JP5354801B2 - Head control apparatus and inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head controller which can be composed with a small area and a few logic elements together with a circuit and a head, achieves the miniaturization and cost reduction, and controls two or more head modules by one head controller. <P>SOLUTION: The head controller includes: a data transfer control circuit (24) which outputs nozzle control data to control the discharging of a nozzle in each head module to the time sharing by a head module unit to the two or more head modules (12a, 12b); a data bus (42) which transmits the signal of nozzle control data output from the data transfer control circuit (24) to the two or more head modules (12a, 12b) commonly; a latch signal transmitting circuit (24) which outputs a data latch signal to set the nozzle control data supplied through the data bus (42) to the head module; and a driving voltage output circuit (28) which outputs a driving voltage signal to drive a discharge energy generating element of each head module. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a head control device that drives and controls an ink jet type droplet discharge head, and more particularly, to a configuration of a control circuit that controls the discharge operation of a plurality of head modules and an ink jet recording apparatus using the control circuit.

  Patent Document 1 discloses a control method in which a plurality of ink ejection mechanisms in a head chip constituting a print head used in an inkjet printer are grouped by a predetermined number, and each grouped block is divided and driven simultaneously in parallel. A technique for reducing the number of control signal lines in a configuration employing the above is disclosed. According to Patent Document 1, a serial-parallel conversion circuit is mounted on a head chip drive circuit, and two signals of divided drive data and a data transfer clock are input, and divided drive data is transferred to the head side. The parallel-to-parallel conversion circuit is employed.

  Patent Document 2 discloses a control signal line having a number smaller than the number of blocks (groups) that are time-division driven and a plurality of control signals for the purpose of reducing the formation area of the control signal line in the drive circuit of the inkjet recording head. A configuration is proposed that includes a logic circuit that designates heaters (discharge energy generating means) to be driven by a combination of bit signals supplied to signal lines in a time-sharing manner.

JP 2003-320671 A JP 2005-66905 A

  In Patent Document 1, one head is divided into a plurality of blocks (nozzle groups), and data signal lines are shared between the divided blocks. However, in the configuration of Patent Document 1, it is necessary to mount a serial / parallel conversion circuit in the head drive circuit, and the processing of the decoder becomes complicated.

  On the other hand, in Patent Document 2, nozzle control data input to the head is decoded by a large number of logic elements inside the head, and an element to be ejected is selected. Such a configuration can reduce the number of input data (number of signal lines) to the head, but requires a logic element of a decoding circuit mounted on the head side, and thus requires a large number of logic ICs. In recent years, means realized by an integrated IC can be considered, but this is not desirable for downsizing and cost reduction.

  The present invention has been made in view of such circumstances, and both the circuit and the head can be configured with a small area and a logic element, and can be reduced in size and cost, and can be realized by one head controller. It is an object of the present invention to provide a head control device capable of controlling a plurality of head modules and an ink jet recording apparatus using the head control device.

  In order to achieve the above object, the following invention modes are provided.

  (Invention 1): A head control device according to Invention 1 is connected to a recording head in which a plurality of head modules each having a plurality of nozzles and ejection energy generating elements corresponding to the nozzles are arranged, and each of the recording heads A head control device that controls the discharge of liquid droplets from nozzles, wherein nozzle control data for controlling the discharge operation of the nozzles in each head module is supplied to the plurality of head modules in units of head modules. A data transfer control circuit that outputs the divided data and a signal transmission path that transmits the nozzle control data signal output from the data transfer control circuit to the plurality of head modules in common. Data bus, and each head module from the data transfer control circuit via the data bus A latch signal transmission circuit for outputting a data latch signal at a timing according to the corresponding head module in order to set the nozzle control data for each head module supplied in common as the nozzle control data of the corresponding head module; And a drive voltage output circuit for outputting a drive voltage signal for driving the ejection force generating element of each head module.

  According to the present invention, since the data bus for transmitting the nozzle control data from the data transfer control circuit to each head module is shared by the plurality of head modules, the number of IC pins of the data transfer control circuit and the circuit Wiring patterns on the substrate can be reduced. According to the present invention, the nozzle control data for each module sent in time order by the common data bus is simultaneously supplied (distributed) to a plurality of head modules. A latch signal is given to the corresponding head module in accordance with the transmission order of the nozzle control data for each module sent in order in a time division manner, so that the nozzle control data for each head module is determined.

  Thus, since the logic control for performing the time-sharing control for each head module is managed on the control signal generation side, both the circuit and the head have a smaller area than the conventional configuration (Patent Documents 1 and 2). It can be configured with logic elements.

  Further, according to the present invention, since the data bus on the control circuit side is made common, even a system that cannot use the conventional wiring-saving head (Patent Document 1) can be downsized.

  According to the present invention, it is possible to control a plurality of head modules with a single head control device, and to realize miniaturization and cost reduction.

  As the “ejection energy generating element”, there are an aspect using a piezoelectric element (piezo jet system), an aspect using an electrostatic actuator, an aspect using a heat generating element (heater) in a thermal jet system, and the like.

  (Invention 2): The head control device according to Invention 2 is the line head according to Invention 1, wherein the recording head is elongated by arranging the plurality of head modules in the width direction of the drawing medium. It is characterized by.

  For example, a length having a nozzle array that covers a whole drawing area of the paper width by arranging a plurality of head modules in the paper width direction (hereinafter referred to as “x direction”) of the paper to be printed (corresponding to “the drawing medium”). A long head (page wide head) is configured, and the long head and the paper are subjected to relative scanning only once in a direction orthogonal to the x direction (hereinafter referred to as the “y direction”). It is suitable as a head control device for a single-pass ink jet recording apparatus that forms an image on the head.

  (Invention 3): The head control device according to Invention 3 is obtained from the host control device via the data communication unit and the data communication unit that performs data communication with the host control device in the first or second aspect. It is characterized by comprising first storage means for storing image data, and second storage means for storing waveform data of the drive voltage signal.

  According to this aspect, the head controller can receive waveform data and image data from the host controller. The “image data” here is, for example, dot arrangement data of pixels corresponding to the recording resolution, and is nozzle control data that designates ejection (drive) / non-ejection (non-drive) from the nozzle corresponding to the pixel position. Equivalent to.

(Invention 4): A head control device according to Invention 4, in any one of Inventions 1 to 3,
The drive voltage signal is individually set for each of the plurality of head modules, and the drive voltage signal is sent by an individual signal line for each head module.

  According to this aspect, it is possible to apply a different drive voltage signal for each head module. When the ejection performance (characteristic) varies among the head modules, a constant ejection performance can be realized for the entire head by applying a drive voltage signal appropriately adjusted for each module. According to the aspect of the present invention, high-quality drawing output is possible by absorbing performance variations between modules (individual differences among head modules).

  (Invention 5): The head control device according to Invention 5 is characterized in that, in any one of Inventions 1 to 3, the common driving voltage signal is applied to the plurality of head modules.

  In this aspect, a common drive voltage signal is applied to the plurality of head modules. For example, this is a configuration that can be adopted in the case of a system configuration that allows a reduction in drawing quality due to individual differences in head modules. Even when such a common drive signal method is adopted, by providing a correction circuit for correcting the drive voltage signal on the head module side, it is possible to suppress variations in ejection characteristics for each head module.

  The number of wirings can be reduced by a configuration in which drive voltage signals are distributed in parallel (common) to a plurality of head modules.

(Invention 6): A head control device according to Invention 6, in any one of Inventions 1 to 5,
The nozzle control data is transferred to each head module in units of recording resolution.

  A mode in which the nozzle control data is transferred in units of recording resolution realized by the nozzle arrangement of the head module is preferable. Such an aspect is suitable for a single pass printing method. The “recording resolution unit” here is a unit of one surface of the head module. When the nozzle arrangement in the head module is a two-dimensional arrangement, one nozzle point corresponds to one pixel.

  (Invention 7): The head control device according to Invention 7 is the data signal according to Invention 6, wherein the nozzle control data of each head module is arranged in time order in module units in accordance with a discharge trigger signal in pixel units corresponding to the recording resolution. It is flowed on the data bus as a row.

  The arrangement order of data arranged in time order for each head module may be an order fixed in advance, or the order may be adaptively changed according to the data processing status or the like.

(Invention 8): A head control device according to Invention 8, in any one of Inventions 1 to 7,
The data transfer control circuit has means for changing the transfer order of nozzle control data for each head module, and the latch signal transmission circuit outputs a data latch signal for the corresponding head module in accordance with the changed transfer order. It is characterized by transmitting.

  The transfer order of the nozzle control data for each head module transferred in a time division manner is arbitrary. Data can be set in the corresponding head module by a combination of the data group of the head module unit and the latch signal corresponding to the head module regardless of the transfer order.

  (Invention 9): An ink jet recording apparatus according to Invention 9 includes the head control device according to any one of Inventions 1 to 8, and the recording head.

  As a configuration example of a print head (recording head) used in an ink jet recording apparatus, a nozzle array in which a plurality of head modules are connected to each other and a plurality of ejection ports (nozzles) extending over the entire width of the drawing medium is arranged. It is possible to use a full line type head having the same. Such a full-line type head is usually arranged along a direction orthogonal to the relative feeding direction (relative conveyance direction) of the drawing medium (paper), but with respect to the direction orthogonal to the conveyance direction. Thus, there may be a mode in which the head is arranged along an oblique direction having a predetermined angle.

  “Drawing medium” is a medium (which may be called a printing medium, an image forming medium, a recording medium, an image receiving medium, a discharged medium, or the like) that receives adhesion of droplets discharged from the discharge port of the head. Various media are included regardless of material or shape, such as continuous paper, cut paper, sealing paper, resin sheets such as OHP sheets, printed boards on which films, cloths, wiring patterns, etc. are formed.

  The transporting means for moving the recording medium and the head relative to each other includes a mode for transporting the recording medium to the stopped (fixed) head, a mode for moving the head with respect to the stopped recording medium, or a head and recording. Any aspect of moving both of the media is included. When a color image is formed using an ink jet print head, a head may be arranged for each color of ink (recording liquid), or a plurality of colors can be ejected from one recording head. It is good also as a simple structure.

  (Invention 10): An ink jet recording apparatus according to Invention 10, in Invention 9, wherein the head control device is connected so as to be able to perform data communication with a host control device, and waveform data and image formation of the drive voltage signal from the host control device. The nozzle control data necessary for the transfer is transferred to the head control device.

  According to the present invention, it is possible to provide a small and inexpensive head control device. Further, the head can be miniaturized, and the system can be miniaturized and the cost can be reduced.

1 is a block diagram showing a configuration of a head control device in an ink jet recording apparatus according to an embodiment of the present invention. Timing chart in the configuration of FIG. The block diagram which shows the structure of the head control apparatus which concerns on a comparative example. Timing chart in the configuration of FIG. Timing chart for controlling three head modules A block diagram showing an example of composition of an embodiment which applies a common drive voltage to a plurality of head modules 1 is a configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. Plane perspective view showing structural example of head Plane perspective view showing a structure example of a line-type head formed by arranging a plurality of head modules Sectional drawing which follows the AA line in FIG. Block diagram showing the configuration of the control system of the ink jet recording apparatus

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration of a head control device in an ink jet recording apparatus according to an embodiment of the present invention. The print head (corresponding to “recording head”) 10 is configured by combining a plurality of inkjet head modules (hereinafter referred to as “head modules”) 12a and 12b. Here, for the sake of simplicity of explanation. Although two head modules 12a and 12b are illustrated, the number of head modules constituting one print head 10 is not particularly limited.

  Although the detailed configuration of the head modules 12a and 12b is not shown, a plurality of nozzles (ink discharge ports) are two-dimensionally arranged at high density on the ink discharge surfaces of the head modules 12a and 12b. The head modules 12a and 12b are provided with ejection energy generating elements (in the case of this example, piezoelectric elements) corresponding to the respective nozzles.

  By connecting a plurality of head modules 12a and 12b in the width direction of a paper (not shown) as a drawing medium, predetermined recording is performed for the entire recordable range (the entire drawing width) in the paper width direction. A long line head (a page wide head capable of single-pass printing) having a nozzle row capable of drawing at a resolution (eg, 1200 dpi) is configured.

  A head control unit 20 (corresponding to a “head control device”) connected to the print head 10 controls the driving of piezoelectric elements corresponding to the nozzles of the plurality of head modules 12a and 12b, and performs an ink ejection operation from the nozzles. It functions as a control means for controlling (the presence / absence of ejection, the droplet ejection amount).

  The head control unit 20 includes an image data memory 22 (corresponding to “first storage unit”), an image data transfer control circuit 24 (corresponding to “data transfer control circuit”), an ejection timing control unit 25, and a waveform data memory 26 ( The driving voltage control circuit 28 (corresponding to the “driving voltage output circuit”), and D / A converters 29a and 29b. In this example, the image data transfer control circuit 24 includes a “latch signal transmission circuit”, and a data latch signal is output from the image data transfer control circuit 24 to each of the head modules 12a and 12b at an appropriate timing.

  The image data memory 22 stores image data expanded into print image data (dot data). The waveform data memory 26 stores digital data of a driving voltage waveform for driving the piezoelectric element. The image data input to the image data memory 22 and the waveform data input to the waveform data memory 26 are managed by the upper data control unit 30 (corresponding to “upper control device”). The upper data control unit 30 can be configured by, for example, a personal computer or a host computer. The head control unit 20 includes a USB (Universal Serial Bus) or other communication interface as data communication means for receiving data from the upper data control unit 30.

  In FIG. 1, only one print head 10 (for one color) is shown for ease of explanation, but a plurality of (for each color) print heads corresponding to each color of a plurality of inks are provided. In the case of an ink jet recording apparatus, a head controller 20 is provided for each color print head 10 individually (in units of heads). For example, in a configuration including print heads for each color corresponding to four colors of cyan (C), magenta (M), yellow (Y), and black (K), the head controller 20 is provided for each of the CMYK print heads. Thus, a configuration is adopted in which one upper data control unit 30 manages the head control units of these colors.

  When the system is activated, waveform data and image data are transferred from the upper data control unit 30 to the head control unit 20 of each color. Note that image data may be transferred in synchronism with paper conveyance during printing. During the printing operation, the ejection timing control unit 25 for each color receives the ejection trigger signal from the paper transport unit 32 and outputs a start trigger for starting the ejection operation to the image data transfer control circuit 24 and the drive voltage control circuit 28. . In response to this start trigger, the image data transfer control circuit 24 and the drive voltage control circuit 28 transfer waveform data and image data in units of resolution from the image data transfer control circuit 24 and the drive voltage control circuit 28 to the head modules 12a and 12b. As a result, a selective ejection operation (on-demand ejection drive control) according to the image data is performed to realize printing of one page.

  Drive voltage waveform data is output from the drive voltage control circuit 28 to the D / A converters 29a and 29b in accordance with a print timing signal (ejection trigger signal) input from the outside, so that the D / A converters 29a and 29b are output. The waveform data is converted into an analog voltage waveform. The output waveforms (analog voltage waveforms) of the D / A converters 29a and 29b are amplified to a predetermined current / voltage suitable for driving the piezoelectric element by an amplifier circuit (power amplification circuit) (not shown), and then the head modules 12a and 12b. To be supplied.

  The image data transfer control circuit 24 can be configured by a central processing unit (CPU) or a field programmable gate array (FPGA). Based on the data stored in the image data memory 22, the image data transfer control circuit 24 supplies the nozzle control data (here, image data corresponding to the dot arrangement of the recording resolution) of each head module 12a, 12b to each head module 12a. , 12b is controlled. The nozzle control data is image data (dot data) that determines whether the nozzle is ON (discharge drive) / OFF (non-drive). The image data transfer control circuit 24 controls the opening / closing (ON / OFF) for each nozzle by transferring the nozzle control data to the head modules 12a and 12b.

  The image data transmission path (reference numeral 42) for transmitting the nozzle control data output from the image data transfer control circuit 24 to each of the head modules 12a and 12b is “image data bus”, “data bus”, “image bus”, or the like. It is called and is composed of a plurality of signal lines (n lines) (n ≧ 2). In the present embodiment, it is hereinafter referred to as a “data bus” (reference numeral 42). A data bus 42 for transmitting image data from the image data transfer control circuit 24 to the print head 10 is shared as an image data transmission path to the plurality of head modules 12a and 12b. One end of the data bus 42 is connected to the output terminal (IC pin) of the image data transfer control circuit 24, and the other end is branched before the head modules 12a and 12b (in this example, the head modules 12a and 12b are connected to the head buses 12a and 12b). A plurality of head modules 12a and 12b are connected in parallel to the branched common data bus 42).

  The data bus 42 may be constituted by a copper wire pattern of an electric circuit board 40 on which the image data transfer control circuit 24, the drive voltage control circuit 28, etc. are mounted, may be constituted by a wire harness, or these It may be a combination. As described above, the data bus 42 is connected to the head modules 12a and 12b by the copper wire pattern or the wire harness of the electric circuit board 40 using the IC pin of the image data transfer control circuit 24 as a signal source.

  In this embodiment, the data bus 42 is shared by a plurality of head modules 12a and 12b to be controlled by one head controller 20 (from the connection point with the IC pin of the image data transfer control circuit 24 to the branch point of parallel connection). This reduction of the IC pins of the image data transfer control circuit 24 and the copper wire pattern (signal line) of the electric circuit board 40 has been achieved.

  While the data bus 42 is shared by the plurality of head modules 12a and 12b, data latch signal signal lines 46a and 46b corresponding to the head modules 12a and 12b are individually provided for the head modules 12a and 12b. It has been. The data latch signal is transmitted from the image data transfer control circuit 24 to the head modules 12a and 12b at a necessary timing in order to set the data signal transferred via the data bus 42 as the nozzle data of the head modules 12a and 12b. Sent. When a certain amount of image data is transmitted from the image data transfer control circuit 24 to the head modules 12a and 12b via the image data bus 42, a signal called a data latch (latch signal) is transmitted to the head modules 12a and 12b. . At the timing of this data latch signal, the ON / OFF data of the displacement of the piezoelectric element in each module is determined. Thereafter, by applying drive voltages a and b to the head modules 12a and 12b, respectively, the piezoelectric element according to the ON setting is slightly displaced, and ink droplets are ejected. Printing with a desired resolution (eg, 1200 dpi) is performed by attaching (landing) the ejected ink droplets to the paper. Note that the piezoelectric element set to OFF does not displace even when a drive voltage is applied, and no droplets are ejected.

<Timing chart>
FIG. 2 is a timing chart according to the present embodiment.

  As shown in the drawing, in order to perform on (discharge) / off (non-discharge) control of the nozzles of the head modules 12a and 12b in accordance with a discharge trigger in units of pixels (described as “pixel trigger” in FIG. 2A). Image data (nozzle control data) is sent in a time-sharing manner as a data sequence in units of head modules via a common data bus 42 (see FIG. 2C).

  In the circuit configuration described with reference to FIG. 1, since the data bus 42 for transferring image data to the plurality of head modules 12a and 12b and the transfer clock (FIG. 2B) are common, one data bus 42 is used. Two types of image data (image data [HEAD a] applied to the head module 12a and image data [HEAD b] applied to the head module 12b) are transferred in a time division manner (see FIG. 2C).

  The data latch a (FIG. 2D) is a latch signal for determining data of the piezoelectric element (nozzle) of the head module 12a. The data latch b (FIG. 2 (f)) is a latch signal for determining the data of the piezoelectric element (nozzle) of the head module 12b. These data latch signals a / b are transferred when the respective image data ([HEAD a], [HEAD b]) of the head modules 12a and 12b are transferred.

  In the case of FIG. 2, when data of the image data (HEAD a) group of the head module 12a is sent, a data latch a is given to determine the data of the head module 12a. Thereafter, the image data (HEAD b) of the head module 12b is further transmitted, and a data latch b is given after a certain amount of data has been transmitted to determine the data of the head module 12b.

  In addition, while the image data (HEAD b) of the head module 12b is being transmitted, the same data is also transmitted to the head module 12a, but the head module 12a is latched by the data latch a. Therefore, the image data (HEAD b) sent is not set.

  Thus, the piezoelectric element ON / OFF data of the head module 12a is determined by the latch signal of the data latch a, and the piezoelectric element ON / OFF data of the head module 12b is determined by the latch signal of the data latch b. Thereafter, the driving voltages a and b are applied to the head modules 12a and 12b at the same timing (see FIGS. 2E and 2G). By applying the driving voltages a and b, droplets are ejected from the corresponding nozzles, and drawing recording is performed. The above processing cycle is repeated in accordance with the paper transport timing, and printing is performed.

  In FIG. 2, the voltage waveform of the drive voltage a (FIG. 2 (e) applied to the head module 12a and the drive voltage b (FIG. 2 (f)) applied to the head module 12b is different. This is because the drive voltage waveform is adjusted for each head module in order to realize the required ejection characteristics in consideration of variations in the ejection characteristics of the modules 12a and 12b. The waveform data of the drive voltage a and the drive voltage b in consideration of the characteristics of 12a and 12b is stored.

<Comparative example>
For comparison, a block diagram (FIG. 3) and a timing chart (FIG. 4) of a configuration in which an image data bus is connected to each head module without using a common data bus are shown.

  3, elements that are the same as or similar to those in the configuration described in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. The configuration according to the comparative example in FIG. 3 is different from the configuration in FIG. 1 in that image data buses 42a and 42b are individually connected from the image data transfer control circuit 24 to the head modules 12a and 12b, respectively. Such a configuration increases the number of IC pins of the image data transfer control circuit 24 and the copper wire pattern on the electric circuit board 40 as the number of head modules to be controlled increases. As a result, the cost increases significantly. Would be disadvantageous.

  FIG. 4 is a timing chart according to the comparative example of FIG. As shown in FIG. 4, in the configuration of FIG. 3, the same processing is performed in parallel for each of the head modules 12a and 12b.

  As is clear from comparison between FIG. 4 and FIG. 2, the circuit according to the embodiment of the present invention (FIGS. 1 and 2) has a higher transfer clock than the circuit according to the comparative example (FIGS. 3 and 4). It has become.

  In the case of the embodiment of the present invention (FIGS. 1 and 2), each image data is sent to the two head modules 12a and 12b in time division (in order of time) via the common image data bus 42. In addition, the frequency of the transfer clock is twice the frequency of the transfer clock in FIGS.

<Explanation when three head modules are connected>
FIG. 5 shows a timing chart when the number of head modules controlled by one head controller 20 is three. The descriptions of image data c, [HEAD c], data latch c, drive voltage c, etc. in FIG. 5 represent signals relating to the third head module added to the example of FIG.

  When the number of head modules is three, the transfer clock is further increased (three times the frequency compared with FIG. 4), and image data corresponding to three head modules ([HEAD a], [HEAD b] , [HEAD c]) in time division. Other processes are the same as those described in FIG.

As long as the transfer rate is increased and the transfer waveform quality and data transfer timing specifications are satisfied, it is possible to control three or more head modules and more head modules on the same bus.
When N head modules are connected to a common data bus in parallel, the frequency of the transfer clock is increased N times.

<Modification 1 of Embodiment>
In FIG. 5, the image data is transferred in the order of the head modules a, b, and c, but the data transfer order is not limited to this. The transfer order of image data can be set (arbitrarily) regardless of the arrangement order of the head modules. The transfer order may be adaptively changed according to the situation, without being limited to a mode in which the transfer is sequentially performed according to a predetermined transfer order (module order). When the transfer order is changed, the transmission timing of the data latch signal is changed accordingly. That is, it is possible to associate data with a head module by a set (pair) of image data groups corresponding to each head module and a data latch signal for the head module, and by these combinations, data transfer can be performed in an arbitrary order. Is possible.

  For example, the image signal processing by the host controller is delayed for some reason, and the generation of any one of the data groups corresponding to the head modules a, b, and c (for example, the data group of the head module a) is likely to be delayed. In this case, it is also possible to transfer the data group a (data of the head modules b and c) first, process the data latches for these modules, and then send the data of the data module a. As described above, by performing data transfer by adaptively changing the transfer order in the order of data ready for transfer, useless processing waiting time can be reduced, and transfer efficiency can be improved.

<Modification 2 of Embodiment>
In the example of FIG. 5 as well, head drive data (drive voltages a, b, and c) can be controlled for each head module. This is to have drive voltage data for each head module in order to absorb the difference in ejection performance due to individual variations of the piezo elements.

  If individual differences in head modules have little effect on drawing quality, for example, in the case of a device that outputs low-quality printed matter such as an inexpensive flyer, drive data (drive voltage data) is classified by module (individually). There is no need to have. In this case, as shown in FIG. 6, the drive voltage signal transmission line can be shared. 6, elements that are the same as or similar to those in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. Therefore, similarly to the transfer of image data, it is possible to distribute the drive voltage to a plurality of head modules by using a common signal line (with a common drive voltage signal line) to obtain the same effect.

<Modification 3 of embodiment>
In the example of FIGS. 1, 5, and 6, the image data memory 22, the waveform data memory 26, the image data transfer control circuit 24, the ejection timing control unit 25, the drive voltage control circuit 28, the D / A converters 29a and 29b, Although an example in which the data bus 42 is mounted on one electric circuit board 40 has been shown, the specific configuration of the head controller 20 is not limited to this example. For example, it is also possible to divide and mount circuit elements constituting the head control unit 20 on a plurality of circuit boards and connect the plurality of circuit boards with a harness.

<Configuration Example of Inkjet Recording Device>
FIG. 7 is an overall configuration diagram showing a configuration example of the ink jet recording apparatus according to the embodiment of the present invention. The ink jet recording apparatus 100 of this example mainly includes a paper feeding unit 112, a treatment liquid application unit (precoat unit) 114, a drawing unit 116, a drying unit 118, a fixing unit 120, and a paper discharge unit 122. The ink jet recording apparatus 100 uses an ink jet head 172M on a recording medium 124 (corresponding to a “drawing medium”, which may hereinafter be referred to as “paper” for convenience) held on an impression cylinder (drawing drum 170) of the drawing unit 116. , 172K, 172C, and 172Y, a single-pass inkjet recording apparatus that forms a desired color image by ejecting droplets of a plurality of colors, and a processing liquid (here, agglomerates) on the recording medium 124 before the droplets are ejected. This is an on-demand type image forming apparatus to which a two-liquid reaction (aggregation) method is applied in which an image is formed on a recording medium 124 by reacting the processing liquid and the ink liquid.

(Paper Feeder)
A recording medium 124 that is a sheet is stacked on the paper feeding unit 112, and the recording medium 124 is fed one by one from the paper feeding tray 150 of the paper feeding unit 112 to the processing liquid application unit 114. In this example, a sheet (cut paper) is used as the recording medium 124, but a configuration in which continuous paper (roll paper) is cut to a required size and fed is also possible.

(Processing liquid application part)
The processing liquid application unit 114 is a mechanism that applies the processing liquid to the recording surface of the recording medium 124. The treatment liquid contains a color material aggregating agent that agglomerates the color material (pigment in this example) in the ink applied by the drawing unit 116, and the ink comes into contact with the treatment liquid and the ink. And the solvent are promoted.

  The processing liquid application unit 114 includes a paper feed cylinder 152, a processing liquid drum (also referred to as “precoat cylinder”) 154, and a processing liquid coating device 156. The treatment liquid drum 154 is a drum that holds and rotates the recording medium 124. The processing liquid drum 154 includes a claw-shaped holding means (gripper) 155 on the outer peripheral surface thereof, and the recording medium 124 is sandwiched between the claw of the holding means 155 and the peripheral surface of the processing liquid drum 154. The tip can be held. The treatment liquid drum 154 may be provided with a suction hole on the outer peripheral surface thereof and connected to a suction unit that performs suction from the suction hole. As a result, the recording medium 124 can be held in close contact with the peripheral surface of the treatment liquid drum 154.

  A processing liquid coating device 156 is provided outside the processing liquid drum 154 so as to face the peripheral surface thereof. The processing liquid coating device 156 includes a processing liquid container in which the processing liquid is stored, an anix roller (measuring roller) partially immersed in the processing liquid in the processing liquid container, the anix roller and the processing liquid drum 154. A rubber roller that is pressed against the upper recording medium 124 and transfers the measured processing liquid to the recording medium 124. According to the processing liquid coating apparatus 156, the processing liquid can be applied to the recording medium 124 while being measured.

  In the present embodiment, the configuration in which the application method using the roller is exemplified, but the present invention is not limited to this. For example, various methods such as a spray method and an ink jet method can be applied.

  The recording medium 124 to which the processing liquid is applied by the processing liquid applying unit 114 is transferred from the processing liquid drum 154 to the drawing drum 170 of the drawing unit 116 via the intermediate transport unit 126.

(Drawing part)
The drawing unit 116 includes a drawing drum (also referred to as “drawing cylinder” or “jetting cylinder”) 170, a sheet pressing roller 174, and inkjet heads 172M, 172K, 172C, 172Y. As the inkjet heads 172M, 172K, 172C, and 172Y for the respective colors and the control devices thereof, the configuration of the print head 10 and the configuration of the head control unit 20 described with reference to FIGS.

  Similar to the treatment liquid drum 154, the drawing drum 170 includes a claw-shaped holding means (gripper) 171 on the outer peripheral surface thereof. The recording medium 124 fixed to the drawing drum 170 is conveyed with the recording surface facing outward, and ink is applied to the recording surface from the inkjet heads 172M, 172K, 172C, 172Y.

  Each of the inkjet heads 172M, 172K, 172C, and 172Y is a full-line inkjet recording head having a length corresponding to the maximum width of the image forming area in the recording medium 124, and image formation is performed on the ink ejection surface thereof. A nozzle row (two-dimensional array nozzle) in which a plurality of nozzles for ejecting ink are arranged over the entire width of the region is formed. Each inkjet head 172M, 172K, 172C, 172Y is installed so as to extend in a direction orthogonal to the conveyance direction of the recording medium 124 (the rotation direction of the drawing drum 170).

  A corresponding color ink cassette is attached to each of the inkjet heads 172M, 172K, 172C, and 172Y. Ink droplets are ejected from the inkjet heads 172M, 172K, 172C, and 172Y toward the recording surface of the recording medium 124 held on the outer peripheral surface of the drawing drum 170.

  As a result, the ink comes into contact with the treatment liquid previously applied to the recording surface, and the color material (pigment) dispersed in the ink is aggregated to form a color material aggregate. As an example of the reaction between the ink and the treatment liquid, in this embodiment, an acid is contained in the treatment liquid, and the pigment dispersion is destroyed and aggregated by the PH down. Avoids droplet ejection interference due to liquid coalescence. Thus, the color material flow on the recording medium 124 is prevented, and an image is formed on the recording surface of the recording medium 124.

  The droplet ejection timings of the ink jet heads 172M, 172K, 172C, and 172Y are synchronized with an encoder (not shown in FIG. 7, reference numeral 294 in FIG. 11) that detects the rotation speed disposed on the drawing drum 170. A discharge trigger signal (pixel trigger) is generated based on the detection signal of the encoder. Thereby, the landing position can be determined with high accuracy. In addition, it learns the speed fluctuation due to the deflection of the drawing drum 170 in advance, corrects the droplet ejection timing obtained by the encoder, and depends on the deflection of the drawing drum 170, the accuracy of the rotation axis, and the speed of the outer peripheral surface of the drawing drum 170 In this case, it is possible to reduce the droplet ejection unevenness.

  Furthermore, maintenance operations such as cleaning the nozzle surfaces of the inkjet heads 172M, 172K, 172C, and 172Y and discharging the thickened ink may be performed by retracting the head unit from the drawing drum 170.

  In this example, the configuration of CMYK standard colors (four colors) is illustrated, but the combination of ink colors and the number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an inkjet head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

  The recording medium 124 on which an image is formed by the drawing unit 116 is transferred from the drawing drum 170 to the drying drum 176 of the drying unit 118 via the intermediate conveyance unit 128.

(Drying part)
The drying unit 118 is a mechanism for drying moisture contained in the solvent separated by the color material aggregating action. As shown in FIG. 7, the drying unit 118 includes a drying drum (also referred to as “drying cylinder”) 176 and a solvent drying device 178. I have. Similar to the processing liquid drum 154, the drying drum 176 includes a claw-shaped holding unit (gripper) 177 on the outer peripheral surface thereof, and the holding unit 177 can hold the leading end of the recording medium 124.

  The solvent drying device 178 is disposed at a position facing the outer peripheral surface of the drying drum 176, and includes a plurality of halogen heaters 180 and hot air ejection nozzles 182 disposed between the halogen heaters 180. Various drying conditions can be realized by appropriately adjusting the temperature and air volume of the hot air blown toward the recording medium 124 from each hot air ejection nozzle 182 and the temperature of each halogen heater 180.

  The recording medium 124 is held on the outer peripheral surface of the drying drum 176 so that the recording surface of the recording medium 124 faces outward (that is, in a state where the recording surface of the recording medium 124 is curved so as to be convex), and is rotated. By drying while being conveyed, the recording medium 124 can be prevented from wrinkling and floating, and drying unevenness caused by these can be surely prevented.

  The recording medium 124 that has been dried by the drying unit 118 is transferred from the drying drum 176 to the fixing drum 184 of the fixing unit 120 via the intermediate conveyance unit 130.

(Fixing part)
The fixing unit 120 includes a fixing drum (also referred to as “fixing cylinder”) 184, a halogen heater 186, a fixing roller 188, and an in-line sensor 190. Like the processing liquid drum 154, the fixing drum 184 includes a claw-shaped holding unit (gripper) 185 on the outer peripheral surface, and the leading end of the recording medium 124 can be held by the holding unit 185.

  With the rotation of the fixing drum 184, the recording medium 124 is conveyed with the recording surface facing outward. The recording surface is preheated by the halogen heater 186, fixing processing by the fixing roller 188, and by the inline sensor 190. Inspection is performed.

  The halogen heater 186 is controlled to a predetermined temperature (for example, 180 ° C.). Thereby, preheating of the recording medium 124 is performed.

  The fixing roller 188 is a roller member that heats and pressurizes the dried ink to weld the self-dispersing polymer fine particles in the ink to form a film of the ink, and is configured to heat and press the recording medium 124. The Specifically, the fixing roller 188 is disposed so as to be in pressure contact with the fixing drum 184 and constitutes a nip roller with the fixing drum 184. As a result, the recording medium 124 is sandwiched between the fixing roller 188 and the fixing drum 184 and nipped at a predetermined nip pressure (for example, 0.15 MPa), and the fixing process is performed.

  The fixing roller 188 is configured by a heating roller in which a halogen lamp is incorporated in a metal pipe such as aluminum having good thermal conductivity, and is controlled to a predetermined temperature (for example, 60 to 80 ° C.). By heating the recording medium 124 with this heating roller, thermal energy equal to or higher than the Tg temperature (glass transition temperature) of the latex contained in the ink is applied, and the latex particles are melted. As a result, pressing and fixing are performed on the unevenness of the recording medium 124, and the unevenness of the image surface is leveled to obtain glossiness.

  In the embodiment shown in FIG. 7, only one fixing roller 188 is provided. However, a structure in which a plurality of fixing rollers 188 are provided may be used depending on the thickness of the image layer and the Tg characteristics of latex particles.

  On the other hand, the inline sensor 190 is a reading unit for measuring an ejection defect check pattern, image density, image defect, and the like for an image (including a test pattern) recorded on the recording medium 124, and is a CCD line sensor. Etc. apply.

  According to the fixing unit 120 configured as described above, the latex particles in the thin image layer formed by the drying unit 118 are heated and pressurized by the fixing roller 188 and are melted. Can be made.

  In addition, instead of the ink containing the high boiling point solvent and the polymer fine particles (thermoplastic resin particles), a monomer component that can be polymerized and cured by ultraviolet (UV) exposure may be contained. In this case, the inkjet recording apparatus 100 includes a UV exposure unit that exposes the ink on the recording medium 124 to UV light instead of the heat-pressure fixing unit (fixing roller 188) using a heat roller. As described above, when ink containing an actinic ray curable resin such as a UV curable resin is used, an actinic ray such as a UV lamp or an ultraviolet LD (laser diode) array is used instead of the fixing roller 188 for heat fixing. Means for irradiating are provided.

(Output section)
As shown in FIG. 7, a paper discharge unit 122 is provided following the fixing unit 120. The paper discharge unit 122 includes a discharge tray 192. Between the discharge tray 192 and the fixing drum 184 of the fixing unit 120, a transfer drum 194, a conveyance belt 196, and a stretching roller 198 are in contact with each other. Is provided. The recording medium 124 is sent to the conveyor belt 196 by the transfer drum 194 and discharged to the discharge tray 192. Although the details of the paper transport mechanism by the transport belt 196 are not shown, the recording medium 124 after printing is held at the front end of the paper by a gripper (not shown) gripped between the endless transport belt 196, and the transport belt 196. Is carried above the discharge tray 192.

  Although not shown in FIG. 7, in addition to the above-described configuration, the ink jet recording apparatus 100 of this example includes an ink storage / loading unit that supplies ink to each of the ink jet heads 172M, 172K, 172C, and 172Y, and a processing liquid. A means for supplying a processing liquid to the applying unit 114 and a head maintenance unit for cleaning each ink jet head 172M, 172K, 172C, 172Y (nozzle surface wiping, purging, nozzle suction, etc.) Are provided with a position detection sensor for detecting the position of the recording medium 124 and a temperature sensor for detecting the temperature of each part of the apparatus.

<Configuration example of inkjet head>
Next, the structure of the inkjet head will be described. Since the inkjet heads 172M, 172K, 172C, and 172Y corresponding to the respective colors have the same structure, the heads are represented by the reference numeral 250 in the following.

  FIG. 8A is a plan perspective view showing an example of the structure of the head 250, and FIG. 8B is an enlarged view of a part thereof. FIG. 9 is a diagram showing an arrangement example of a plurality of head modules constituting the head 250. 10 is a cross-sectional view (A- in FIG. 8) showing a three-dimensional configuration of a droplet ejection element (an ink chamber unit corresponding to one nozzle 251) for one channel serving as a recording element unit (ejection element unit). It is sectional drawing which follows the A line.

  As shown in FIG. 8, the head 250 of this example has a matrix of a plurality of ink chamber units (droplet discharge elements) 253 including nozzles 251 serving as ink discharge ports and pressure chambers 252 corresponding to the nozzles 251. The nozzle spacing (projection nozzle pitch) is projected (orthogonal projection) so as to be aligned along the longitudinal direction of the head (direction perpendicular to the paper feed direction). High density is achieved.

  Corresponds to the entire width Wm of the drawing area of the recording medium 124 in a direction (arrow M direction; corresponding to “second direction”) substantially orthogonal to the feeding direction (arrow S direction; corresponding to “first direction”) of the recording medium 124. In order to configure a nozzle row longer than the length, for example, as shown in FIG. 9A, a short head module 250 ′ in which a plurality of nozzles 251 are two-dimensionally arranged is arranged in a staggered manner. Construct a line-type head. Alternatively, as shown in FIG. 9B, it is possible to connect the head modules 250 ″ in a line. The head modules 250 ′ or 250 ″ shown in FIG. This corresponds to the modules 12a and 12b.

  Note that the full-line print head for single pass printing is not limited to the case where the entire surface of the recording medium 124 is set as the drawing range, but when a part of the surface of the recording medium 124 is the drawing area (for example, paper In the case of providing a non-drawing area (margin part) around the periphery, it is only necessary to form nozzle rows necessary for drawing in a predetermined drawing area.

  The pressure chamber 252 provided corresponding to each nozzle 251 has a substantially square planar shape (see FIGS. 8A and 8B), and the nozzle 251 is provided at one of the diagonal corners. An outlet for supplying ink (supply port) 254 is provided on the other side. Note that the shape of the pressure chamber 252 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  As shown in FIG. 10, the head 250 (head modules 250 ′ and 250 ″) includes a nozzle plate 251A in which the nozzles 251 are formed, and a flow path plate 252P in which flow paths such as the pressure chambers 252 and the common flow path 255 are formed. The nozzle plate 251A constitutes a nozzle surface (ink ejection surface) 250A of the head 250, and a plurality of nozzles 251 communicating with the respective pressure chambers 252 are two-dimensionally formed. .

  The flow path plate 252P forms a side wall of the pressure chamber 252 and a flow path that forms a supply port 254 as a narrowed portion (most narrowed portion) of an individual supply path that guides ink from the common flow path 255 to the pressure chamber 252. It is a forming member. For convenience of explanation, although shown in FIG. 10 in a simplified manner, the flow path plate 252P has a structure in which one or a plurality of substrates are stacked.

  The nozzle plate 251A and the flow path plate 252P can be processed into a required shape by a semiconductor manufacturing process using silicon as a material.

  The common flow channel 255 communicates with an ink tank (not shown) as an ink supply source, and ink supplied from the ink tank is supplied to each pressure chamber 252 via the common flow channel 255.

  A piezo actuator (piezoelectric element) 258 having individual electrodes 257 is joined to a diaphragm 256 constituting a part of the pressure chamber 252 (the top surface in FIG. 10). The diaphragm 256 of this example is made of silicon (Si) with a nickel (Ni) conductive layer functioning as a common electrode 259 corresponding to the lower electrode of the piezoelectric actuator 258, and is arranged corresponding to each pressure chamber 252. It also serves as a common electrode for the actuator 258. It is also possible to form the diaphragm with a non-conductive material such as resin. In this case, a common electrode layer made of a conductive material such as metal is formed on the surface of the diaphragm member. Moreover, you may comprise the diaphragm which serves as a common electrode with metals (conductive material), such as stainless steel (SUS).

  By applying a driving voltage to the individual electrode 257, the piezo actuator 258 is deformed and the volume of the pressure chamber 252 is changed, and ink is ejected from the nozzle 251 due to the pressure change accompanying this. When the piezo actuator 258 returns to its original state after ink ejection, new ink is refilled into the pressure chamber 252 from the common channel 255 through the supply port 254.

  As shown in FIG. 8B, the ink chamber units 253 having such a structure are arranged in a fixed manner along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. By arranging a large number of patterns in a lattice pattern, the high-density nozzle head of this example is realized. In this matrix arrangement, when the interval between adjacent nozzles in the sub-scanning direction is Ls, in the main scanning direction, each nozzle 251 is substantially equivalent to a linear arrangement with a constant pitch P = Ls / tan θ. It can be handled.

  In the implementation of the present invention, the arrangement form of the nozzles 251 in the head 250 is not limited to the illustrated example, and various nozzle arrangement structures can be applied. For example, instead of the matrix arrangement described with reference to FIG. 18, a V-shaped nozzle arrangement, a zigzag nozzle arrangement (such as a W-shape) having a V-shaped arrangement as a repeating unit, or the like is also possible. .

  The means for generating the discharge pressure (discharge energy) for discharging the droplets from each nozzle in the inkjet head is not limited to the piezo actuator (piezoelectric element), but the thermal method (the pressure of film boiling due to the heating of the heater) Various pressure generating elements (ejection energy generating elements) such as heaters (heating elements) and other actuators based on other systems can be applied. Corresponding energy generating elements are provided in the flow path structure according to the ejection method of the head.

<Description of control system>
FIG. 11 is a principal block diagram showing the system configuration of the inkjet recording apparatus 100. The ink jet recording apparatus 100 includes a communication interface 270, a system controller 272, a print controller 274, an image buffer memory 276, a head driver 278, a motor driver 280, a heater driver 282, a processing liquid application controller 284, a drying controller 286, and a fixing control. 288, a memory 290, a ROM 292, an encoder 294, and the like.

  The communication interface 270 is an interface unit that receives image data sent from the host computer 350. As the communication interface 270, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 350 is taken into the inkjet recording apparatus 100 via the communication interface 270 and temporarily stored in the memory 290.

  The memory 290 is a storage unit that temporarily stores an image input via the communication interface 270, and data is read and written through the system controller 272. The memory 290 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 272 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 100 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 272 controls each unit such as the communication interface 270, the print control unit 274, the motor driver 280, the heater driver 282, the treatment liquid application control unit 284, the communication control with the host computer 350, and the memory 290. In addition to performing read / write control, a control signal for controlling the motor 296 and the heater 298 of the transport system is generated.

  The ROM 292 stores programs executed by the CPU of the system controller 272 and various data necessary for control. The ROM 292 may be a non-rewritable storage unit or a rewritable storage unit such as an EEPROM. The memory 290 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU.

  The motor driver 280 is a driver that drives the motor 296 in accordance with instructions from the system controller 272. In FIG. 11, various motors arranged in each part in the apparatus are represented by a reference numeral 296. For example, the motor 296 shown in FIG. 11 includes a motor for driving rotation of the paper feed drum 152, the processing liquid drum 154, the drawing drum 170, the drying drum 176, the fixing drum 184, the transfer drum 194, and the like. A pump drive motor for sucking negative pressure from the suction hole, a retraction mechanism motor for moving the head units of the inkjet heads 172M, 172K, 172C, and 172Y to the maintenance area outside the drawing drum 170, and the like. .

  The heater driver 282 is a driver that drives the heater 298 in accordance with an instruction from the system controller 272. In FIG. 11, various heaters arranged in each part in the apparatus are represented by reference numeral 298 as a representative. For example, the heater 298 shown in FIG. 11 includes a preheater (not shown) for heating the recording medium 124 to an appropriate temperature in the paper feeding unit 112 in advance.

  The print control unit 274 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the memory 290 according to the control of the system controller 272, and the generated print A control unit that supplies data (dot data) to the head driver 278.

  The dot data is generally generated by performing color conversion processing and halftone processing on multi-tone image data. In the color conversion process, image data expressed in sRGB or the like (for example, 8-bit image data for each RGB color) is converted into color data for each color of ink used in the inkjet recording apparatus 100 (in this example, KCMY color data). It is a process to convert.

  The halftone process is a process of converting the color data of each color generated by the color conversion process into dot data of each color (KCMY dot data in this example) by processes such as an error diffusion method and a threshold matrix.

  Necessary signal processing is performed in the print control unit 274, and the ejection amount and ejection timing of the ink droplets of the head 250 are controlled via the head driver 278 based on the obtained dot data. Thereby, a desired dot size and dot arrangement are realized. The dot data here corresponds to “nozzle control data”.

  The print control unit 274 includes an image buffer memory (not shown), and image data, parameters, and other data are temporarily stored in the image buffer memory when the print control unit 274 processes image data. Also possible is an aspect in which the print control unit 274 and the system controller 272 are integrated to form a single processor.

  An overview of the flow of processing from image input to print output is as follows. Image data to be printed is input from the outside via the communication interface 270 and stored in the memory 290. At this stage, for example, RGB image data is stored in the memory 290. In the inkjet recording apparatus 100, a pseudo continuous tone image is formed by changing the droplet ejection density and the dot size of fine dots by ink (coloring material) to the human eye. It is necessary to convert to a dot pattern that reproduces the gradation (shading of the image) as faithfully as possible. Therefore, the original image (RGB) data stored in the memory 290 is sent to the print control unit 274 via the system controller 272, and the print control unit 274 performs halftoning processing using a threshold matrix, an error diffusion method, or the like. Is converted into dot data for each ink color. In other words, the print control unit 274 performs processing for converting the input RGB image data into dot data of four colors K, C, M, and Y. Thus, the dot data generated by the print control unit 274 is stored in an image buffer memory (not shown).

  The head driver 278 outputs a drive signal for driving an actuator corresponding to each nozzle of the head 250 based on print data (that is, dot data stored in the image buffer memory 276) given from the print control unit 274. . The head driver 278 may include a feedback control system for keeping the head driving condition constant.

  When the drive signal output from the head driver 278 is applied to the head 250, ink is ejected from the corresponding nozzle. An image is formed on the recording medium 124 by controlling ink ejection from the head 250 while conveying the recording medium 124 at a predetermined speed. Note that the inkjet recording apparatus 100 shown in this example applies a common drive power waveform signal in units of modules to each piezoelectric actuator 258 of the head 250 (head module), and according to the ejection timing of each piezoelectric actuator 258. A drive system is employed in which ink is ejected from the nozzles 251 corresponding to each piezo actuator 258 by switching on / off of switch elements (not shown) connected to individual electrodes of each piezo actuator 258.

  The head driver 278 and the print controller 274 (with built-in image buffer memory) correspond to the head controller 20 described with reference to FIG. Further, the system controller 272 of FIG. 11 corresponds to the upper data control unit 30 described with reference to FIG.

  The treatment liquid application control unit 284 controls the operation of the treatment liquid application device 156 (see FIG. 7) in accordance with an instruction from the system controller 272. The drying control unit 286 controls the operation of the solvent drying device 178 (see FIG. 7) in accordance with an instruction from the system controller 272.

  The fixing control unit 288 controls the operation of the fixing pressure unit 299 including the halogen heater 186 and the fixing roller 188 (see FIG. 7) of the fixing unit 120 according to an instruction from the system controller 272.

  As described with reference to FIG. 7, the in-line sensor 190 is a block including an image sensor, reads an image printed on the recording medium 124, performs necessary signal processing, etc. Variation, optical density, etc.) are detected, and the detection results are provided to the system controller 272 and the print controller 274.

  The print controller 274 performs various corrections (non-ejection correction, density correction, etc.) on the head 250 based on information obtained from the in-line sensor 190, and cleaning operations (nozzles, etc.) such as preliminary ejection, suction, and wiping as necessary. Control to implement recovery operation).

[Modification]
In the above embodiment, an ink jet recording apparatus of a method (direct recording method) in which an ink droplet is directly formed on the recording medium 124 has been described. However, the scope of application of the present invention is not limited to this, and once, The present invention is also applied to an intermediate transfer type image forming apparatus that forms an image (primary image) on an intermediate transfer member and transfers the image onto a recording sheet in a transfer unit to form a final image. be able to.

  Further, in the above embodiment, an inkjet recording apparatus using a page-wide full-line head having a nozzle row having a length corresponding to the entire width of the recording medium (single-pass image for completing an image by one sub-scanning). However, the scope of application of the present invention is not limited to this, and an inkjet that performs image recording by scanning a plurality of heads while moving a short recording head such as a serial (shuttle scan) head. The present invention can also be applied to a recording apparatus.

<Means for moving the head and paper relative to each other>
In the above-described embodiment, the configuration in which the recording medium is transported to the stopped head is exemplified. However, in the implementation of the present invention, a configuration in which the head is moved with respect to the stopped recording medium (the drawing medium) is also possible. is there.

<Application examples of the present invention>
In the above embodiment, application to an inkjet recording apparatus for graphic printing has been described as an example, but the scope of application of the present invention is not limited to this example. For example, a wiring drawing apparatus for drawing a wiring pattern of an electronic circuit, a manufacturing apparatus for various devices, a resist printing apparatus that uses a resin liquid as a functional liquid for ejection, a color filter manufacturing apparatus, and a material deposition material. The present invention can be widely applied to an inkjet system that draws various shapes and patterns using a liquid functional material, such as a fine structure forming apparatus that forms a structure.

  DESCRIPTION OF SYMBOLS 10 ... Print head, 12a, 12b ... Head module, 20 ... Head control part, 22 ... Image data memory, 24 ... Image data transfer control circuit, 26 ... Waveform data memory, 28 ... Drive voltage control circuit, 30 ... High-order data control , 42 ... Data bus, 100 ... Inkjet recording apparatus, 124 ... Recording medium, 170 ... Drawing drum, 172M, 172K, 172C, 172Y ... Inkjet head, 190 ... Inline sensor, 250 ... Head, 251 ... Nozzle, 272 ... System Controller, 274 ... Print control unit, 294 ... Encoder

Claims (10)

A head control device that is connected to a recording head in which a plurality of head modules having a plurality of nozzles and ejection energy generating elements corresponding to the nozzles are arranged, and controls the ejection of droplets from each nozzle of the recording head. There,
A data transfer control circuit that outputs nozzle control data for controlling the ejection operation of the nozzles in each head module to the plurality of head modules in a time division manner in units of head modules;
A data bus shared for the plurality of head modules as a signal transmission path for commonly transmitting the nozzle control data signal output from the data transfer control circuit to the plurality of head modules;
In order to set the nozzle control data for each head module, which is commonly supplied from the data transfer control circuit to the head modules via the data bus, as the nozzle control data for the corresponding head module, the corresponding head A latch signal transmission circuit that outputs a data latch signal at a timing according to the module;
A drive voltage output circuit for outputting a drive voltage signal for driving the ejection energy generating element of each head module;
A head control device comprising: In claim 1,
The head control apparatus according to claim 1, wherein the recording head is a line type head that is elongated by arranging the plurality of head modules in a width direction of a drawing medium. In claim 1 or 2,
Data communication means for performing data communication with the host control device;
First storage means for storing image data acquired from the host controller via the data communication means;
Second storage means for storing waveform data of the drive voltage signal;
A head control device comprising: In any one of Claims 1 thru | or 3,
The head control apparatus, wherein the drive voltage signal is individually set for each of the plurality of head modules, and the drive voltage signal is sent by an individual signal line for each head module. In any one of Claims 1 thru | or 3,
A head control apparatus, wherein the common drive voltage signal is applied to the plurality of head modules. In any one of Claims 1 thru | or 5,
The nozzle control data is transferred to each of the head modules in units of recording resolution. In claim 6,
The head control device according to claim 1, wherein the nozzle control data of each head module is flowed on the data bus as a data signal sequence arranged in time order in module units according to a discharge trigger signal in pixel units corresponding to recording resolution. In any one of Claims 1 thru | or 7,
The data transfer control circuit has means for changing the transfer order of nozzle control data for each head module;
The head control device according to claim 1, wherein the latch signal transmission circuit transmits a data latch signal for the corresponding head module in accordance with the changed transfer order. A head control device according to any one of claims 1 to 8;
An inkjet recording apparatus comprising the recording head. In claim 9,
The head control device is connected to a host control device so that data communication is possible,
An ink jet recording apparatus, wherein waveform data of the drive voltage signal and the nozzle control data necessary for image formation are transferred from the host control apparatus to the head control apparatus.

Images