JP2020116866A - Recording device and recording method - Google Patents

Abstract

To provide a recording device capable of performing recording with desired contours on each of a wide variety of recording media.SOLUTION: A printing system 1 as a recording device includes: a print head 13 which discharges ink to a recording medium and forms dots on the recording medium; a moving section 20 which relatively moves the printing head 13 and the recording medium in a relative movement direction; and a control section 120 which controls the print head 13 and the moving section 20 and performs printing with dots. The control section 120 selects a prescribed drive pulse from a plurality of drive pulses for driving the print head 13 prepared for each edge pixel located at an end in the relative movement direction of a line drawing to be printed on the recording medium according to a kind of the recording medium, thereby determining a print position for forming dots to print the edge pixels.SELECTED DRAWING: Figure 2

Description

The present invention relates to a recording apparatus provided with a recording head that ejects liquid droplets and a recording method by the recording apparatus.

Conventionally, for example, as described in Patent Document 1, in printing characters by an inkjet printer, there is known a technique of smoothing the outline by appropriately arranging large dots and small dots in the outline portion of the character. ing.

JP, 2004-82448, A

However, there are various types of recording media on which printing is performed, and depending on the specifications of the recording media, printing with a desired contour may not be possible with the conventional technique alone. Specifically, for example, in printing a barcode, there is a problem that the contour of the desired bar width may not be obtained depending on the degree of easiness of ink bleeding onto the medium.

A recording apparatus according to the present application, a recording head that ejects liquid onto a recording medium to form dots on the recording medium, a moving unit that relatively moves the recording head and the recording medium in a relative movement direction, A control unit that controls the recording head and the moving unit to perform recording by the dots, the control unit according to the type of the recording medium, the relative position of the line drawing recorded on the recording medium. The dots for recording the edge pixels are formed by selecting a predetermined drive pulse from a plurality of drive pulses for driving the recording head prepared for each edge pixel located at the end in the moving direction. Characterized by determining the position.

In the above recording apparatus, it is preferable that the control unit determines the size of the dot for recording the edge pixel by selecting the predetermined drive pulse according to the type of the recording medium.

In the above recording apparatus, it is preferable that the plurality of drive pulses are generated in a process in which the recording head and the recording medium relatively move by one pixel of the edge pixel.

In the above recording apparatus, it is preferable that the line drawing is a bar code.

In the above recording apparatus, it is preferable that the control section selects the predetermined drive pulse according to the degree of easiness of the liquid bleeding onto the recording medium.

A recording method of the present application, a recording head that ejects liquid to a recording medium to form dots on the recording medium, a moving unit that relatively moves the recording head and the recording medium in a relative movement direction, A recording method for performing recording using the dots in a recording apparatus comprising: prepared for each edge pixel located at an end in the relative movement direction of a line drawing recorded on the recording medium, according to the type of the recording medium. By selecting a predetermined driving pulse from a plurality of driving pulses for driving the recording head, the position for forming the dot for recording the edge pixel is determined.

1 is a front view showing the configuration of a printing system as a recording apparatus according to a first embodiment. FIG. 1 is a block diagram showing a configuration of a printing system as a recording device according to a first embodiment. FIG. FIG. 6 is a schematic diagram illustrating an example of an array of nozzles when viewed from the lower surface of the print head. FIG. 3 is a cross-sectional view of a main part of the print head. FIG. 3 is an explanatory diagram of basic functions of a printer driver. FIG. 3 is a block diagram illustrating an example of a configuration of a drive control system that drives a print head. 6 is a timing chart for explaining a drive signal for ejecting ink. It is a conceptual diagram which shows the example of the barcode as a line drawing. It is the conceptual diagram which expanded and displayed a part of barcode. It is a conceptual diagram which shows the example in case the dot corresponding to an edge pixel is comprised by the small dot. 6 is a timing chart for explaining a drive signal for ejecting ink. 6 is a timing chart for explaining a drive signal for ejecting ink. It is a conceptual diagram which shows the example at the time of selecting a waveform selection signal and ejecting an ink drop. It is a conceptual diagram which shows the example at the time of selecting a waveform selection signal and ejecting an ink drop. It is a conceptual diagram which shows the example at the time of selecting a waveform selection signal and ejecting an ink drop. FIG. 6 is a front view showing the configuration of a printing system according to a second embodiment. 6 is a block diagram showing the configuration of a printing system according to a second embodiment. FIG. FIG. 6 is a schematic diagram illustrating an example of an array of nozzles when viewed from the lower surface of the print head. 9 is a timing chart showing a drive signal for ink ejection in Modification 1. 9 is a block diagram illustrating a configuration of a drive control system according to Modification 2. FIG. 9 is a timing chart showing a predetermined drive pulse according to Modification 2.

Embodiments embodying the present invention will be described below with reference to the drawings. The following is an embodiment of the present invention and does not limit the present invention. In addition, in each of the following drawings, the scale may be different from the actual scale in order to make the description easy to understand. Further, in the coordinates appended to the drawings, the Z-axis direction is the vertical direction, the +Z direction is the upward direction, the X-axis direction is the front-back direction, the -X direction is the forward direction, the Y-axis direction is the horizontal direction, and the +Y direction is the left direction. The XY plane is the horizontal plane.

(Embodiment 1)
FIG. 1 is a front view showing the configuration of a printing system 1 as a recording apparatus according to the first embodiment, and FIG. 2 is a block diagram of the same. Printing of images, characters, symbols, and the like, which is one form of recording, will be described below. The recording includes printing of images, characters, symbols, etc., recording of digital information performed by applying droplets to desired positions on a recording medium, and application of constituent materials and modeling materials of products. ..
Note that the printing as the recording in the present embodiment is targeted especially when the image to be printed includes a line drawing. The line drawing is, for example, each bar in a barcode or a line in a drawing.

The printing system 1 includes a printer 100 and an image processing device 110 connected to the printer 100. The printer 100 is an inkjet serial printer that prints a desired image on a long roll paper 5 as a recording medium that is supplied in a rolled state based on print data received from the image processing apparatus 110. It is a printer. As the roll paper 5, for example, high-quality paper, cast paper, art paper, coated paper, synthetic paper or the like can be used.

<Basic configuration of image processing device>
The image processing apparatus 110 includes a print control unit 111, an input unit 112, a display unit 113, a storage unit 114, etc., and controls a print job that causes the printer 100 to print. The image processing apparatus 110 is configured using a personal computer as a suitable example.
The software that the image processing apparatus 110 operates includes general image processing application software that handles image data to be printed, printer driver software that controls the printer 100, and generates print data for causing the printer 100 to perform printing. included. In the following description, the image processing application software is simply referred to as an application. Further, the printer driver software is simply called a printer driver.
Here, the image data is image information including a line drawing, and is RGB digital image information including text data and full-color image data.

The print control unit 111 includes a CPU 115, an ASIC 116, a DSP 117, a memory 118, a printer interface unit 119, and the like, and performs centralized management of the entire printing system 1.
Here, CPU means Central Processing Unit, ASIC means Application Specific Integrated Circuit, and DSP means Digital Signal Processor. The printer interface unit 119 may also be referred to as I/F 119 in the drawings.
The input unit 112 is an information input unit as a human interface. Specifically, for example, it is a port to which a keyboard, a mouse pointer, or an information input device is connected.
The display unit 113 is an information display unit as a human interface, and under the control of the print control unit 111, information input from the input unit 112, an image to be printed on the printer 100, information related to a print job, and the like are displayed. Is displayed.
The storage unit 114 is a rewritable storage medium such as a hard disk drive or a memory card, and is a program that operates in the print control unit 111 as software that operates the image processing apparatus 110, an image to be printed, and information related to a print job. Are remembered.
The memory 118 is a storage medium that secures an area for storing a program in which the CPU 115 operates, a work area in which the CPU 115 operates, and includes a storage element such as a RAM or an EEPROM. Here, RAM means Random access memory, and EEPROM means Electrically Erasable Programmable Read-Only Memory.

<Basic configuration of the printer 100>
The printer 100 includes a printing unit 10, a moving unit 20, a printer control unit 30, and the like. Upon receiving the print data from the image processing apparatus 110, the printer 100 controls the printing unit 10 and the moving unit 20 based on the print data to print the image on the roll paper 5.
The print data is data for image formation in which the image data is converted by the application and the printer driver included in the image processing apparatus 110 so as to be printed by the printer 100, and includes commands for controlling the printer 100.

The printing unit 10 includes a head unit 11, an ink supply unit 12, and the like.
The moving unit 20 includes a main scanning unit 40, a sub-scanning unit 50, and the like. The main scanning unit 40 includes a carriage 41, a guide shaft 42, a carriage motor, and the like. The sub-scanning unit 50 includes a supply unit 51, a storage unit 52, a transport roller 53, a platen 55, and the like. Illustration of the carriage motor is omitted.

The head unit 11 includes a print head 13 as a recording head including a plurality of nozzle rows in which a plurality of nozzles that eject printing ink as a liquid as ink droplets are arranged, and a head controller 14. The head unit 11 is mounted on the carriage 41 and reciprocates in the X-axis direction along with the carriage 41 that moves in the X-axis direction as the main scanning direction. The print head 13 provided in the head unit 11 mounted on the carriage 41 ejects ink droplets onto the roll paper 5 supported by the platen 55 under the control of the printer controller 30 while moving in the X-axis direction. As a result, a plurality of dot rows along the X-axis direction are formed on the roll paper 5.
In the following description, the operation of ejecting ink from the print head 13 to form dots while moving in the X-axis direction is called a pass operation, or simply a pass. One pass operation means dot formation associated with one movement in the X-axis direction. A desired image based on the image data is printed by combining the partial images printed by dot formation with one movement in the X-axis direction with the Y-axis direction as the sub-scanning direction intersecting the main scanning direction. ..

In this embodiment, the relative movement direction in which the print head 13 and the roll paper 5 relatively move is the X-axis direction.
Further, in the present embodiment, the print control unit 111 and the printer control unit 30 configure a control unit 120 that controls the print head 13 and the moving unit 20 based on image data to perform printing.

The ink supply unit 12 includes an ink tank and an ink supply path that supplies ink from the ink tank to the print head 13. Illustration of the ink supply path is omitted.
The ink includes, for example, an ink set of a dark ink composition, an ink set of four colors obtained by adding black to an ink set of three colors of cyan, magenta, and yellow. Further, for example, there is an ink set of 8 colors including an ink set of light cyan, light magenta, light yellow, light black, etc., which is made of a light ink composition in which the concentration of each color material is lightened. The ink tank, the ink supply path, and the ink supply path to the nozzle that ejects the same ink are provided independently for each ink.

A piezo method is used as an inkjet method for ejecting ink droplets. The piezo method applies pressure according to a print information signal to an ink stored in the pressure generating chamber by an actuator using a piezo element as a piezoelectric element, and ejects ink droplets from a nozzle communicating with the pressure generating chamber to print. It is a method.
It should be noted that the method of ejecting ink droplets is not limited to this, and another printing method of ejecting ink in the form of droplets to form a dot group on a print medium may be used. For example, a method in which ink is continuously ejected in a droplet form from a nozzle by a strong electric field between a nozzle and an accelerating electrode placed in front of the nozzle, and a printing information signal is given from a deflection electrode while an ink droplet is flying to perform printing, Alternatively, an electrostatic suction method that ejects ink droplets in response to a print information signal without deflection, a pressure is applied to the ink by a small pump, and the nozzle is mechanically vibrated by a crystal oscillator or the like to force the ink A method of ejecting droplets, a thermal jet method of ejecting ink droplets by performing thermal foaming of ink with microelectrodes according to a print information signal, and performing printing may be used.

The moving unit 20, that is, the main scanning unit 40 and the sub-scanning unit 50 moves the roll paper 5 relative to the print head 13 under the control of the printer control unit 30.
The guide shaft 42 extends in the X-axis direction and supports the carriage 41 in a slidable contact state. Further, the carriage motor serves as a drive source when the carriage 41 is reciprocated along the guide shaft 42. That is, the main scanning unit 40 moves the carriage 41, that is, the print head 13 in the X-axis direction along the guide shaft 42 under the control of the printer control unit 30.

The supply unit 51 rotatably supports a reel around which the roll paper 5 is wound, and sends the roll paper 5 to the transport path. The storage unit 52 rotatably supports a reel that winds the roll paper 5, and winds the roll paper 5 on which printing is completed from the transport path.
The transport roller 53 includes a drive roller that moves the roll paper 5 in the sub-scanning direction on the upper surface of the platen 55, a driven roller that rotates as the roll paper 5 moves, and the like. A transport path for transporting to the storage section 52 via the print area of the above. The print area is an area where the print head 13 moves in the X-axis direction on the upper surface of the platen 55.

The printer control unit 30 includes an interface unit 31, a CPU 32, a memory 33, a drive control unit 34, a touch panel 60, and the like, and controls the printer 100.
The interface unit 31 is connected to the printer interface unit 119 of the image processing apparatus 110, and transmits/receives data between the image processing apparatus 110 and the printer 100.
The CPU 32 is an arithmetic processing device for controlling the entire printer 100.
The memory 33 is a storage medium that secures an area for storing a program for operating the CPU 32, a working area for operating, and the like, and is configured by a storage element such as a RAM or an EEPROM.
The CPU 32 controls the printing unit 10 and the moving unit 20 via the drive control unit 34 according to the program stored in the memory 33 and the print data received from the image processing apparatus 110.
The touch panel 60 is an information input/output unit as a human interface capable of inputting operation instruction information to the printer control unit 30 and displaying various information processing results of the printer control unit 30.

The drive control unit 34 includes firmware that operates under the control of the CPU 32, and controls the drive of the head unit 11, the ink supply unit 12, the main scanning unit 40, and the sub-scanning unit 50 of the moving unit 20. .. The drive control unit 34 is composed of a drive control circuit including a movement control signal generation circuit 35, a discharge control signal generation circuit 36, a drive signal generation circuit 37, etc., a ROM or a flash memory containing firmware for controlling these drive control circuits, and the like. Has been done. The ROM and the flash memory that incorporate the firmware that controls the drive control circuit are not shown. Here, the ROM means a read-only memory.

The movement control signal generation circuit 35 is a circuit that generates a signal for controlling the main scanning unit 40 and the sub-scanning unit 50 of the moving unit 20 based on the print data according to an instruction from the CPU 32.
The ejection control signal generation circuit 36 generates a head control signal HC for selecting a nozzle that ejects ink, selecting an ejection amount, controlling ejection timing, and the like, based on the print data, according to an instruction from the CPU 32. Circuit. The head control signal HC will be described later.
The drive signal generation circuit 37 is a circuit that generates a drive signal COM as a drive waveform for driving the pressure generation unit 72 included in the print head 13. The pressure generator 72 and the drive signal COM will be described later.

<Print head>
FIG. 3 is a schematic diagram showing an example of the arrangement of nozzles as seen from the lower surface of the print head 13.
The print head 13 includes six nozzle groups 130 so as to eject ink of six colors of black K, cyan C, magenta M, yellow Y, gray LK, and light cyan LC.
The nozzle group 130 is configured by a nozzle row in which 400 nozzles #1 to #400 are arranged in a row at a constant interval along the Y-axis direction.
The nozzle group 130 is manufactured by a MEMS manufacturing process to which a semiconductor process is applied, for example, using a silicon wafer as a basic material, and the nozzles 74 included in the nozzle group 130 form a nozzle group having the same or similar ink ejection characteristics. ing. Here, MEMS means Micro Electro Mechanical Systems.

FIG. 4 is a cross-sectional view of the main parts of the print head 13.
The print head 13 includes a nozzle 74 that ejects ink and a pressure generation unit 72 that is provided so as to correspond to the nozzle 74.
The pressure generating section 72 includes a cavity 73 as a pressure generating chamber, a vibration plate 71, an actuator 77, and the like.

The cavity 73 communicates with the nozzle 74 and is filled with ink.
The diaphragm 71 constitutes the ceiling surface of the cavity 73, and the volume of the cavity 73, that is, the internal pressure increases or decreases due to the bending of the diaphragm 71.
The actuator 77 includes a piezoelectric thin film 77a composed of a piezo element, an electrode 77b provided so as to cover one surface of the piezoelectric thin film 77a, and an electrode provided so as to cover the other surface of the piezoelectric thin film 77a. 77c and the like. The actuator 77 is laminated on the vibrating plate 71 so that the vibrating plate 71 is sandwiched between the actuator 77 and the cavity 73, and a voltage is applied between the electrode 77b and the electrode 77c to deform the piezoelectric thin film 77a. As a result, the diaphragm 71 can be bent.

The nozzle 74 is formed on the nozzle plate 75. Further, a cavity substrate 76 positioned so as to be sandwiched by the nozzle plate 75 and the vibration plate 71 is provided with a cavity 73 and a reservoir 78 communicating with the cavity 73 via an ink supply port 79. The reservoir 78 communicates with the ink tank via the ink supply path. Illustration of the ink tank is omitted.

In the pressure generating section 72 having such a configuration, by applying the drive signal COM for changing the voltage level between the electrodes 77b and 77c, the diaphragm 71 is flexibly vibrated as shown by the arrow in FIG. Thus, it is possible to change the pressure inside the cavity 73, vibrate the ink inside the cavity 73, or eject ink droplets from the nozzle 74.

With the above configuration, the printer control unit 30 moves the carriage 41 that supports the print head 13 along the guide shaft 42 in the X-axis direction with respect to the roll paper 5 that is supplied to the printing area by the supply unit 51 and the transport roller 53. A desired image is printed on the roll paper 5 by repeating the operation of ejecting ink droplets from the print head 13 while moving the roll paper 5 and the operation of moving the roll paper 5 in the +Y direction intersecting the X axis direction by the transport roller 53. ..

<Basic functions of the printer driver>
FIG. 5 is an explanatory diagram of basic functions of the printer driver.
Printing on the roll paper 5 is started by transmitting print data from the image processing apparatus 110 to the printer 100. The print data is generated by the printer driver.
The print data generation process will be described below with reference to FIG.

The printer driver receives the image data from the application, converts the image data into print data in a format that the printer 100 can interpret, and outputs the print data to the printer 100. When converting image data from an application into print data, the printer driver performs resolution conversion processing, color conversion processing, halftone processing, rasterization processing, command addition processing, and the like.

The resolution conversion process is a process of converting the image data output from the application into the resolution for printing on the roll paper 5. For example, when the resolution for printing is specified as 720×720 dpi, the vector format image data received from the application is converted into bitmap format image data having a resolution of 720×720 dpi. Each pixel data of the image data after the resolution conversion processing is composed of pixels arranged in a matrix. Each pixel has a gradation value of 256 gradations in the RGB color space. That is, the pixel data after the resolution conversion indicates the gradation value of the corresponding pixel.
Of the pixels arranged in a matrix, pixel data corresponding to one column of pixels arranged in a predetermined direction is called raster data. The predetermined direction in which the pixels corresponding to the raster data are arranged corresponds to the moving direction of the print head 13 when printing an image, specifically, the X-axis direction. The moving direction of the print head 13 is a relative moving direction in which the print head 13 and the roll paper 5 relatively move.

The color conversion process is a process of converting RGB data into data in the CMYK color system space. The CMYK colors are cyan C, magenta M, yellow Y, and black K, and the image data in the CMYK color system space is data corresponding to the ink colors of the printer 100. Therefore, for example, when the printer 100 uses eight types of CMYK color system ink, the printer driver generates image data in the CMYK color system 8-dimensional space based on the RGB data.
This color conversion processing is performed based on a color conversion lookup table in which the gradation values of RGB data and the gradation values of CMYK color system data are associated with each other. The pixel data after the color conversion processing is, for example, CMYK color system data of 256 gradations represented by the CMYK color system space.

The halftone process is a process of converting data having a high gradation number, for example, data having 256 gradations into data having a gradation number that can be formed by the printer 100. By this halftone processing, data indicating 256 gradations is, for example, 1-bit data indicating 2 gradations with or without dots, or 2 bits indicating 4 gradations of no dot, small dot, medium dot, and large dot. Converted to data. Specifically, the dot generation rate corresponding to the gradation value is obtained from the dot generation rate table in which the gradation values of 0 to 255 correspond to the dot generation rate. For the dot generation rate obtained corresponding to the gradation value, for example, in the case of 4 gradations, the respective generation rates of no dot, small dot, medium dot, and large dot are obtained. At each of the obtained generation rates, the pixel data is created by using the dither method, the error diffusion method, or the like so that the dots are dispersedly formed.

The rasterize process is a process of rearranging the above-mentioned 1-bit or 2-bit pixel data arranged in a matrix according to the dot formation order at the time of printing. The rasterizing process includes a pass allocating process for allocating image data composed of pixel data after the halftone process to each pass for ejecting ink droplets while the print head 13 moves. When the pass allocation is completed, the actual nozzles that form each raster line forming the printed image are allocated.

The command addition process is a process of adding command data according to the printing method to the rasterized data. The command data includes, for example, sub-scanning data related to the sub-scanning specification of the roll paper 5. The sub-scanning specifications are, for example, the movement amount and speed of the roll paper 5 on the upper surface of the platen 55 in the sub-scanning direction.
The series of processes by the printer driver is performed by the ASIC 116 and the DSP 117 under the control of the CPU 115, and in the print data transmission process, the print data generated by the series of processes is transferred to the printer 100 via the printer interface unit 119. Sent.

<Drive control of print head in basic configuration>
Next, with reference to FIG. 6, basic contents of drive control of the print head 13 will be described. FIG. 6 is a block diagram illustrating an example of the configuration of a drive control system that drives the print head 13.
As described above, the head unit 11 includes the print head 13, the head controller 14, and the like. Further, the drive control unit 34 includes an ejection control signal generation circuit 36 and a drive signal generation circuit 37, and drives and controls the print head 13 via the head control unit 14.
More specifically, the drive control unit 34 causes each of the head control units 14 via the head control unit 14 based on the head control signal HC generated by the ejection control signal generation circuit 36 and the drive signal COM generated by the drive signal generation circuit 37. The pressure generator 72 corresponding to each of the nozzles 74 is selectively driven.

The drive signal COM is a basic drive for the head controller 14 to change the level of the voltage to be applied to drive the actuator 77 and cause pressure variation in the ink in the cavity 73 to eject ink from the nozzle 74. It is a signal. That is, by changing the drive signal COM and applying it to the actuator 77, it is possible to eject a desired amount of ink from the nozzle 74.
The head control signal HC includes drive pulse selection data SI&SP, a clock signal CLK, a latch signal LAT, a channel signal CH and the like.
The drive pulse selection data SI&SP includes pixel data SI that specifies the actuator 77 corresponding to the nozzle 74 that should eject an ink droplet, and waveform pattern data SP of the drive signal COM that is related to the ejection amount.
The latch signal LAT and the channel signal CH are control signals that determine the timing of the drive signal COM. A series of drive signals COM starts to be output by the latch signal LAT, and a drive pulse PS is output for each channel signal CH.

<Ink ejection drive>
Next, a basic driving principle for ejecting ink will be described.
As shown in FIG. 6, the head controller 14 includes a control circuit 90, a shift register 91, a latch circuit 92, a level shifter 93, a selection switch 94, and the like.
The head controller 14 causes the control circuit 90 to generate the waveform selection signals q0 to q3 from the head control signal HC received from the ejection control signal generation circuit 36. The waveform selection signals q0 to q3 are signals for selectively generating the drive pulse PS to be applied to the actuator 77 from the drive signal COM, and include the waveform pattern data SP, the clock signal CLK, the latch signal LAT, and the channel signal CH. It is generated based on the timing signal. The description of the step of generating the waveform selection signals q0 to q3 is omitted.

The pixel data SI is sequentially input to the shift register 91, and the storage area is sequentially shifted from the initial stage to the subsequent stage according to the input pulse of the clock signal CLK. After the pixel data SI for the number of nozzles is stored in the shift register 91, the latch circuit 92 latches each output signal of the shift register 91 by the input latch signal LAT. The signal stored in the latch circuit 92 is converted by the level shifter 93 into a voltage level at which each switch included in the selection switch 94 at the next stage can be turned on/off, that is, the drive signal COM can be connected/cut off. The drive signal COM is connected to the actuator 77 when each switch included in the selection switch 94 is turned on by the output of the level shifter 93. That is, the drive pulse PS is applied to the actuator 77.

FIG. 7 is a timing chart for explaining a drive signal for ejecting ink. The drive pulses PS1 to PS3 shown in FIG. 7 are waveforms of drive signals applied to the actuator 77, and show signals based on the drive signal COM for ejecting ink droplets. Further, in FIG. 7, the period T which is the repeating period corresponds to the period in which the nozzle 74 moves by one pixel in the X-axis direction. For example, when the print resolution is 720 dpi, the period T corresponds to the period for the nozzle 74 to move 1/720 inch with respect to the roll paper 5.

The head controller 14 applies drive pulses PS1 to PS3 to the actuator 77 as signals for selectively ejecting ink from the drive signal COM according to the drive pulse selection data SI&SP and the waveform selection signals q0 to q3. That is, by selectively applying the drive pulses PS1 to PS3 based on the drive signal COM by the waveform selection signals q0 to q3, ink droplets having different sizes are ejected in one pixel, and a plurality of gradations are expressed. ..
In the channel signal CH, the period T is divided into periods T1 to T4, and the drive pulse PS is output for each channel signal CH in the periods T2 to T4 following the latch signal LAT.

More specifically, as shown in FIG. 7, when a large dot is formed, that is, when the 2-bit pixel data is [11], the drive signal COM is changed by the waveform selection signal q3 in the periods T1 to T3. The drive pulse PS1, the drive pulse PS2, and the drive pulse PS3 based on are selected and applied to the actuator 77.
When the medium dot is formed, that is, when the pixel data is [10], the drive pulse PS1 and the drive pulse PS2 based on the drive signal COM are selected by the waveform selection signal q2 in the periods T1 and T2 and applied to the actuator 77. To be done.
When forming a small dot, that is, when the pixel data is [01], the drive pulse PS1 based on the drive signal COM is selected by the waveform selection signal q1 and applied to the actuator 77 in the period T1.
When dots are not formed, that is, when the pixel data is [00], the drive signal COM is not selected by the waveform selection signal q0 over the period T. Therefore, the signal for ejecting ink is not applied to the actuator 77.

The drive signal COM and the drive pulses PS1 to PS3 are formed in a waveform including a trapezoidal wave. Since the drive signal COM and the drive pulses PS1 to PS3 need to accurately control the timing of ejecting ink droplets and the ejection amount per ejection, the trapezoidal wave, that is, its output value can be changed with time. It is composed of waveforms.

FIG. 8 is a conceptual diagram showing an example of the barcode 6 as a line drawing, and FIG. 9 is a conceptual diagram in which a part of the barcode 6 is enlarged and displayed. FIG. 9 shows a lower end portion of one bar 7 included in the barcode 6. Hereinafter, a bar code will be described as an example of a line drawing.
In the example of the bar 7 shown in FIG. 9, five dot rows each including a plurality of large dots DL arranged in the Y-axis direction are arranged in the X-axis direction. A circle indicated by DL in FIG. 9 conceptually shows dots formed by ink droplets landed on the roll paper 5, and the width of the bar 7 to be printed is, for example, the width W1 when the ink soaks into the roll paper 5 and spreads. become that way. Further, depending on the type of the roll paper 5, the easiness of bleeding of the ink is different, and for example, the width W2 shown in FIG. 9 may be wider than the width W1. As described above, the width of the bar 7 may differ depending on the degree of ease of ink bleeding of the roll paper 5, and in some cases, the width becomes too wide and the quality required for the barcode may not be satisfied. is there.
On the other hand, for example, with respect to the roll paper 5 on which the ink easily bleeds, the dots corresponding to the pixels at the ends in the width direction of the bar 7, that is, the edge pixels at the ends in the X axis direction in the example shown in FIG. By reducing the size of the bar 7, it is possible to prevent the width of the bar 7 from becoming too wide.

FIG. 10 is a conceptual diagram showing an example in which the dots corresponding to the edge pixels at both ends in the X-axis direction are made up of small dots DS, in contrast to the example shown in FIG.
The example illustrated in FIG. 10 illustrates a case where the print head 13 moves in the +X direction and ejects ink droplets from the black K nozzle group 130, for example.
The dot row DS1 of the small dots DS corresponding to the edge pixel is formed by the drive pulse PS1 as shown in FIG. That is, the edge pixel is formed by the drive signal generated in the period T1 of the period T corresponding to one pixel. Further, the large dots DL forming pixels other than the edge pixels are formed by the drive pulses PS1 to PS3, as shown in FIG. That is, the pixels other than the edge pixels are formed by the drive signals generated in the periods T1 to T3 of the period T corresponding to one pixel.
As a result, as shown in FIG. 10, the dots formed by landing on the roll paper 5 correspond to the moving direction of the print head 13 and are arranged on the left and right of the width direction of the bar 7 in the dot rows DS1 that form edge pixels. And the columns of pixels other than the edge pixels are different in distance.

As described above, in the printing by the basic configuration of the printing system 1, the contour of the bar 7 in the moving direction of the print head 13, that is, the relative moving direction of the print head 13 and the roll paper 5 shows different aspects on both sides thereof. become.
Further, in the printing with the basic configuration of the printing system 1, the size of the dots at both ends of the bar 7 can be changed, but the interval d1 cannot be changed.
As a result of these, for example, in the printing of a bar code, depending on the degree of ease of ink bleeding on the medium, the dot size corresponding to the edge pixels at both ends in the width direction of the bar 7 may be controlled. However, there is a problem that the contour of the desired bar width may not be obtained. That is, in printing an image including a line drawing such as a barcode, further improvement in print quality has been required.

On the other hand, in the printing system 1 as the recording apparatus of the present embodiment, the control unit 120 further adds X to the line drawing printed on the roll paper 5 according to the type of the roll paper 5 in addition to the basic configuration described above. A predetermined drive pulse is selected from a plurality of drive pulses for driving the print head 13 prepared for each edge pixel located at the end in the relative movement direction of the print head 13 and the roll paper 5 in the axial direction. This makes it possible to determine the position where the dot for printing the edge pixel is formed. Further, the control unit 120 drives a plurality of print heads 13 prepared for each edge pixel located at the end in the X-axis direction of the line image printed on the roll paper 5 according to the type of the roll paper 5. By selecting a predetermined drive pulse from the drive pulses, it is possible to determine the size of a dot for printing an edge pixel.
This will be specifically described below.

<Characteristics of print head drive control in this embodiment>
11 and 12 are timing charts for explaining a drive signal for ejecting ink.
In this embodiment, when the pixel data after the halftone processing is 2-bit data, the timing for generating the drive signal for ejecting the ink droplet of the small dot or the medium dot can be selected in the period T.
Specifically, when a small dot is formed, that is, when the pixel data is [01], as shown in FIG. 11, in addition to the waveform selection signal q1 of the period T1, the waveform selection signal q12 of the period T2 and the period T3. The waveform selection signal q13 can be selectively generated. Further, when the medium dot is formed, that is, when the pixel data is [10], as shown in FIG. 12, in addition to the waveform selection signal q2 in the period T1 to T2, the waveform selection signal q22 in the period T2 to T3 is added. Can be selectively generated.

FIG. 13 shows a case where the waveform selection signal q13 is selected as a waveform selection signal when the small dots DS forming the −X side edge pixel are selected, and ink droplets are ejected, as compared with the example shown in FIG. It is a conceptual diagram which shows an example.
The dot row DS3 formed by selecting the waveform selection signal q13 and ejecting ink droplets is formed by the drive signal generated in the period T3 of the period T corresponding to one pixel, that is, the drive pulse PS3. As shown in FIG. 13, it is possible to bring the dot rows closer to the dot rows that form pixels other than the edge pixels formed in the next period T. As a result, the small dots DS forming the edge pixels on the +X side and the dot rows forming the pixels other than the edge pixels can be brought closer to each other, so that the contours on both sides of the bar 7 in the X-axis direction are different. Is reduced.
Further, the distance d2 between the pixels on both ends of the bar 7 can be made narrower than the distance d1 shown in FIG. Therefore, for example, when the degree of bleeding on the roll paper 5 is large, it is possible to perform printing with the influence thereof suppressed.

14 is different from the example shown in FIG. 10 in that the waveform selection signal q12 is selected as a waveform selection signal when the small dots DS forming the edge pixels on both sides in the X-axis direction are formed, and ink droplets are ejected. It is a conceptual diagram which shows the example of a case.
The dot row DS2 formed by selecting the waveform selection signal q12 and ejecting ink droplets is formed by the drive signal generated in the period T2 of the period T corresponding to one pixel, that is, the drive pulse PS2. As shown in FIG. 14, the −X side dot row DS2 can be closer to the dot row forming pixels other than the edge pixels than the −X side dot row DS1 shown in FIG. The dot row DS2 can be separated from the dot row DS1 on the +X side shown in FIG. 10 farther from the dot rows forming pixels other than the edge pixels. As a result, it is reduced that the contours on both sides of the bar 7 in the X-axis direction show different appearances.
The distance d1 between the pixels on both ends of the bar 7 is the same as the distance d1 shown in FIG.

FIG. 15 shows a case where the waveform selection signal q22 is selected and an ink droplet is ejected as a waveform selection signal when forming dots forming edge pixels on both sides in the X-axis direction with respect to the example shown in FIG. It is a conceptual diagram which shows an example. Since the waveform selection signal q22 is selected, the dots forming the edge pixels on both sides in the X-axis direction are medium dots DM.
The dot row DM2 formed by selecting the waveform selection signal q22 and ejecting ink droplets is a drive signal generated in the period T2 to the period T3 of the period T corresponding to one pixel, that is, the drive pulse PS2 and the drive. Since it is formed by the pulse PS3, as shown in FIG. 15, the dot row DM2 on the −X side is a dot row that forms pixels other than the edge pixels rather than the dot row DS1 on the −X side shown in FIG. The center of gravity can be located closer to each other, and the dot row DM2 on the +X side can be located farther from the dot row forming pixels other than the edge pixels than the dot row DS1 on the +X side shown in FIG. You can As a result, it is reduced that the contours on both sides of the bar 7 in the X-axis direction show different appearances.
Further, the distance d1 between the pixels on both ends of the bar 7 is the same as the distance d1 shown in FIG. 10, but since the dots are changed from the small dots DS to the medium dots DM, the degree to which the width of the bar 7 is narrowed is shown in FIG. It is smaller than the case shown in.

As described above, in the printing system 1, control for changing the dot size of the edge pixels and the timing of ink droplet ejection in the relative movement direction of the line drawing print head 13 and the roll paper 5, that is, the waveform selection signal q1, the waveform By controlling any one of the selection signal q12, the waveform selection signal q13, the waveform selection signal q2, the waveform selection signal q22, and the waveform selection signal q3, the print quality of the line drawing can be controlled. This control can be performed according to the type of the roll paper 5 as the recording medium.

In order to enable this control for the edge pixels, the print control unit 111 in the control unit 120 includes an edge pixel detection unit and an edge pixel correction unit as its functional units. The function unit is a unit configured to exhibit a predetermined function by software or firmware operating in the print control unit 111.

The edge pixel detection unit is a functional unit that detects whether the image data to be printed includes a line drawing. Specifically, the edge pixel detection unit analyzes the gradation value distribution of the raster data lined up in the X-axis direction in the image data in the bitmap format after the resolution conversion processing, to thereby obtain a predetermined specification in the Y-axis direction. The presence/absence of a line drawing extending with is detected. When a predetermined line drawing is detected, the edge pixel of the line drawing is detected based on the predetermined threshold value of the gradation value. Note that the predetermined specifications of the line drawing for detecting the line drawing and the predetermined threshold value of the gradation value for detecting the edge pixels are set in advance according to the print quality and the printing specifications of the line drawing targeted by the printing system 1. It is necessary to make a decision based on sufficient evaluation.

The edge pixel correction unit is a functional unit that determines the printing specifications of the edge pixels detected by the edge pixel detection unit. Specifically, based on the degree of easiness of ink bleeding on the roll paper 5, the waveform selection signals for printing the dots forming the edge pixels are the waveform selection signal q1, the waveform selection signal q12, the waveform selection signal q13, By selecting from the waveform selection signal q2, the waveform selection signal q22, and the waveform selection signal q3, the dot size of the edge pixel when printing the edge pixel and the timing of ink droplet ejection are determined.
The selection result of the waveform selection signal by the edge pixel correction unit is reflected in the drive pulse selection data SI&SP. As shown in FIG. 6, the control circuit 90 that receives the drive pulse selection data SI&SP in which the selection result of the waveform selection signal by the edge pixel correction unit is received generates the corresponding waveform selection signal in the printing of the edge pixel. Thus, the printing in which the printing specifications of the edge pixels are optimized is executed.

The degree of ease of ink bleeding on the roll paper 5 is stored in advance in the storage unit 114 as information corresponding to the type of the roll paper 5 to be printed. Specifically, the storage unit 114 stores in advance information on the waveform selection signal to be selected for each type of the roll paper 5 classified according to the degree of bleeding.
The type of the roll paper 5 to be printed is information such as the material and type of the roll paper 5, and is input by the user from the input unit 112 prior to printing, for example. When the information such as the material and type of the roll paper 5 is obtained, the edge pixel correction unit can determine the print specifications of the edge pixels based on the degree of easiness of ink bleeding.

The degree of easiness of ink bleeding on the roll paper 5 is, for example, ranked into a plurality of levels corresponding to the degree, and a waveform selection signal to be selected is determined and stored for each level. It may be stored in the unit 114. In the case where the type of roll paper 5 cannot be specified, the user can perform desired printing by appropriately changing the level while performing print evaluation.

In the present embodiment, the drive pulses PS1 to PS3 are a plurality of drive pulses for driving the print head 13 prepared for each edge pixel located at the end of the line image printed on the roll paper 5 in the X-axis direction. .. Further, in this embodiment, a plurality of drive pulses are selected by selecting any one of the waveform selection signal q1, the waveform selection signal q12, the waveform selection signal q13, the waveform selection signal q2, the waveform selection signal q22, and the waveform selection signal q3. The drive pulse selected from the drive pulses PS1 to PS3 is a predetermined drive pulse.
That is, the control unit 120 drives a plurality of drive heads 13 provided for each edge pixel located at the end in the X-axis direction of the line image printed on the roll paper 5 according to the type of the roll paper 5. A position for forming a dot for printing an edge pixel is determined by selecting a predetermined drive pulse from the drive pulses. Further, the control unit 120 determines a dot size for printing an edge pixel by selecting a predetermined drive pulse according to the type of the roll paper 5.

Further, the control unit 120 selects the waveform selection signal stored in the storage unit 114, which is determined to be selected in advance according to the degree of ease of ink bleeding on the roll paper 5.
That is, the control unit 120 selects a predetermined drive pulse according to the degree of ease of ink bleeding on the roll paper 5.

Further, as described with reference to FIG. 7, the period T corresponds to the period in which the nozzle 74, that is, the print head 13 moves by one pixel in the X-axis direction, and the drive pulses PS1 to PS3 are It is generated in the period T1 to the period T3.
That is, the drive pulses PS1 to PS3 as the plurality of drive pulses are generated in the process in which the print head 13 and the roll paper 5 relatively move by one pixel of the edge pixel.

Further, as described above, the feature of the printing method as the recording method in the present embodiment is that, depending on the type of the roll paper 5, each edge pixel located at the end in the X-axis direction of the line image printed on the roll paper 5 By selecting a predetermined drive pulse from a plurality of drive pulses for driving the print head 13 prepared in step 1, the position for forming a dot for printing an edge pixel and the size of the dot are determined.

As described above, according to the recording apparatus of this embodiment, the following effects can be obtained.
The control unit 120 selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image such as the bar 7 of the barcode 6 to be printed on the roll paper 5, and the print head is selected. By using a drive pulse for driving 13, it is possible to control the position where dots are formed in printing of edge pixels. That is, it is possible to print the edge pixels by forming dots at positions having a resolution higher than the resolution of pixels other than the edge pixels. Since this control can be performed according to the type of roll paper 5, it is possible to perform printing in which the print positions of the edge pixels of the line drawing are optimized for each roll paper 5.
For example, when printing is performed on the roll paper 5 that easily causes ink bleeding, by controlling the printing position of the edge pixel of the line drawing to a position where the thickness of the line drawing becomes thinner, the thickness of the line drawing becomes larger due to the ink bleeding. Is more preferably suppressed. Here, the edge pixel is a pixel located at the end of the line drawing in the X-axis direction in which the print head 13 and the roll paper 5 move relative to each other.

In addition, the control unit 120 selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image printed on the roll paper 5, and drives the print head 13. By doing so, it is possible to control the size of the dots for printing the edge pixels. Since this control can be performed according to the type of the roll paper 5, the dot size in printing the edge pixels of the line drawing is optimized for each roll paper 5, for example, according to the degree of ease of ink bleeding. Printing can be performed.

Further, the predetermined drive pulse can be selected from the drive pulses PS1 to PS3 generated in the process in which the print head 13 and the roll paper 5 relatively move by one pixel of the edge pixel. Therefore, it is not necessary to prepare in advance a plurality of drive pulses for selecting according to the type of roll paper 5.

When the line drawing to be printed is a bar code, the control unit 120 selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the bar code printed on the roll paper 5, By using a drive pulse for driving the print head 13, it is possible to control the position where dots are formed in the printing of edge pixels. In addition, a predetermined drive pulse is selected from a plurality of drive pulses prepared for each edge pixel and is set as a drive pulse for driving the print head 13 to control the size of dots for printing the edge pixel. be able to. Since these controls can be performed according to the type of the roll paper 5, it is possible to perform printing in which the printing of the edge pixels of the barcode is suitable for each roll paper 5. Here, the edge pixel capable of performing the optimized printing is a pixel located at the end of each bar of the barcode in the X-axis direction in which the print head 13 and the roll paper 5 relatively move. .. Therefore, the effect is obtained when the bar direction of the bar code is the direction intersecting the X-axis direction between the print head 13 and the roll paper 5.

Further, since the control unit 120 selects a predetermined drive pulse according to the degree of ease of ink bleeding on the roll paper 5, it is preferable to print edge pixels of the line drawing against the influence of ink bleeding on the line drawing. It is possible to print in a simplified form.

Further, according to the recording method of the present embodiment, a predetermined drive pulse is selected from a plurality of drive pulses prepared for each edge pixel located at the end of the line image printed on the roll paper 5, and the print head 13 is driven. By using the drive pulse for driving, the position where the dot is formed in the printing of the edge pixel can be determined. Since the predetermined drive pulse is selected according to the type of the roll paper 5, it is possible to perform the printing in which the edge pixels of the line drawing are optimized for each roll paper 5. Here, the edge pixel is a pixel located at the end of the line drawing in the X-axis direction in which the print head 13 and the roll paper 5 move relative to each other.

(Embodiment 2)
Next, a recording device and a recording method according to the second embodiment will be described. In the description, the same components as those in the above-described embodiment are designated by the same reference numerals, and the duplicate description will be omitted.
Although the printer 100 included in the printing system 1 is a serial printer in the first embodiment, the printer included in the printing system 1 may be a line printer.
FIG. 16 is a front view showing the configuration of the printing system 1L according to the second embodiment, and FIG. 17 is a block diagram of the same.
The printing system 1L includes a printer 100L instead of the printer 100 according to the first embodiment. The printer 100L is an inkjet line printer that prints a desired image on the roll paper 5 based on print data received from the image processing apparatus 110.

<Basic configuration of printer 100L>
The printer 100L includes a printing unit 10L, a moving unit 20L, a printer control unit 30, and the like. The printer 100L that receives the print data from the image processing apparatus 110 controls the printing unit 10L and the moving unit 20L by the printer control unit 30 based on the print data, and prints an image on the roll paper 5.
The printing unit 10L includes a head unit 11L, an ink supply unit 12, and the like.
The moving unit 20L includes a sub-scanning unit 50 and the like. The sub-scanning unit 50 includes a supply unit 51, a storage unit 52, a transport roller 53, a platen 55, and the like.

The head unit 11L includes a print head 13L including a plurality of heads 131 in which 400 nozzles 74 #1 to #400 are arranged, and a head controller 14L.
FIG. 18 is a schematic diagram showing an example of the arrangement of the nozzles 74 as seen from the lower surface of the print head 13L.
As shown in FIG. 18, the print head 13L includes six nozzle groups 130L for ejecting inks of six colors of black K, cyan C, magenta M, yellow Y, gray LK, and light cyan LC. The print head 13L is a so-called line head, and each of the six nozzle groups 130L includes a plurality of heads 131 in which nozzles 74 that eject the same ink are arranged in a row in the X-axis direction. It is provided so as to extend in the width direction of the roll paper 5 that intersects the Y-axis direction, that is, in the X-axis direction, with a length exceeding the maximum width of the roll paper 5. Further, the heads 131 are provided so as to overlap in the Y-axis direction so that the positions of the four nozzles 74 at the ends of the heads 131 adjacent to each other in the X-axis direction are the same in the X-axis direction. ..

The head control unit 14L is controlled by the printer control unit 30 based on the print data and drives the print head 13L. A description of the configuration of the head controller 14L is omitted.
The print data is a rasterize process in which the pixel data, which is generated based on the image data and is arranged in a matrix after the halftone process, is expanded to the six nozzle groups 130L included in the print head 13L, that is, the first embodiment. It is generated by a rasterize process or the like that does not perform the assigned path.
The printer control unit 30 performs an operation of ejecting ink droplets from the print head 13L while moving the roll paper 5 supplied to the print area by the supply unit 51 and the transport roller 53 by the transport roller 53 in the Y-axis direction. A desired image is printed on the roll paper 5.
In this embodiment, the relative movement direction in which the print head 13L and the roll paper 5 relatively move is the Y-axis direction.

In the printing system 1L as the recording apparatus of the present embodiment, the control unit 120 is prepared for each edge pixel located at the end in the Y-axis direction of the line image printed on the roll paper 5 according to the type of the roll paper 5. By selecting a predetermined drive pulse from a plurality of drive pulses for driving the print head 13L, the position for forming a dot for printing an edge pixel can be determined. In addition, the control unit 120 drives a plurality of print heads 13L prepared for each edge pixel located at the end in the Y-axis direction of the line image printed on the roll paper 5 according to the type of the roll paper 5. By selecting a predetermined drive pulse from the drive pulses, it is possible to determine the size of a dot for printing an edge pixel.

Regarding the basic operation of printing an image by ejecting ink droplets from the print head 13L while the print head 13L and the roll paper 5 move relatively, the case of the first embodiment, that is, the print head 13 and the roll paper This is similar to the case where an image is printed by ejecting ink droplets from the print head 13 while moving relative to the paper 5. The control for selecting a predetermined drive pulse from the plurality of drive pulses for driving the print head 13L prepared for each edge pixel is the same as the control in the first embodiment described with reference to FIGS. 11 and 12. The same is true. Therefore, although the specific description of the drive control of the print head 13L is omitted, the same effect as that of the first embodiment can be obtained even in the printing by the line head having such a configuration.

That is, the control unit 120 selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image printed on the roll paper 5, and drives the print head 13L. With this, it is possible to control the positions where dots are formed in the printing of the edge pixels. That is, it is possible to print the edge pixels by forming dots at positions having a resolution higher than the resolution of pixels other than the edge pixels. Further, the control unit 120 selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image printed on the roll paper 5, and a drive pulse for driving the print head 13L. By doing so, it is possible to control the size of the dots for printing the edge pixels.
Since these controls can be performed according to the type of the roll paper 5, it is possible to perform printing in which the print positions of the edge pixels of the line drawing are optimized for each roll paper 5. Here, the edge pixel capable of performing the optimized printing is a pixel located at the end of the line drawing in the Y-axis direction in which the print head 13L and the roll paper 5 relatively move.

The invention of the present application is not limited to the above-described embodiments, and various modifications and improvements can be added to the above-described embodiments. A modified example will be described below.

(Modification 1)
In the first embodiment, as shown in FIG. 7, the case where printing is performed with four gradations of no dot, small dot, medium dot, and large dot has been described as an example, but it is limited to the case of such a printing method. is not. For example, the printing may be performed in three gradations of no dot, small dot, and medium dot.
FIG. 19 is a timing chart showing a drive signal for ink ejection in Modification 1.
In this modification, the dots forming the edge pixels can be selected from three gradations of no dot, small dot, and medium dot, and when the small dot is selected, the timing of forming the small dot is set to the period T. In, the period T1 and the period T2 can be selected.
Specifically, when a small dot is formed, that is, when the pixel data is [01], the timing for generating a drive signal for ejecting an ink droplet of a small dot is set in the period T as shown in FIG. , Period T1 and period T2. More specifically, in addition to the waveform selection signal q31 in the period T1, the waveform selection signal q32 in the period T2 can be selectively generated.
When forming a medium dot, that is, when the pixel data is [10], the waveform selection signal q41 in the period T1 to the period T2 is selected.

That is, the dots forming the edge pixel can be selected from three gradations of no dot, small dot, and medium dot. Further, when the edge pixel is configured by the small dot, the position of the small dot is formed by the drive pulse PS1 generated by the waveform selection signal q31 in the period T1 with respect to the position of the dot configuring the pixel other than the edge pixel. It is possible to select from the position of the small dot that is formed and the position of the small dot that is formed by the drive pulse PS2 that is generated by the waveform selection signal q32 in the period T2.

As described above, according to the present modification as well, the dot size of the edge pixels of the line drawing is controlled according to the type of the roll paper 5, and/or the edge pixel of the line drawing is controlled according to the type of the roll paper 5. By controlling the positions of the small dots that are formed, it is possible to perform printing in which the printing positions of the edge pixels of the line drawing are optimized for each roll paper 5.

(Modification 2)
In the first embodiment, the second embodiment, and the modified example 1, it is described that the drive signal COM selected by the selection switch 94 based on the head control signal HC is applied to the actuator 77 as the drive pulses PS1 to PS3. Therefore, the predetermined drive pulse selected from the drive pulses PS1 to PS3 as the plurality of drive pulses, that is, the drive signal for forming the dots forming the edge pixels of the line drawing is in the period T, that is, the print head. 13 and the roll paper 5 are signals synchronized with the drive signal COM generated in the process of relatively moving by one edge pixel. However, the predetermined drive pulse is not limited to this as long as it is a drive pulse selected from a plurality of drive pulses for driving the print head 13 prepared for each edge pixel. For example, the drive pulse may be independent of the drive signal COM.

FIG. 20 is a block diagram illustrating the configuration of the drive control system according to the second modification. In addition, FIG. 21 is a timing chart showing a predetermined drive pulse according to the second modification.
The printing system 1 of this modification includes a drive control unit 34v instead of the drive control unit 34, and a head control unit 14v instead of the head control unit 14. The head control unit 14v includes a selection switch 94v instead of the selection switch 94. In addition, the software that operates the control unit 120 that controls these is also modified in accordance with these.

The drive control unit 34v further includes a drive signal generation circuit 38 that generates a drive pulse PS4n and a drive pulse PS5m as drive waveforms dedicated to the edge pixels with respect to the drive control unit 34. That is, the drive pulse PS4n and the drive pulse PS5m are asynchronous drive signals independent of the drive signal COM. Further, in the present modification, the drive pulse PS4n and the drive pulse PS5m are a plurality of drive pulses for driving the print head 13 prepared for each edge pixel.

The drive pulse PS4n is a drive signal for forming a small dot that constitutes an edge pixel of a line drawing when printing is performed with four gradations of no dot, small dot, medium dot, and large dot. It is a pulse having a waveform equivalent to the waveform for one cycle of the period T1. Further, the rising timing can be arbitrarily changed within a range in which the pulse is completed in the period T1 to the period T3, as shown in FIG. Specifically, the drive pulse PS4n is prepared as a plurality of drive pulses PS41 to PS4n having different rising timings. Note that n is a natural number.
The drive pulse PS5m is a drive signal for forming a medium dot that constitutes an edge pixel of a line image when printing is performed with four gradations of no dot, small dot, medium dot, and large dot. It is a pulse having a waveform equivalent to the waveform for two cycles of the period T1 to the period T2. Further, the rising timing can be arbitrarily changed within a range in which the pulse is completed in the period T1 to the period T3, as shown in FIG. Specifically, the drive pulse PS5m is prepared as a plurality of drive pulses PS51 to PS5m having different rising timings. Note that m is a natural number.

The control of the drive signal generation circuit 38, that is, the control of generation of the drive pulse PS4n and the drive pulse PS5m is performed by the CPU 32. Specifically, in advance, under a sufficient evaluation, a suitable drive signal specification for forming dots forming edge pixels of a line drawing is stored in the memory 33 for each type of roll paper 5, The CPU 32 generates a drive pulse PS4n or a drive pulse PS5m for the edge pixel detected by the edge pixel detection unit based on the specifications of the drive signal corresponding to the roll paper 5.

The specifications of the drive signal corresponding to each type of roll paper 5 are, for example, selection information of no dot, small dot, medium dot, and large dot, and a plurality of drive pulses PS4n when small dot and medium dot are selected. , Numerical information of n and m for selecting a drive pulse from the drive pulse PS5m.
When the small dot and the medium dot are selected, the specification of the drive signal corresponding to each type of the roll paper 5 may be time information of the rising timing of the drive pulse PS4n and the drive pulse PS5m.

Further, the CPU 32 controls the selection switch 94v via the discharge control signal generation circuit 36 so that the drive signal for driving the actuator 77 is selected. Specifically, when the drive pulse PS4n or the drive pulse PS5m is generated in the printing of the edge pixel, the CPU 32 does not select the output of the drive signal generation circuit 37 via the ejection control signal generation circuit 36, The selection switch 94v is controlled so that the output of the drive signal generation circuit 38 is selected. Further, in printing dots forming pixels other than the edge pixels, the output of the drive signal generation circuit 38 is not selected, and the selection switch 94v is controlled so that the output of the drive signal generation circuit 37 is selected. The selection switch 94v is different from the selection switch 94 in that the output of the drive signal generation circuit 37 and the output of the drive signal generation circuit 38 can be selected.

According to the recording apparatus of the present modification, the timing of ejecting small dots or medium dots can be set arbitrarily in accordance with the specifications of the roll paper 5 in the period T1 to the period T3. It is possible to further optimize the recording of the edge pixels of and print.

The contents derived from the embodiment will be described below.

A recording apparatus according to the present application, a recording head that ejects liquid onto a recording medium to form dots on the recording medium, a moving unit that relatively moves the recording head and the recording medium in a relative movement direction, A control unit that controls the recording head and the moving unit to perform recording by the dots, the control unit according to the type of the recording medium, the relative position of the line drawing recorded on the recording medium. The dots for recording the edge pixels are formed by selecting a predetermined drive pulse from a plurality of drive pulses for driving the recording head prepared for each edge pixel located at the end in the moving direction. Characterized by determining the position.

According to this configuration, the control unit selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image recorded on the recording medium, and drives the recording head. By using pulses, it is possible to change the timing of ejecting the liquid for forming dots. That is, it is possible to control the positions where dots are formed in the recording of the edge pixels. That is, it is possible to print the edge pixels at a resolution position higher than the resolution of pixels other than the edge pixels. Since this control can be performed according to the type of recording medium, it is possible to perform recording in which the recording positions of the edge pixels of the line drawing are optimized for each recording medium.
For example, when recording is performed on a recording medium that is prone to liquid bleeding, by controlling the recording position of the edge pixel of the line drawing to a position where the thickness of the line drawing becomes thinner, the line drawing becomes thinner due to the liquid bleeding. The thickening is suppressed. Here, the edge pixel is a pixel located at the end of the line drawing in the relative movement direction in which the recording head and the recording medium relatively move.

In the above recording apparatus, it is preferable that the control unit determines the size of the dot for recording the edge pixel by selecting the predetermined drive pulse according to the type of the recording medium.

According to this configuration, the control unit selects a predetermined drive pulse from a plurality of drive pulses prepared for each edge pixel located at the end of the line image recorded on the recording medium, and drives the recording head. By using a pulse, it is possible to control the size of a dot for recording an edge pixel. Since this control can be performed according to the type of recording medium, it is possible to perform the recording in which the dot size in the recording of the edge pixels of the line drawing is optimized for each recording medium, for example, according to the degree of ease of liquid bleeding. It can be carried out.

In the above recording apparatus, it is preferable that the plurality of drive pulses are generated in a process in which the recording head and the recording medium relatively move by one pixel of the edge pixel.

According to this configuration, the predetermined drive pulse can be selected from a plurality of drive pulses generated in the process in which the recording head and the recording medium relatively move by one pixel of the edge pixel. Therefore, it is not necessary to prepare in advance a plurality of drive pulses for selection according to the type of recording medium. For example, in order to make the size of the liquid ejected for each pixel, that is, the dot size to be formed variable, the drive pulse for ejecting the liquid uses a plurality of pulses generated during the period for forming each pixel. In the case of the above configuration, the pulses can be used as a plurality of drive pulses for determining the predetermined drive pulse.

In the above recording apparatus, it is preferable that the line drawing is a bar code.

According to this configuration, the control unit selects a predetermined driving pulse from a plurality of driving pulses prepared for each edge pixel located at the end of the barcode recorded on the recording medium, and drives the recording head. By using a drive pulse, the position where a dot is formed in recording an edge pixel can be controlled. Also, the size of dots for recording edge pixels can be controlled. Since these controls can be performed according to the type of the recording medium, it is possible to perform the recording in which the recording of the edge pixel of the barcode is suitable for each recording medium. Here, the edge pixel capable of performing the optimized recording is a pixel located at the end of each bar of the barcode in the relative movement direction in which the recording head and the recording medium relatively move. Therefore, the effect is obtained when the bar direction of the bar code is a direction intersecting with the relative movement direction of the recording head and the recording medium.

In the above recording apparatus, it is preferable that the control section selects the predetermined drive pulse according to the degree of easiness of the liquid bleeding onto the recording medium.

According to this configuration, the control unit selects the predetermined drive pulse according to the degree of easiness of bleeding of the liquid on the recording medium, so that the edge pixel of the line drawing is recorded against the influence of the bleeding of the liquid on the line drawing. It is possible to perform optimized recording.

A recording method of the present application, a recording head that ejects liquid to a recording medium to form dots on the recording medium, a moving unit that relatively moves the recording head and the recording medium in a relative movement direction, A recording method for performing recording using the dots in a recording apparatus comprising: prepared for each edge pixel located at an end in the relative movement direction of a line drawing recorded on the recording medium, according to the type of the recording medium. By selecting a predetermined driving pulse from a plurality of driving pulses for driving the recording head, the position for forming the dot for recording the edge pixel is determined.

According to this method, a predetermined drive pulse is selected from a plurality of drive pulses prepared for each edge pixel located at the end of the line image recorded on the recording medium, and used as a drive pulse for driving the recording head. Thus, it is possible to determine the position where the dot is formed in the recording of the edge pixel. Since a predetermined drive pulse is selected according to the type of recording medium, it is possible to perform recording in which recording of edge pixels of a line drawing is optimized for each recording medium. Here, the edge pixel is a pixel located at the end of the line drawing in the relative movement direction in which the recording head and the recording medium relatively move.

DESCRIPTION OF SYMBOLS 1... Printing system, 5... Roll paper, 6... Bar code, 7... Bar, 10... Printing part, 11... Head unit, 12... Ink supply part, 13... Print head, 14... Head control part, 20... Moving part , 30... Printer control unit, 32... CPU, 33... Memory, 34... Drive control unit, 35... Movement control signal generation circuit, 36... Discharge control signal generation circuit, 37... Drive signal generation circuit, 38... Drive signal generation circuit , 40... Main scanning section, 41... Carriage, 42... Guide shaft, 50... Sub-scanning section, 51... Supply section, 52... Storage section, 53... Conveying roller, 55... Platen, 60... Touch panel, 71... Vibration plate, 72... Pressure generating part, 73... Cavity, 74... Nozzle, 75... Nozzle plate, 76... Cavity substrate, 77... Actuator, 77a... Piezoelectric thin film, 77b... Electrode, 77c... Electrode, 78... Reservoir, 79... Ink supply port , 90... Control circuit, 91... Shift register, 92... Latch circuit, 93... Level shifter, 94... Selection switch, 100... Printer, 110... Image processing device, 111... Print control section, 112... Input section, 113... Display Section, 114... storage section, 115... CPU, 116... ASIC, 117... DSP, 118... memory, 119... printer interface section, 120... control section, 130... nozzle group, 131... head.

Claims (6)

A recording head that ejects liquid to a recording medium to form dots on the recording medium,
A moving unit that relatively moves the recording head and the recording medium in a relative movement direction,
A control unit that controls the recording head and the moving unit to perform recording using the dots;
The control unit drives a plurality of drives for driving the recording head prepared for each edge pixel located at an end of the line image recorded on the recording medium in the relative movement direction, according to the type of the recording medium. A recording apparatus, wherein a position for forming the dot for recording the edge pixel is determined by selecting a predetermined drive pulse from the pulses. The said control part determines the size of the said dot for recording the said edge pixel by selecting the said predetermined drive pulse according to the kind of the said recording medium. Recording device. The drive pulse according to claim 1 or 2, wherein the plurality of drive pulses are generated in a process in which the recording head and the recording medium relatively move by one pixel of the edge pixel. Recording device. The recording device according to claim 1, wherein the line drawing is a bar code. The recording apparatus according to claim 1, wherein the control unit selects the predetermined drive pulse according to a degree of easiness of bleeding of the liquid with respect to the recording medium. .. A recording apparatus comprising: a recording head that ejects liquid to a recording medium to form dots on the recording medium; and a moving unit that relatively moves the recording head and the recording medium in a relative movement direction, A recording method for recording with the dots,
Predetermined driving from a plurality of drive pulses for driving the recording head prepared for each edge pixel located at the end in the relative movement direction of the line image recorded on the recording medium according to the type of the recording medium. A recording method, wherein a position for forming the dot for recording the edge pixel is determined by selecting a pulse.

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