JP2012131149A - Liquid injection device, and control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and reliably perform flushing operation.SOLUTION: A printing apparatus 100 includes: a temperature sensor S1 detecting a temperature; a recording head 24 injecting ink form a nozzle; and a control section 60 outputting a modified temperature in which a correction temperature is subtracted from a temperature detected at the flushing operation to a drive signal generation section 64 while outputting a temperature at printing operation. The drive signal generation section 64 generates and supplies the drive signal according to the supplied temperature to the recording head 24.

Description

  The present invention relates to a technique for ejecting a liquid such as ink.

2. Description of the Related Art Conventionally, a liquid ejecting technique for ejecting liquid (for example, ink) in a pressure chamber from a nozzle by changing the pressure in the pressure chamber by a pressure generating element such as a piezoelectric vibrator or a heating element has been proposed. In this technique, a flushing operation for forcibly ejecting liquid from each nozzle is employed in order to prevent nozzle clogging and the like.
Patent Document 1 discloses a technique for changing the number of ejections according to the temperature in relation to the flushing operation.
Patent Document 2 discloses a technique for performing a flushing operation using a waveform used for printing.

JP 2005-238780 A JP 2002-36594 A

However, in the technique described in Patent Document 1, the number of ejections varies depending on the temperature, so that the flushing time varies depending on the temperature. Further, when the degree of thickening is large, there is a problem that even if the number of ejections is increased, the liquid cannot be ejected with a weak ejection force.
Further, the technique described in Patent Document 2 performs flushing using a waveform that is the same as that used for printing at a certain temperature, and thus the ejection force during the flushing operation is the same as that of the printing operation. For this reason, there has been a problem that it is not always possible to perform flushing reliably when the liquid is thickened.
In consideration of the above circumstances, an object of the present invention is to perform a flushing operation more reliably.

In order to solve the above problems, a liquid ejecting apparatus of the present invention includes a temperature detection unit that detects temperature, a pressure chamber filled with liquid, a nozzle that communicates with the pressure chamber, and a pressure in the pressure chamber. A pressure generating unit for causing the liquid in the pressure chamber to be ejected from the nozzle in response to a change in pressure in the pressure chamber, and generating a printing signal in accordance with the temperature detected during a printing operation. A signal generation unit that generates a flushing signal having a larger ejection force than the printing signal during the flushing operation and supplies the flushing signal to the pressure generation unit.
According to the present invention, the flushing signal has a larger ejection force than the printing signal whose ejection force varies depending on the temperature. Therefore, even when the liquid is thickened, the liquid in the vicinity of the nozzle can be discharged more reliably, and the printing reliability can be improved.

  In the liquid ejecting apparatus described above, it is preferable that the signal generation unit generates the printing signal corresponding to a temperature lower than the detected temperature as the flushing signal during the flushing operation. According to the present invention, since the flushing is performed using the printing signal having a temperature lower than the detected temperature, the ejection force during the flushing operation can be increased as compared with the printing operation. Further, since the flushing signal can be used also as the printing signal, the configuration can be simplified.

  In the liquid ejecting apparatus described above, the signal generation unit generates, as the flushing signal, the printing signal corresponding to a corrected temperature obtained by subtracting a certain correction temperature from the detected temperature during the flushing operation. Is preferred. According to the present invention, since a fixed correction temperature is adopted, a corrected temperature can be easily generated. In addition, if a corrected temperature is generated instead of the detected temperature, the print signal can be used as the flushing signal, so that the configuration can be simplified.

  In the liquid ejecting apparatus described above, a humidity detection unit that detects humidity is provided, and the signal generation unit is configured to perform flushing having a larger ejection force than the printing signal based on the detected temperature and the detected humidity during the flushing operation. It is preferable to generate a signal for use and supply it to the pressure generator. The thickening of the liquid near the nozzle is partly due to the evaporation of the liquid from the meniscus, but the degree of evaporation depends on the humidity. According to the present invention, since the flushing signal is generated in consideration of not only the temperature but also the humidity, it is possible to more reliably discharge the thickened liquid and improve the printing reliability.

  More specifically, the signal generation unit generates a correction temperature based on the detected temperature and the detected humidity during the flushing operation, and a corrected temperature obtained by subtracting the correction temperature from the detected temperature. It is preferable that the printing signal corresponding to is generated as the flushing signal. According to the present invention, not only the temperature but also the humidity is reflected in the correction temperature. Therefore, when the printing signal is generated according to the temperature, the printing signal can be easily used as the flushing signal in consideration of the humidity. It becomes possible.

  In the liquid ejecting apparatus described above, a lower limit temperature at which a printing operation can be performed is determined, and the signal generation unit is configured to perform the printing corresponding to the lower limit temperature when the correction temperature is lower than the lower limit temperature during a flushing operation. It is preferable to generate a flushing signal having a larger ejection force than the signal. According to the present invention, even when the lower limit temperature of the printing signal is determined, a flushing signal with a larger ejection force can be generated, so that even if the temperature is low, the flushing can be performed reliably. Can do.

  In the liquid ejecting apparatus described above, the signal generation unit generates a flushing signal having a larger ejection force than the printing signal from the start of the flushing operation to a predetermined number of ejections, and the predetermined number of ejections has elapsed. After that, it is preferable to generate the printing signal corresponding to the detected temperature as a flushing signal. Immediately after starting the flushing operation, it is necessary to discharge the thickened liquid in the vicinity of the meniscus, so it is necessary to drive the pressure generating unit with a signal with a larger discharge force, but after the thickened liquid is discharged Can perform flushing with a normal discharge force. According to the present invention, since a signal having a large discharge force is used only at the start of flushing, the thickened liquid can be discharged reliably, and the amount of liquid to be discharged can be reduced.

  The method for controlling a liquid ejecting apparatus according to the present invention includes a temperature detection unit that detects temperature, a pressure chamber filled with liquid, a nozzle that communicates with the pressure chamber, and a pressure generation unit that varies the pressure in the pressure chamber. A liquid ejecting apparatus comprising: an ejecting unit that ejects the liquid in the pressure chamber from the nozzle in accordance with a change in pressure in the pressure chamber, the temperature detected during a printing operation In response to this, a printing signal is generated and supplied to the pressure generating unit, and the printing signal corresponding to a temperature lower than the detected temperature during the flushing operation is generated as the flushing signal to the pressure generating unit. It is characterized by supplying. According to the present invention, the flushing signal has a larger ejection force than the printing signal whose ejection force varies depending on the temperature. Therefore, even when the liquid is thickened, the liquid in the vicinity of the nozzle can be discharged more reliably, and the printing reliability can be improved.

It is a partial schematic diagram of the printing apparatus according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view of a recording head. 1 is a block diagram of an electrical configuration of a printing apparatus according to a first embodiment. It is a wave form diagram of a drive signal. FIG. 2 is a block diagram of an electrical configuration of a recording head. It is a wave form diagram which shows the relationship between temperature and an injection pulse. It is a wave form diagram which shows an example of the injection pulse for flushing in the case of falling below a minimum temperature. It is a wave form diagram which shows an example of the injection pulse for flushing in the case of falling below a minimum temperature. It is a wave form diagram which shows an example of the injection pulse for flushing in the case of falling below a minimum temperature. It is a block diagram of the electric constitution of the printing apparatus of 2nd Embodiment. It is explanatory drawing which shows an example of the memory content of a table.

<A: First Embodiment>
FIG. 1 is a partial schematic view of an ink jet printing apparatus 100 according to a first embodiment of the present invention. The printing apparatus 100 is a liquid ejecting apparatus that ejects fine droplet-shaped ink onto the recording paper 300, and includes a carriage 12, a moving mechanism 14, a sheet conveying mechanism 16, and a cap 18.

  An ink cartridge 22 and a recording head 24 are mounted on the carriage 12. The ink cartridge 22 is a container that stores ink (liquid) ejected onto the recording paper 300. The recording head 24 functions as a liquid ejection unit that ejects the ink stored in the ink cartridge 22 onto the recording paper 300. A configuration in which the ink cartridge 22 is fixed to a housing (not shown) of the printing apparatus 100 and ink is supplied to the recording head 24 can also be employed.

  The moving mechanism 14 in FIG. 1 reciprocates the carriage 12 along the guide shaft 122 in the main scanning direction (width direction of the recording paper 300). The position of the carriage 12 is detected by a detector (not shown) such as a linear encoder and used for controlling the moving mechanism 14. The paper transport mechanism 16 moves the recording paper 300 in the sub-scanning direction in parallel with the reciprocation of the carriage 12. When the carriage 12 reciprocates, the recording head 24 ejects ink onto the recording paper 300, whereby a desired image is recorded (printed) on the recording paper 300.

  The moving mechanism 14 can move the recording head 24 to a position outside the range where the ejection surface faces the recording paper 300 (hereinafter referred to as “retraction position”). The cap 18 is disposed so as to face the ejection surface of the recording head 24 in the retracted position. The cap 18 seals the ejection surface of the recording head 24. A wiper (not shown) for wiping the discharge surface is disposed in the vicinity of the cap 18.

  FIG. 2 is a cross-sectional view of the recording head 24 (cross section perpendicular to the main scanning direction). As shown in FIG. 2, the recording head 24 includes a vibration unit 42, a container 44, and a flow path unit 46. The vibration unit 42 includes a piezoelectric vibrator 422, a cable 424, and a fixed plate 426. The piezoelectric vibrator 422 is a longitudinal vibration type piezoelectric element in which piezoelectric materials and electrodes are alternately stacked, and vibrates according to a drive signal supplied via the cable 424. The vibration unit 42 is housed in the housing body 44 in a state where the fixed plate 426 to which the piezoelectric vibrator 422 is fixed is bonded to the inner wall surface of the housing body 44.

  The flow path unit 46 is a structure in which a flow path forming plate 466 is inserted in a gap between the substrates 462 and 464 facing each other. The flow path forming plate 466 forms a space including the pressure chamber 50, the supply path 52, and the storage chamber 54 in the gap between the substrate 462 and the substrate 464. The pressure chamber 50 is individually partitioned by a partition for each vibration unit 42 and communicates with the storage chamber 54 via the supply path 52. Ink supplied from the ink cartridge 22 is stored in the storage chamber 54. Each nozzle 56 is formed on the substrate 462 so as to correspond to each pressure chamber 50. Each nozzle 56 is a through hole that allows the outside of the flow path unit 46 to communicate with the pressure chamber 50. As understood from the above description, an ink flow path is formed from the storage chamber 54 to the outside via the supply path 52, the pressure chamber 50, and the nozzle 56.

  The substrate 464 is a flat plate made of an elastic material. An island-shaped diaphragm 48 is formed in a region of the substrate 464 opposite to the pressure chamber 50. A front end surface (free end) of the piezoelectric vibrator 422 is joined to the vibration plate 48. Therefore, when the piezoelectric vibrator 422 is vibrated by the supply of the drive signal, the substrate 464 is displaced via the vibration plate 48, whereby the volume of the pressure chamber 50 is changed and the pressure of the ink in the pressure chamber 50 is changed. That is, the piezoelectric vibrator 422 functions as a pressure generating element that varies the pressure in the pressure chamber 50. Ink can be ejected from the nozzle 56 in accordance with the fluctuation of the pressure in the pressure chamber 50 described above. That is, the element constituted by the piezoelectric vibrator 422, the pressure chamber 50, and the nozzle 56 functions as a unit for ejecting ink (hereinafter referred to as “unit ejecting unit U”).

  FIG. 3 is a block diagram of an electrical configuration of the printing apparatus 100. As illustrated in FIG. 3, the printing apparatus 100 includes a control device 102 and a print processing unit (print engine) 104. The control device 102 is an element that controls the entire printing apparatus 100, and includes a control unit 60, a storage unit 62, a drive signal generation unit 64, an external I / F (interface) 66, and an internal I / F 68. Print data DP indicating an image to be printed on the recording paper 300 is supplied from an external device (for example, a host computer) 300 to the external I / F 66, and the print processing unit 104 is connected to the internal I / F 68. The print processing unit 104 is an element that records an image on the recording paper 300 under the control of the control device 102, and includes the recording head 24, the moving mechanism 14, and the paper transport mechanism 16 described above.

  The operation period of the printing apparatus 100 includes a print execution period and a print preparation period. The print execution period is a period during which the print processing unit 104 records an image on the recording paper 300 under the control of the control device 102 (that is, a period during which printing is actually executed). On the other hand, the print preparation period is a period for preparing an operation in the print execution period, and is set immediately after the printing apparatus 100 is turned on (before the start of the print execution period), for example. The ink in each pressure chamber 50 thickens with time due to evaporation of moisture from the surface (meniscus) exposed in the nozzle 56. In the print preparation period, the recording head 24 (each unit is set so that the state in which the ejection of the ink in the pressure chamber 50 is hindered due to thickening or the like is improved to the state in which the ink is properly ejected from the nozzle 56. This is the period for adjusting the injection part U). Specifically, the application of fine vibration and the flushing operation are executed during the print preparation period. The timing of the print preparation period is arbitrary. For example, a configuration in which the print preparation period is set periodically is also employed.

  The storage unit 62 includes a ROM that stores a control program and the like, and a RAM that temporarily stores various data necessary for image printing. The control unit 60 comprehensively controls each element (for example, the print processing unit 104) of the printing apparatus 100 by executing the control program stored in the storage unit 62. For example, the control unit 60 generates control data DC instructing either ejection of ink in the pressure chamber 50 or application of fine vibration to the ink (that is, non-ejection). The slight vibration means such vibration that ink in the pressure chamber 50 is not ejected from the nozzle 56.

The temperature sensor S <b> 1 detects the environmental temperature and outputs it to the control unit 60. The control unit 60 generates control data DC instructing ink ejection / non-ejection (fine vibration) in the print execution period according to the print data DP supplied from the external device 400 to the external I / F 66. That is, the recording head 24 is caused to execute an operation of recording an image corresponding to the print data DP on the recording paper 300 by ejecting ink onto the recording paper 300. In addition, the control unit 60 controls the recording head 24 so that a fine vibration is applied and a flushing operation is performed during the print preparation period.
Further, the controller 60 outputs a temperature signal to the drive signal generator 64. More specifically, a temperature signal indicating the temperature detected by the temperature sensor S1 is output during the printing execution period, and a temperature indicating a temperature lower than the temperature detected by the temperature sensor S1 during the flushing operation during the printing preparation period. Output a signal.

  Each of the ejection pulse PD1 and the ejection pulse PD2 is a drive pulse that vibrates the pressure chamber 50 so that a predetermined amount of ink is ejected from the nozzle 56 when supplied to the piezoelectric vibrator 422. In this example, the first ejection pulse PD1 can form a larger dot than the second ejection pulse PD2.

  FIG. 5 is a schematic diagram of an electrical configuration of the recording head 24. As shown in FIG. 5, the recording head 24 includes a plurality of drive circuits 32 corresponding to different unit injection units U. The drive signal COM1 and the drive signal COM2 generated by the drive signal generator 64 are commonly supplied to the plurality of drive circuits 32 via the internal I / F 68. The control data DC generated by the control unit 60 is supplied to each drive circuit 32 via the internal I / F 68.

  Each drive circuit 32 selects a section corresponding to the control data DC supplied from the control unit 60 from the drive signal COM 1 or the drive signal COM 2 and supplies the selected section to the piezoelectric vibrator 422. For example, when the control data DC instructs ink ejection, the drive circuit 32 selects the ejection pulse PD1 of the drive signal COM1 and the ejection pulse PD2 of the drive signal COM2 and supplies them to the piezoelectric vibrator 422. Therefore, the ink in the pressure chamber 50 is ejected from the nozzle 56.

  By the way, the viscosity of the ink increases as the temperature decreases. In order to eject the same amount of ink in a low temperature state as compared to a high temperature state, it is necessary to supply a pulse having a larger ejection force to the piezoelectric vibrator 422. For this reason, the control unit 60 supplies the temperature signal to the drive signal generation unit 64. The drive signal generator 64 generates a drive signal COM1 and a drive signal COM2 in which the ejection force is adjusted according to the temperature signal.

  Specifically, the pulse waveform is adjusted so that the ink ejection force increases as the temperature decreases. FIG. 6 shows the relationship between the injection pulse PD1 and the temperature. When T1 <T2 <T3 in terms of temperature, the potential difference between the highest potential Vh and the lowest potential VL of the ejection pulse PD1 is w11> w12> w13. By controlling the ink ejection force according to the temperature as described above, the ink can be stably ejected even if the viscosity of the ink changes according to the temperature.

  The control unit 60 also functions as means for causing the recording head 24 to perform a flushing operation. The controller 60 causes the recording head 24 to perform a flushing operation during the print preparation period. The flushing operation is an operation for forcibly ejecting ink to each unit ejection unit U in a state where the recording head 24 is moved to the retracted position (on the cap 18). The control unit 60 supplies the control data DC instructing ink ejection to each drive circuit 32 to cause each unit ejection unit U to perform a flushing operation (that is, selection of the ejection pulse PD1 and the ejection pulse PD2). Ink ejected from each nozzle 56 in the flushing operation is received by the cap 18 at the retreat position. By the above flushing operation, clogging of each nozzle 56 and intrusion of bubbles into the pressure chamber 50 are eliminated and ink thickening is eliminated. The amount of ink ejected from each unit ejection unit U in the flushing operation is variably controlled by the control unit 60 supplying control data DC to each unit ejection unit U and setting the number of ink ejections.

  By the way, the flushing operation is executed in order to suppress the thickening of the ink in the vicinity of the meniscus resulting from the evaporation of water from the meniscus of the nozzle. For this reason, at the time of the flushing operation, there is a possibility that ink cannot be ejected even if the piezoelectric vibrator 422 is driven by the ejection pulse for printing corresponding to the temperature at that time. Therefore, in this embodiment, the flushing operation is performed using an ejection pulse having a larger ejection force than the ejection pulse for printing. For this reason, at the time of the flushing operation, the control unit 60 controls the drive signal generation unit 64 so as to generate an injection pulse corresponding to a temperature lower than the temperature detected by the temperature sensor S1. That is, the control unit 60 and the drive signal generation unit 64 generate a printing ejection pulse (printing signal) according to the temperature detected during the printing operation, and discharge force is generated from the printing ejection pulse during the flushing operation. It functions as a means for generating a large flushing injection pulse (flushing signal) and supplying it to the piezoelectric vibrator 422.

  Specifically, when the temperature detected by the temperature sensor S1 is Tx, the control unit 60 subtracts the correction temperature Th from the temperature Tx to obtain a corrected temperature Ts (= Tx−Th). Then, the controller 60 supplies the corrected temperature Ts to the drive signal generator 64. The drive signal generator 64 generates the drive signal COM1 and the drive signal COM2 corresponding to the corrected temperature Ts that is lower than the actual temperature Tx by the correction temperature Th. Note that the control unit 60 may output the correction temperature Ts during the entire flushing operation, but in the present embodiment, the control unit 60 outputs the correction temperature Ts only during a period corresponding to a predetermined number of ink ejections from the start of the flushing period. In the subsequent flushing period, the detected temperature Tx is output. Accordingly, the drive signal generation unit 64 generates a flushing ejection pulse having a larger ejection force than the printing ejection pulse at the detected temperature Tx from the start of the flushing operation to a predetermined number of ejections. After the number of times has elapsed, a printing ejection pulse corresponding to the detected temperature Tx is generated. Immediately after the start of the flushing operation, it is necessary to eject the thickened ink near the meniscus. Therefore, it is necessary to drive the piezoelectric vibrator 422 with an ejection pulse having a larger ejection force, but the thickened ink is ejected. After that, flushing can be performed with a normal discharge force. Thus, since the ejection pulse having a large ejection force is used only at the start of flushing, the thickened ink can be ejected reliably, and the amount of ink to be ejected can be reduced.

  Further, the correction temperature Th may be constant or variable. In the case of making it variable, the corrected temperature Ts may be calculated by calculation using the detected temperature Tx as a variable. Further, a table stored in association with the temperature Tx detected by the temperature sensor S1 and the correction temperature Th may be provided in the storage unit 62, and the correction temperature Th may be acquired with reference to this table. Further, a table storing the detected temperature Tx and the corrected temperature Ts in association with each other may be provided in the storage unit 62, and the corrected temperature Ts may be directly acquired with reference to the table. When the correction temperature Th is kept constant, the configuration can be simplified because calculations and tables can be dispensed with. Further, when the correction temperature Th is made variable, a fine response can be made according to the temperature characteristics of the ink, so that flushing can be performed more reliably.

  By the way, the potential difference between the highest potential and the lowest potential of the ejection pulse for printing becomes the largest at the lower limit temperature Tmin of the operating temperature range of the printing apparatus 100. The power supply voltage of the drive signal generator 64 is designed so that an injection pulse having the largest potential difference between the highest potential and the lowest potential with respect to the lower limit temperature Tmin can be generated, and there is a case where an injection pulse having a potential difference higher than that cannot be generated. is there. When the corrected temperature Ts is lower than the lower limit temperature Tmin, the drive signal generator 64 may generate the drive signal COM1 and the drive signal COM2 corresponding to the lower limit temperature Tmin during the flushing operation, but it is not always possible to perform flushing reliably. Absent. Therefore, when the corrected temperature Ts is lower than the lower limit temperature Tmin, the drive signal generator 64 may generate a drive signal for flushing.

In this case, as shown in FIG. 7, the injection pulse may be such that the reference potential VREF, the lowest potential VL, and the differential voltage Vc are smaller in the flushing injection pulse.
Alternatively, as shown in FIG. 8, the waveform of the ejection pulse in the period p1 may be steep (the rise time is shortened).
Further, an ejection pulse having a stronger ejection force may be generated using the resonance of the recording head 24. Specifically, when the natural vibration period of the recording head 24 is Tc, as shown in FIG. 9, the difference between the time from the start of expansion of the pressure chamber to the start of contraction and the half time of the natural vibration period Tc. The injection pulse may be generated so that becomes smaller. In this case, the following formula (1) is established.
| T1-Tc / 2 |> | T2-Tc / 2 | ...... Formula (1)

  As described above, in this embodiment, the printing ejection pulse corresponding to the temperature is generated, and the printing ejection pulse having a temperature lower than the temperature is generated as the flushing ejection pulse. As a result, the ink having increased viscosity can be ejected using ejection pulses having a larger ejection force than that of normal printing, so that the reliability of printing can be improved. Furthermore, since the flushing ejection pulse can also be used as the printing ejection pulse, the configuration can be further simplified. In addition, since flushing injection pulses having different ejection forces depending on the temperature can be generated, flushing can be performed reliably. Further, when the temperature is high, the flushing injection pulse having a small potential difference between the highest potential and the lowest potential is used compared to when the temperature is low, so that power consumption can be reduced.

<B: Second Embodiment>
In the first embodiment described above, a printing ejection pulse corresponding to a temperature lower than the temperature detected by the temperature sensor S1 is used as a flushing ejection pulse. On the other hand, the printing apparatus 200 according to the second embodiment shown in FIG. 10 is different in that it includes a humidity sensor S2 and a correction table TBL, and the others are similar to the printing apparatus 100 of the first embodiment shown in FIG. It is configured.
The humidity sensor S2 detects the environmental humidity Wx and outputs it to the control unit 60. In the correction table TBL, the detected temperature Tx and humidity Wx and the correction temperature Th are stored in association with each other. FIG. 11 shows an example of the contents stored in the correction table TBL. In this example, focusing on the same temperature range, the correction temperature Th decreases as the humidity increases. That is, an ejection pulse with a small ejection force is used. This is because as the humidity increases, the amount of ink evaporated from the meniscus decreases, and the degree of thickening decreases.
As described above, in the second embodiment, since the ejection pulse used for the flushing is generated in consideration of not only the temperature but also the humidity, it is possible to eject the thickened ink more reliably and improve the printing reliability. be able to. The correction table TBL may be provided in the storage unit 62.

<C: Modification>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined as long as they do not contradict each other.
(1) Modification 1
In each of the above embodiments, a plurality of systems of drive signals (COM1, COM2) are supplied to the recording head 24. However, only one system of drive signals is used to drive each piezoelectric vibrator 422, or three or more systems of drive signals. A configuration in which each is used for driving each piezoelectric vibrator 422 may also be employed. In a configuration using one system of drive signals, for example, a drive signal in which the ejection pulse PD1, the fine vibration pulse PS1, and the fine vibration pulse PS2 are arranged in time series is supplied to the recording head 24. The pulse height and waveform of each pulse (PD1, PD2, PS1, PS2) of the drive signal are arbitrary.

(2) Modification 2
The degree of ink thickening differs depending on the type of ink. Therefore, a memory storing data indicating the ink type is provided in the ink cartridge 22, and the control unit 60 reads out the data indicating the ink type from the ink cartridge 22 mounted on the carriage 12, and corrects the correction temperature according to the ink type. Th may be changed. According to the first embodiment, a fixed correction temperature Th is switched, or a memory storing the detected temperature Tx and the correction temperature Th in association with each other is prepared according to the type of ink, and this is switched. You can do it. In the second embodiment, the table TBL may be prepared according to the type of ink and switched. As a result, the thickened ink can be discharged more reliably.

(3) Modification 3
In each of the above embodiments, the longitudinal vibration type piezoelectric vibrator 422 is illustrated, but the configuration of the element (pressure generating element) that changes the pressure in the pressure chamber 50 is not limited to the above examples. For example, a vibrating body such as a flexural vibration type piezoelectric vibrator 422 or an electrostatic actuator may be used. Further, the pressure generating unit of the present invention is not limited to an element that imparts mechanical vibration to the pressure chamber 50. For example, a heat generating element (heater) that changes the pressure in the pressure chamber 50 by generating bubbles by heating the pressure chamber 50 can be used as the pressure generating unit. That is, the pressure generator of the present invention is included as an element for changing the pressure in the pressure chamber 50, and the method for changing the pressure (piezo method / thermal method) and the configuration are not questioned.

(4) Modification 4
The printing apparatus 100 of each of the above forms can be employed in various devices such as a plotter, a facsimile machine, and a copier. However, the application of the liquid ejecting apparatus of the present invention is not limited to image printing. For example, a liquid ejecting apparatus that ejects a solution of each color material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. In addition, a liquid ejecting apparatus that ejects a liquid conductive material is used as an electrode manufacturing apparatus that forms electrodes of a display device such as an organic EL (Electroluminescence) display device or a field emission display (FED). The A liquid ejecting apparatus that ejects a bioorganic solution is used as a chip manufacturing apparatus that manufactures biochemical elements (biochips, microarrays).

  Further, in each of the above embodiments, the serial type printing apparatus 100 in which the carriage 12 on which the recording head 24 is mounted moves in the main scanning direction is illustrated, but a plurality of nozzles are arranged over the entire area in the width direction of the recording paper. The present invention can also be applied to a printing apparatus using a line-type recording head that is elongated in the main scanning direction.

DESCRIPTION OF SYMBOLS 100 ... Printing apparatus, 12 ... Carriage, 14 ... Movement mechanism, 16 ... Paper conveyance mechanism, 18 ... Cap, 20 ... Ejection detection part, 22 ... Ink cartridge, 24 ... Recording head, 32 ... ... Drive circuit, 42 ... Vibration unit, 422 ... Piezoelectric vibrator, 60 ... Control part, 62 ... Storage part, 64 ... Drive signal generation part, 66 ... External I / F, 68 ... Internal I / F, 72... Landing member, 76... Detection circuit, 200 .. recording paper, 300 .. external device, S1... Temperature sensor, S2 .. humidity sensor, correction TBL ... table, PD1, PD2. Injection pulse.

Claims (8)

A temperature detector for detecting the temperature;
A pressure chamber filled with a liquid, a nozzle communicating with the pressure chamber, and a pressure generating unit that varies the pressure in the pressure chamber, and the liquid in the pressure chamber is changed according to the pressure variation in the pressure chamber. An injection unit for injecting from the nozzle;
A signal generation unit that generates a printing signal according to the temperature detected during the printing operation, generates a flushing signal having a larger ejection force than the printing signal during the flushing operation, and supplies the flushing signal to the pressure generation unit;
A liquid ejecting apparatus comprising:   The liquid ejecting apparatus according to claim 1, wherein the signal generation unit generates the printing signal corresponding to a temperature lower than the detected temperature as the flushing signal during a flushing operation.   The signal generation unit generates the printing signal corresponding to a correction temperature obtained by subtracting a fixed correction temperature from the detected temperature as the flushing signal during a flushing operation. The liquid ejecting apparatus according to 1. It has a humidity detector that detects humidity,
The signal generation unit generates a flushing signal having a larger ejection force than the printing signal based on the detected temperature and the detected humidity during the flushing operation, and supplies the flushing signal to the pressure generation unit.
The liquid ejecting apparatus according to claim 1. The signal generating unit generates a correction temperature based on the detected temperature and the detected humidity during the flushing operation, and the printing unit corresponding to the correction temperature obtained by subtracting the correction temperature from the detected temperature Generating a signal as the flushing signal;
The liquid ejecting apparatus according to claim 4. The lower limit temperature at which printing operation is possible is set,
The signal generation unit generates a flushing signal having a larger ejection force than the printing signal corresponding to the lower limit temperature when the correction temperature is lower than the lower limit temperature during the flushing operation.
The liquid ejecting apparatus according to claim 3, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.   The signal generator generates a flushing signal having a larger ejection force than the printing signal from the start of the flushing operation to a predetermined number of ejections, and the detected temperature after the predetermined number of ejections has elapsed. The liquid ejecting apparatus according to claim 1, wherein the printing signal corresponding to the frequency is generated as a flushing signal. A temperature detector that detects temperature; a pressure chamber filled with liquid; a nozzle that communicates with the pressure chamber; and a pressure generator that varies the pressure in the pressure chamber. A control method for a liquid ejecting apparatus comprising: an ejection unit that ejects the liquid in the pressure chamber from the nozzle in response.
A printing signal is generated according to the detected temperature during the printing operation and supplied to the pressure generating unit,
Generating the printing signal corresponding to a temperature lower than the detected temperature during the flushing operation as the flushing signal and supplying the signal to the pressure generating unit;
A control method for a liquid ejecting apparatus.

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