JP2018001639A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording device including a recording head that is further light weight and has further reduced calorific value to operate while reducing impact to recording quality.SOLUTION: A printer 100 includes: a print head 13 for recording on a roll sheet 5; a drive signal generating circuit 37 for generating a drive waveform for driving the print head 13 to drive the print head 13 via a cable 60; and a correction drive circuit 61 (61A, 61B) for correcting and driving the drive waveform that is supplied from the cable 60. The correction drive circuit 61 is installed on a side of the print head 13 relative to the cable 60.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a recording apparatus equipped with a recording head for recording on a recording medium.

Inkjet printers as recording devices have become increasingly finer, higher quality, and larger in size due to the expansion of applications, and the number of nozzles associated with the finer (higher density) nozzles mounted on recording heads has increased. The size of the recording head is increasing.
Along with the increase in size of the apparatus, the cable connecting the recording head and the drive signal generation circuit becomes long, and deterioration and distortion of the driving waveform supplied to the recording head becomes a problem. Therefore, Patent Document 1 describes a technique for improving drive waveform distortion.

JP 2003-305843 A

  However, the technique for improving the distortion of the driving waveform described in Patent Document 1 is to improve the distortion of the waveform by using a passive element such as a resistance element or a coil element, and the resistance of the cable is reduced. Since it was necessary to keep it low, there was a limit to dealing with the lengthening of the cable as the recording apparatus and recording head further increased in size. That is, in order to apply a high-voltage driving waveform to the recording head as a waveform with less distortion (deterioration), it is necessary to drive the driving waveform by an active element or the like closer to the recording head. However, there is a problem in that it is necessary to suppress an increase in the weight of the recording head due to the circuit that drives the driving waveform and the influence on the recording quality due to the heat generation of the circuit.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A recording apparatus according to this application example generates a recording head that performs recording on a recording medium, a drive waveform that drives the recording head, and drives the recording head via a cable. And a second drive circuit that corrects and drives the drive waveform supplied by the cable, and the second drive circuit is provided closer to the recording head than the cable. And

According to this application example, the recording apparatus generates a driving waveform for driving the recording head, and corrects and drives the first driving circuit for driving the recording head via the cable and the driving waveform supplied by the cable. And a second drive circuit. Therefore, a drive waveform that is distorted (deteriorated) when supplied through a cable can be corrected by the second drive circuit.
Further, the second drive circuit is provided on the recording head side with respect to the cable. That is, the circuit for driving the recording head includes a first drive circuit that is driven via a cable and a second drive circuit that is driven without a cable. Therefore, the recording head can be configured to be lighter than when the drive circuit is mounted only on the recording head.
In addition, by separating the drive circuit, the heat generated by driving the drive circuit can be dispersed to a distant position via the cable. Therefore, as compared with the case where the drive circuit is mounted only on the recording head, it is possible to suppress the recording head from becoming high temperature and to reduce the influence on the recording quality.

  Application Example 2 In the recording apparatus according to the application example, the cable supplies a first drive signal line for supplying the drive waveform from the first drive circuit to the recording head, and the drive waveform is supplied to the first drive circuit. And a second drive signal line supplied to the second drive circuit.

  According to this application example, the cable supplies the drive waveform from the first drive circuit to the recording head, and the second drive signal line that supplies the drive waveform from the first drive circuit to the second drive circuit. And have. Since the second drive signal line is separated from the circuit for driving the recording head, the input impedance from the first drive circuit to the second drive circuit can be made higher. By configuring the input impedance to the second drive circuit higher, distortion (deterioration) of the drive waveform supplied to the second drive circuit via the second drive signal line can be further reduced. That is, a driving waveform with less distortion (deterioration) can be supplied to the second driving circuit provided on the recording head side with respect to the cable. Therefore, the second drive circuit can correct and drive the drive waveform supplied to the recording head by using the drive waveform with the smaller distortion (deterioration) as a reference.

  Application Example 3 In the recording apparatus according to the application example described above, an output of the second drive circuit that drives the recording head is connected to an output of the first drive circuit that drives the recording head. And

  According to this application example, a circuit for driving the recording head can be simply configured by the first drive circuit and the second drive circuit.

  Application Example 4 In the recording apparatus according to the application example, the recording head is mounted, and includes a carriage that moves separately from the first drive circuit disposed via the cable, and the carriage includes the second driving circuit. A drive circuit is mounted.

  According to this application example, the recording apparatus includes the recording head and the second drive circuit, and includes a carriage that moves separately from the first drive circuit. That is, by disposing the first drive circuit separately from the second drive circuit, the recording head can be configured as a serial head that is lighter and suppressed from becoming hot.

1 is a front view illustrating a configuration of a recording apparatus according to a first embodiment. 1 is a block diagram illustrating a configuration of a recording apparatus according to a first embodiment. Illustration of basic functions of the printer driver Schematic diagram showing an example of nozzle arrangement viewed from the bottom of the print head Cross section of the main part of the print head Block diagram schematically showing the drive control system of the print head in the prior art Waveform diagram schematically showing an example of the waveform of the drive signal generated by the drive signal generation circuit and the drive signal of the signal supply destination via the cable Block diagram for explaining an example of the configuration of a drive control system for driving a print head Circuit diagram showing a specific example of the correction drive circuit Block diagram for explaining a modification of the print head drive control system

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding. Further, in the coordinates added 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 left-right direction, The XY plane is a horizontal plane.

(Embodiment 1)
FIG. 1 is a front view showing a configuration of a printer 100 as a recording apparatus according to the first embodiment, and FIG. 2 is a block diagram of the same.
The printer 100 constitutes the printing system 1 together with the image processing apparatus 110 connected to the printer 100. Based on print data including pixel data received from the image processing apparatus 110, the printer 100 prints a desired image on the roll paper 5 as a long “recording medium” supplied in a rolled state. This is an ink jet printer for recording (hereinafter referred to as printing).

<Basic configuration of image processing apparatus>
The image processing apparatus 110 includes a printer control unit 111, an input unit 112, a display unit 113, a storage unit 114, and the like, and controls a print job that causes the printer 100 to perform printing. The image processing apparatus 110 is configured using a personal computer as a preferred example.
Software that operates the image processing apparatus 110 includes general image processing application software (hereinafter referred to as an application) that handles image data to be printed, print data for controlling the printer 100 and causing the printer 100 to execute printing. Includes printer driver software to be generated (hereinafter referred to as printer driver).

The printer control unit 111 includes a CPU (Central Processing Unit) 115, an ASIC (Application Specific Integrated Circuit) 116, a DSP (Digital Signal Processor) 117, a memory 118, a printer interface unit (I / F) 119, and the like. 1. Centralized management of the whole.
The input unit 112 is information input means as a human interface. Specifically, for example, a port to which a keyboard or an information input device is connected.
The display unit 113 is an information display unit (display) as a human interface, and is related to information input from the input unit 112, an image to be printed on the printer 100, and a print job under the control of the printer control unit 111. Information etc. are displayed.
The storage unit 114 is a rewritable storage medium such as a hard disk drive (HDD) or a memory card. The storage unit 114 stores software (a program operated by the printer control unit 111) that operates the image processing apparatus 110, images to be printed, and print jobs. Related information and the like are stored.
The memory 118 is a storage medium that secures an area for storing a program for the CPU 115 to operate, a work area for the operation, and the like, and includes a storage element such as a RAM or an EEPROM.

<Basic configuration of printer 100>
The printer 100 includes a printing unit 10, a moving unit 20, a control unit 30, and the like. The printer 100 that has received the print data from the image processing apparatus 110 controls the printing unit 10 and the moving unit 20 by the control unit 30 to print an image on the roll paper 5 (image formation).
For the print data, for example, general image data (for example, RGB digital image information) obtained by a digital camera or the like is converted so that it can be printed by the printer 100 by an application and printer driver included in the image processing apparatus 110. This is data for image formation, 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 scanning unit 40, a transport unit 50, and the like. The scanning unit 40 includes a carriage 41, a guide shaft 42, a carriage motor (not shown), and the like. The conveyance unit 50 includes a supply unit 51, a storage unit 52, a conveyance roller 53, a platen 55, and the like.

  The head unit 11 includes a print head 13 as a “recording head” and a head control unit 14 having a plurality of nozzles (nozzle rows) that eject printing ink (hereinafter referred to as ink) as ink droplets. The head unit 11 is mounted on the carriage 41 and reciprocates in the scanning direction along with the carriage 41 moving in the scanning direction (X-axis direction shown in FIG. 1). While the head unit 11 (printing head 13) moves in the scanning direction, the ink droplets are ejected onto the roll paper 5 supported by the platen 55 under the control of the control unit 30 to thereby form a row of dots along the scanning direction. (Raster line) is formed on the roll paper 5.

The ink supply unit 12 includes an ink tank and an ink supply path (not shown) that supplies ink from the ink tank to the print head 13.
As the ink, for example, as an ink set made of a dark ink composition, a four-color ink set obtained by adding black (K) to a three-color ink set of cyan (C), magenta (M), and yellow (Y), etc. There is. Further, for example, eight colors including ink sets such as light cyan (Lc), light magenta (Lm), light yellow (Ly), and light black (Lk) made of a light ink composition in which the density of each color material is lightened. There are ink sets. 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 a method for ejecting ink droplets (inkjet method). The piezo method is a method in which a pressure corresponding to a print information signal is applied to ink stored in a pressure chamber by a piezoelectric element (piezo element), and ink droplets are ejected (discharged) from a nozzle communicating with the pressure chamber for printing.

The moving unit 20 (scanning unit 40, conveying unit 50) moves the roll paper 5 relative to the printing unit 10 under the control of the control unit 30.
The guide shaft 42 extends in the scanning direction and supports the carriage 41 in a slidable contact state, and the carriage motor serves as a driving source for reciprocating the carriage 41 along the guide shaft 42. That is, the scanning unit 40 (carriage 41, guide shaft 42, carriage motor) moves the carriage 41 (that is, the print head 13) in the scanning direction along the guide shaft 42 under the control of the control unit 30.

The supply unit 51 rotatably supports a reel on which the roll paper 5 is wound in a roll shape, and sends the roll paper 5 to the conveyance path. The storage unit 52 rotatably supports a reel that winds up the roll paper 5, and winds up the roll paper 5 that has been printed from the conveyance path.
The transport roller 53 includes a drive roller that moves the roll paper 5 in the transport direction (Y-axis direction shown in FIG. 1) that intersects the scanning direction, a driven roller that rotates as the roll paper 5 moves, and the like. Is conveyed from the supply unit 51 to the storage unit 52 via the printing region of the printing unit 10 (the region in which the print head 13 scans and moves on the upper surface of the platen 55).

The control unit 30 includes an interface unit (I / F) 31, a CPU (Central Processing Unit) 32, a memory 33, a drive control unit 34, 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 image processing apparatus 110 and the printer 100 may be directly connected by a cable or the like, or may be indirectly connected via a network or the like. Further, data transmission / reception may be performed between the image processing apparatus 110 and the printer 100 via wireless communication.
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 the CPU 32 to operate, a work area for the operation, and the like, and includes 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 drive control unit 34 controls the drive of the printing unit 10 (head unit 11 and ink supply unit 12) and the moving unit 20 (scanning unit 40 and transport unit 50) based on the control of the CPU 32. The drive control unit 34 includes a movement control signal generation circuit 35, a discharge control signal generation circuit 36, and a drive signal generation circuit 37 as a “first drive circuit”.
The movement control signal generation circuit 35 is a circuit that generates a signal for controlling the movement unit 20 (scanning unit 40, conveyance unit 50) in accordance with an instruction from the CPU 32.
The discharge control signal generation circuit 36 and the drive signal generation circuit 37 will be described later.

  With the above configuration, the control unit 30 moves the carriage 41 that supports the print head 13 along the guide shaft 42 with respect to the roll paper 5 supplied to the printing region by the conveyance unit 50 (the supply unit 51 and the conveyance roller 53). An operation of ejecting ink droplets from the print head 13 while moving in the scanning direction (X-axis direction), and an operation of moving the roll paper 5 in the transport direction (+ Y direction) intersecting the scanning direction by the transport unit 50 (transport roller 53). Is repeated to form (print) a desired image on the roll paper 5.

<Basic functions of the printer driver>
FIG. 3 is an explanatory diagram of the basic functions of the printer driver.
Printing on the roll paper 5 is started when print data is transmitted 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 image data (for example, text data or full-color image data) from the application, converts the print data into a format that can be interpreted by the printer 100, 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 for converting the image data output from the application into a resolution (printing resolution) when printing on the roll paper 5. For example, when the print resolution is specified as 720 × 720 dpi, the vector format image data received from the application is converted into bitmap format image data with a resolution of 720 × 720 dpi. Each pixel data of the image data after the resolution conversion process is composed of pixels arranged in a matrix. Each pixel has a gradation value of, for example, 256 gradations in the RGB color space. That is, the pixel data after resolution conversion indicates the gradation value of the corresponding pixel.
Pixel data corresponding to one column of pixels arranged in a predetermined direction among pixels arranged in a matrix is called raster data. The predetermined direction in which the pixels corresponding to the raster data are arranged corresponds to the moving direction (scanning direction) of the print head 13 when printing an image.

The color conversion process is a process for 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 color that the printer 100 has. Therefore, for example, when the printer 100 uses 10 types of inks of the CMYK color system, the printer driver generates image data in a 10-dimensional space of the CMYK color system based on the RGB data.
This color conversion processing is performed based on a table (color conversion lookup table LUT) in which gradation values of RGB data and gradation values of CMYK color system data are associated with each other. Note that 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 high gradation number (256 gradations) data into gradation number data that can be formed by the printer 100. By this halftone processing, data indicating 256 gradations indicates, for example, 1-bit data indicating 2 gradations (with or without dots) or 4 gradations (without dots, small dots, medium dots, large dots). Converted to 2-bit data. Specifically, from the dot generation rate table corresponding to the gradation value (0 to 255) and the dot generation rate, the dot generation rate corresponding to the gradation value (for example, in the case of 4 gradations, no dot, small Pixel data is created so that dots are formed in a dispersed manner using the dither method, error diffusion method, etc. at the obtained generation rate. The

  The rasterizing process is a process of rearranging pixel data arranged in a matrix (for example, 1-bit or 2-bit data as described above) according to the dot formation order at the time of printing. The rasterizing process includes a path allocating process in which image data composed of pixel data after halftone processing is allocated to each path in which ink droplets are ejected while the print head 13 (nozzle array) scans and moves. When the pass assignment is completed, the actual nozzles forming each raster line constituting the print image are assigned.

The command addition process is a process for adding command data corresponding to the printing method to the rasterized data. The command data includes, for example, transport data related to the transport specifications of the medium (the amount of movement in the transport direction, the speed, etc.).
These processes by the printer driver are performed by the ASIC 116 and the DSP 117 (see FIG. 2) under the control of the CPU 115, and the generated print data is transmitted to the printer 100 via the printer interface unit 119 by the print data transmission process. Is done.

<Nozzle row>
FIG. 4 is a schematic diagram illustrating an example of the arrangement of nozzles as viewed from the lower surface of the print head 13.
As shown in FIG. 4, the print head 13 has a nozzle row in which a plurality of nozzles for ejecting ink of each color are formed side by side (in the example shown in FIG. 4, 400 nozzles # 1 to # 400, respectively). A black ink nozzle row K, a cyan ink nozzle row C, a magenta ink nozzle row M, a yellow ink nozzle row Y, a gray ink nozzle row LK, and a light cyan ink nozzle row LC).

  The plurality of nozzles in each nozzle row are aligned and arranged at regular intervals (nozzle pitch) along the transport direction (Y-axis direction). In addition, the plurality of nozzle rows are aligned and arranged in parallel with each other at a constant interval (nozzle row pitch) along a direction (X-axis direction) intersecting the transport direction. In FIG. 4, the nozzles in each nozzle row are assigned a lower number as the nozzles on the downstream side (# 1 to # 400). That is, the nozzle # 1 is located downstream of the nozzle # 400 in the transport direction. Each nozzle is provided with a drive element (the above-described piezo element) for driving each nozzle to eject ink droplets.

FIG. 5 is a cross-sectional view of the main part of the print head 13.
The print head 13 includes a vibration plate 71, a piezoelectric actuator 72 as a pressure generating unit that displaces the vibration plate 71, and a pressure chamber in which ink is filled and the internal pressure is increased or decreased by the displacement of the vibration plate 71. And a nozzle 74 that communicates with the cavity 73 and discharges ink as droplets by increasing or decreasing the pressure in the cavity 73.

  The nozzle 74 is formed in the nozzle plate 75, and a cavity 73 and a reservoir 78 communicating with the ink through the ink supply port 83 are formed by the cavity substrate 76 positioned so as to be sandwiched between the nozzle plate 75 and the vibration plate 71. ing. The reservoir 78 communicates with an ink tank (not shown) via an ink supply path.

  The actuator 72 includes comb-shaped electrodes 79a and 79b arranged opposite to each other, and piezoelectric elements 77 (piezo elements) alternately stacked with the comb teeth of the electrodes 79a and 79b. As shown in FIG. 5, the actuator 72 has one end fixed to a fixed plate 81 fixed to the housing 80 of the print head 13 and the other end connected to a vibration plate via a joining plate 82. 71 is joined.

  In the actuator 72 having such a configuration, by applying a drive signal between the electrodes 79a and 79b, the diaphragm 71 is moved up and down as shown by arrows in FIG. Thus, the ink inside the cavity 73 can be vibrated, or ink droplets can be ejected from the nozzles 74.

<Print head drive control>
Next, the drive control of the print head 13 will be described with reference to FIG. FIG. 6 is a block diagram for explaining an example of the configuration in the prior art of the drive control system for driving the print head 13.
As described above, the drive control unit 34 includes the ejection control signal generation circuit 36 and the drive signal generation circuit 37, and drives and controls the head unit 11 (head control unit 14 and print head 13).
The ejection control signal generation circuit 36 generates a head control signal for selecting a nozzle for ejecting ink, selecting an ejection amount, controlling ejection timing, and the like according to an instruction from the CPU 32 based on the print data. It is.
The drive signal generation circuit 37 is a circuit that generates a basic drive signal including a drive signal as a “drive waveform” for driving the actuator 72 (piezoelectric element 77) of the print head 13.
The drive control unit 34 selectively drives the actuator 72 (piezoelectric element 77) corresponding to each nozzle 74 based on the head control signal and the basic drive signal.

The head control signal includes drive pulse selection data SI & SP, clock signal CLK, latch signal LAT, channel signal CH, and the like.
The drive pulse selection data SI & SP includes pixel data SI designating the piezoelectric elements 77 corresponding to the nozzles to which ink droplets are to be ejected and waveform pattern data SP of the drive signal COM relating 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 in response to the latch signal LAT, and a drive pulse PS is output for each channel signal CH.

Among the basic drive signals, the drive signal COM shown in FIG. 6 is a basic signal for ejecting ink from the nozzles 74 by driving the actuator 72 and causing pressure fluctuations in the ink in the cavity 73 (see FIG. 5). It is.
Among the basic drive signals, the base signal VBS shown in FIG. 6 is a signal that gives a reference potential for applying the drive pulse PS to the piezoelectric element 77 due to a potential difference with the drive signal COM.
Note that the basic drive signal includes a basic signal (not shown) for driving the actuator 72 to apply fine vibration to the ink in the cavity 73.

The head controller 14 includes a shift register 91, a latch circuit 92, a level shifter 93, a selection switch 94, and the like.
The drive register selection data SI & SP is sequentially input to the shift register 91, and the storage area is sequentially shifted from the first stage to the subsequent stage in accordance with the input pulse of the clock signal CLK. The latch circuit 92 latches each output signal of the shift register 91 by the input latch signal LAT after the drive pulse selection data SI & SP for the number of nozzles is stored in the shift register 91. The signal stored in the latch circuit 92 is converted by the level shifter 93 into a voltage level that can turn on / off (connect / cut off) the selection switch 94 in the next stage. This is because the drive signal COM is higher than the output voltage of the latch circuit 92, and the operating voltage range of the selection switch 94 is set higher accordingly. Accordingly, the piezoelectric element 77 connected with the selection switch 94 turned on by the level shifter 93 is connected to the drive signal COM at the connection timing of the drive pulse selection data SI & SP. That is, the drive pulse PS is applied to the piezoelectric element 77.

  After the drive pulse selection data SI & SP of the shift register 91 is stored in the latch circuit 92, the next print information is input to the shift register 91, and the stored data in the latch circuit 92 is sequentially updated in accordance with the liquid ejection timing. . Even after the selection switch 94 disconnects the piezoelectric element 77 from the drive signal COM (drive pulse PS), the input voltage of the piezoelectric element 77 is maintained at the voltage just before disconnection.

In order to reduce the weight of the head unit 11, the ejection control signal generation circuit 36 and the drive signal generation circuit 37 are provided outside (the printer 100 main body) separate from the head unit 11, and the head control signal and the basic drive signal are It is configured to be supplied via a cable 60. That is, the head control signal and the basic drive signal are generated by the drive control unit 34 and transmitted to the print head 13 via the cable 60 and the head control unit 14.
As the cable 60, a flexible flat cable is used as a preferred example.

  According to the drive control system of the print head 13 in the related art described above, there is a problem that the degree of distortion (deterioration) of the transmitted signal increases as the cable 60 becomes longer. In particular, the distortion (deterioration) of the drive waveform (drive signal COM) for driving the print head 13 becomes the distortion (deterioration) of the drive pulse PS based on this (that is, the deterioration of the ink ejection characteristics), which directly affects the print quality. In order to provide this, various corresponding technologies have been studied.

FIG. 7 shows the drive signal COM (COMi) generated by the drive signal generation circuit 37 and the drive signal COM (COMo, that is, the print head) that is input to the signal supply destination selection switch 94 via the cable 60 and selected. It is a wave form diagram which shows typically an example of a waveform of drive pulse PS) applied to 13 actuators 72 (piezoelectric element 77).
For example, the drive signal COMo (drive pulse PS) may be applied as a waveform with an overshoot as shown in FIG. 7 due to the influence of the inductance and capacitance of the cable 60. Such distortion (deterioration) of the waveform not only directly affects the print quality but also, for example, when the voltage waveform exceeds the absolute maximum rating of the elements constituting the selection switch 94 and the actuator 72, There was also a risk that the device would be destroyed.
In the present embodiment, on the other hand, a correction drive circuit 61 as a “second drive circuit” for correcting and driving the drive signal COM supplied by the cable 60 is provided.
This will be specifically described below.

  FIG. 8 is a block diagram illustrating an example of a configuration of a drive control system that drives the print head 13 in the present embodiment. The head control signal shown in FIG. 6 is not shown. The circuit from the shift register 91 controlled by the head control signal generation and the head control signal to the output of the level shifter 93 is the same as the prior art shown in FIG.

In the present embodiment, the cable 60 that connects the drive control unit 34 and the head control unit 14 includes a first drive signal line 62A, a second drive signal line 63A, a first drive signal line 62B, and a second drive signal line 63B. Have.
As shown in FIG. 8, the first drive signal line 62 </ b> A includes a terminal that outputs a drive signal COM (drive waveform) in the drive control unit 34, and a terminal connected to the input of the selection switch 94 in the head control unit 14. And connected. The output of the selection switch 94 is connected to the print head 13 (one electrode of the piezoelectric element 77).
The second drive signal line 63A connects the terminal from which the drive signal COM (drive waveform) is output in the drive controller 34 and the terminal connected to the input of the correction drive circuit 61A in the head controller 14. . The output of the correction drive circuit 61A is connected to the input of the selection switch 94.
The first drive signal line 62B connects a terminal from which the base signal VBS is output in the drive control unit 34 and a terminal connected to the print head 13 (the other electrode of the piezoelectric element 77) in the head control unit 14. ing.
The second drive signal line 63B connects a terminal from which the base signal VBS is output in the drive control unit 34 to a terminal connected to the input of the correction drive circuit 61B in the head control unit 14. The output of the correction drive circuit 61B is connected to the print head 13 (the other electrode of the piezoelectric element 77).

  Here, with respect to the drive signal COM supplied through the first drive signal line 62A, the drive signal supplied through the second drive signal line 63A is referred to as a drive signal COMr. Further, the base signal supplied through the second drive signal line 63B is referred to as a base signal VBSr with respect to the base signal VBS supplied through the first drive signal line 62B.

The correction drive circuit 61A is a circuit provided in the head controller 14 (that is, a circuit provided closer to the print head 13 than the cable 60), and the cable 60 (first drive) with reference to the drive signal COMr. The drive signal COM supplied by the signal line 62A) is corrected, and the selected switch 94 is turned on to drive the selected actuator 72 (piezoelectric element 77).
Similarly, the correction drive circuit 61B is a circuit provided in the head control unit 14 (that is, a circuit provided closer to the print head 13 than the cable 60), and uses the cable 60 (with the base signal VBSr as a reference). The base signal VBS supplied by the first drive signal line 62B) is corrected and supplied to the actuator 72 (piezoelectric element 77).

As the correction drive circuit 61 (61A, 61B), a voltage follower as shown in FIG. 9 is used as a preferred example. By using a voltage follower with high input impedance, the output is driven to the value of the drive signal COMr or base signal VBSr with reference to the input signal (drive signal COMr or base signal VBSr) in which distortion (deterioration) is further suppressed. be able to. That is, the distorted (deteriorated) drive signal COM and base signal VBS supplied by the cable 60 can be corrected to the drive signal COMr and base signal VBSr in which distortion (deterioration) is further suppressed.
The power (VDD, VEE) for driving the correction drive circuit 61 (voltage follower) is supplied by a cable 60 as shown in FIG.

As shown in FIG. 8, the output of the correction driving circuit 61A is output to the wiring terminal (the print head 13 (one of the piezoelectric elements 77) via the selection switch 94) connected to the first driving signal line 62A to which the driving signal COM is supplied. Terminal) connected to the electrode). That is, the print head 13 (one electrode of the piezoelectric element 77) is driven by the drive signal generation circuit 37 (first drive circuit) and the correction drive circuit 61A (second drive circuit).
Further, as shown in FIG. 8, the output of the correction drive circuit 61B is output to a wiring terminal (print head 13 (the other electrode of the piezoelectric element 77)) to which the first drive signal line 62B to which the base signal VBS is supplied is connected. Connected terminal). That is, the print head 13 (the other electrode of the piezoelectric element 77) is driven by the drive signal generation circuit 37 (first drive circuit) and the correction drive circuit 61B (second drive circuit).

As described above, the printer 100 (recording apparatus) of the present embodiment includes the print head 13 (recording head) that performs recording (printing) on the roll paper 5 (recording medium) and the drive signal COM that drives the print head 13. A driving signal generation circuit 37 (first driving circuit) that generates (driving waveform) and drives the print head 13 via the cable 60, and a correction driving circuit that corrects and drives the driving signal COM supplied by the cable 60. 61 (second drive circuit), and the correction drive circuit 61 (61A, 61B) is provided closer to the print head 13 than the cable 60.
Further, the cable 60 supplies a drive signal COM (drive waveform) from the drive signal generation circuit 37 (first drive circuit) to the print head 13 (recording head), and a drive signal COM (drive waveform). ) From the drive signal generation circuit 37 (first drive circuit) to the correction drive circuit 61A (second drive circuit).

According to the recording apparatus of the present embodiment, the following effects can be obtained.
The printer 100 generates a drive signal COM (drive waveform) for driving the print head 13 and corrects the drive signal generation circuit 37 for driving the print head 13 via the cable 60 and the drive waveform supplied by the cable 60. And a correction drive circuit 61A for driving. Therefore, the drive signal COM (drive waveform) that is distorted (deteriorated) when supplied via the cable 60 can be corrected by the correction drive circuit 61A.
Further, a correction drive circuit 61B for correcting the base signal VBS supplied by the cable 60 is provided. Therefore, the reference potential (base signal VBS) that becomes unstable as the print head 13 is driven can be stabilized by the correction drive circuit 61B.

Further, the correction drive circuit 61A is provided on the print head 13 side with respect to the cable 60. In other words, the circuit that drives the print head 13 includes a drive signal generation circuit 37 that is driven via the cable 60 and a correction drive circuit 61 that is driven without the cable 60. Therefore, the print head 13 can be configured to be lighter than when the drive circuit is mounted only on the print head 13.
In addition, by separating the drive circuit, the heat generated by driving the drive circuit can be dispersed to a distant position via the cable 60. Therefore, compared with the case where the drive circuit is mounted only on the print head 13, it is possible to suppress the print head 13 from becoming high temperature, and to reduce the influence on the recording quality.

  Further, according to the present embodiment, the cable 60 drives the first drive signal line 62 </ b> A that supplies the drive signal COM (drive waveform) from the drive signal generation circuit 37 to the print head 13 and the drive signal COM (drive waveform). And a second drive signal line 63A that is supplied from the signal generation circuit 37 to the correction drive circuit 61A. Since the second drive signal line 63A is separated from the circuit that drives the print head 13, the input impedance from the drive signal generation circuit 37 to the correction drive circuit 61A can be made higher. By configuring the input impedance to the correction drive circuit 61A higher, distortion (deterioration) of the drive waveform supplied to the correction drive circuit 61A via the second drive signal line 63A can be further reduced. That is, it is possible to supply a drive waveform with less distortion (deterioration) to the correction drive circuit 61A provided on the print head 13 side than the cable 60. Therefore, the correction drive circuit 61A can correct and drive the drive waveform supplied to the print head 13 by using the drive waveform with the smaller distortion (deterioration) as a reference.

In addition, according to the present embodiment, the printer 100 includes the carriage 41 that is mounted with the print head 13 and the correction drive circuit 61 and moves, in addition to the drive signal generation circuit 37 disposed via the cable 60. That is, by disposing the drive signal generation circuit 37 separately from the correction drive circuit 61, the print head 13 can be configured as a serial head that is lighter and is suppressed from becoming hot.
Note that an increase in the number of nozzles accompanying the increase in nozzle density may increase the number of actuators 72 (piezoelectric elements 77) and increase the current flowing through the first drive signal line 62A that supplies the drive signal COM. This embodiment is also effective for an increase in the number of nozzles because an increase in current affects waveform distortion (deterioration).

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

(Modification 1)
FIG. 10 is a block diagram illustrating a modification of the configuration of the drive control system that drives the print head 13. As with FIG. 8, the head control signals shown in FIG. 6 are not shown. The circuit from the shift register 91 controlled by the head control signal generation and the head control signal to the output of the level shifter 93 is the same as the prior art shown in FIG.
In the first embodiment, as shown in FIG. 8, a correction drive circuit 61A that drives the correction drive circuit 61 by correcting the drive signal COM (drive waveform), and a correction drive circuit 61B that corrects and supplies the base signal VBS. However, the present invention is not limited to this. For example, when the signal line that supplies the base signal VBS can be configured as a signal line having a lower resistance (that is, not the signal lines of both the first drive signal line 62A and the first drive signal line 62B, If the signal line (the first drive signal line 62B) can be configured as a signal line having a lower resistance), the signal line (first drive signal line 62B) may be configured only by the correction drive circuit 61A that drives by correcting the drive signal COM (drive waveform). .

(Modification 2)
In the first embodiment, the printer 100 is described as a serial printer including a serial head. However, the line printer includes a line head that does not include the carriage 41 and extends in the width direction of the roll paper 5. It may be.
Even in the case of a line printer, since the heat generating portion can be divided and provided at a position away from the line head via a cable, it is possible to suppress deterioration in print quality due to the influence of heat.

  DESCRIPTION OF SYMBOLS 1 ... Printing system, 5 ... Roll paper, 10 ... Printing part, 11 ... Head unit, 12 ... Ink supply part, 13 ... Print head, 14 ... Head control part, 20 ... Moving part, 30 ... Control part, 31 ... Interface 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, 40 ... Scanning unit, 41 ... Carriage, 42 ... Guide shaft, 50 ... conveying section, 51 ... supplying section, 52 ... storage section, 53 ... conveying roller, 55 ... platen, 60 ... cable, 61 (61A, 61B) ... correction driving circuit, 62A, 62B ... first driving signal 63A, 63B ... second drive signal line, 71 ... diaphragm, 72 ... actuator, 73 ... cavity, 74 ... nozzle, 75 ... nozzle plate, 76 ... cavity substrate, DESCRIPTION OF SYMBOLS 7 ... Piezoelectric element, 78 ... Reservoir, 79a, 79b ... Electrode, 80 ... Housing, 81 ... Fixed plate, 82 ... Joining plate, 83 ... Ink supply port, 91 ... Shift register, 92 ... Latch circuit, 93 ... Level shifter , 94 ... selection switch, 100 ... printer, 110 ... image processing apparatus, 111 ... printer control unit, 112 ... input unit, 113 ... display unit, 114 ... storage unit, 115 ... CPU, 116 ... ASIC, 117 ... DSP, 118 ... memory, 119 ... printer interface.

Claims (4)

A recording head for recording on a recording medium;
A first driving circuit for generating a driving waveform for driving the recording head and driving the recording head via a cable;
A second drive circuit that corrects the drive waveform supplied by the cable and drives the recording head;
The recording apparatus, wherein the second drive circuit is provided closer to the recording head than the cable.   A first drive signal line for supplying the drive waveform from the first drive circuit to the recording head; and a second drive signal line for supplying the drive waveform from the first drive circuit to the second drive circuit. The recording apparatus according to claim 1, further comprising:   The recording apparatus according to claim 1, wherein an output of the second driving circuit that drives the recording head is connected to an output of the first driving circuit that drives the recording head. .   The carriage is mounted with the recording head and moved separately from the first drive circuit arranged via the cable, and the carriage is mounted with the second drive circuit. The recording apparatus according to any one of claims 1 to 3.

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