further, when an image is recorded on the paper 3 using a plurality of nozzles mounted on the recording head 14, the transport amount is determined based on the plurality of nozzles, and the paper 3 is transported in the transport direction by the determined transport amount ( Control is performed so that the sheet is conveyed in the sub-scanning direction). However, the printing process using a plurality of nozzles mounted on the recording head 14 is a normal known printing process, and is obvious to those skilled in the art, and therefore a specific process is omitted.

  In the present embodiment, if it is possible to select any one of the printing process using the used nozzle and the printing process using a plurality of nozzles, the selection condition and selection of the printing process are selected. The timing, selection method, etc. are not particularly limited, and any design method can be applied.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, the control operation of each unit constituting the recording apparatus of the present embodiment described above can be executed using hardware, software, or a combined configuration of both.

  In the case of executing processing using software, it is possible to install and execute a program in which a processing sequence is recorded in a memory in a computer incorporated in dedicated hardware. Alternatively, the program can be installed and executed on a general-purpose computer capable of executing various processes.

  For example, the program can be recorded in advance on a hard disk or ROM (Read Only Memory) as a recording medium. Alternatively, the program can be stored (recorded) temporarily or permanently in a removable recording medium. Such a removable recording medium can be provided as so-called package software. Examples of the removable recording medium include a floppy (registered trademark) disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disk, a DVD (Digital Versatile Disc), a magnetic disk, and a semiconductor memory.

  The program is installed on the computer from the removable recording medium as described above. In addition, it is wirelessly transferred from the download site to the computer. In addition, it is transferred to a computer via a network by wire.

  The recording apparatus according to the present embodiment is not only executed in time series according to the processing operation described in the above embodiment, but also the processing capability of the apparatus that executes the process, or in parallel or individually as required. It is also possible to build to run on

  The present invention is suitable for an ink jet recording apparatus.

13 Carriage 14 Recording head 3 Paper (recording medium)
90 Host 91 Printer Driver 100 Control Unit 101 CPU
102 ROM
103 RAM
104 NVRAM
105 ASIC
106 Host I / F
107 Head Drive Control Unit 108 Head Driver 110 Main Scan Motor 111 Main Scan Motor Drive Unit 112 Sub Scan Motor 113 Sub Scan Motor Drive Unit 114 High Voltage Circuit 116 I / O
117 Operation panel 118 Environmental sensor 33 Conveying belt 34 Charging roller

JP 2004-322374 A JP 2003-291338 A

Claims (7)

A recording apparatus for recording an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. Nozzle selection means to select;
Recording means for recording an image on the recording medium using the use nozzle;
A transport unit that transports the recording medium based on the use nozzle, and transports the recording medium in the transport direction by the determined transport amount;
A recording apparatus comprising: Each time the recording medium is transported, the recording means does not change the use nozzle, and the image on the recording medium is scanned N times (N is an integer of 1 or more) in the same region using the use nozzle. When recording
The conveying means is
2. The value obtained by dividing a distance corresponding to the number of nozzles in the transport direction of the used nozzles by the N is determined as the transport amount, and the recording medium is transported by the determined transport amount. Recording device. The nozzle selection unit selects the nozzle to be used every time the recording medium is conveyed,
In the case where the recording unit records an image on the recording medium in one scan in the same region using the used nozzle selected by the nozzle selection unit for each conveyance,
The conveying means is
The distance corresponding to the number of nozzles in the transport direction of the used nozzles selected by the nozzle selection unit for each transport is determined as the transport amount, and the recording medium is transported by the determined transport amount. The recording apparatus according to claim 1 or 2. The nozzle selection unit selects the nozzle to be used every time the recording medium is conveyed,
In the case where the recording unit records an image on the recording medium by scanning N (N is an integer of 2 or more) times in the same region using the used nozzle selected by the nozzle selection unit for each conveyance,
The conveying means is
N-1 upper end position in the transport direction of the used nozzle selected by the nozzle selection unit when an image of the scanned area is recorded;
The difference between the nozzle used when the image of the area that has been scanned N-1 times and the upper end position in the transport direction is calculated, the calculated difference is determined as the transport amount, and the determined transport amount The recording apparatus according to claim 1, wherein the recording medium is transported only by the amount of the recording medium. The recording means includes
First recording means for recording an image on the recording medium using the use nozzle;
Second recording means for recording an image on the recording medium using a plurality of nozzles mounted on the recording head,
The conveying means is
When recording an image on the recording medium using the first recording unit, the conveyance amount is determined based on the use nozzle, and the recording medium is conveyed in the conveyance direction by the determined conveyance amount,
When recording an image on the recording medium using the second recording unit, the transport amount is determined based on the plurality of nozzles, and the recording medium is transported in the transport direction by the determined transport amount. The recording apparatus according to claim 1, wherein the recording apparatus is a recording apparatus. A control method performed by a recording apparatus that records an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. A nozzle selection process to select;
A recording step of recording an image on the recording medium using the use nozzle;
A conveyance step of determining a conveyance amount for conveying the recording medium based on the use nozzle, and conveying the recording medium in a conveyance direction by the determined conveyance amount;
A control method characterized by comprising: A program to be executed by a recording apparatus that records an image on a recording medium using a plurality of nozzles mounted on a recording head,
Based on the usage rate of each nozzle used when recording an image on the recording medium, a nozzle including a nozzle whose usage rate is smaller than a predetermined value is used as a new nozzle used when recording an image. Nozzle selection process to select,
A recording process for recording an image on the recording medium using the use nozzle;
A transport amount for transporting the recording medium is determined based on the use nozzle, and a transport process for transporting the recording medium in the transport direction by the determined transport amount;
A program characterized by causing a computer to execute.

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