JP2005081565A - Liquid injection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet type recording apparatus, widely a liquid injection apparatus which can realize a "sharp" quality at an edge part while edge processing of preventing bleeding of ink is realized. <P>SOLUTION: The liquid injection apparatus includes a head member 10 with a nozzle opening 13, a horizontal scanning means for moving the head member 10 in a horizontal scanning direction relatively to a medium for recording, a liquid discharge means 15 for making a liquid in a liquid chamber discharged via the nozzle opening, and a tone data setting means for setting one select tone data from a plurality of tone data on the basis of discharge data that constitute columns corresponding to horizontal scanning. The tone data setting means sets the select tone data of a relatively low density on the basis of forefront outline data and last outline data, sets the select tone data of a relatively middle density on the basis of forefront solid data and last solid data, and sets the select tone data of a relatively high density on the basis of solid internal data. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid droplets from nozzle openings, and more particularly to a liquid ejecting apparatus that can eject a plurality of types of liquid droplets having different liquid amounts from the same nozzle opening.

  An ink jet recording apparatus (a type of liquid ejecting apparatus) such as an ink jet printer or an ink jet plotter moves a recording head (head member) along the main scanning direction and also transfers a recording paper (a type of printing recording medium). An image (character) is recorded on the recording paper by moving along the scanning direction and ejecting ink droplets from the nozzle openings of the recording head in conjunction with the movement. The ink droplets are ejected, for example, by expanding and contracting a pressure generating chamber that communicates with the nozzle opening.

  The expansion / contraction of the pressure generating chamber is performed using, for example, deformation of the piezoelectric vibrator. In such a recording head, the piezoelectric vibrator is deformed in accordance with the supplied driving pulse, thereby changing the volume of the pressure chamber, and this volume change causes a pressure fluctuation in the ink in the pressure chamber, and the nozzle opening. Ink droplets are ejected.

  In such a recording apparatus, a drive signal formed by connecting a plurality of drive pulses in series is generated. On the other hand, print data (discharge data) including gradation information is transmitted to the recording head. Then, based on the transmitted print data, only the necessary drive pulse is selected from the drive signal and supplied to the piezoelectric vibrator. Thereby, the amount of ink droplets ejected from the nozzle openings is changed according to the gradation information.

  More specifically, for example, non-recording print data (gradation information 00), small dot print data (gradation information 01), medium dot print data (gradation information 10), and large dot printing In a printer in which four gradations composed of data (gradation information 11) are set, ink droplets having different ink amounts are ejected according to each gradation.

  In order to realize the four-tone recording as described above, for example, a drive signal as shown in FIG. 18 can be used. As shown in FIG. 18, this drive signal includes a first pulse signal PAPS1 arranged in the period PAT1, a second pulse signal PAPS2 arranged in the period PAT2, and a third pulse signal PAPS3 arranged in the period PAT3. Are connected in series, and are pulse train waveform signals repeatedly generated at the recording cycle PATA.

  In this case, the first pulse signal PAPS1 is the first drive pulse PADP1, the second pulse signal PAPS2 is the second drive pulse PADP2, and the third pulse signal PAPS3 is the third drive pulse PADP3.

  The first drive pulse PADP1, the second drive pulse PADP2, and the third drive pulse PADP3 have the same waveform shape, and are signals that can eject ink droplets independently. That is, by supplying each of these drive pulses to the piezoelectric vibrator, an ink droplet in an amount capable of forming a small dot is ejected from the nozzle opening.

  In this case, as shown in FIG. 19, gradation control can be performed by increasing or decreasing the number of drive pulses supplied to the piezoelectric vibrator. For example, small dots are recorded by supplying one drive pulse, medium dots are recorded by supplying two drive pulses, and large dots are recorded by supplying three drive pulses. Can do.

  The invention described in Japanese Patent Application Laid-Open No. 2002-292848, which is a prior application of the present application, relates to a technique for ejecting ink to print an image on a print medium.

  When line drawings such as characters and illustrations are printed with an ink jet printer, ink bleeding may occur in the outline of the line drawing. Such ink bleeding is caused by the fact that the ink ejected to the line drawing area cannot be absorbed by the print medium, forms an ink reservoir, and flows toward the area where the ink dots should not be formed.

  An object of the present invention is to suppress bleeding of ink in a contour portion in a printing apparatus that prints an image by ejecting ink droplets.

  In the printing control apparatus according to the present invention, the contour line is extracted, and the ink amount of dots formed on the pixels adjacent to the contour line is regularly reduced. Thereby, in particular, when text is printed on a printing paper such as plain paper that absorbs a small amount of ink, it is possible to suppress ink bleeding.

However, in the invention described in Japanese Patent Application Laid-Open No. 2002-292848, the inventor of the present invention has an outline sharpened to a “beard shape” due to various conditions such as the type of ink and the type of recording paper, and the sharpness of the outline. I found out that is lost.
JP2002-292848 JP-A-8-11298 JP 10-16227 A

  The present invention has been made in consideration of such points, and realizes edge processing for preventing ink bleeding while at the same time realizing an “sharp” quality at the edge portion. In general, it is an object to provide a liquid ejecting apparatus.

  The present invention relates to a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and liquid ejection for ejecting liquid in the liquid chamber through the nozzle opening. Means, gradation data setting means for setting one selected gradation data from a plurality of gradation data based on discharge data constituting a column corresponding to main scanning, and drive signal generating means for generating an ejection drive signal A drive pulse generating means for generating a drive pulse based on the selected gradation data and the discharge drive signal, and a control main body for driving the liquid discharge means based on the drive pulse, and the discharge data column is , Continuous injection data corresponding to 5 or more continuous areas of relatively high density gradation data are included, and the continuous injection data includes the earliest contour data which is the earliest in the main scanning direction and the main scanning direction. The last contour data that is the last, and the inner actual data sandwiched between the earliest contour data and the last contour data, the inner actual data is the earliest inner actual data that is the earliest in the main scanning direction, Last internal real data which is the last in the main scanning direction, and internal internal data sandwiched between the earliest actual data and the last actual data, and the gradation data setting means includes the earliest contour data and the last contour Based on the data, set relatively low density selection gradation data, based on the first actual data and the last actual data, set relatively medium density selection gradation data, based on the internal internal data, The liquid ejecting apparatus is characterized in that selection gradation data having a relatively high density is set.

  According to the present invention, in the main scanning direction, liquid ejection is performed using relatively low density selection gradation data based on the earliest contour data and the last contour data, and the earliest actual data and the last inner actual data among the inner actual data. Based on the data, liquid ejection can be performed based on relatively medium density selected gradation data, and based on the actual internal data, liquid ejection based on relatively high density selected gradation data can be performed. Therefore, since the outer peripheral portion of the continuous region gradually decreases in density in the main scanning direction, the possibility that the liquid flows in a “whisker” shape is significantly reduced, and a “sharp” quality can be realized.

  Preferably, the ejection drive signal is a periodic signal having a plurality of pulse waveforms, and the drive pulse generation means generates a rectangular pulse train corresponding to one cycle of the ejection drive signal from each gradation data, and the rectangular pulse train and the ejection drive. The drive pulse is generated by AND with the signal, and the plurality of gradation data includes first low density gradation data and second low density gradation data, and the gradation data The setting means is configured to set the first low density gradation data based on the earliest contour data and the second low density gradation data based on the last contour data. In one cycle, a first small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening, a second small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening, and a first small dot pulse waveform And a third pulse waveform provided between the two small dot pulse waveforms, and the drive pulse generating means is configured to select the first gradation level data of the selected gradation data based on the ejection drive signal. Only the first small dot pulse waveform is used as the drive pulse when the grayscale data is selected, and only the second small dot pulse waveform is used as the drive pulse when the selected grayscale data is the second low density grayscale data. It has become.

  In this case, the liquid discharge mode based on the earliest contour data and the liquid discharge mode based on the last contour data can be set independently. Further, in this aspect, the liquid discharge position based on the earliest contour data is shifted to the far side with respect to the continuous region, and the liquid discharge position based on the last contour data is also shifted to the far side with respect to the continuous region. According to these various experimental results, by adopting such a liquid discharge position, it is possible to realize a “sharp” quality.

  In this case, generally, the small liquid droplet ejected from the nozzle opening by the first small dot pulse waveform has the same volume as the small liquid droplet ejected from the nozzle opening by the second small dot pulse waveform.

  Alternatively, preferably, the ejection drive signal is a periodic signal having a plurality of pulse waveforms, and the drive pulse generation unit generates a rectangular pulse train corresponding to one cycle of the ejection drive signal from each gradation data, and the rectangular pulse train The drive pulse is generated by AND with the ejection drive signal, and the plurality of gradation data includes first intermediate density gradation data and second intermediate density gradation data. The tone data setting means sets the first medium density gradation data based on the earliest actual data, and sets the second medium density gradation data based on the last actual data. Includes a first small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening, a second small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening, and a first small dot pulse in one cycle. And a third pulse waveform provided between the second waveform and the second small dot pulse waveform, and the drive pulse generation means has the selected gradation data based on the ejection drive signal as the first gradation data. When the first medium density gradation data is used, the first small dot pulse waveform and the third pulse waveform are used as drive pulses. When the selected gradation data is the second medium density gradation data, the second small dot pulse is used. The waveform and the third pulse waveform are used as drive pulses.

  In this case, the liquid ejection mode based on the earliest actual data and the liquid ejection mode based on the last actual data can be set separately and independently. Further, in this aspect, the liquid discharge position based on the earliest internal actual data is shifted closer to the continuous area, and the liquid discharge position based on the last contour data is also shifted closer to the continuous area. According to these various experimental results, by adopting such a liquid discharge position, it is possible to realize a “sharp” quality.

  In this case, generally, the small liquid droplets ejected from the nozzle opening by the first small dot pulse waveform and the third pulse waveform are ejected from the nozzle opening by the second small dot pulse waveform and the third pulse waveform. The same volume as the small liquid drop.

  The present invention also provides a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and the head member relative to the recording medium. Sub-scanning means for moving in the sub-scanning direction perpendicular to the main scanning direction, liquid discharge means for discharging the liquid in the liquid chamber through the nozzle openings, and one selection from a plurality of gradation data based on the discharge data Gradation data setting means for setting gradation data, drive signal generation means for generating an ejection drive signal, drive pulse generation means for generating a drive pulse based on the selected gradation data and the ejection drive signal, and driving A control main body that drives the liquid discharge means based on the pulse, and the discharge data has continuous injection data corresponding to five or more continuous regions in the sub-scanning direction. The first contour data that is the earliest in the scanning direction, the last contour data that is the last in the sub-scanning direction, and the actual data sandwiched between the first contour data and the last contour data. The data includes the earliest actual data that is the earliest in the sub-scanning direction, the last actual data that is the last in the sub-scanning direction, and the inner actual internal data sandwiched between the earliest actual data and the last actual data The gradation data setting means sets relatively low density selected gradation data based on the earliest contour data and the last contour data, and relatively medium based on the earliest actual data and the last actual data. The liquid ejecting apparatus is characterized in that density selective gradation data is set, and comparatively high density selective gradation data is set based on the actual internal data.

  According to the present invention, in the sub-scanning direction, liquid discharge is performed with relatively low density selected gradation data based on the earliest contour data and the last contour data. Based on the data, liquid ejection can be performed based on relatively medium density selected gradation data, and based on the actual internal data, liquid ejection based on relatively high density selected gradation data can be performed. Accordingly, since the outer peripheral portion of the continuous region gradually decreases in concentration in the sub-scanning direction, the possibility that the liquid flows in a “whisker” shape is significantly reduced, and “sharp” quality can be realized.

  The present invention also provides a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and the head member relative to the recording medium. Sub-scanning means for moving in the sub-scanning direction perpendicular to the main scanning direction, liquid discharge means for discharging the liquid in the liquid chamber through the nozzle openings, and one selection from a plurality of gradation data based on the discharge data Gradation data setting means for setting gradation data, drive signal generation means for generating an ejection drive signal, drive pulse generation means for generating a drive pulse based on the selected gradation data and the ejection drive signal, and driving And a control main body that drives the liquid ejection means based on the pulse, and the ejection data is in each of the main scanning direction and the sub-scanning direction on a plane defined by the main scanning direction and the sub-scanning direction. Injection continuous data corresponding to a comparatively high density continuous region of 5 or more, and the continuous injection data is the main of the continuous injection data in the plane defined by the main scanning direction and the sub-scanning direction. The contour data that is the earliest in at least one of the scanning direction and the sub-scanning direction or that is the last in at least one of the main scanning direction and the sub-scanning direction of the continuous ejection data is surrounded by the contour data. The internal real data is the first in at least one of the main scanning direction and the sub-scanning direction of the internal real data, or the main scanning direction of the internal real data and Solid inner contour data last in at least one of the sub-scanning directions; solid inner data surrounded by the inner contour data; The gradation data setting means sets relatively low density selection gradation data based on the contour data, and sets relatively medium density selection gradation data based on the actual contour data. The liquid ejecting apparatus is characterized in that relatively high density selection gradation data is set based on the internal data.

  According to the present invention, liquid discharge is performed using relatively low density selected gradation data based on the contour data, and liquid discharge is performed based on relatively medium density selected gradation data based on the actual actual contour data. Based on the internal data, liquid ejection can be performed with relatively high density selected gradation data. Accordingly, since the outer peripheral portion of the continuous area gradually decreases in density in the main scanning direction and the sub-scanning direction, the possibility that the liquid flows in a “whisker” shape is significantly reduced, and “sharp” quality is realized. Can do.

The present invention also provides a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and discharging liquid in the liquid chamber via the nozzle opening. A control device for controlling a liquid ejecting apparatus including a liquid ejecting unit,
A gradation data setting means for setting one selected gradation data from a plurality of gradation data, a drive signal generating means for generating an ejection drive signal, and a selection based on the ejection data constituting the column corresponding to the main scan A drive pulse generating means for generating a drive pulse based on the gradation data and the discharge drive signal, and a control main body for driving the liquid discharge means based on the drive pulse. It has ejection continuous data corresponding to 5 or more continuous areas of high-density gradation data, and the ejection continuous data is the earliest contour data that is the earliest in the main scanning direction and the last in the main scanning direction. Last contour data, inner actual data sandwiched between the earliest contour data and the last contour data, the inner actual data being the earliest inner actual data that is the earliest in the main scanning direction, and the main scanning Last internal real data that is the last in the direction, and internal internal data sandwiched between the earliest internal real data and the final internal real data, and the gradation data setting means includes the earliest contour data and the final contour data. Based on the internal real data, set the comparatively low density selection gradation data, set the comparatively medium density selection gradation data based on the earliest internal real data and the last internal real data, A control device is characterized in that it selects high-density selected gradation data.

The present invention also provides a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and the head member relative to the recording medium. A control device for controlling a liquid ejecting apparatus comprising: a sub-scanning unit that moves in a sub-scanning direction orthogonal to the main scanning direction; and a liquid ejection unit that ejects liquid in a liquid chamber through a nozzle opening,
Based on the ejection data, gradation data setting means for setting one selection gradation data from a plurality of gradation data, drive signal generation means for generating an ejection drive signal, selection gradation data and ejection drive signal And a control body for driving the liquid discharge means based on the drive pulse, and the discharge data is ejected corresponding to five or more continuous regions in the sub-scanning direction. The continuous injection data is sandwiched between the earliest contour data that is the earliest in the sub-scanning direction, the last contour data that is the last in the sub-scanning direction, the earliest contour data and the last contour data. The internal real data, the internal real data is the earliest internal real data that is the earliest in the sub-scanning direction, and the last internal real data that is the last in the sub-scanning direction, The internal real data sandwiched between the real internal data and the final internal data, and the gradation data setting means selects a relatively low density selected gradation based on the earliest outline data and the final outline data. The data is set, the relatively medium density selected gradation data is set based on the first actual data and the last actual data, and the relatively high density selected gradation data is set based on the internal data. It is the control device characterized by being.

The present invention also provides a head member having a nozzle opening, main scanning means for moving the head member in the main scanning direction relative to the recording medium, and the head member relative to the recording medium. A control device for controlling a liquid ejecting apparatus comprising: a sub-scanning unit that moves in a sub-scanning direction orthogonal to the main scanning direction; and a liquid ejection unit that ejects liquid in a liquid chamber through a nozzle opening,
Based on the ejection data, gradation data setting means for setting one selection gradation data from a plurality of gradation data, drive signal generation means for generating an ejection drive signal, selection gradation data and ejection drive signal And a control main body for driving the liquid discharge means based on the drive pulse, and the discharge data is in a plane defined by the main scanning direction and the sub-scanning direction. In the main scanning direction and the sub-scanning direction, continuous injection data corresponding to a relatively high density continuous region of 5 or more is provided, and the continuous injection data is defined by the main scanning direction and the sub-scanning direction. In the plane, it is the first in at least one of the main scanning direction and the sub-scanning direction of the continuous ejection data, or the main scanning direction of the continuous ejection data And contour data that is the last in at least one direction of the sub-scanning direction and internal real data surrounded by the contour data, the internal real data being the main scanning direction and the sub-scanning direction of the internal real data The internal contour data that is the earliest in the at least one direction or the last of the actual data in at least one of the main scanning direction and the sub-scanning direction, and the internal internal data surrounded by the internal actual contour data, The gradation data setting means sets relatively low density selected gradation data based on the contour data, and relatively medium density selected gradation data based on the actual contour data. The control device is characterized in that the selected gradation data having a relatively high density is set based on the internal internal data.

  Each control device or each element means of each control device may be realized by a computer system.

  Further, a program for causing a computer system to implement each device or each means and a computer-readable recording medium recording the program are also subject to protection in this case.

  Here, the recording medium includes not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.

  FIG. 1 is a schematic perspective view of an ink jet printer 1 which is a liquid ejecting apparatus according to the present embodiment. In the inkjet printer 1, a carriage 2 is movably attached to a guide member 3. The carriage 2 is connected to a timing belt 6 that is stretched between a drive pulley 4 and an idle pulley 5. The drive pulley 4 is joined to the rotating shaft of the pulse motor 7. With the above configuration, the carriage 2 is moved (main scanning) in the width direction of the recording paper 8 by driving the pulse motor 7.

  A recording head 10 (head member) is attached to the surface (lower surface) of the carriage 2 facing the recording paper 8.

  As shown in FIG. 2, the recording head 10 has a reservoir 12 to which ink from an ink cartridge 11 (see FIG. 1) is supplied and a plurality (for example, 64) of nozzle openings 13 arranged in a row in the sub-scanning direction. A nozzle plate 14 and a plurality of pressure chambers 16 provided corresponding to the nozzle openings 13 are mainly provided. The pressure chamber 16 expands and contracts due to deformation of the piezoelectric vibrator 15.

  The reservoir 12 and the pressure chamber 16 communicate with each other via an ink supply port 18 and a supply side communication hole 17. The pressure chamber 16 and the nozzle opening 13 are communicated with each other via a first nozzle communication hole 19 and a second nozzle communication hole 20. That is, a series of ink flow paths from the reservoir 12 through the pressure chamber 16 to the nozzle opening 13 is formed for each nozzle opening 13.

  The nozzle plate 14 in the present embodiment is configured as an ink repellent nozzle plate 14. The ink repellent nozzle plate 14 has a uniformly formed ink repellent film carried on the surface of a nozzle plate substrate. The ink repellent treatment nozzle plate 14 includes a plurality of nozzle openings 13 provided as through holes.

  The nozzle opening 13 is opened on the outer surface of the nozzle plate 14 facing the recording paper 8 with a relatively small diameter, whereas the nozzle opening 13 is relatively large on the back side of the nozzle plate on the second nozzle communication hole 20 side. It is open at. For this reason, the inner wall surface of the nozzle opening 13 has a funnel shape or a cone shape. The ink repellent film is formed on at least the outer surface of the nozzle plate 14.

  The piezoelectric vibrator 15 is a so-called flexural vibration mode piezoelectric vibrator 15. When the piezoelectric vibrator 15 in the flexural vibration mode is used, the piezoelectric vibrator 15 contracts in a direction orthogonal to the electric field by charging and the pressure chamber 16 contracts, and the charged piezoelectric vibrator 15 is discharged. 15 expands in the direction orthogonal to the electric field, and the pressure chamber 16 expands.

  That is, in the recording head 10, the capacity of the corresponding pressure chamber 16 changes as the piezoelectric vibrator 15 is charged / discharged. Ink droplets can be ejected from the nozzle openings 13 using such pressure fluctuations in the pressure chamber 16.

  Instead of the above-described flexural vibration mode piezoelectric vibrator 15, a so-called longitudinal vibration mode piezoelectric vibrator may be used. The piezoelectric vibrator in the longitudinal vibration mode is a piezoelectric vibrator that expands the pressure chamber by deformation due to charging and contracts the pressure chamber by deformation due to discharge.

  The printer 1 configured as described above ejects ink from the recording head 10 as ink droplets in synchronization with the main scanning of the carriage 2 during the recording operation. On the other hand, the platen is rotated in conjunction with the reciprocating movement of the carriage 2 to move the recording paper 8 in the paper feed direction (ie, sub-scanning). As a result, images, characters and the like based on the recording data are recorded on the recording paper 8.

  Next, the electrical configuration of the ink jet printer will be described. As shown in FIG. 3, the printer 1 includes a printer controller 23 and a print engine 24.

  The printer controller 23 includes an external interface (external I / F) 25, a RAM 26 that temporarily stores various data, a ROM 27 that stores a control program, a control unit 28 that includes a CPU, a clock, and the like. An oscillation circuit 29 that generates a signal (CK), a drive signal generation circuit 30 that generates a drive signal (COM) to be supplied to the recording head 10 (details will be described later), a drive signal, and print data (discharge data) And an internal interface (internal I / F) 31 that transmits the dot pattern data (bitmap data) and the like developed based on () to the print engine 24.

  The external I / F 25 receives print data including, for example, a character code, a graphic function, image data, and the like from a host computer (not shown). Further, a vichy signal (BUSY) and an acknowledge signal (ACK) are output to the host computer or the like through the external I / F 25.

  In the present embodiment, the print data received by the external I / F 25 includes continuous ejection data corresponding to a relatively high density continuous area, and the continuous ejection data further includes the continuous ejection data. The contour data that is the earliest in at least one of the main scanning direction and the sub-scanning direction or the last in at least one of the main scanning direction and the sub-scanning direction of the continuous ejection data, and the contour data The internal real data is further surrounded by at least one of the internal real data in at least one of the main scanning direction and the sub-scanning direction. The internal solid contour data that is the last in at least one of the main scanning direction and the sub scanning direction, and the internal solid data surrounded by the internal actual contour data. It assumed to have data and, (see FIG. 9).

  Here, the contour data and the actual contour data are extracted by using, for example, a primary differential filter as shown in FIG. 4A in a contour extraction unit (not shown) in the host computer. obtain. This filter is a filter having directionality in the sub-scanning direction, and can extract a contour line parallel to the main scanning direction. Here, the contour line is a one-pixel wide area that forms the outermost periphery of an image area formed of a pixel group in which a specific type of dot is formed, and a feature value (dot size or color) that defines the image area. ) Adjacent to the discontinuity. The discontinuous portion is, for example, a boundary between pixels where dots are formed and pixels where dots are not formed.

  The contour line extraction filter may be a filter having directionality as shown in FIG. 4B or a filter having no directionality as shown in FIG. Further, by using a filter having directivity in the main scanning direction as shown in FIG. 4D, a contour line parallel to the sub-scanning direction can be extracted.

  The external I / F 25 of the present embodiment functions as image quality mode setting means for setting the normal mode or the sharp edge processing mode with respect to the recording accuracy on the recording paper 8 (recording medium) according to the present embodiment. Are connected to the interface device 100.

  The RAM 26 includes a reception buffer, an intermediate buffer, an output buffer, and a work memory (not shown). The reception buffer temporarily stores print data received via the external I / F 25, the intermediate buffer stores intermediate code data converted by the control unit 28, and the output buffer stores dot pattern data. Remember. Here, the dot pattern data is print data obtained by decoding (translating) the intermediate code data.

  The ROM 27 stores font data, graphic functions, and the like in addition to a control program (control routine) for performing various data processing.

  The control unit 28 performs various controls according to the control program stored in the ROM 27. For example, the print data in the reception buffer is read and the print data is converted into intermediate code data, and the intermediate code data is stored in the intermediate buffer. In addition, the control unit 28 analyzes the intermediate code data read from the intermediate buffer and develops (decodes) it into dot pattern data with reference to the font data and graphic functions stored in the ROM 27. Then, the control unit 28 stores the dot pattern data in the output buffer after performing necessary decoration processing. Each dot pattern data is composed of 2-bit data in this case as gradation information. That is, the control unit 28 functions as a gradation data setting unit.

  If dot pattern data for one line that can be recorded by one main scan of the recording head 10 is obtained, the dot pattern data for one line is sequentially transferred from the output buffer to the recording head 10 through the internal I / F 31. Is output. When dot pattern data for one line is output from the output buffer, the developed intermediate code data is erased from the intermediate buffer, and the development process for the next intermediate code data is performed.

  Further, the control unit 28 constitutes a part of the timing signal generating means, and supplies a latch signal (LAT) and a channel signal (CH) to the recording head 10 through the internal I / F 31. These latch signals and channel signals define the supply start timing of the pulse signal that constitutes the drive signal (COM).

  On the other hand, the print engine 24 includes a paper feed motor 35 as a paper feed mechanism, a pulse motor 7 as a carriage feed mechanism, and an electric drive system 33 of the recording head 10. The paper feed motor 35 rotates the platen 34 (see FIG. 1) to move the recording paper 8, and the pulse motor 7 causes the carriage 2 to travel via the timing belt 6.

  As shown in FIG. 3, the electric drive system 33 of the recording head 10 includes a shift register circuit including a first shift register 36 and a second shift register 37, and a latch circuit including a first latch circuit 39 and a second latch circuit 40. A decoder 42, a control logic 43, a level shifter 44, a switch circuit 45, and a piezoelectric vibrator 15.

  Each of these shift registers, latch circuits, decoders, switch circuits, and piezoelectric vibrators are provided as first shift registers 36A to 36N provided for each nozzle opening 13 of the recording head 10, as shown in FIG. 2 shift registers 37A to 37N, first latch circuits 39A to 39N, second latch circuits 40A to 40N, recorders 42A to 42N, switch circuits 45A to 45N, and piezoelectric vibrators 15A to 15N.

  With such an electric drive system 33, the recording head 10 ejects ink droplets based on print data (gradation information) from the printer controller 23. Print data (SI) from the print controller 23 is serially transmitted from the internal I / F 31 to the first shift register 36 and the second shift register 37 in synchronization with the clock signal (CK) from the oscillation circuit 29.

  The print data from the printer controller 23 is 2-bit data as described above. Specifically, four gradations consisting of non-recording, small dots, medium dots, and large dots are available, non-recording is (00), small dots are (01), and medium dots are (10 ) And a large dot is represented by (11).

  Such print data is set for each dot, that is, for each nozzle opening 13. Then, the lower bit data for all nozzle openings 13 is input to the first shift register 36 (36A to 36N), and the upper bit data for all nozzle openings 13 is input to the second shift register 37 (37A to 37N). Is done.

  As shown in FIG. 3, a first latch circuit 39 is electrically connected to the first shift register 36. Similarly, a second latch circuit 40 is electrically connected to the second shift register 37. When a latch signal (LAT) from the print controller 23 is input to the latch circuits 39 and 40, the first latch circuit 39 latches the lower bit data of the print data, and the second latch circuit 40 prints the print data. Latch the upper bits of.

  As described above, the circuit unit including the first shift register 36 and the first latch circuit 39 and the circuit unit including the second shift register 37 and the second latch circuit 40 each function as a memory circuit. That is, these circuit units temporarily store print data (gradation information) before being input to the decoder 42.

  The print data latched by the latch circuits 39 and 40 is input to the decoders 42A to 42N. The decoder 42 translates 2-bit print data (gradation data) to generate pulse selection data (pulse selection information). The pulse selection data is composed of a plurality of bits equal to or greater than the gradation data, and each bit corresponds to each pulse waveform constituting the drive signal (COM). The supply / non-supply of the drive pulse waveform to the piezoelectric vibrator 15 is selected in accordance with the contents of each bit (for example, (0), (1)). Details of the supply of the drive signal (COM) and the drive pulse waveform will be described later.

  On the other hand, a timing signal from the control logic 43 is also input to the decoder 42. The control logic 43 functions as a timing signal generating unit together with the control unit 28, and generates a timing signal based on the latch signal (LAT) and the channel signal (CH).

  The pulse selection data translated by the decoder 42 is input to the level shifter 44 every time the timing defined by the timing signal comes in order from the higher bit side. For example, the most significant bit data of the pulse selection data is input to the level shifter 44 at the first timing in the recording cycle, and the second bit data of the pulse selection data is input to the level shifter 44 at the second timing.

  The level shifter 44 functions as a voltage amplifier. When the pulse selection data is “1”, the level shifter 44 outputs an electric signal boosted to a voltage capable of driving the switch circuit 45, for example, a voltage of about several tens of volts.

  The pulse selection data “1” boosted by the level shifter 44 is supplied to a switch circuit 45 that functions as drive pulse generation means and a control main body. The switch circuit 45 selects a drive pulse included in the drive signal (COM) based on the pulse selection data generated by the translation of the print data, generates a drive pulse, and sends the drive pulse to the piezoelectric vibrator 15. To supply. Therefore, the drive signal (COM) from the drive signal generation circuit 30 is supplied to the input side of the switch circuit 45, and the piezoelectric vibrator 15 is connected to the output side thereof.

  The pulse selection data controls the operation of the switch circuit 45. For example, during the period when the pulse selection data applied to the switch circuit 45 is “1”, the switch circuit 45 is in a connected state, and the drive pulse of the drive signal is supplied to the piezoelectric vibrator 15. As a result, the potential level of the piezoelectric vibrator 15 changes.

  On the other hand, while the pulse selection data applied to the switch circuit 45 is “0”, the level shifter 44 does not output an electrical signal for operating the switch circuit 45. For this reason, the switch circuit 45 is disconnected, and the drive pulse of the drive signal is not supplied to the piezoelectric vibrator 15. In the period in which the pulse selection data is “0”, the piezoelectric vibrator 15 maintains the potential level immediately before the pulse selection data is switched to “0”.

  Next, a drive signal (COM) generated by the drive signal generation circuit 30 and ink droplet ejection control based on this drive signal will be described in detail.

  An example of the drive signal (COM) is shown in FIG. As shown in FIG. 6, the drive signal COM includes a first pulse signal PS1 arranged in the period T1, a second pulse signal PS2 arranged in the period T2, and a third pulse signal PS3 arranged in the period T3. Are connected in series, and are pulse train waveform signals repeatedly generated at the recording cycle TA. In this case, the set frequency of the recording cycle TA is 8.57 kHz (1/3 of 25.71 kHz). In the drive signal COM, the first pulse signal PS1 is the first drive pulse DP1, the second pulse signal PS2 is the second drive pulse DP2, and the third pulse signal PS3 is the third drive pulse DP3.

  The first drive pulse DP1, the second drive pulse DP2, and the third drive pulse DP3 all have the same waveform shape, and are signals that can individually eject ink droplets.

  That is, each drive pulse DP1, DP2, DP3 has a first discharge element P1 that drops from the intermediate potential VM to the lowest potential VL along the gradient θ1, and a first hold element P2 that maintains this lowest potential VL for a short time. The first charging element P3 that raises the potential from the lowest potential VL to the highest potential VH along the steep slope θ2 in a very short time, the second hold element P4 that maintains the highest potential, and the slope θ3 from the highest potential VH. And a second discharge element P5 that lowers the potential to the intermediate potential VM.

  When these drive pulses are supplied to the piezoelectric vibrator 15, ink droplets of an amount capable of forming small dots are ejected from the nozzle openings 13.

  More specifically, when the first discharge element P1 is supplied and the piezoelectric vibrator 15 is discharged from the intermediate potential VM, the volume of the pressure generating chamber 16 expands from the reference volume to the maximum volume. And the pressure generation chamber 16 contracts rapidly to the minimum volume by the first charging element P3. The contracted state of the pressure generating chamber 16 is maintained over a period during which the second hold element P4 is supplied. By abruptly contracting the pressure generating chamber 16 and maintaining the contracted state, the ink pressure in the pressure generating chamber 16 is rapidly increased, and ink droplets are ejected from the nozzle openings 13. The amount of ink droplets ejected at this time is about 13 pL, for example. Then, the pressure generating chamber 16 is expanded and restored by the second discharge element P5 in order to converge the meniscus vibration in a short time.

  Here, the normal mode will be described in detail.

  As shown in FIG. 7, gradation control can be performed by increasing or decreasing the number of drive pulses supplied to the piezoelectric vibrator 15. For example, small dots are recorded by supplying one drive pulse, medium dots are recorded by supplying two drive pulses, and large dots are recorded by supplying three drive pulses. Can do.

  The pulse selection data generated according to the dot pattern data for small dots (gradation information 01), the dot pattern data for medium dots (gradation information 10), and the dot pattern data for large dots (gradation information 11) I will explain it.

  In this case, the decoder 42 does not record dot pattern data (gradation information 00), small dot pattern data (gradation information 01), medium dot pattern data (gradation information 10), and large dot dots. 3-bit pulse selection data is generated according to the pattern data (gradation information 11).

  Each bit of the 3-bit pulse selection data corresponds to each pulse signal. That is, the most significant bit of the pulse selection data corresponds to the first pulse signal PS1 (first driving pulse DP1), the second bit corresponds to the second pulse signal PS2 (second driving pulse DP2), and the highest bit. The lower bits correspond to the third pulse signal PS3 (third drive pulse DP3).

  In this case, pulse selection data (000) is generated from non-recorded dot pattern data (gradation information 00). Then, pulse selection data (010) is generated from the dot pattern data (gradation information 01) of small dots. Similarly, pulse selection data (101) is generated from dot pattern data for medium dots (gradation information 10), and pulse selection data (111) is generated from dot pattern data for large dots (gradation information 11).

  When the most significant bit of the pulse selection data is “1”, from the first timing signal (latch signal) corresponding to the beginning of the period T1 to the second timing signal (CH signal) corresponding to the beginning of the period T2. During this period, the switch circuit 45 (driving pulse supply means) is connected. When the second bit is “1”, the switch circuit 45 is in a connected state from the second timing signal to the third timing signal (CH signal) corresponding to the start end of the period T3. Similarly, when the least significant bit is “1”, the switch circuit 45 is in the connected state from the third timing signal to the timing signal (latch signal) corresponding to the beginning of the period T1 in the next printing cycle TA. Become.

  Thereby, based on the dot pattern data of small dots, only the second drive pulse DP2 is supplied to the corresponding piezoelectric vibrator 15. Similarly, the first drive pulse DP1 and the third drive pulse DP3 are supplied based on the dot pattern data for medium dots, and the first drive pulse DP1 and the second drive pulse are supplied based on dot pattern data for large dots. The pulse DP2 and the third drive pulse DP3 are continuously supplied.

  As a result, 13 pL of ink droplets are ejected once from the nozzle openings 13 corresponding to the dot pattern data of small dots, and small dots are formed on the recording paper 8. Corresponding to the dot pattern data of medium dots, 13 pL ink droplets are ejected twice from the nozzle openings 13, and medium dots are formed on the recording paper 8 by a total of 26 pL ink droplets. Similarly, in response to the dot pattern data of large dots, 13 pL ink droplets are ejected from the nozzle opening 13 three times in succession, and large dots with a total of 39 pL ink droplets are formed on the recording paper 8. On the other hand, ink droplets are not ejected corresponding to non-recorded dot pattern data.

  More specifically, for example, when an alphabetic character “T” is printed, since the character is usually not given a gradation, printing is executed as shown in FIG. 8 in the normal mode. That is, the dot pattern data (11) of large dots as high density gradation data is set for the solid color for the pixels included in the portion of the character “T” (continuous region), and for the other pixels. In this case, zero gradation data (00) is set as the dot pattern data.

  In the case of the normal mode as described above, in a situation where the ink easily bleeds due to the characteristics of the ink and the characteristics of the recording paper 8, the contour line of the letter “T” extends into a “beard shape”, and the sharpness of the contour is reduced. May be lost. Therefore, the present embodiment provides a sharp edge processing mode for such a situation.

  Next, the sharp edge processing mode will be described in detail.

  Even in this mode, gradation control can be performed by increasing or decreasing the number of drive pulses supplied to the piezoelectric vibrator 15. Here, for comparison with FIG. 8 showing the normal mode, a case where the alphabet letter “T” is printed will be described with reference to FIG. 9.

  Of the pixels (continuous ejection data) included in the character “T” portion (continuous region) by the control unit 28 as gradation data setting means, the pixels (contour data) constituting the contour of the character “T”, that is, , Dot pattern data of small dots as low-density gradation data for the first or last pixel in at least one of the main scanning direction and the sub-scanning direction among the pixels included in the character “T” portion (01) is set.

  Among the pixels (injection continuous data) included in the portion of the character “T” (continuous region), the pixels (internal data) surrounded by the contour data further include the main scanning direction and the sub-scanning direction among the pixels. The pixel is the first or last pixel in the at least one direction (internal actual contour data) and the other pixels (internal internal data). Then, medium dot pattern data (10) as medium density gradation data is set for the former pixel, and large dot pattern data as high density gradation data is set only for the latter pixel. (11) is set.

  For other non-printed (no ink ejected) pixels, zero gradation data (00) is set as dot pattern data.

  In this case as well, the decoder 42 does not print (no ink ejection) dot pattern data (gradation information 00), small dot dot pattern data (gradation information 01), and medium dot dot pattern data (gradation information 10). ) And large dot pattern data (gradation information 11). That is, pulse selection data (000) is generated from non-printing (no ink ejection) dot pattern data (gradation information 00), and pulse selection data (010) is generated from small dot dot pattern data (gradation information 01). The pulse selection data (101) is generated from the dot pattern data for medium dots (gradation information 10), and the pulse selection data (111) is generated from the dot pattern data for large dots (gradation information 11) ( (See FIG. 7).

  When the most significant bit of the pulse selection data is “1”, from the first timing signal (latch signal) corresponding to the beginning of the period T1 to the second timing signal (CH signal) corresponding to the beginning of the period T2. During this period, the switch circuit 45 (driving pulse supply means) is connected. When the second bit is “1”, the switch circuit 45 is in a connected state from the second timing signal to the third timing signal (CH signal) corresponding to the start end of the period T3. Similarly, when the least significant bit is “1”, the switch circuit 45 is in the connected state from the third timing signal to the timing signal (latch signal) corresponding to the beginning of the period T1 in the next printing cycle TA. Become.

  Thereby, based on the dot pattern data of small dots, only the second drive pulse DP2 is supplied to the corresponding piezoelectric vibrator 15. Similarly, the first drive pulse DP1 and the third drive pulse DP3 are supplied based on the dot pattern data for medium dots, and the first drive pulse DP1 and the second drive pulse are supplied based on dot pattern data for large dots. The pulse DP2 and the third drive pulse DP3 are continuously supplied.

  As a result, 13 pL of ink droplets are ejected once from the nozzle openings 13 corresponding to the dot pattern data of small dots, and small dots are formed on the recording paper 8. Corresponding to the dot pattern data of medium dots, 13 pL ink droplets are ejected twice from the nozzle openings 13, and medium dots are formed on the recording paper 8 by a total of 26 pL ink droplets. Similarly, in response to the dot pattern data of large dots, 13 pL ink droplets are ejected from the nozzle opening 13 three times in succession, and large dots with a total of 39 pL ink droplets are formed on the recording paper 8. On the other hand, ink droplets are not ejected corresponding to non-recorded dot pattern data.

  That is, as shown in FIG. 9, small dots are formed on the recording paper 8 corresponding to the contour data, and medium dots are formed on the recording paper 8 corresponding to the internal actual contour data, corresponding to the internal internal data. As a result, a large dot is formed on the recording paper 8 to be in a solid state.

  Such a printing mode is suitable particularly in a situation where ink tends to spread. In such a situation, due to ink bleeding, the outer peripheral portion of the continuous area, which is gradually reduced in density, can be appropriately filled, but the outline of the letter “T” may be extended to a “beard” shape. And the sharpness of the outline is not lost. That is, the edge processing suitable for the case where the ink bleeding tendency is strong can be achieved with higher quality.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, contour data and internal contour data are extracted only in the main scanning direction. In other words, in the present embodiment, the print data received by the external I / F 25 has continuous ejection data corresponding to a relatively high density continuous area forming the character “T” as shown in FIG. The continuous injection data further includes contour data that is the earliest in the main scanning direction of the continuous injection data, or the final contour data in the main scanning direction of the continuous injection data, and the contour data. The internal real data is further first in the main scanning direction of the internal real data or last in the main scanning direction of the internal real data. Assume that it has internal real contour data and internal internal data sandwiched between the internal actual contour data.

  In the sharp edge processing mode of the present embodiment, the control unit 28 serving as the gradation data setting means performs the character “T” among the pixels (ejection continuous data) included in the portion (continuous region) of the character “T”. Of the pixel (contour data) constituting the contour in the main scanning direction, that is, the first or last pixel in the main scanning direction among the pixels included in the portion of the character “T”. Small dot pattern data (01) is set as data.

  Among the pixels (injection continuous data) included in the part of the character “T” (continuous area), the pixel (internal data) sandwiched between the contour data is further the first or It is divided into the last pixel (internal actual contour data) and other pixels (internal internal data). Then, medium dot pattern data (10) as medium density gradation data is set for the former pixel, and large dot pattern data as high density gradation data is set only for the latter pixel. (11) is set.

  The other configuration of the present embodiment is substantially the same as that of the first embodiment described above, and a description thereof will be omitted.

  According to the present embodiment, as shown in FIG. 10, small dots are formed on the recording paper 8 corresponding to the contour data in the main scanning direction, and the recording paper 8 corresponding to the actual contour data in the main scanning direction. A medium dot is formed on the top, and a large dot is formed on the recording paper 8 corresponding to the actual internal data in the main scanning direction so as to be solid.

  Such a printing mode is also suitable in a situation where ink tends to bleed. In such a situation, due to ink bleeding, the outer peripheral portion of the continuous region in the main scanning direction, which is gradually reduced in density, can be appropriately filled, and the outline extending in the sub-scanning direction of the character “T” is “ It does not extend like a “whisker”, and the sharpness of the contour in the main scanning direction is not lost. That is, the edge processing suitable for the case where the ink bleeding tendency is strong can be achieved with higher quality.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, contour data and internal contour data are extracted only in the sub-scanning direction. In other words, in the present embodiment, the print data received by the external I / F 25 has ejection continuous data corresponding to a relatively high density continuous area forming the character “T” as shown in FIG. In addition, the continuous injection data is the first in the sub-scanning direction of the continuous injection data or the last contour data in the sub-scanning direction of the continuous injection data, and the contour data The internal real data is further first in the sub-scanning direction of the internal real data or last in the sub-scanning direction of the internal real data. Assume that it has internal real contour data and internal internal data sandwiched between the internal actual contour data.

  In the sharp edge processing mode of the present embodiment, the control unit 28 serving as the gradation data setting means performs the character “T” among the pixels (ejection continuous data) included in the portion (continuous region) of the character “T”. ”In the sub-scanning direction, that is, the pixel that is the first or last pixel in the sub-scanning direction among the pixels included in the portion of the character“ T ”(contour data). Small dot pattern data (01) is set as data.

  Among the pixels (injection continuous data) included in the portion of the character “T” (continuous region), the pixel (internal data) sandwiched between the contour data is further the first or It is divided into the last pixel (internal actual contour data) and other pixels (internal internal data). Then, medium dot pattern data (10) as medium density gradation data is set for the former pixel, and large dot pattern data as high density gradation data is set only for the latter pixel. (11) is set.

  The other configuration of the present embodiment is substantially the same as that of the first embodiment described above, and a description thereof will be omitted.

  According to the present embodiment, as shown in FIG. 11, small dots are formed on the recording paper 8 corresponding to the contour data in the sub-scanning direction, and the recording paper 8 corresponding to the actual contour data in the sub-scanning direction. A medium dot is formed on the top, and a large dot is formed on the recording paper 8 corresponding to the actual internal data in the sub-scanning direction so as to be solid.

  Such a printing mode is also suitable in a situation where ink tends to bleed. In such a situation, due to ink bleeding, the outer peripheral portion of the continuous region in the sub-scanning direction, which has been gradually reduced in density, can be appropriately filled, and the outline extending in the main scanning direction of the character “T” is “ It does not extend like a “whisker”, and the sharpness of the contour in the sub-scanning direction is not lost. That is, the edge processing suitable for the case where the ink bleeding tendency is strong can be achieved with higher quality.

  Next, a fourth embodiment of the present invention will be described with reference to FIG.

  Also in the present embodiment, the contour data and the actual contour data are extracted only in the main scanning direction, as in the second embodiment. In other words, in the present embodiment, the print data received by the external I / F 25 has ejection continuous data corresponding to a relatively high density continuous area forming the character “T” as shown in FIG. The continuous injection data further includes contour data that is the earliest in the main scanning direction of the continuous injection data, or the final contour data in the main scanning direction of the continuous injection data, and the contour data. The internal real data is further first in the main scanning direction of the internal real data or last in the main scanning direction of the internal real data. Assume that it has internal real contour data and internal internal data sandwiched between the internal actual contour data.

  On the other hand, in the present embodiment, as shown in FIG. 13, the shift register circuit of the electric drive system 33 ′ of the recording head 10 includes a first shift register 36, a second shift register 37, and a third shift register 38. The latch circuit of the electric drive system 33 ′ of the recording head 10 includes a first latch circuit 39, a second latch circuit 40, and a third latch circuit 41.

  As shown in FIG. 14, the third shift register 38 and the third latch circuit 41 also include third shift registers 38A to 38N and third latch circuits 41A to 41N provided for each nozzle opening 13 of the recording head 10, respectively. It is configured.

  With such an electric drive system 33, the recording head 10 ejects ink droplets based on print data (gradation information) from the printer controller 23. Print data (SI) from the print controller 23 is synchronized with the clock signal (CK) from the oscillation circuit 29 from the internal I / F 31 to the first shift register 36, the second shift register 37, and the third shift register 38. Serial transmission is designed.

  The print data from the printer controller 23 is 3-bit data in this embodiment. Specifically, six gradations consisting of non-recording, first small dot, second small dot, first medium dot, second medium dot, and large dot are available, and non-recording is (000), The first small dot is (001), the second small dot is (010), the first medium dot is (011), the second medium dot is (100), and the large dot is (101). It is represented by

  Such print data is set for each dot, that is, for each nozzle opening 13. Then, the lower bit data for all the nozzle openings 13 is input to the first shift register 36 (36A to 36N), and the middle bit data for all the nozzle openings 13 is input to the second shift register 37 (37A to 37N). The high-order bit data for all the nozzle openings 13 is input to the third shift register 38 (38A to 38N).

  As shown in FIG. 13, a first latch circuit 39 is electrically connected to the first shift register 36. Similarly, a second latch circuit 40 is electrically connected to the second shift register 37. Similarly, a third latch circuit 41 is electrically connected to the third shift register 38. When a latch signal (LAT) from the print controller 23 is input to each of the latch circuits 39, 40, 41, the first latch circuit 39 latches the lower bit data of the print data, and the second latch circuit 40 The middle bit of the print data is latched, and the third latch circuit 41 latches the upper bit of the print data.

  Thus, from the circuit unit composed of the first shift register 36 and the first latch circuit 39, the circuit unit composed of the second shift register 37 and the second latch circuit 40, the third shift register 38 and the third latch circuit 41. Each circuit unit functions as a memory circuit. That is, these circuit units temporarily store print data (gradation information) before being input to the decoder 42.

  The print data latched by the latch circuits 39, 40, 41 is input to the decoders 42A to 42N. The decoder 42 translates 3-bit print data (gradation data) to generate pulse selection data (pulse selection information). The pulse selection data is composed of a plurality of bits equal to or greater than the gradation data, and each bit corresponds to each pulse waveform constituting the drive signal (COM). The supply / non-supply of the drive pulse waveform to the piezoelectric vibrator 15 is selected in accordance with the contents of each bit (for example, (0), (1)).

  Other configurations of the present embodiment are substantially the same as those of the above-described embodiment, and thus description thereof is omitted.

  Next, the normal mode of the present embodiment will be described in detail.

  As shown in FIG. 7, gradation control can be performed by increasing or decreasing the number of drive pulses supplied to the piezoelectric vibrator 15. For example, small dots are recorded by supplying one drive pulse, medium dots are recorded by supplying two drive pulses, and large dots are recorded by supplying three drive pulses. Can do.

  The dot pattern data of the first small dots (gradation information 001), the dot pattern data of the second small dots (gradation information 010), the dot pattern data of the first medium dots (gradation information 011), and the second medium dots The pulse pattern data generated according to the dot pattern data (gradation information 100) and the large dot pattern data (gradation information 101) will be described in detail.

  In this case, the decoder 42 includes non-printing dot pattern data (gradation information 00), first and second small dot dot pattern data (gradation information 001, 010), and first and second medium dot pattern. 3-bit pulse selection data is generated in accordance with the data (gradation information 011 and 100) and the large dot pattern data (gradation information 101).

  Each bit of the 3-bit pulse selection data corresponds to each pulse signal. That is, the most significant bit of the pulse selection data corresponds to the first pulse signal PS1 (first driving pulse DP1), the second bit corresponds to the second pulse signal PS2 (second driving pulse DP2), and the highest bit. The lower bits correspond to the third pulse signal PS3 (third drive pulse DP3).

  In this case, pulse selection data (000) is generated from non-recorded dot pattern data (gradation information 000). Then, pulse selection data (010) is generated from the dot pattern data (gradation information 001, 010) of the first and second small dots. Similarly, pulse selection data (101) is generated from the dot pattern data (gradation information 100, 101) of the first and second medium dots, and pulse selection data (101) is generated from the dot pattern data (gradation information 101) of the large dots. 111) is generated.

  When the most significant bit of the pulse selection data is “1”, from the first timing signal (latch signal) corresponding to the beginning of the period T1 to the second timing signal (CH signal) corresponding to the beginning of the period T2. During this period, the switch circuit 45 (driving pulse supply means) is connected. When the second bit is “1”, the switch circuit 45 is in a connected state from the second timing signal to the third timing signal (CH signal) corresponding to the start end of the period T3. Similarly, when the least significant bit is “1”, the switch circuit 45 is in the connected state from the third timing signal to the timing signal (latch signal) corresponding to the beginning of the period T1 in the next printing cycle TA. Become.

  Thereby, based on the dot pattern data of small dots, only the second drive pulse DP2 is supplied to the corresponding piezoelectric vibrator 15. Similarly, the first drive pulse DP1 and the third drive pulse DP3 are supplied based on the dot pattern data for medium dots, and the first drive pulse DP1 and the second drive pulse are supplied based on dot pattern data for large dots. The pulse DP2 and the third drive pulse DP3 are continuously supplied.

  As a result, 13 pL of ink droplets are ejected once from the nozzle openings 13 corresponding to the dot pattern data of small dots, and small dots are formed on the recording paper 8. Corresponding to the dot pattern data of medium dots, 13 pL ink droplets are ejected twice from the nozzle openings 13, and medium dots are formed on the recording paper 8 by a total of 26 pL ink droplets. Similarly, in response to the dot pattern data of large dots, 13 pL ink droplets are ejected from the nozzle opening 13 three times in succession, and large dots with a total of 39 pL ink droplets are formed on the recording paper 8. On the other hand, ink droplets are not ejected corresponding to non-recorded dot pattern data.

  More specifically, for example, when an alphabetic character “T” is printed, since the character is usually not given a gradation, printing is executed as shown in FIG. 8 in the normal mode. That is, large dot pattern data (101) as high-density gradation data is set for solid pixels for the pixels included in the character “T” portion (continuous area), and other pixels are set. In this case, zero gradation data (000) is set as the dot pattern data.

  In the case of the normal mode as described above, in a situation where the ink easily bleeds due to the characteristics of the ink and the characteristics of the recording paper 8, the contour line of the letter “T” extends into a “beard shape”, and the sharpness of the contour is reduced. May be lost. Therefore, the present embodiment provides a sharp edge processing mode for such a situation.

  Next, the sharp edge processing mode will be described in detail.

  Even in this mode, gradation control can be performed by increasing or decreasing the number of drive pulses supplied to the piezoelectric vibrator 15. Here, for comparison with FIG. 8 showing the normal mode, the case where the alphabet character “T” is printed will be described with reference to FIG. 12.

  By the control unit 28 as the gradation data setting means, the first pixel (first edge contour data) in the main scanning direction among the pixels (ejection continuous data) included in the character “T” portion (continuous area). Thus, the dot pattern data (001) of the first small dots as the low density gradation data is set, and the main scanning direction of the pixels (ejection continuous data) included in the character “T” portion (continuous area) is set. For the last pixel (last contour data), dot pattern data (010) of the second small dots as low density gradation data is set.

  Of the pixels (injection continuous data) included in the portion of the character “T” (continuous region), the pixel (internal data) sandwiched between the earliest contour data and the last contour data is further the main pixel among the pixels. The pixel is divided into the first pixel in the scanning direction (first actual data), the last pixel in the main scanning direction (last actual data), and the other pixels (internal internal data). Then, the dot pattern data (011) of the first medium dot as the medium density gradation data is set for the pixel of the innermost actual data, and the dot pattern data (011) of the last actual data is set as the medium density gradation data. The dot pattern data (100) of the second medium dot is set, and the dot pattern data (101) of the large dots as the high density gradation data is set only for the pixels of the internal internal data.

  For other non-printed (no ink ejected) pixels, zero gradation data (000) is set as the dot pattern data.

  In this case, the decoder 42 does not print (no ink ejection) dot pattern data (gradation information 000), first small dot dot pattern data (gradation information 001), and second small dot dot pattern data (floor information). Key information 010), dot pattern data of first medium dots (gradation information 011), dot pattern data of second medium dots (gradation information 100), and dot pattern data of large dots (gradation information 101). 3-bit pulse selection data is generated. That is, as shown in FIG. 15, pulse selection data (000) is generated from non-printing (no ink ejection) dot pattern data (gradation information 000), and dot pattern data (gradation information 001) of the first small dots. ) Is generated from the second small dot dot pattern data (tone information 010), and the pulse selection data (001) is generated from the second small dot dot pattern data (tone information 010). ) To generate pulse selection data (011), to generate pulse selection data (110) from dot pattern data of second medium dots (gradation information 100), and from dot pattern data of large dots (gradation information 101). Pulse selection data (111) is generated.

  When the most significant bit of the pulse selection data is “1”, from the first timing signal (latch signal) corresponding to the beginning of the period T1 to the second timing signal (CH signal) corresponding to the beginning of the period T2. During this period, the switch circuit 45 (driving pulse supply means) is connected. When the second bit is “1”, the switch circuit 45 is in a connected state from the second timing signal to the third timing signal (CH signal) corresponding to the start end of the period T3. Similarly, when the least significant bit is “1”, the switch circuit 45 is in the connected state from the third timing signal to the timing signal (latch signal) corresponding to the beginning of the period T1 in the next printing cycle TA. Become.

  Accordingly, only the first drive pulse DP1 is supplied to the corresponding piezoelectric vibrator 15 based on the dot pattern data of the first small dots. Further, only the third drive pulse DP3 is supplied to the corresponding piezoelectric vibrator 15 based on the dot pattern data of the second small dots. Similarly, the second drive pulse DP2 and the third drive pulse DP3 are supplied based on the dot pattern data of the first medium dot, and the first drive pulse DP1 is set based on the dot pattern data of the second medium dot. The second drive pulse DP2 is supplied, and the first drive pulse DP1, the second drive pulse DP2, and the third drive pulse DP3 are continuously supplied based on the dot pattern data of large dots.

  As a result, 13 pL of ink droplets are ejected once from the nozzle openings 13 corresponding to the dot pattern data of small dots, and small dots are formed on the recording paper 8. Corresponding to the dot pattern data of medium dots, 13 pL ink droplets are ejected twice from the nozzle openings 13, and medium dots are formed on the recording paper 8 by a total of 26 pL ink droplets. Similarly, in response to the dot pattern data of large dots, 13 pL ink droplets are ejected from the nozzle opening 13 three times in succession, and large dots with a total of 39 pL ink droplets are formed on the recording paper 8. On the other hand, ink droplets are not ejected corresponding to non-recorded dot pattern data.

  That is, as shown in FIG. 12, small dots are formed on the recording paper 8 corresponding to the contour data, and medium dots are formed on the recording paper 8 corresponding to the internal actual contour data, corresponding to the internal internal data. As a result, a large dot is formed on the recording paper 8 to be in a solid state.

  Further, as is clear from comparison with FIG. 10, the position where the small dots are formed is shifted to the far side from the continuous region with respect to the center of the pixel, and the position where the medium dots are formed is the center of the pixel. Is shifted closer to the continuous region. As a result, a gap area exists between the small dots and the medium dots.

  Such a printing mode is suitable particularly in a situation where ink tends to spread. In such a situation, due to ink bleeding, the gap region can be appropriately filled, while the contour line extending in the sub-scanning direction of the character “T” does not extend in a “whisker-like” shape, and the main scanning direction The sharpness of the outline is not lost. That is, the edge processing suitable for the case where the ink bleeding tendency is strong can be achieved with higher quality.

  In this embodiment, both the small dot formation position and the medium dot formation position are shifted from the pixel center. However, only the small dot formation position is shifted from the pixel center (see FIG. 16) or medium dots. A mode (see FIG. 17) in which only the formation position is shifted from the pixel center may also be employed.

  In each of the embodiments described above, as edge processing control, the sharp edge processing mode gradation data is used for the BK ink nozzle rows, and the normal mode gradation data is used for the nozzle rows other than the BK ink. It may be used. In this case, a plurality of types of gradation data supplied for each nozzle row are present simultaneously.

  Further, the drive signal generation circuit 30 may be formed by a DAC circuit or an analog circuit.

  The drive signal COM (FIG. 6) in the above embodiment has the same waveform shape for the first drive pulse DP1, the second drive pulse DP2, and the third drive pulse DP3. The embodiment is not particularly limited to this embodiment.

  Further, the liquid ejecting element for ejecting ink from the liquid chamber (corresponding to the pressure chamber 16 in the embodiment) is not limited to the piezoelectric vibrator 15. For example, a magnetostrictive element may be used as the liquid discharge element, and the liquid chamber may be expanded and contracted by the magnetostrictive element to generate pressure fluctuations. Alternatively, the heat generating element may be used as the liquid discharge element, and heat from the heat generating element may be generated. The liquid in the liquid chamber may be discharged from the nozzle opening by bubbles that expand and contract. .

  As described above, the printer controller 1 is configured by a computer system. However, a program for causing the computer system to realize each element and a computer-readable recording medium 201 on which the program is recorded are also protected in this case. Can be a target.

  Further, when each of the above elements is realized by a program such as an OS that operates on a computer system, a program including various instructions for controlling the program such as the OS and a recording medium 202 that records the program are also included in the present invention. Can be protected.

  Here, the recording media 201 and 202 include not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  Although the above description has been made with respect to an ink jet recording apparatus, the present invention is intended for a wide range of liquid ejecting apparatuses in general. As an example of the liquid, in addition to ink, glue, nail polish, liquid electrode material, bioorganic liquid, and the like can be used. Furthermore, the present invention can also be applied to an apparatus for manufacturing a color filter in a display body such as a liquid crystal.

1 is a schematic perspective view of an ink jet printer according to a first embodiment of the present invention. 2 is a cross-sectional view illustrating an internal structure of a recording head. FIG. 2 is a block diagram illustrating an electrical configuration of the printer according to the first embodiment of this invention. It is a figure which shows the filter which can be utilized for extraction of an outline. FIG. 2 is a block diagram illustrating an electric drive system of the recording head according to the first embodiment of the invention. It is a figure which shows an example of a drive signal. It is a figure explaining the drive pulse produced | generated based on the drive signal of FIG. It is a figure which shows an example of the discharge state of each liquid drop in normal mode. It is a figure which shows an example of the discharge state of each liquid drop in sharp edge process mode. It is a figure which shows an example of the discharge state of each liquid drop in the sharp edge processing mode of the 2nd Embodiment of this invention. It is a figure which shows an example of the discharge state of each liquid drop in the sharp edge processing mode of the 3rd Embodiment of this invention. It is a figure which shows an example of the discharge state of each liquid drop in the sharp edge processing mode of the 4th Embodiment of this invention. It is a block diagram explaining the electrical constitution of the printer of the 4th Embodiment of this invention. FIG. 10 is a block diagram illustrating an electric drive system of a recording head according to a fourth embodiment of the invention. It is a figure explaining the drive pulse produced | generated based on the drive signal of FIG. It is a figure which shows an example of the discharge state of each liquid drop in the sharp edge processing mode of the 5th Embodiment of this invention. It is a figure which shows an example of the discharge state of each liquid drop in the sharp edge processing mode of the 6th Embodiment of this invention. It is a figure showing an example of the conventional drive signal. It is a figure explaining the drive pulse produced | generated based on the drive signal of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Carriage 3 Guide member 4 Drive pulley 5 Free pulley 6 Timing belt 7 Pulse motor 8 Recording paper 10 Recording head 11 Ink cartridge 12 Reservoir 13 Nozzle opening 14 Nozzle plate 15 Piezoelectric vibrator 16 Pressure chamber 17 Supply side communication Hole 18 Ink supply port 19 First nozzle communication hole 20 Second nozzle communication hole 23 Printer controller 24 Print engine 25 External interface 26 RAM
27 ROM
28 Control Unit 29 Oscillation Circuit 30 Drive Signal Generation Circuit 31 Internal Interfaces 33, 33 ′ Recording Head Electric Drive System 34 Platen 35 Paper Feed Motor 36 First Shift Register 37 Second Shift Register 38 Third Shift Register 39 First Latch Circuit 40 Second latch circuit 41 Third latch circuit 42 Decoder 43 Control logic 44 Level shifter 45 Switch circuit 100 Interface device 200 Recording medium 201 Recording medium

Claims (7)

A head member having a nozzle opening;
Main scanning means for moving the head member in the main scanning direction relative to the recording medium;
Liquid ejection means for ejecting the liquid in the liquid chamber through the nozzle opening;
Gradation data setting means for setting one selected gradation data from a plurality of gradation data based on ejection data constituting a row corresponding to main scanning;
Drive signal generating means for generating an ejection drive signal;
Drive pulse generation means for generating a drive pulse based on the selected gradation data and the ejection drive signal;
A control main body for driving the liquid ejection means based on the drive pulse;
With
The column of ejection data has continuous ejection data corresponding to 5 or more continuous areas of relatively high density gradation data,
Injection continuous data is
Earliest contour data that is earliest in the main scanning direction;
Last contour data that is last in the main scanning direction;
The actual data sandwiched between the earliest contour data and the last contour data,
Have
The actual data is
Actual data in the earliest in the main scanning direction,
The last actual data that is last in the main scanning direction;
Internal real data sandwiched between the first real data and the last real data,
Have
The gradation data setting means is
Based on the earliest contour data and the last contour data, set relatively low density selection gradation data,
Based on the earliest actual data and the last actual data, a relatively medium density selection gradation data is set,
A liquid ejecting apparatus, wherein selected gradation data having a relatively high density is set on the basis of internal data. The ejection drive signal is a periodic signal having a plurality of pulse waveforms,
The drive pulse generating means generates a rectangular pulse train corresponding to one period of the ejection drive signal from each gradation data, and generates a drive pulse by ANDing the rectangular pulse train and the ejection drive signal.
The plurality of gradation data includes first low density gradation data and second low density gradation data,
The gradation data setting means is configured to set the first low density gradation data based on the earliest contour data and the second low density gradation data based on the last contour data.
The ejection drive signal is
A first small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening;
A second small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening;
A third pulse waveform provided between the first small dot pulse waveform and the second small dot pulse waveform;
A periodic signal having
The drive pulse generating means is based on the ejection drive signal,
When the selected gradation data is the first low density gradation data, only the first small dot pulse waveform is used as the drive pulse,
2. The liquid ejecting apparatus according to claim 1, wherein when the selected gradation data is the second low density gradation data, only the second small dot pulse waveform is used as the drive pulse. 3. The small liquid droplet ejected from the nozzle opening by the first small dot pulse waveform has the same volume as the small liquid droplet ejected from the nozzle opening by the second small dot pulse waveform. The liquid ejecting apparatus according to 1. The plurality of gradation data includes first medium density gradation data and second medium density gradation data,
The gradation data setting means sets the first medium density gradation data based on the earliest actual data, and sets the second medium density gradation data based on the last actual data.
The drive pulse generating means is based on the ejection drive signal,
When the selected gradation data is the first medium density gradation data, the first small dot pulse waveform and the third pulse waveform are used as drive pulses,
4. The method according to claim 2, wherein when the selected gradation data is the second medium density gradation data, the second small dot pulse waveform and the third pulse waveform are used as drive pulses. The liquid ejecting apparatus described. The ejection drive signal is a periodic signal having a plurality of pulse waveforms,
The drive pulse generating means generates a rectangular pulse train corresponding to one period of the ejection drive signal from each gradation data, and generates a drive pulse by ANDing the rectangular pulse train and the ejection drive signal.
The plurality of gradation data includes first medium density gradation data and second medium density gradation data,
The gradation data setting means sets the first medium density gradation data based on the earliest actual data, and sets the second medium density gradation data based on the last actual data.
The ejection drive signal is
A first small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening;
A second small dot pulse waveform for ejecting a small liquid droplet from the nozzle opening;
A third pulse waveform provided between the first small dot pulse waveform and the second small dot pulse waveform;
A periodic signal having
The drive pulse generating means is based on the ejection drive signal,
When the selected gradation data is the first medium density gradation data, the first small dot pulse waveform and the third pulse waveform are used as drive pulses,
2. The selection pulse data according to claim 1, wherein when the selected gradation data is the second medium density gradation data, the second small dot pulse waveform and the third pulse waveform are used as drive pulses. Liquid ejector. A head member having a nozzle opening;
Main scanning means for moving the head member in the main scanning direction relative to the recording medium;
Sub-scanning means for moving the head member in a sub-scanning direction perpendicular to the main scanning direction relative to the recording medium;
Liquid ejection means for ejecting the liquid in the liquid chamber through the nozzle opening;
Gradation data setting means for setting one selected gradation data from a plurality of gradation data based on the discharge data;
Drive signal generating means for generating an ejection drive signal;
Drive pulse generation means for generating a drive pulse based on the selected gradation data and the ejection drive signal;
A control main body for driving the liquid ejection means based on the drive pulse;
With
The ejection data has ejection continuous data corresponding to 5 or more continuous areas in the sub-scanning direction,
Injection continuous data is
Earliest contour data that is earliest in the sub-scanning direction;
Last contour data that is last in the sub-scanning direction;
The actual data sandwiched between the earliest contour data and the last contour data,
Have
The actual data is
The earliest actual data that is the earliest in the sub-scanning direction;
The last actual data that is last in the sub-scanning direction;
Internal real data sandwiched between the first real data and the last real data,
Have
The gradation data setting means is
Based on the earliest contour data and the last contour data, set relatively low density selection gradation data,
Based on the earliest actual data and the last actual data, a relatively medium density selection gradation data is set,
A liquid ejecting apparatus, wherein selected gradation data having a relatively high density is set on the basis of internal data. A head member having a nozzle opening;
Main scanning means for moving the head member in the main scanning direction relative to the recording medium;
Sub-scanning means for moving the head member in a sub-scanning direction perpendicular to the main scanning direction relative to the recording medium;
Liquid ejection means for ejecting the liquid in the liquid chamber through the nozzle opening;
Gradation data setting means for setting one selected gradation data from a plurality of gradation data based on the discharge data;
Drive signal generating means for generating an ejection drive signal;
Drive pulse generation means for generating a drive pulse based on the selected gradation data and the ejection drive signal;
A control main body for driving the liquid ejection means based on the drive pulse;
With
The ejection data has continuous ejection data corresponding to a relatively high density continuous area of 5 or more in each of the main scanning direction and the sub-scanning direction on a plane defined by the main scanning direction and the sub-scanning direction.
The ejection continuous data is in a plane defined by the main scanning direction and the sub-scanning direction,
Contour data that is first in at least one of the main scanning direction and sub-scanning direction of the continuous ejection data, or last in at least one direction of the main scanning direction and sub-scanning direction of the continuous ejection data; ,
The actual data surrounded by the contour data;
Have
The actual data is
Internal contour data that is first in at least one direction of the main scanning direction and sub-scanning direction of the internal real data, or is last in at least one direction of the main scanning direction and sub-scanning direction of the internal real data;
Internal solid data surrounded by the solid outline data;
Have
The gradation data setting means is
Based on the contour data, select relatively low density selection gradation data,
Based on the actual contour data, select relatively medium density selection gradation data,
A liquid ejecting apparatus, wherein selected gradation data having a relatively high density is set on the basis of internal data.

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