JP2009184150A - Controller for inkjet head, inkjet head and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately eject a plurality of inks whose types and quantity states are different. <P>SOLUTION: The controller 1a for the inkjet head is equipped with an inkjet head 3 ejecting the ink to paper S in accordance with a drive voltage pulse, and a control part 63 acquiring the pulse width of the drive voltage pulse in accordance with the ink type that is the type of the ink and the ink state quantity that is the quantity of the state of the ink. A control circuit 32 has a storage part 65 storing data (ink information-pulse width table 65b) on the appropriate pulse width of the drive voltage univocally corresponding to each of a plurality of ink types or each of a plurality of ink state quantities in advance, an ink information acquiring part 67 acquiring ink information, and a control part 63 acquiring the pulse width corresponding to the ink information by retrieving the ink information-pulse width table 65b stored in the storage part 65 based on the ink information acquired by the ink information acquiring part 67. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet head control device, an inkjet head, and an inkjet recording apparatus.

2. Description of the Related Art Conventionally, for example, in an inkjet head that ejects ink droplets from nozzles connected to an ink chamber by pressurizing an ink chamber that stores ink with a piezoelectric body, the pulse width of a drive voltage applied to the piezoelectric body is Is set to a value that is approximately an integral multiple of the time T required for the pressure wave of the ink generated when the pressure chamber is pressurized to propagate the length of the ink chamber. An inkjet head is known (see, for example, Patent Document 1).
JP-A-9-277517

  By the way, in the inkjet head according to the above-described example of the prior art, the discharge is substantially maximum with respect to a predetermined single state (for example, a predetermined temperature state) of a predetermined single type of ink that is normally used. Only the pulse width of the drive voltage is set so as to obtain speed, and it is not considered to correspond to different states of different types of ink or single type of ink, for example, the type and state of ink When the amount (for example, temperature, etc.) changes, the value of the pulse width at which a substantially maximum discharge speed is obtained does not become an optimum value, but is a so-called droplet smaller than an ink droplet having a desired droplet diameter. There is a possibility that the ink ejection state may become unstable due to problems such as the generation of satellites.

  The present invention has been made in view of the above circumstances, and controls an inkjet head capable of appropriately ejecting a plurality of different types of ink and a plurality of different state quantities (for example, temperature). An object is to provide an apparatus, an inkjet head, and an inkjet recording apparatus.

  In order to solve the above-described problems and achieve the object, an inkjet head control apparatus according to the present invention ejects ink onto a recording medium (for example, paper S in the embodiment) according to a drive voltage pulse. An inkjet head control device for controlling a head (for example, the inkjet head 3 in the embodiment), which acquires a pulse width of the drive voltage pulse according to an ink type which is the type of the ink (For example, the control unit 63 in the embodiment).

  According to the ink jet head control device of the present invention, for example, an appropriate pulse width that is uniquely associated with an ink type such as an ink type or a color is selected in advance, and a drive voltage pulse having this pulse width is used. By ejecting ink, it is possible to appropriately eject a plurality of ink types from a single inkjet head.For example, even if the ink type changes, the ink ejection state is not good due to the occurrence of satellites, etc. It can be prevented from becoming stable.

  In addition, the inkjet head control apparatus of the present invention is an inkjet head that ejects ink onto a recording medium (for example, the paper S in the embodiment) in accordance with a drive voltage pulse (for example, the inkjet head 3 in the embodiment). And a pulse width acquisition unit (for example, a control unit in the embodiment) that acquires a pulse width of the drive voltage pulse in accordance with an ink state quantity that is the ink state quantity. 63).

  According to the inkjet head control device of the present invention, as the acquisition of the pulse width, for example, an appropriate pulse width that is uniquely associated in advance with the ink state quantity such as the temperature and viscosity of the ink is selected, or For example, the pulse width corresponding to the ink state quantity is set with reference to the correspondence (formula etc.) created in advance for the change in the ink state quantity and the change in the appropriate pulse width. By ejecting ink with voltage pulses, a plurality of ink state quantities of ink can be appropriately ejected from a single inkjet head. For example, even if the ink state quantity changes, ink is generated by the occurrence of satellites, etc. Can be prevented from becoming unstable.

  In addition, the inkjet head control apparatus of the present invention is an inkjet head that ejects ink onto a recording medium (for example, the paper S in the embodiment) in accordance with a drive voltage pulse (for example, the inkjet head 3 in the embodiment). And a pulse width acquisition means for acquiring the pulse width of the drive voltage pulse in accordance with the ink type as the ink type and the ink state quantity as the ink state quantity. (For example, the control unit 63 in the embodiment).

  According to the control device for an ink jet head of the present invention, an appropriate pulse width that is uniquely associated with an ink type such as an ink type or a color, for example, is selected and, for example, an ink temperature or viscosity is selected. For example, an appropriate pulse width uniquely associated with an ink state quantity in advance is selected or, for example, a correspondence relationship (formula etc.) created in advance for a change in ink state quantity and an appropriate pulse width change By setting the pulse width according to the ink state quantity and discharging the ink with the drive voltage pulse according to these pulse widths, a single ink of a plurality of ink types and a plurality of ink state quantities can be obtained. For example, even if the ink type or the ink state quantity changes, the ink jet head can Can click ejection state of is prevented from becoming unstable.

  Further, the ink jet head control apparatus of the present invention stores data for storing correspondence data between the ink type and the pulse width of the drive voltage pulse (for example, ink information-pulse width table 65b in the embodiment). Means (for example, the storage unit 65 in the embodiment) and an ink type acquisition unit (for example, the ink information acquisition unit 67 in the embodiment) for acquiring the ink type, and the pulse width acquisition unit includes: The data stored in the storage unit is searched based on the ink type acquired by the ink type acquisition unit, and the pulse width corresponding to the ink type is selected.

  According to the ink jet head control apparatus of the present invention, the ink type acquisition means is, for example, an input operation by an operator, or a detection signal output from a sensor that reads information on the ink type recorded in, for example, a container for containing ink. The ink type is acquired according to the above. The pulse width acquisition means is uniquely associated in advance with each of a plurality of ink types such as ink type and color based on the ink type acquired by the ink type acquisition means and stored in the storage means. The appropriate pulse width data is searched, and the pulse width corresponding to the ink type acquired by the ink type acquisition means is selected. As a result, for example, even when the ink type is changed, the ink ejection state is prevented from becoming unstable due to the occurrence of satellites, etc., and a plurality of ink types can be easily and appropriately supplied from a single inkjet head. Can be discharged.

  Further, in the ink jet head control device of the present invention, the ink state quantity is a temperature state quantity related to the temperature of the ink.

  According to the inkjet head control device of the present invention, even when the temperature of the ink changes, the ink can be appropriately ejected from a single inkjet head. For example, the ejection state of the ink due to the occurrence of satellites, etc. Can be prevented from becoming unstable.

  Furthermore, the ink jet recording apparatus of the present invention further includes a temperature state quantity acquisition unit (for example, the head temperature detection unit 64 in the embodiment) that acquires the temperature state quantity of the ink, and the pulse width acquisition unit includes: Based on the temperature state quantity acquired by the temperature state quantity acquisition means, the pulse width that changes in an increasing trend as the temperature of the ink rises is acquired.

  According to the control device for an ink jet head of the present invention, the pulse width acquisition means, as acquisition of the pulse width, for example, an appropriate pulse width that changes in an increasing tendency that is uniquely associated in advance with an increase in ink temperature. Or, for example, by referring to a correspondence (formula etc.) created in advance with respect to a rise in ink temperature and a change in an increase tendency of an appropriate pulse width, a pulse width corresponding to the ink temperature is set. Even if the temperature of the ink rises by ejecting the ink with the drive voltage pulse having this pulse width, the ink is discharged from a single inkjet head with an appropriate pulse width that changes in an increasing trend. For example, it is possible to prevent the ink discharge state from becoming unstable due to generation of satellites.

  The ink jet head of the present invention includes the ink jet head control device of the present invention, and discharges the ink onto the recording medium in accordance with the drive voltage pulse.

  According to the ink jet head of the present invention, even if the ink type or the ink state quantity is changed by the control device capable of appropriately ejecting the ink of the plurality of ink types or the plurality of ink state quantities, for example, It is possible to prevent the ink ejection state from becoming unstable due to the occurrence.

  Furthermore, the ink jet recording apparatus of the present invention includes a control device for the ink jet head of the present invention or the ink jet head of the present invention, and a relative movement means for moving the recording medium and the ink jet head relative to each other (for example, in the embodiment). A carriage 7).

  According to the ink jet recording apparatus of the present invention, desired recording can be appropriately performed by ejecting ink onto the recording medium while relatively moving the recording medium and the ink jet head by the relative movement means. In addition, since the ink jet head control device or the ink jet head that can prevent the ejection state of the ink of a plurality of ink types or a plurality of ink state quantities from becoming unstable is provided, the quality of the ink jet recording apparatus itself is improved. Can be achieved.

According to the inkjet head control device of the present invention, it is possible to appropriately eject a plurality of ink types or a plurality of ink state quantities from a single inkjet head. For example, when the ink type or the ink state quantity changes However, it is possible to prevent the ink ejection state from becoming unstable due to the occurrence of satellites or the like.
Further, according to the inkjet head of the present invention, even when the ink type or the ink state quantity is changed by the control device capable of appropriately ejecting the inks of the plurality of ink types or the plurality of ink state quantities, for example. It is possible to prevent the ink ejection state from becoming unstable due to the occurrence of satellites or the like.
Further, according to the ink jet recording apparatus of the present invention, desired recording can be appropriately performed by ejecting ink onto the recording medium while the recording medium and the head are relatively moved by the relative movement unit. In addition, since the ink jet head control device or the ink jet head that can prevent the ejection state of the ink of a plurality of ink types or a plurality of ink state quantities from becoming unstable is provided, the quality of the ink jet recording apparatus itself is improved. Can be achieved.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an inkjet head control device, an inkjet head, and an inkjet recording apparatus according to the present invention will be described below with reference to the accompanying drawings.
The inkjet head control apparatus 1a according to this embodiment is provided in an inkjet recording apparatus 1. The inkjet recording apparatus 1 includes, as shown in FIG. 1, for example, an apparatus main body 2 as a main body and a plurality of colors provided for each color. And an inkjet head 3.

  The apparatus main body 2 includes a housing 6 having a substantially rectangular parallelepiped shape. A pair of guide rails 8 extending in the width direction (for example, the longitudinal direction) W is provided in the housing 6. These guide rails 8 are provided with a carriage 7 to which a plurality of inkjet heads 3 are fixed. That is, the carriage 7 is supported by the guide rail 8 so as to be able to reciprocate in the width direction W.

The carriage 7 includes a flat base 7a. The inkjet head 3 is fixed to the base 7a. The base 7a is provided with a rising wall portion 7b raised from the base 7a. A wiring substrate 5 is provided on the rising wall portion 7b.
The wiring board 5 is provided with various electronic components for operating the components of the ink jet recording apparatus 1.

A motor 11 is provided at one end of the housing 6 in the width direction W. The output shaft of the motor 11 is directed in the depth direction (for example, the short direction) D of the housing 6. A pulley 12 is provided on the output shaft of the motor 11. On the other hand, the pulley 13 is also arranged opposite to the other end portion in the width direction in the housing 6. A timing belt 14 is provided so as to span the pulleys 12 and 13. A carriage 7 is fixed to the timing belt 14.
Accordingly, when the motor 11 is driven, the carriage 7 reciprocates in the width direction W via the pulleys 12 and 13 and the timing belt 14.

  An ink cartridge 17 that supplies ink is provided at the other end in the housing 6. The ink cartridge 17 is connected to the inkjet head 3 attached to the carriage 7 via an ink supply pipe 18 made of, for example, a flexible tube. Various inks are supplied from the ink cartridge 17 to the inkjet head 3 via the ink supply pipe 18.

Furthermore, an opening (not shown) disposed opposite to each other is provided on the front surface and the rear back surface of one end portion of the housing 6. A pair of carry-out rollers 22 extending in the longitudinal direction W is provided at a position facing one end of the housing 6 facing the opening on the front surface. On the other hand, a pair of carry-in rollers 21 extending in the longitudinal direction W are provided at positions facing the rear rear opening.
As a result, the paper (recording medium) S is inserted from the opening on the rear back surface, and the carry-in roller 21 and the carry-out roller 22 are driven so that the paper S is discharged from the opening on the front surface.

  Moreover, the inkjet head 3 is provided with the rectangular attachment base 25 as shown in FIG. The mounting base 25 is attached to the base 7a of the carriage 7 via screws (not shown). An inkjet head chip 26 to be described later is attached to the upper surface of the attachment base 25. On the upper surface of the inkjet head chip 26, a rectangular channel substrate 27 extending over the entire length in the longitudinal direction is provided. A connecting portion 30 is provided at the center in the longitudinal direction on the upper surface of the flow path substrate 27.

  Further, the mounting base 25 is provided with a rectangular base plate 31 raised from the mounting base 25. The base plate 31 is made of, for example, aluminum. A wiring substrate 35 is provided on one main surface of the base plate 31 (the main surface disposed on the inkjet head chip 26 side). A control circuit 32 that performs various controls of the inkjet head chip 26 is mounted on the wiring board 35.

The base plate 31 is provided with a support portion 37 at the upper end, extending to one main surface side. The support portion 37 is provided with a pressure adjusting portion 38 having a storage chamber for storing ink. An ink communication tube 39 that communicates with the storage chamber is provided below the pressure adjustment unit 38.
The ink communication tube 39 is connected to the connecting portion 30 of the flow path substrate 27 via an O-ring.
On the other hand, an ink intake port 42 that communicates with the storage chamber is provided in the upper portion of the pressure adjustment unit 38. The ink supply pipe 18 is attached to the ink intake port 42.
With such a configuration, when ink is supplied from the ink cartridge 17 via the ink supply pipe 18, this ink is taken into the storage chamber in the pressure adjustment unit 38 via the ink intake port 42. Further, a predetermined amount of ink is supplied to the inkjet head chip 26 via the ink communication tube 39 and the flow path substrate 27.

As shown in FIGS. 3 and 4, the inkjet head chip 26 includes a substantially rectangular piezoelectric ceramic plate 44. The piezoelectric ceramic plate 44 is made of, for example, PZT (lead zirconate titanate). A long groove 45 extending in the short direction E is formed on the upper surface of the piezoelectric ceramic plate 44. The long grooves 45 have a substantially rectangular cross section, and a plurality of the long grooves 45 are arranged over the entire length in the longitudinal direction F of the piezoelectric ceramic plate 44. That is, the long groove 45 is divided by the side wall 46. As shown in FIG. 4, for example, the bottom surface of the long groove 45 is a front flat surface 44a extending from the front side of the piezoelectric ceramic plate 44 to a substantially central portion in the short direction E, and from the rear portion of the front flat surface 44a toward the rear side. The inclined surface 44b whose depth gradually decreases and the rear flat surface 44c extending rearward from the rear portion of the inclined surface 44b.
The rear end portion of the long groove 45 is sealed by a sealing portion (not shown).

A drive electrode portion 50 extending in a plate shape is provided in the long groove 45. That is, the drive electrode portions 50 are provided by vapor deposition at the upper end portions of both main surfaces of the side wall 46, respectively. The drive electrode unit 50 is electrically connected to the control circuit 32 by, for example, a wire 47 shown in FIG.
A nozzle plate 51 made of polyimide, for example, is provided on the front surface of the piezoelectric ceramic plate 44. One main surface of the nozzle plate 51 is a bonding surface to the piezoelectric ceramic plate 44, and the other main surface is provided with a water repellent film having water repellency for preventing adhesion of ink and the like.

  A plurality of nozzle openings 52 are formed in the nozzle plate 51 at a predetermined interval (interval equivalent to the pitch of the long grooves 45) in the longitudinal direction F. The nozzle opening 52 is formed in the nozzle plate 51 such as a polyimide film using, for example, an excimer laser device. These nozzle openings 52 are arranged in alignment with the long grooves 45, respectively.

Further, a rectangular ink chamber plate 55 is provided on the upper surface of the piezoelectric ceramic plate 44. The length dimension in the short direction E of the ink chamber plate 55 is shorter than the length dimension in the short direction E of the piezoelectric ceramic plate 44. The front end surface of the ink chamber plate 55 and the front end surface of the piezoelectric ceramic plate 44 are flush with each other.
The ink chamber plate 55 is formed with a rectangular opening 56 extending in the longitudinal direction. The opening 56 extends over the entire long groove 45 in the longitudinal direction F of the piezoelectric ceramic plate 44. That is, all the long grooves 45 are opened outward through the openings 56.
In addition, a rectangular nozzle support plate 57 is fitted and bonded to the rear back surface of the piezoelectric ceramic plate 44.

  As a result, when a predetermined amount of ink is supplied from the storage chamber in the pressure adjusting unit 38 to the flow path substrate 27 through the ink communication pipe 39 and the connecting unit 30, the ink passes through the opening 56 and passes through the long groove. 45 is sent in. That is, the long groove 45 functions as an ink chamber into which ink is put.

  Further, on the lower surface of the piezoelectric ceramic plate 44, for example, a thermistor 61 shown in FIG. 5 is provided. The thermistor 61 outputs a voltage corresponding to the temperature of the piezoelectric ceramic plate 44. The thermistor 61 is electrically connected to the control circuit 32.

The inkjet head control device 1a according to this embodiment includes, for example, an inkjet head 3 and a control circuit 32. The control circuit 32 includes, for example, a control unit 63 and a head temperature detection unit 64 as shown in FIG. A storage unit 65, a drive voltage generation unit 66, and an ink information acquisition unit 67.
A head temperature detector 64 connected to the thermistor 61 is connected to the controller 63. The head temperature detector 64 detects the temperature of the piezoelectric ceramic plate 44 from the voltage output from the thermistor 61 and outputs it as a temperature information signal.

The control unit 63 is connected to a storage unit 65 that stores various types of information.
The storage unit 65 stores a temperature-voltage table 65 a indicating a predetermined correspondence between the temperature of each piezoelectric ceramic plate 44 and the drive voltage value for each of the plurality of piezoelectric ceramic plates 44.
The temperature-voltage table 65a shows, for example, the correspondence between a change in temperature and a change in drive voltage value within a predetermined temperature range set in advance using a predetermined reference liquid for each of the plurality of piezoelectric ceramic plates 44. In order to ensure or maintain a desired discharge state (for example, a discharge speed and a discharge amount) corresponding to a change in the state of the reference liquid (for example, a change in viscosity) according to a temperature change in a predetermined temperature range The change of the required drive voltage value is shown.

The control unit 63 is connected to the ink information acquisition unit 67.
The ink information acquisition unit 67 is, for example, an input device (not shown) that outputs a command signal corresponding to an input operation by an operator, or an ink type (for example, an IC chip provided in the ink cartridge 17) (for example, It is connected to a sensor (not shown) that reads information (ink information, etc.) of ink type and color), acquires ink information output from an input device or various sensors, and outputs it as an ink information signal.

Furthermore, the storage unit 65 stores a table of data of appropriate pulse widths of the drive voltages uniquely associated with the plurality of ink types in advance for each of the plurality of piezoelectric ceramic plates 44 (ink information-pulses). Width table) 65b is stored.
The ink information-pulse width table 65b is created in advance based on experimental data, for example, and is appropriate for each of a plurality of ink types (for example, ink type and color) for each of the plurality of piezoelectric ceramic plates 44. The pulse width of the drive voltage that provides a stable discharge state (that is, a stable discharge state free from defects such as satellite generation) is uniquely associated with each ink type.

As the pulse width P of the drive voltage varies, for example, as shown in FIG. 6, the ink ejection speed varies substantially periodically, and the ink chamber formed of the long grooves 45 is pressurized by the piezoelectric ceramic plate 44. In contrast to the time T required to propagate the pressure wave of the ink generated by the length of the ink chamber (that is, the length of the long groove 45 in the short direction E) L, the pulse is an odd multiple of this time T. The ink discharge speed is substantially maximum in the width P (= T, 3T,...), And the ink discharge speed is substantially minimum in the pulse width P (= 2T, 4T,...) That is an even multiple of the time T.
For this reason, for example, by changing the pulse width P from one time (T) of time T to two times (2T) of time T, the ink ejection speed tends to decrease from about maximum to about minimum. Will change.

The control unit 63 is connected to a drive voltage generation unit 66 that generates a drive voltage for driving the piezoelectric ceramic plate 44.
The control unit 63 calculates the drive voltage value obtained by searching the temperature-voltage table 65a of the storage unit 65 based on the temperature of each piezoelectric ceramic plate 44 according to the temperature information signal output from the head temperature detection unit 64, and the ink. A pulse width obtained by retrieving (selecting) an ink information-pulse width table 65b of the storage unit 65 based on ink information (that is, ink type information) corresponding to the ink information signal output from the information obtaining unit 67; A control signal instructing generation of the drive voltage by the drive voltage generator 66 is output.
The drive voltage generator 66 applies a drive voltage corresponding to the control signal output from the controller 63 to the piezoelectric ceramic plate 44.

  The ink jet recording apparatus 1 according to the present embodiment has the above-described configuration. Next, the operation of the ink jet recording apparatus 1 will be described.

When printing is instructed from a computer or the like connected to the inkjet recording apparatus 1, the control unit 63 reads out the temperature information signal output from the head temperature detection unit 64 and ink information output from the ink information acquisition unit 67. Read the signal.
Then, the control unit 63 retrieves the drive voltage value from the temperature-voltage table 65a of the storage unit 65 based on the temperature of each piezoelectric ceramic plate 44 corresponding to the temperature information signal, and ink information corresponding to the ink information signal (that is, the ink information signal). , Ink type information), the pulse width is retrieved from the ink information-pulse width table 65b of the storage unit 65.
Then, the control unit 63 outputs a control signal instructing that the drive voltage generation unit 66 generate a drive voltage based on the drive voltage value and the pulse width obtained by the search.

Then, the drive voltage generator 66 selectively applies a drive voltage corresponding to the control signal output from the controller 63 to the piezoelectric ceramic plate 44 of the predetermined inkjet head 3.
Thereby, for example, the side wall 46 shown in FIG. 3 is distorted, and the volume of the long groove 45 is enlarged. Then, the ink temporarily stored in the storage chamber in the pressure adjusting unit 38 is sent into the long groove 45 through the flow path substrate 27.
When the control unit 63 selectively inputs a drive voltage to the predetermined drive electrode unit 50, the volume of the long groove 45 is reduced, and the ink fed into the long groove 45 is ejected through the nozzle opening 52. The As a result, ink droplets land on the surface of the paper S.
That is, while the paper S is sent in the depth direction D from the rear side to the front side of the apparatus main body 2, the carriage 7 is moved in the width direction W, and ink is ejected at an appropriate timing, whereby predetermined printing is performed on the paper S. Is done.

Hereinafter, a first example and a second example in which two inkjet heads 3 having different lengths in the ink chamber are employed in the inkjet recording apparatus 1 according to the above-described embodiment will be described.
First, as shown in Table 1 below, for example, the inkjet head 3 in the first embodiment includes inks A and B of two different ink types (for example, ink A having an aqueous viscosity of 4.5 mPa · s, a solvent system) In addition, for the ink B having a viscosity of 4.0 mPa · s, the time T required for the pressure wave of the ink generated when the ink chamber is pressurized to propagate through the ink chamber is a predetermined first time (for example, The ink chamber has a length L of T = 6.6 μs).
In this first embodiment, the pulse width P for water-based ink A is set between P = 8.6 μs and P = 10.6 μs, and the pulse width for solvent-based ink B is set. By setting P between P = 8.6 μs and P = 9.6 μs, it is possible to prevent the ejection states of the inks A and B from becoming unstable due to problems such as the occurrence of satellites. .
For this reason, in the first embodiment, in the ink information-pulse width table 65b, a predetermined pulse width P between P = 8.6 μs and P = 10.6 μs with respect to the information of the ink type designating the ink A. Are uniquely associated, and a predetermined pulse width P between P = 8.6 μs and P = 9.6 μs is uniquely associated with the ink type information designating ink B.

In addition, as shown in Table 2 below, for example, the inkjet head 3 in the second embodiment includes inks A and B having two different predetermined viscosities (for example, ink A having an aqueous viscosity of 4.5 mPa · s, a solvent system) In addition, with respect to ink B having a viscosity of 4.0 mPa · s, a time T required for the pressure wave of the ink generated when the ink chamber is pressurized to propagate through the ink chamber is a predetermined second time (for example, T = 5.2 μs), and has a length L in the ink chamber.
In this second embodiment, the pulse width P for water-based ink A is set between P = 6.8 μs and P = 8.4 μs, and the pulse width for solvent-based ink B is set. By setting P between P = 8.6 μs and P = 9.6 μs, it is possible to prevent the ejection states of the inks A and B from becoming unstable due to the occurrence of satellites, for example.
For example, FIGS. 7A and 7B show printing results on the paper S when the pulse width P is set to P = 1.00T and 1.46T for the ink B, respectively. In this case, the discharge state of the ink B becomes unstable, the variation in the discharge position of the ink B becomes large, and the occurrence of satellites is remarkable.
On the other hand, for example, FIGS. 7C and 7D show printing on the paper S when the pulse width P is set to P = 1.65T and 1.85T, which are appropriate for the ink B, respectively. In these cases, the discharge state of the ink B is prevented from becoming unstable, and variations in the discharge position of the ink B and generation of satellites are suppressed.
For this reason, in the second embodiment, in the ink information-pulse width table 65b, a predetermined pulse width P between P = 6.8 μs and P = 8.4 μs with respect to the information of the ink type designating the ink A. Are uniquely associated, and a predetermined pulse width P between P = 8.6 μs and P = 9.6 μs is uniquely associated with the ink type information designating ink B.

  As described above, according to the inkjet head control device 1a of this embodiment, the ink information-pulse width table 65b created in advance, that is, the drive voltage uniquely associated with each of the plurality of ink types. Is stored in the storage unit 65, and an appropriate pulse width corresponding to the information of the ink type (for example, ink type and color) acquired by the ink information acquisition unit 67 is stored in the ink. By selecting from the information-pulse width table 65b, the ink-jet head 3 can appropriately deal with inks of a plurality of ink types. For example, even when the ink types change, ink ejection is caused by the occurrence of satellites, etc. It is possible to prevent the state from becoming unstable.

  Further, according to the ink jet recording apparatus 1 according to this embodiment, desired recording can be appropriately performed by ejecting ink onto the paper S while moving the ink jet head 3 relative to the paper (recording medium) S by the carriage 7. It can be performed. In addition, the inkjet recording apparatus 1 itself includes the inkjet head control apparatus 1a that can prevent the ejection state of inks of a plurality of different ink types (for example, ink types and colors) from becoming unstable. The quality can be improved.

In the above-described embodiment, the ink information is information on the ink type (for example, the type and color of the ink). However, the present invention is not limited to this, and the first modification of the above-described embodiment is an ink. The information may be, for example, information on an ink state quantity (for example, ink temperature or viscosity).
In the ink jet head control apparatus 1a according to the first modification, the ink information acquisition unit 67, for example, an ink state quantity (not shown) that is output from an input device (not shown) that outputs a command signal according to an input operation of the operator. For example, information (ink information) such as ink temperature and viscosity is acquired and output as an ink information signal.
The control unit 63 acquires an information signal (ink information signal) of the ink state quantity (for example, ink temperature and viscosity) output from the ink information acquisition unit 67 and is connected to the thermistor 61, for example. The ink temperature is detected based on the temperature information (temperature information signal) of the piezoelectric ceramic plate 44 output from the head temperature detector 64.

Furthermore, the storage unit 65 stores a table (ink information−) of an appropriate pulse width of the drive voltage uniquely associated with each of the plurality of ink state quantities for each of the plurality of piezoelectric ceramic plates 44. (Pulse width table) 65b is stored.
The ink information-pulse width table 65b is created in advance based on, for example, experimental data, and for each of a plurality of ink state quantities (for example, ink temperature and viscosity) with respect to each of the plurality of piezoelectric ceramic plates 44. The pulse width of the drive voltage that can obtain an appropriate ejection state (that is, a stable ejection state free from defects such as satellite generation) is uniquely associated with each ink state amount.
For example, in the ink information-pulse width table 65b, an appropriate pulse width is uniquely associated with each of a plurality of different temperature ranges with respect to the ink temperature. The correspondence relationship is such that, for example, the pulse width changes in an increasing trend as the temperature range increases.

  Then, the control unit 63 calculates the drive voltage value obtained by searching the temperature-voltage table 65a of the storage unit 65 based on the temperature of each piezoelectric ceramic plate 44 according to the temperature information signal output from the head temperature detection unit 64. Ink information corresponding to the ink information signal output from the ink information acquisition unit 67 (that is, information on the ink state amount) and information on the temperature of the piezoelectric ceramic plate 44 output from the head temperature detection unit 64 (temperature information signal) Control for instructing generation of a drive voltage from the drive voltage generator 66 based on the ink information detected from the ink information-pulse width table 65b in the storage unit 65 and the pulse width acquired (selected) from the table 65b. Output a signal.

  According to the inkjet head control device 1a according to the first modification, the temperature range increases in the ink information-pulse width table 65b in which appropriate pulse widths are uniquely associated with a plurality of different temperature ranges. As a result, the corresponding pulse width changes in an increasing trend, and for example, a predetermined usable temperature range is set on the premise that ejection is performed with a predetermined drive voltage for appropriate ink. Even in such a case, since an appropriate pulse width is selected according to the temperature range of the ink, the usable temperature range of the ink can be expanded.

In the first modification of the above-described embodiment, the storage unit 65 stores a table (ink information) of an appropriate pulse width of a driving voltage that is uniquely associated with each of a plurality of ink state quantities in advance. -Pulse width table) 65b is stored, but the present invention is not limited to this. For example, the ink information-pulse width table 65b of the inkjet head control device 1a according to the second modification shown in FIG. Instead, for example, data (ink information-pulse width data) 65c of a correspondence relationship (formula etc.) created in advance for a change in the ink state quantity and a change in the pulse width may be stored.
In the second modified example, the ink information-pulse width data 65c is created in advance based on, for example, experimental data, and the ink state quantity (for example, the temperature and viscosity of the ink) for each of the plurality of piezoelectric ceramic plates 44. The relationship between the change in the pulse width of the drive voltage and the change in the amount of ink state that can obtain an appropriate ejection state (that is, a stable ejection state free from defects such as the occurrence of satellites) For example, it is stored as data such as mathematical expressions.
For example, with respect to the ink temperature, in the ink information-pulse width data 65c, as the ink temperature rises, the pulse width changes in an increasing trend.

  Then, the control unit 63 searches the drive voltage value from the temperature-voltage table 65a of the storage unit 65 based on the temperature of each piezoelectric ceramic plate 44 according to the temperature information signal output from the head temperature detection unit 64. Further, the control unit 63 sets the ink information corresponding to the ink information signal output from the ink information acquisition unit 67 (that is, information on the ink state quantity) and the temperature of the piezoelectric ceramic plate 44 output from the head temperature detection unit 64. The pulse width is set with reference to the ink information-pulse width data 65c stored in the storage unit 65 based on the detected ink temperature (temperature information signal). Then, the control unit 63 outputs a control signal instructing the drive voltage generation unit 66 to generate a drive voltage with a drive voltage value and a pulse width.

In the above-described embodiment, the ink information is information on the ink type (for example, ink type and color). However, the present invention is not limited to this, and ink information is provided as a third modification of the above-described embodiment. May be information on ink type (for example, ink type and color) and ink state quantity (for example, ink temperature and viscosity).
In the third modified example, the storage unit 65 has appropriate drive voltages that are uniquely associated with a plurality of ink types and a plurality of ink state quantities in advance for each of the plurality of piezoelectric ceramic plates 44. A pulse width data table (ink information-pulse width table) 65b may be stored, or an appropriate pulse width data of a drive voltage uniquely associated with a plurality of ink types in advance. Both table (ink information-pulse width table) 65b and data (ink information-pulse width data) 65c of correspondence (formula etc.) created in advance for changes in ink state quantity and pulse width are stored. You may do it.

  In the third modified example, the control unit 63 uses the ink in the storage unit 65 based on the ink information (that is, the ink type information and the ink state amount information) corresponding to the ink information signal output from the ink information acquisition unit 67. The pulse width may be retrieved from the information-pulse width table 65b and acquired (selected). In addition, the control unit 63 searches for the pulse width from the ink information-pulse width table 65 b of the storage unit 65 based on the ink information (that is, information on the ink type) corresponding to the ink information signal output from the ink information acquisition unit 67. The ink information corresponding to the ink information signal output from the ink information acquisition unit 67 (that is, information on the ink state quantity) and the piezoelectric ceramic plate 44 output from the head temperature detection unit 64 are acquired (selected). The pulse width may be set by referring to the ink information-pulse width data 65c stored in the storage unit 65 based on the temperature of the ink (temperature information signal).

In the above-described embodiment, the inkjet head control device 1a is configured to include the inkjet head 3 and the control circuit 32. However, the present invention is not limited to this. For example, the inkjet head control device 1a The ink jet head 3 may be provided separately and provided with only the control circuit 32.
In the above-described embodiment, the control circuit 32 is mounted on the mounting base 25 provided in the inkjet head 3. However, the present invention is not limited to this, and the control circuit 32 is different from the inkjet head 3, for example. The body may be provided in the housing 6 of the apparatus main body 2, or may be provided outside the apparatus main body 2, for example.

1 is a perspective view illustrating a case of an ink jet recording apparatus according to an embodiment of the present invention. It is a principal part enlarged view of the inkjet head which concerns on embodiment of this invention. It is a principal part enlarged view which fractures | ruptures and shows a part of longitudinal direction of the inkjet head chip which concerns on embodiment of this invention. FIG. 2 is an exploded perspective view showing an enlarged main part of an ink jet head chip according to an embodiment of the present invention. It is a functional block block diagram of the control apparatus of the inkjet head which concerns on embodiment of this invention. It is a graph which shows an example of the correspondence of the pulse width of the drive voltage and discharge speed which concern on embodiment of this invention. It is a figure which shows the example of the printing result in the 2nd Example which concerns on embodiment of this invention. It is a functional block block diagram of the control apparatus of the inkjet head which concerns on the 2nd modification of embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Inkjet recording device 1a Inkjet head control device 3 Inkjet head 7 Carriage (relative movement means) 32 Control circuit 44 Piezoelectric ceramic plate (piezoelectric body) 51 Nozzle plate (nozzle) 63 Control section (pulse width acquisition means) 64 Head temperature detection (Temperature state quantity acquisition means) 65 storage section (storage means) 67 ink information acquisition section (ink information acquisition means)

Claims (8)

An inkjet head control device that controls an inkjet head that ejects ink onto a recording medium in response to a drive voltage pulse,
An inkjet head control apparatus comprising: a pulse width acquisition unit that acquires a pulse width of the drive voltage pulse according to an ink type that is the type of ink. An inkjet head control device that controls an inkjet head that ejects ink onto a recording medium in response to a drive voltage pulse,
An inkjet head control apparatus comprising: a pulse width acquisition unit configured to acquire a pulse width of the drive voltage pulse in accordance with an ink state quantity that is the ink state quantity. An inkjet head control device that controls an inkjet head that ejects ink onto a recording medium in response to a drive voltage pulse,
An inkjet head control apparatus comprising: a pulse width acquisition unit configured to acquire a pulse width of the drive voltage pulse in accordance with an ink type as the ink type and an ink state amount as the ink state amount. Storage means for storing data of correspondence relationship between the ink type and the pulse width of the drive voltage pulse;
An ink type acquisition means for acquiring the ink type;
The pulse width acquisition unit searches the data stored in the storage unit based on the ink type acquired by the ink type acquisition unit, and selects the pulse width corresponding to the ink type. The control device for an ink jet head according to claim 1, wherein:   4. The ink jet head control apparatus according to claim 2, wherein the ink state quantity is a temperature state quantity related to a temperature of the ink. A temperature state quantity acquisition means for acquiring the temperature state quantity of the ink;
The pulse width acquisition unit acquires the pulse width that changes in an increasing trend as the temperature of the ink rises based on the temperature state amount acquired by the temperature state amount acquisition unit. The inkjet head control apparatus according to claim 5.   An ink jet head comprising the ink jet head control device according to claim 1, wherein the ink is ejected onto the recording medium in accordance with the drive voltage pulse.   A control device for an ink jet head according to any one of claims 1 to 6, or an ink jet head according to claim 7, and a relative movement means for relatively moving the recording medium and the ink jet head. An ink jet recording apparatus.