JP2006281456A - Liquid ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid ejector using the so-called multi-dot system which can finely adjust positions of dots to be formed. <P>SOLUTION: In the liquid ejector which ejects a liquid and forms a plurality of kinds of unit dots of different diameters, each of the unit dots is formed by a combination of the presence or absence of each basic dot in a predetermined number of not smaller than two basic dots. A formation position of the unit dot can be shifted by each basic dot. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus such as an ink jet printer, and more particularly to a liquid ejecting apparatus capable of adjusting the position of dots to be formed more finely than in the past.

  In an ink jet printer that is one of liquid ejecting apparatuses, a head having a plurality of nozzles that eject ink is usually moved relative to a print medium, and the ink is arranged by ink ejected (ejected) from each nozzle. Dots are formed on each pixel.

  In an ink jet printer or the like having such a mechanism, it is known that there is a deviation in the position of each formed dot because of variations in the ink ejection characteristics of each of a plurality of nozzles provided. Several methods for adjusting the deviation have been proposed (for example, an apparatus described in Patent Document 1 below).

On the other hand, an ink jet printer that employs a so-called multi-dot printing method capable of discharging a plurality of ink droplets during one printing cycle for the purpose of improving image quality has been known (for example, the following patent document). 2).
JP 2000-318145 A Japanese Patent Laid-Open No. 2003-1824

  However, with regard to the dot position deviation adjustment described above, in the conventional method, the position adjustment is performed in units of one pixel. For example, in an image having a resolution of 360 DPI, the minimum unit for position adjustment is 1/360 inch. Therefore, conventionally, fine adjustment of one pixel unit or less could not be performed.

  In addition, in the inkjet printers, etc., the multi-dot printing method described above has been adopted, and there is a trend toward higher resolution and higher quality as the various technologies improve. It is desirable to be able to do this.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid ejecting apparatus that uses a so-called multi-dot method and that can finely adjust the positions of dots to be formed.

  In order to achieve the above object, according to one aspect of the present invention, there is provided a liquid ejecting apparatus that ejects liquid to form a plurality of types of unit dots having different diameters, wherein each unit dot has a predetermined number of two or more. The basic dot is formed by a combination of the presence or absence of each basic dot, and the unit dot formation position can be shifted in units of the basic dot. Therefore, according to the present invention, it is possible to finely adjust the position of the dot to be formed as compared with the prior art.

  Furthermore, in the above-described invention, a preferred aspect is characterized in that it has a plurality of nozzles for ejecting the liquid, and the shift amount of the unit dot formation position is variable for each nozzle.

  In order to achieve the above object, according to another aspect of the present invention, liquid is ejected to form a plurality of types of unit dots having different diameters, and each unit dot is a predetermined number of basic dots of 2 or more. The liquid ejecting apparatus formed by the combination of the presence / absence of each basic dot stores storage means for storing the discharge data representing each unit dot based on the type, and reads the discharge data stored in the storage means A means for performing data conversion, the current data that is the ejection data that is the subject of the data conversion, the previous data that is the ejection data that is the subject of the previous data conversion, and the formation positions of the unit dots Data conversion means for executing the data conversion based on the basic dot unit shift amount, and a nozzle for ejecting the liquid based on the data converted data. It is to have a printing means having a le.

  Furthermore, in the above invention, a preferred aspect is characterized in that the data after the data conversion represents the presence or absence of each basic dot.

  Further, in the above invention, a preferred aspect is characterized in that the data conversion means includes a conversion table that associates the previous data, the current data, and the shift amount with the data after the data conversion.

  Furthermore, in the above invention, a preferred aspect is characterized in that the data conversion means includes a buffer for storing the previous data.

  Furthermore, in the above invention, a preferred aspect is characterized in that a plurality of the nozzles are provided, the data conversion means holds the shift amount for each nozzle, and the shift amount is variable for each nozzle. .

  In the above invention, a preferred aspect is that the data conversion means receives an instruction as to whether or not to perform the data conversion, and if the instruction does not perform the data conversion, the data conversion means The read ejection data and the first parameter data that associates the ejection data with the presence / absence of each basic dot are transferred to the printing means without performing the conversion, and the instruction performs the data conversion. In this case, the data conversion is executed to transfer the data after the data conversion and second parameter data that associates the data with the presence or absence of each basic dot to the printing unit, and the printing unit Based on the discharge data and the first parameter data, or the transferred data converted data and the second parameter data. Determining the presence or absence of bets, characterized by injecting the liquid in accordance with the decision.

  Further, in the above invention, a preferred aspect is that the data after the data conversion is larger in size than the ejection data not subjected to the data conversion, and the size of the data transferred from the data conversion unit to the printing unit in one cycle. Are the same, and the transfer period from the data conversion means to the printing means is more often when the data conversion is performed.

  In the above invention, according to one aspect, the printing unit and the data conversion unit are provided in a carriage that moves relative to a medium that is a target of the liquid ejection.

  Further objects and features of the present invention will become apparent from the embodiments of the invention described below.

  Embodiments of the present invention will be described below with reference to the drawings. However, such an embodiment does not limit the technical scope of the present invention. In the drawings, the same or similar elements are denoted by the same reference numerals or reference symbols.

  FIG. 1 is a configuration diagram according to an embodiment of a liquid ejecting apparatus to which the present invention is applied. The printer 1 in FIG. 1 is a liquid ejecting apparatus to which the present invention is applied. One dot representing one pixel (hereinafter referred to as a pixel dot) (unit dot) is composed of a combination of a plurality of basic dots. The so-called multi-dot method is used, and when correcting the position of the dots to be formed, the print data (discharge data) that forms the basis of dot formation can be converted by a predetermined method to adjust the position in units of the basic dots. By doing so, an attempt is made to perform finer position adjustment than before.

  The printer 1 according to the present embodiment is, as an example, an inkjet printer. As shown in FIG. 1, the I / F 2, the CPU 3, the image processing unit 4, the memory 10, the local bus 11, the DSP 12, and the head 13 ( Printing means) and the like. A print request and print data transmitted from the outside such as a host computer are stored in the memory 10 via the I / F 2. Thereafter, the received compressed print data is subjected to decompression processing, color conversion processing, halftone processing, pass separation processing, and data rearrangement processing by the image processing unit 4, DSP 12, etc. The subsequent data is output to the head 13 in an appropriate order. The head 13 sequentially ejects ink based on the transferred print data and executes printing on the print medium.

  The I / F 2 is a part that controls an interface with the outside of the printer 1 such as a host computer, and the CPU 3 is a part that controls the various image processes. The memory 10 is an external memory provided outside the image processing unit 4 and stores each print data in a predetermined area in a state received from the outside and a state after the processing of each image processing described above. Accordingly, data after halftone processing, data after pass decomposition, data after rearrangement processing, and the like are stored in the memory 10, respectively.

  Next, as shown in FIG. 1, the image processing unit 4 includes a path control unit 5, a decompression unit 6, a path decomposition unit 7, a rearrangement processing unit 8, a head output unit 9, and a print position correction unit 14 (data conversion unit 14). And the like, specifically, an ASIC. The path control unit 5 is a part that performs transfer control of data input to the printer 1 via the I / F 2, and the decompression unit 6 is a part that performs the decompression process of the compressed print data.

  The pass separation unit 7 is a part that performs a process of dividing the print data after the halftone process for each scan (pass) of the head 13. The head 13 has a nozzle row having a plurality of nozzles for ejecting ink in the sub-scanning direction for each color, and sequentially ejects ink while moving in the main scanning direction. Since one line in the scanning direction is printed by a plurality of scans (passes), it is necessary to distribute the print data of one raster for each scan (pass), and such pass separation processing is performed.

  Next, the rearrangement processing unit 8 is a part that performs processing for rearranging the print data after the pass decomposition for each unit data.

  The head output unit 9 is a part that reads the print data rearranged by the rearrangement processing unit 8 and outputs the print data to the head 13 in an appropriate order. The print data buffer 91 stores therein the read print data. (Storage means).

  The print position correction unit 14 is a characteristic part of the printer 1 and will be described later in detail. The print data output from the head output unit 9 is used to correct the dot formation position. Is transferred to the head 13, and parameter data for data conversion, which will be described later, is transferred to the head 13 and latch timing to be sent to the head 13 is added.

  Next, the DSP 12 is a processor (Digital Signal Processor) that performs the color conversion process and the halftone process described above, reads predetermined print data stored in the memory 10, executes the process, and processes the processed data. Write back to the memory 10 again.

  As shown in FIG. 1, each processing unit of the image processing unit 4 and the memory 10 are connected by a local bus 11 for performing high-speed data communication with the memory 10 necessary for each processing unit. The local bus 11 is a so-called data bus, and a CPU bus that connects each processing unit in the image processing unit 4 and the CPU 3 is not shown in the image processing unit 4.

  Finally, the head 13 has a nozzle row for each ink color as described above, and sequentially ejects ink according to the print data transferred from the head output unit 9 and the print position correction unit 14 while moving in the main scanning direction. This is the part that performs printing on the printing medium. The nozzle provided in the head 13 is provided with an epizo element (drive device). When a predetermined drive voltage (drive waveform) is applied from a control circuit (not shown), the epizo element is The ink is distorted and discharged.

  FIG. 2 is a diagram illustrating the configuration of the print position correction unit 14 that is a characteristic part of the printer 1. The print data buffer 91 shown in FIG. 2 is print data storage means provided in the head output unit 9 as described above, and stores print data before conversion output to the head 13 with a predetermined width. The print data stored here is data indicating the on / off state of the pixel dot for each pixel. Since the printer 1 has three types of large, medium, and small diameters as the pixel dot, each print data is large. In order to identify dots, medium dots, small dots, and no dots, the data is 2 bits. That is, “11”, “10”, “01”, and “00” represent large dots, medium dots, small dots, and no dots, respectively.

  As shown in FIG. 2, the print position correction unit 14 includes a previous data buffer 141, a delay amount table 142, a conversion table 143, a selector 144, a latch timing, parameter data selection unit 145, and the like. The previous data buffer 141 performs processing at that time and outputs print data for one nozzle row (N nozzles where N is the number of nozzles arranged in the nozzle row) to be output to the head 13 (here, This is a data buffer that temporarily stores print data (hereinafter referred to as previous data) for one nozzle row processed immediately before the current data (hereinafter referred to as current data). The data stored in this buffer is rewritten sequentially as the processing proceeds. Further, when the previous data can be left in the print data buffer 91 described above, the previous data buffer 141 may not be provided in the print position correction unit 14.

  The delay amount table 142 is a table that stores a shift amount for each nozzle. As will be described later, since the printer 1 can adjust the position in units of basic dots, the shift amount is in units of basic dots. Indicated. Therefore, for example, in the example shown in FIG. 2, the position of two basic dots is adjusted for the uppermost nozzle. The delay amount table 142 stores values for N nozzles, and the position adjustment amount can be changed for each nozzle in the nozzle row. However, if the same shift amount is sufficient for all nozzles, this delay amount table 142 The quantity table 142 may not be provided. The data stored in the previous data buffer 141 and the delay amount table 142 is read out when the current data is processed, corresponding to the nozzle being processed.

  Next, the conversion table 143 is a conversion table for converting the read current data when data conversion is designated to adjust the dot formation position. Although specifically described later, the conversion table 143 includes current data for one nozzle (print data for one pixel to be processed), pre-data corresponding to the nozzle, and post-conversion print data corresponding to the shift amount. Is contained. The conversion table 143 is composed of a RAM in this embodiment, and the data is written in advance at a predetermined address by the CPU 3 in advance. If the data to be stored is not changed, it may be constituted by a ROM or the like.

  The selector 144 is a part that selects print data to be transferred to the head 13 based on designation of whether or not to perform data conversion, and sequentially outputs the selected print data to the head 13. The corresponding parameter data selected by the latch timing and parameter data selection unit 145 is also output to the head 13.

  The latch timing / parameter data selection unit 145 is a part for selecting appropriate latch timing and parameter data based on the designation of whether or not to perform data conversion. Then, the selected latch timing is generated and sent to the head 13. The parameter data will be described later.

  As described above, the printer 1 according to the present embodiment having the above-described configuration has a feature in adjusting the dot formation position, and the contents thereof will be described below. FIG. 3 is a diagram for explaining pixel dots having a plurality of diameters, basic dots, the driving waveform, and the like employed in the printer 1. FIG. 3A shows the relationship between the pixel dots of each diameter and the basic dots. First, in the printer 1, as shown at the top of the figure, the same shape is formed for one pixel dot. A drive waveform (basic waveform) having four peaks is given.

  Below that, pixel dots of a plurality of diameters and basic dots representing them are shown. In the case of the large dots described above, all four peaks of the basic waveform are turned on and given to the epizo element. As a result, as shown in the figure, four basic dots are ejected. Similarly, even in the case of medium dots, small dots, and no dots, an actual waveform (solid line portion) as shown in the figure is given, and the corresponding basic dots are ejected to form each dot.

  FIG. 3B illustrates a dot formation state accompanying the movement of the head 13, and in this example, the resolution is 360 DPI. Therefore, as shown in the figure, one pixel dot is arranged at 1/360 inch intervals, and each pixel dot is expressed by the above-described four basic dots on / off. In this example, large dots, medium dots, and small dots are sequentially printed. Further, the drive waveform by the four peaks is triggered every 1/360 inch based on the encoder signal of the carriage 15 on which the head 13 is mounted.

  Further, as shown at the bottom in FIG. 3B, data transfer to the head 13 is performed in parallel with the generation of the drive waveform, and the next pixel is based on the sent print data. On / off of each basic dot in the dot is determined. In the example shown in the drawing, the data for the next medium dot is transferred in parallel with the large dot ejection, and then the medium dot (two basic dots) is ejected based on this data. The data transfer timing is for the case where the print data is not converted by the print position correction unit 14, and the case where the conversion is performed will be described later. Further, as described above, the on / off state of each basic waveform is determined from the transferred data. The data that associates the transfer data with the on / off state of the basic waveform is the parameter data, which will be described in detail later.

  FIG. 4 is a diagram for explaining the adjustment of the dot position in the printer 1. As described above, in the printer 1, position adjustment is performed in units of basic dots that are equal to or less than the unit of pixel dots. The example shown in FIG. 4 shows a case where adjustment is performed by shifting the position by one basic dot, and printing aligned with large dots, medium dots, and small dots is adjusted as “after adjustment” in the figure. That is, printing is performed with the waveform shifted to the right by one peak.

  In order to enable such position adjustment, the printer 1 converts print data in the print position correction unit 14 described above. More specifically, 2 bits of print data before conversion representing one pixel dot is converted into 4 bits of data in which the print data directly represents on / off of four peaks of the drive waveform. In the example shown in FIG. 4, the print data (1, 0) before conversion of the middle pixel dot is converted into (1, 1) and (0, 1). As is apparent from the figure, the post-conversion data represents ON / OFF of the basic dots. Further, in order to determine the data after conversion from the print data before conversion, it is necessary to know the state of the previous pixel dot and the shift amount, as can be seen from the figure. As described in the description of 143, the current data, the previous data, and the shift amount need to be input in order to determine the post-conversion data. In this way, the printer 1 can perform fine position adjustment below the resolution (in the example shown in FIG. 4, 1/360 inch or less), in other words, within one printing cycle.

  FIG. 5 is a diagram for explaining the parameter data. First, FIG. 5A shows a case where the above-described data conversion is not performed, and parameter data in this case is stored in original print data (print data buffer 91) representing large, medium, and small pixel dots. Data) and the on / off state of basic dots (driving peaks) shown in FIG. 3A are associated with each other. Therefore, the matrix of the left side print data 2 bits and the basic dot on / off values shown on the right side shown in FIG. 5A is parameter data in this case.

  As a specific expression method, the on / off value of each basic dot on the right side is 8 bits, and as shown in the lower part of the figure, the values of the states (0 to 7) of the driving waveforms are arranged in order from the top. Then, it is arranged from the state 7 side to be “00008CAC”. The parameter data is transferred to the head 13 together with the print data, and the head 13 translates the print data transferred by the parameter data into on / off of the drive waveform and discharges the corresponding basic dots.

  FIG. 5B shows parameter data when data conversion is performed. As described with reference to FIG. 4, since the converted print data is 4-bit data for one pixel dot, when transferring to the head 13, the upper 2 bits and lower 2 bits are separated. Do. Accordingly, the parameter data in this case also associates the converted print data 2 bits with the on / off of the drive waveform. The left side data shown in the figure shows the 2-bit converted print data, and the right side shows the ON / OFF value of the corresponding basic dot. In this case as well, the matrix shown in the figure is parameter data, and is expressed in 000000AC as shown in the lower part of the figure, as in the case of no conversion. As described above, the post-conversion print data represents the ON / OFF state of the basic dot as it is, and therefore, in FIG. 5B, the print data and the values of state 0 and state 1 are the same.

  In addition, as shown in FIG. 5B, the two driving waveform peaks corresponding to the converted data of the upper 2 bits and the lower 2 bits are called sections here. In the parameter data, as shown in the figure, an 8-bit basic dot on / off value is prepared, which is applicable to a drive waveform composed of 8 peaks for one pixel dot.

  As described above, in the printer 1, parameter data having the same format as the 2-bit print data is transferred to the head 13 regardless of whether or not data conversion is performed. However, the same processing may be performed. Therefore, it is not necessary to improve the head 13 by adding a data conversion function in the print position correction unit 14 which is a feature of the printer 1.

  FIG. 6 is a diagram showing the timing of data transfer to the head 13. When data conversion is not performed, as described with reference to FIG. 3B, print data for the next pixel is transferred at the trigger timing of one pixel dot. Note that this data transfer includes the print data for one nozzle row and the parameter data when not converted.

  On the other hand, when data conversion is performed, data transfer is performed in two sections (upper 2 bits, lower 2 bits) for one pixel dot as described above, so the data transfer timing to the head 13 is as shown in FIG. As shown at the bottom. That is, data transfer is performed twice as often as when conversion is not performed. Therefore, when data conversion is performed, it is necessary to change (add) the latch timing generated in the print position correction unit 14, and the switching is performed by the latch timing and parameter data selection unit 145 described above. Even when data conversion is performed, the data transfer shown in the drawing includes the parameter data for conversion with converted print data (upper or lower) for one nozzle row.

  FIG. 7 is a flowchart illustrating a processing procedure in the print position correction unit 14. Hereinafter, specific processing contents in the print position correction unit 14 will be described with reference to FIG. First, when data is transferred from the head output unit 9 to the head 13, the print position correction unit 14 receives an instruction as to whether or not to perform data conversion (step S1). If the instruction is not to perform conversion (No in step S1), the latch timing / parameter data selection unit 145 selects the above-described latch timing and parameter data when data conversion is not performed ( Step S2).

  Then, print data (2 bits) for one pixel dot is read from the print data buffer 91, and the read print data is transferred from the selector 144 to the head 13 (step S3). Data transfer processing to the head 13 is performed for N nozzles (one nozzle row) (step S4), and then the parameter data when the selected data conversion is not performed is transferred to the head 13 (step S5). . Then, a latch timing for not performing the selected data conversion is generated and transmitted to the head 13 (step S6).

  In this way, the processing for one printing cycle (one nozzle row) in the case of not performing data conversion is completed, and in the head 13, the transferred print data is converted into the drive waveform by the parameter data transferred together. It is converted to on / off, and actual dot formation is performed based on the subsequent actual waveform.

  On the other hand, if there is a data conversion instruction in step S1 (Yes in step S1), the latch timing / parameter data selection unit 145 selects the above-described latch timing and parameter data for data conversion. (Step S7). Thereafter, print data (2 bits) for one pixel dot is read from the print data buffer 91 (step S8).

  Next, the print position correction unit 14 generates the above-described converted print data composed of upper 2 bits and lower 2 bits from the read print data (step S9). That is, data conversion processing is performed. Specifically, the data in the previous data buffer 141 and the shift amount in the delay amount table 142 corresponding to the nozzle (number) that has read the print data this time are read out, and these values and the read print data (current data) are read out. ) Is an address for reading data stored in the conversion table 143 (printed data after conversion).

  In the print position correction unit 14, data stored at the address in the conversion table 143 is read, that is, data conversion is performed, and the read converted print data (upper 2 bits, lower 2 bits) is read. It is sent to the selector 144.

  FIG. 8 is a diagram for explaining the conversion table 143. Shown at the left end and lower part of the figure are the previous data, current data, and shift amount, which are input values of the conversion table 143. Also, [Previous data, current data] shown at the left end shows all 16 possible combinations. The generated data at each shift amount indicates the corresponding [previous data, current data] and post-conversion print data corresponding to the shift amount, that is, the output value from the conversion table 143.

  Further, the circles shown for each shift amount indicate basic dots formed when the corresponding shift amount is adjusted in the case of corresponding [previous data, current data]. Note that the portion painted in gray corresponds to the pixel position of the current data. Therefore, the generated data (the upper 2 bits and the lower 2 bits) represents the on / off state of the basic dot in the portion.

  For example, the portion indicated by A in FIG. 8 is a basic dot after adjustment when the previous data (11) is a large dot, the current data (01) is a small dot, and the shift amount is one basic dot. Is shown. In this example, since the first peak and the third peak of the drive waveform are turned on, the converted print data is 1010 as shown as the generated data.

  The conversion table 143 stores the generated data so that the generated data corresponding to each input value shown in FIG. 8 can be output. Specifically, the previous data, which is the input value, the current data, and Four bits of generated data (converted print data) corresponding to the input value are stored in an address represented by a total of 6 bits of data each representing the shift amount in 2 bits. In the printer 1, the RAM constituting the conversion table 143 has a width of 8 bits, and the stored 4-bit data is represented by 8 bits. For example, in the case indicated by A in FIG. 8 described above, the address based on the previous data, the current data, and the shift amount is 110101, and the generated data 10100000 is stored at this address position.

  Returning to FIG. 7, next, print data (upper 2 bits) for the first section of the converted print data 4 bits is transferred from the selector 144 to the head 13 (step S10). At this time, the lower 2 bits remain in the selector 144. Further, the read current data is written at the corresponding nozzle position in the previous data buffer 141, and the data in the previous data buffer 141 is rewritten (step S11). This data is used as previous data in the next printing cycle.

  When such processing from reading the print data (S8) to rewriting the previous data buffer (S11) is performed for the number of N nozzles (one nozzle row) (step S12), the selected parameter data at the time of conversion Is transferred to the head 13 (step S13), and the latch timing at the time of the selected conversion is generated and transmitted to the head 13 (step S14).

  When the processing for the upper 2 bits is completed in this way, the lower 2 bits of the converted print data generated in step S9 corresponding to each nozzle remain in the selector 144. Transfer is performed (step S15). When the number of N nozzles (one nozzle row) is implemented, the selected conversion parameter data is transferred to the head 13 (step S16), and the selected conversion latch timing is generated to generate the head 13 (Step S17).

  When the processing for the lower 2 bits is thus completed, the processing in the printing position correction unit 14 for one printing cycle is completed. In the head 13, an actual drive waveform is generated from the transferred print data after conversion and the corresponding parameter data, as in the case where conversion is not performed, and actual dot formation is performed.

  The processing described above is repeated, and print data is transferred from the head output unit 9 to the head 13 via the print position correction unit 14 based on the designation of whether or not to perform data conversion, and data conversion is performed. When performing the above, position adjustment is performed in units of basic dots based on the set shift amount.

  In the above description, the upper 2 bits and the lower 2 bits are generated by a single conversion. However, first, the upper 2 bits are generated, transferred for N nozzles, and then the lower 2 bits are processed. Therefore, the lower 2 bits may be generated and transferred sequentially. In this case, the previous data buffer 141 is rewritten (step S11 in FIG. 7) after the process for the lower 2 bits.

  At the time of data conversion, as described above, data transfer from the print position correction unit 14 to the head 13 is performed twice as often as when data conversion is not performed. This is the image processing unit 4 (main circuit). ) And the head 13, the required data transfer frequency is increased. Usually, the main circuit and the head 13 are connected by an FFC cable (Flexible Flat Cable) or the like, and such a cable cannot easily increase the transfer frequency due to mechanical conditions such as a long path or cost factors. There is. Therefore, the print position correction unit 14 may be provided on the head 13 side.

  FIG. 9 is a diagram showing a configuration in such a case. As shown in the figure, in this example, the print position correction unit 14 described above is provided on a carriage 15 on which the head 13 is mounted, and is printed by a cable 16 that connects the image processing unit (main substrate) 4 and the head 13 side. Normal data transfer is performed when data conversion is not performed until just before the position correction unit 14. The data transferred immediately before the print position correction unit 14 is temporarily buffered in order to cope with the frequent data transfer from the print position correction unit 14 to the head 13. By adopting such a configuration, it is not necessary to increase the data transfer frequency between the main board and the vicinity of the head 13 (cable 16).

  As described above, the printer 1 according to the present embodiment employs a multi-dot method in which one pixel dot is configured by turning on and off a plurality of basic dots (driving waveform peaks), and the basic dots (driving waveform Adjust the position of the dots to be formed in units of crests. Therefore, compared with the conventional position adjustment in units of one pixel dot (one printing cycle), fine position adjustment is possible.

  In addition, by converting the print data expressing pixel dots of multiple diameters to data expressing the on / off state of each basic dot after adjusting the basic dot unit, the basic dot (driving waveform peak) unit. Can be adjusted.

  Also, whether or not this data conversion is performed, parameter data in the same format as the print data of the same size is transferred to the head 13, so that the same processing is performed in the head 13 in either case. The same head can be used. When data conversion is performed, the amount of data transferred to the head 13 increases, but the printing speed is not lowered by increasing the latch timing (transfer frequency).

  Furthermore, as described above, by providing a portion for performing data conversion in the vicinity of the head 13, it is possible to avoid increasing the data transfer frequency between the main board and the vicinity of the head 13.

  In the present embodiment, one pixel dot is configured with a drive waveform of four peaks, but the number of peaks is an example, and is configured with a drive waveform of six peaks or eight peaks. It doesn't matter. When the number of peaks is an odd number, it is possible to perform the same processing by combining two pixel dots into a set of even peaks and dividing them into the aforementioned sections.

  Further, in the present embodiment, a plurality of peaks constituting one pixel dot are the same, but even when they are not the same, the same pattern constituted by a plurality of peaks is repeated a plurality of times to obtain one pixel dot. In the case of configuring the above, it is possible to perform the same by replacing this one pattern with one mountain in the present embodiment. In such a case, the position can be adjusted in units of one pattern.

  The protection scope of the present invention is not limited to the above-described embodiment, but covers the invention described in the claims and equivalents thereof.

1 is a configuration diagram according to an embodiment of a liquid ejecting apparatus to which the present invention is applied. 2 is a diagram illustrating a configuration of a print position correction unit 14 of the printer 1. FIG. It is a figure for demonstrating a pixel dot, a basic dot, a drive waveform, etc. FIG. FIG. 4 is a diagram for explaining dot position adjustment in the printer. It is a figure for demonstrating parameter data. FIG. 6 is a diagram illustrating timing of data transfer to the head 13. 5 is a flowchart illustrating an example of a processing procedure in a print position correction unit. 5 is a diagram for explaining a conversion table 143. FIG. FIG. 6 is a diagram illustrating a configuration when a print position correction unit is provided on the head side.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer, 2 I / F, 3 CPU, 4 Image processing unit, 5 Pass control part, 6 Decompression part, 7 Pass decomposition | disassembly part, 8 Rearrangement process part, 9 Head output part, 10 Memory, 11 Local bus, 12 DSP , 13 head (printing means), 14 print position correction section (data conversion means), 15 carriage, 16 cable, 91 print data buffer (storage means), 141 previous data buffer, 142 delay amount table, 143 conversion table, 144 selector 145 Latch timing, parameter data selection part

Claims (10)

A liquid ejecting apparatus for ejecting liquid to form a plurality of types of unit dots having different diameters,
Each unit dot is formed by a combination of the presence or absence of each basic dot in a predetermined number of basic dots of 2 or more,
The liquid ejecting apparatus, wherein the unit dot formation position can be shifted in units of the basic dots. In claim 1,
A plurality of nozzles for ejecting the liquid;
The liquid ejecting apparatus, wherein the shift amount of the unit dot formation position is variable for each nozzle. This is a liquid ejecting apparatus in which a plurality of types of unit dots having different diameters are formed by ejecting liquid, and each unit dot is formed by a combination of the presence or absence of each basic dot in a predetermined number of basic dots of 2 or more. And
Storage means for storing discharge data representing each unit dot based on the type;
A means for reading the discharge data stored in the storage means and performing data conversion, the current data being the discharge data subject to the data conversion and the discharge data being the target in the previous data conversion Data conversion means for performing the data conversion based on certain previous data and the shift amount of the basic dot unit with respect to the unit dot formation position;
A liquid ejecting apparatus comprising: a printing unit including a nozzle that ejects the liquid based on the data after the data conversion. In claim 3,
The data after the data conversion represents the presence / absence of each of the basic dots. In claim 3 or claim 4,
The liquid conversion apparatus, wherein the data conversion unit includes a conversion table that associates the previous data, the current data, the shift amount, and the data after the data conversion. In any one of Claims 3 thru | or 5,
The liquid conversion apparatus, wherein the data conversion means includes a buffer for storing the previous data. In any one of Claims 3 thru | or 6,
A plurality of the nozzles;
The data conversion means holds the shift amount for each nozzle,
The liquid ejecting apparatus, wherein the shift amount is variable for each nozzle. In any one of Claims 3 thru | or 7,
The data conversion means receives an instruction as to whether or not to perform the data conversion, and when the instruction is not to perform the data conversion, the read ejection data without performing the data conversion. And the first parameter data that associates the ejection data with the presence or absence of each basic dot is transferred to the printing means, and if the instruction is to perform the data conversion, the data conversion is executed. Transferring the data after the data conversion and the second parameter data associating the data with the presence or absence of each basic dot to the printing means;
The printing means determines the presence / absence of each basic dot based on the transferred ejection data and first parameter data, or the transferred data converted data and second parameter data, and according to the determination A liquid ejecting apparatus characterized by ejecting the liquid. In claim 8,
The data after the data conversion is larger in size than the ejection data not subjected to the data conversion,
The size of data transferred in one cycle from the data conversion means to the printing means is the same,
The liquid ejecting apparatus according to claim 1, wherein a transfer cycle from the data conversion unit to the printing unit is more often when the data conversion is performed. In any one of Claims 3 thru | or 9,
The liquid ejecting apparatus, wherein the printing unit and the data converting unit are provided in a carriage that moves relative to a medium that is a liquid ejection target.

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