JP2009061622A - Fluid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid jet apparatus designed to more surely enhance a striking position accuracy of fluid. <P>SOLUTION: The fluid jet apparatus is equipped with a fluid jet head 3 with a nozzle opening face 43a where a plurality of nozzles 47 for jetting the fluid L are formed, a jet speed detecting means 7 which detects a fluid jet speed from the nozzles 47, a platen gap adjusting mechanism 130 which adjusts a platen gap PG between a surface of a platen where a jetting object of the fluid is placed and the nozzle opening face 43a, and a platen gap control means 91 which adjusts to widen the platen gap PG when the fluid jet speed detected by the jet speed detecting means 7 is higher than a regulation value C and adjusts to narrow the platen gap PG when the fluid jet speed is lower than the regulation value C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fluid ejecting apparatus.

The fluid ejecting apparatus is an apparatus that includes a fluid ejecting head capable of ejecting a fluid and ejects various fluids from the fluid ejecting head.
As a typical fluid ejecting apparatus, for example, an ink jet recording head (hereinafter simply referred to as a recording head) as a fluid ejecting head is provided, and liquid ink is recorded as ink droplets from the nozzle (opening) of the recording head. An image recording apparatus such as an ink jet printer that performs recording by forming dots by being ejected and landed on an ejection target such as paper can be given.
In recent years, the fluid ejecting apparatus is applied not only to the image recording apparatus but also to various manufacturing apparatuses such as a manufacturing apparatus for a color filter such as a liquid crystal display.

In such an image recording apparatus, for example, ink stored in a liquid storage unit such as an ink tank or an ink cartridge is introduced into the pressure chamber of the recording head, and a drive signal is applied to a pressure generation source such as a piezoelectric vibrator. By driving this, pressure fluctuations are generated in the ink in the pressure chamber, and ink drops are ejected from the nozzles by controlling the pressure fluctuations.
The recording head increases or decreases the liquid volume (weight / volume) of the ink droplets ejected from the nozzle according to the drive voltage (potential difference from the lowest voltage to the highest voltage) of the drive signal supplied to the pressure source and the waveform. It is supposed to be.

  Further, when cleaning the recording head for the purpose of ensuring the recording head cleaning operation and improving the reliability of the recording apparatus, the state of the platen gap is judged, and the platen gap is not suitable for the head cleaning action. In some cases, it is known that the platen gap is adjusted by the control means so that an appropriate wiping action by the cleaning member can be enjoyed (Patent Document 1).

Further, in the printer that drives the carriage, the response characteristic of the DC motor is detected. If the detected value is not less than the allowable limit value and the carriage moving distance required for one line printing is shorter than the predetermined distance, one line printing is required. By correcting the movement distance of the carriage to be equal to or larger than the predetermined travel distance, the average current flowing through the DC motor is reduced by increasing the carriage travel distance required for one line printing. For this reason, there is known one in which the heat generation temperature of the DC motor does not exceed the allowable limit temperature (Patent Document 2).
JP-A-11-115275 JP-A-6-1031

  By the way, since the fluid ejection speeds of the fluid ejection heads in the mass-produced fluid ejection devices are different and the fluid ejection speed is different, the variation is corrected so as to eliminate the adverse effect that the fluid landing position accuracy does not increase. In addition, there is a problem that automation is desired because considerable time and labor are required to correct this variation.

  The present invention has been made in view of the above-mentioned problems, performs control suitable for the purpose of obtaining a desired fluid ejection result, and responds to variations in fluid ejection heads in mass-produced fluid ejection devices. An object of the present invention is to provide a fluid ejecting apparatus in which the landing position accuracy of the is reliably increased.

In order to achieve the above object, the present invention provides a fluid ejecting head having a nozzle opening surface in which a plurality of nozzles ejecting fluid are formed, an ejecting speed detecting means for detecting a fluid ejecting speed from the nozzle, and the fluid A platen gap adjusting mechanism that adjusts the platen gap between the surface of the platen on which the injection target is placed and the nozzle opening surface, and the platen gap when the fluid injection speed detected by the injection speed detecting means is faster than a specified value. And a platen gap control means for adjusting the platen gap to be narrowed when the fluid ejection speed is slower than a specified value.
Thereby, it is possible to provide a fluid ejecting apparatus that can obtain a desired fluid ejecting result.

Further, in the present invention, a platen gap calculating means for calculating an optimum value of the platen gap based on the fluid ejection speed at the time of initial operation after completion of assembly or at the time of initial operation after a non-use period of a predetermined length, A configuration comprising platen gap initial setting means for initially setting the optimum value is adopted.
Accordingly, it is possible to provide a fluid ejecting apparatus in which the landing position accuracy of the fluid is improved in response to variations in the fluid ejecting heads in the mass-produced fluid ejecting apparatuses.

In the present invention, a fluid ejecting head having a nozzle opening surface on which a nozzle for ejecting fluid is formed, an ejecting speed detecting means for detecting the fluid ejecting speed from the nozzle, and the fluid ejecting head are mounted. A carriage that scans, a carriage moving mechanism that reciprocates the carriage at a predetermined carriage speed, and when the fluid ejection speed detected by the ejection speed detection means is faster than a specified value, the carriage speed is increased, and the fluid ejection speed is A configuration including a carriage speed control unit that controls the carriage speed so as to reduce the carriage speed when it is slower than a specified value is adopted.
Thereby, it is possible to provide a fluid ejecting apparatus that can obtain a desired fluid ejecting result.

Further, in the present invention, a carriage speed calculating means for calculating an optimum value of the carriage speed based on the fluid ejection speed at the time of the initial operation after completion of the assembly or at the time of the initial operation after the non-use period of a predetermined length. Carriage speed initial setting means for initially setting the optimum value;
A configuration including the above is adopted.
Accordingly, it is possible to provide a fluid ejecting apparatus in which the landing position accuracy of the fluid is improved in response to variations in the fluid ejecting heads in the mass-produced fluid ejecting apparatuses.

In the present invention, a fluid ejection head having a nozzle opening surface in which a plurality of nozzles for ejecting fluid are formed, an ejection speed detecting means for detecting a fluid ejection speed from the nozzle, and an object to be ejected with the fluid are placed. A platen gap adjusting mechanism for adjusting the platen gap between the surface of the platen and the nozzle, and when the fluid ejection speed detected by the ejection speed detecting means is faster than a specified value, the platen gap is widened to define the fluid ejection speed. A platen gap control means for adjusting the platen gap to be narrowed when the value is slower than the value, a carriage moving mechanism for reciprocally moving a scanning carriage mounted with the fluid ejection head at a predetermined carriage speed, and the fluid ejection speed If it is faster than the specified value, the carriage speed is increased, and the fluid ejection speed is slower than the specified value. If and a carriage speed control means for controlling the carriage velocity to slow the carriage speed, to adopt a configuration for controlling at least one of said platen gap the carriage speed.
Thereby, it is possible to provide a fluid ejecting apparatus that can obtain a desired fluid ejecting result.

In the present invention, there is further provided mode selection means that allows a user to select either a speed priority mode in which only the carriage speed can be controlled or a platen gap priority mode in which only the platen gap can be controlled. Adopt the configuration.
Accordingly, the user can arbitrarily select one of the speed priority mode and the platen gap priority mode according to the status of the paper used by the user, a request regarding usability, and other preferences.

In the present invention, a configuration is adopted in which both the platen gap and the carriage speed are controlled simultaneously.
Accordingly, it is possible to provide a fluid ejecting apparatus that can obtain a reliable control effect and obtain a desired fluid ejecting result.

In the present invention, the ejection speed detecting means applies an electric field between the detection unit arranged to face the nozzle opening surface with a predetermined gap therebetween, and the detection unit and the nozzle opening surface. A configuration including a voltage application unit and a voltage detection unit that outputs a change in the voltage value of the detection unit based on electrostatic induction when the fluid moves from the nozzle to the detection unit as the detection signal is adopted. .
As a result, the ejection speed at which the fluid moves from the nozzle to the detection unit is provided as control information for detecting the ejection speed detection means and controlling the platen gap and / or the carriage speed, thereby ensuring more accurate landing position accuracy of the fluid. By increasing the height, it is possible to provide a fluid ejecting apparatus that can obtain a desired fluid ejecting result.

Hereinafter, a fluid ejection device according to the present invention will be described with reference to the drawings. In the present embodiment, an ink jet printer (hereinafter referred to as a printer 1) is exemplified as the fluid ejecting apparatus according to the invention.
FIG. 1 is a partially exploded view showing a schematic configuration of a main part of a printer (fluid ejecting apparatus) 1 according to the present embodiment.
The printer 1 includes a carriage 4 on which a sub tank 2 and a recording head (jet head) 3 are mounted, and a printer main body 5.
The printer main body 5 includes a carriage moving mechanism 65 (see FIG. 4) that reciprocates the carriage 4 and a paper feeding mechanism 66 (see FIGS. 2 and 3) that transports a recording paper 35 (see FIGS. 2 and 3) that is a fluid ejection target. And a capping mechanism 14 used for a cleaning operation for sucking the ink (fluid) L thickened from each nozzle 47 (see FIG. 4) of the recording head 3 and the ink L supplied to the recording head 3 were stored. An ink cartridge 6 is provided.

  The printer 1 also includes an ink droplet sensor 7 (see FIG. 4) that can detect an ink droplet (fluid) D ejected from the recording head 3. The ink droplet sensor (ejection speed detection means) 7 charges the ink droplet D ejected from the recording head 3 and outputs a voltage change based on electrostatic induction when the charged ink droplet D flies as a detection signal. It is comprised so that it may do. Details of the ink droplet sensor 7 will be described later.

The carriage moving mechanism 65 includes a guide shaft 8 installed in the width direction of the printer body 5, a pulse motor 9, a drive pulley 10 that is connected to a rotation shaft of the pulse motor 9 and is driven to rotate by the pulse motor 9, The drive pulley 10 is an idle pulley 11 provided on the opposite side of the printer body 5 in the width direction, and a timing belt 12 that is spanned between the drive pulley 10 and the idle pulley 11 and connected to the carriage 4. , Is composed of.
The carriage 4 is configured to reciprocate in the main scanning direction along the guide shaft 8 by driving the pulse motor 9.
The paper feed mechanism 66 includes a paper feed motor M and a paper feed roller 133 (see FIG. 2) that is rotationally driven by the paper feed motor M (hereinafter referred to as “PF motor”) M, and the like. The paper is sequentially fed onto the platen 13 in conjunction with the recording (printing / printing) operation.

Next, the configuration of the platen gap adjusting mechanism 130 will be described with reference to FIGS. 2 and 3.
FIG. 2 is a side view showing an example of the platen gap adjusting mechanism 130 of the printer 1 according to the present embodiment. FIG. 3 is a side view showing a state in which the platen gap PG is largely adjusted in the platen gap adjusting mechanism 130 shown in FIG.

  The guide rod 102 for guiding the carriage 4 is composed of two rods 102A and 102B. The rods 102A and 102B are biased in the same direction via eccentric pins 131 and 132 provided at both ends thereof. A guide frame (not shown) is rotatably attached. Then, the carriage 4 is rotated in the same direction by a platen gap adjusting mechanism 130 described later, and the supported carriage 4 can be separated or approached in parallel to the platen 13. The paper feed mechanism 66 includes a paper feed motor M (see FIG. 1) and a paper feed roller 133 driven by the paper feed motor M.

Next, the platen gap adjustment mechanism 130 will be described.
A switching lever 135 is loosely fitted to the shaft 134 that is rotationally driven by the PF motor M so as to be movable in the axial direction. A sun gear 136 is arranged at the center of the switching lever 135. For example, a part of the shaft 134 is slidable in the direction of the shaft 134 and connected in the rotational direction. It is formed on the angular axis.

  Two planetary gears 137, 138 that are always meshed with the sun gear 136 are rotatably attached to the switching lever 135, and when the switching lever 135 is pressed by the movement of the carriage 4, it moves in the direction of the shaft 134, Depending on the rotation direction of the PF motor M, either one of the planetary gears 137 or 138 is configured to mesh with an intermediate gear 139 described later.

  The intermediate gear 139 is configured to selectively mesh with each of the two planetary gears 137 and 138, and the amount of rotation of the planetary gears 137 and 138 is determined by a modified geneva gear portion 140 that engages and disengages with the sector gear 141 described later. Regardless of the above, the fan gear 141 is rotated by a certain amount, and the sector gear 141 is rotated by a certain angle.

  On the other hand, the sector gear 141 is fixed to the end of the shaft 132 so as to rotate integrally with the one guide rod 102B. Further, the small sector gear 142 integrated with the sector gear 141 meshes with a sector sector gear 143 disposed between the guide rods 102A and 102B, and the shaft of the other guide rod 102A is interposed via the gear 143. 131 is configured to transmit rotation in the same direction to a small sector gear 144 fixed to the end of 131.

  When the platen gap adjusting mechanism 130 configured as described above performs printing on thick paper such as color-only paper or postcards, for example, if an operation button or the like arranged on a panel (not shown) is operated, PF The motor M rotates the shaft 134 shown in FIG. 3 counterclockwise.

  Along with this, the switching lever 135 disposed at the shaft end rotates counterclockwise, and the intermediate gear 139 rotates in the direction of the arrow in the drawing via the planetary gear 137 meshing with the sun gear 136. Further, the sector gear 141 that meshes with the deformed geneva gear portion 140 of the intermediate gear 139 is rotated by a certain amount to a position where it abuts against the stopper 141a, and one eccentric pin 132 integrated therewith is rotated clockwise in the figure.

At the same time, the sector-shaped sector gear 143 is rotated in the direction of the arrow through the small sector gear 142 integrated with the sector gear 141 and the other eccentric pin 131 is engaged with the other small sector gear 144 meshing with the sector gear. Are rotated in the same direction. As a result, the carriage 4 is pulled up parallel to the print reference plane, that is, the platen 13 by the guide rods 102A and 102B.
Needless to say, the platen gap PG can be narrowed by rotating the PF motor M in the opposite direction to the state shown in FIG.

FIG. 4 is a schematic diagram illustrating a schematic configuration of the recording head 3, the ink cartridge 6, the ink droplet sensor (ejection speed detection means) 7, and the control unit 60 of the printer 1 according to the present embodiment.
The ink droplet sensor 7 can detect the ejection state of the ink L ejected from the nozzles 47 of the recording head 3 as will be described later, and information on the ejection speed (fluid ejection speed) and ejection amount of the ink L. Can also be detected.

The ink cartridge 6 includes a case member 51 formed in a hollow box shape and an ink pack 52 formed of a plastic material. The ink pack 52 is accommodated in a storage chamber in the case member 51.
The ink cartridge 6 communicates with one end of the ink supply tube 34 and is configured to supply the ink L in the ink pack 52 to the recording head 3 side due to a water head difference from the nozzle opening surface 43a of the recording head 3. Has been. Specifically, the relative positional relationship between the ink cartridge 6 and the recording head 3 in the gravitational direction is set so that a slight negative pressure is applied to the meniscus of the nozzle 47. Then, the ink L is ejected by a pressure change caused by driving the piezoelectric vibrator 38 (see FIG. 5).

  In the embodiment of the present invention, any driving principle of fluid ejection may be used, but a piezoelectric element (laminated) type is illustrated as an embodiment of the recording head 3. Further, as the piezoelectric element 38, a type other than the laminated type (for example, monomorph, unimorph, bimorph, Mooney type, multi-Mooney type, cymbal type, etc.) may be used. Furthermore, without being limited to the piezo jet type using the piezoelectric element 38, for example, a thermal method can be adopted. Thus, any driving principle of injection may be used.

The control unit 60 includes a basic control function of the printer 1, that is, a function of outputting ejection data of the ink L to the recording head 3 based on print data input from an external device, and a maintenance control function (non- In addition, a platen gap control means 91, a carriage speed control means 93, and a mode selection means 96 are provided.
The platen gap control means 91 is based on a sensor detection value (detection signal) output from the ink droplet sensor 7 and a platen gap calculation means 97 for calculating an optimum value and a platen gap for initially setting the platen gap using the optimum value. An initial setting unit 92 is provided and has a function of controlling the platen gap adjusting mechanism 130.

  The carriage speed control means 93 is a carriage speed calculation means 94 for calculating an optimum value based on the sensor detection value output from the ink droplet sensor 7 and a carriage speed initial setting means 95 for initially setting the carriage speed using the optimum value. And has a function of controlling the carriage speed with respect to the carriage moving mechanism 65.

  The mode selection unit 96 is a function for the user to arbitrarily select one of a speed priority mode in which only the carriage speed can be controlled and a platen gap priority mode in which only the platen gap PG can be controlled. The microcomputer includes a microcomputer having a mode switching function according to a selection signal from a mode selection switch arranged on a panel (not shown), a program thereof, an electronic circuit, and the like.

FIG. 5 is a cross-sectional view illustrating the configuration of the recording head 3 of the printer 1 according to this embodiment.
The recording head 3 in this embodiment includes an introduction needle unit 17, a head case 18, a flow path unit 19, and an actuator unit 20 as main components.
Two ink introduction needles 22 are mounted side by side on the upper surface of the introduction needle unit 17 with the filter 21 interposed. The sub tanks 2 are respectively attached to these ink introduction needles 22. An ink introduction path 23 corresponding to each ink introduction needle 22 is formed inside the introduction needle unit 17.
The upper end of the ink introduction path 23 communicates with the ink introduction needle 22 via the filter 21, and the lower end communicates with the case flow path 25 formed inside the head case 18 via the packing 24.
In this embodiment, since two types of ink are used, two subtanks 2 are provided. However, the present invention is naturally applicable to a configuration using three or more types of ink. Is.

The sub tank 2 is molded from a resin material such as polypropylene. The sub-tank 2 is formed with a recess that becomes the ink chamber 27, and the ink chamber 27 is partitioned by attaching a transparent elastic sheet 26 to the opening surface of the recess.
In addition, a needle connection portion 28 into which the ink introduction needle 22 is inserted projects downward from the lower portion of the sub tank 2. The ink chamber 27 in the sub-tank 2 has a shallow mortar shape, and an opening on the upstream side of the connection channel 29 communicating with the needle connection portion 28 is located slightly below the vertical center on the side surface. The tank part filter 30 which filters the ink L is attached to this upstream side opening.
A seal member 31 into which the ink introduction needle 22 is liquid-tightly fitted is fitted in the internal space of the needle connection portion 28. As shown in FIG. 4, the sub-tank 2 is formed with an extending portion 32 having a communication groove portion 32 ′ communicating with the ink chamber 27, and an ink inlet 33 projects from the upper surface of the extending portion 32. It is installed.

An ink supply tube 34 that supplies ink L stored in the ink cartridge 6 is connected to the ink inlet 33. Accordingly, the ink L that has passed through the ink supply tube 34 flows into the ink chamber 27 from the ink inlet 33 through the communication groove 32 ′.
The elastic sheet 26 can be deformed in a direction in which the ink chamber 27 contracts and a direction in which the ink chamber 27 expands. The pressure variation of the ink L is absorbed by the damper function due to the deformation of the elastic sheet 26. That is, the sub tank 2 functions as a pressure damper by the action of the elastic sheet 26. Therefore, the ink L is supplied to the recording head 3 side in a state where pressure fluctuation is absorbed in the sub tank 2.

The head case 18 is a hollow box-shaped member made of synthetic resin, and a flow path unit 19 is joined to the lower end surface, the actuator unit 20 is accommodated therein, and an upper end surface opposite to the flow path unit 19 is provided. The introduction needle unit 17 is attached with the packing 24 interposed.
A case channel 25 is provided inside the head case 18 so as to penetrate the height direction. The upper end of the case flow path 25 communicates with the ink introduction path 23 of the introduction needle unit 17 via the packing 24.
Further, the lower end of the case channel 25 communicates with a common ink chamber (not shown) in the channel unit 19. Therefore, the ink L introduced from the ink introduction needle 22 is supplied to the common ink chamber side through the ink introduction path 23 and the case flow path 25.

As shown in FIG. 4, the ink droplet sensor 7 includes a cap member 15 as a droplet receiving portion disposed at the home position, an inspection region 74 provided inside the cap member 15, and the inspection region 74. A voltage application circuit (voltage application unit) 75 that applies a voltage to the nozzle substrate 43 of the recording head 3 and a voltage detection circuit (voltage detection unit) 76 that detects a voltage in the inspection region 74 are configured.
The ink droplet sensor 7 applies an electric field between the nozzle opening surface 43 a and the electrode member 78, and detects a sensor detection value (voltage [voltage [] when the ink droplet D moves from the nozzle 47 to the electrode member 78. V] value) is output to control unit 60 as a detection signal (see FIG. 7). The control unit 60 can perform arithmetic processing on the detection signal output from the ink droplet sensor 7 and can acquire information on the discharge speed and discharge amount of the ink L based on the detection waveform.

The cap member 15 is a tray-like member having an open upper surface, and is formed of an elastic member such as an elastomer. An ink absorber 77 is disposed inside the cap member 15. For the ink absorber 77, for example, a nonwoven fabric such as felt is used as a material having a high holding power of the ink L.
A mesh-shaped electrode member 78 is disposed on the upper surface of the ink absorber 77. The surface of the electrode member 78 corresponds to the inspection region 74. The electrode member 78 is formed as a lattice mesh made of a metal such as stainless steel. Therefore, the ink droplets D that have landed on the electrode member 78 are absorbed and held by the absorber 77 disposed on the lower side through the gap between the grid-like electrode members 78.
Although the surface of the electrode member 78 that is the inspection region 74 may be immersed in the ink L, the suction pump 16 sucks and discharges the ink L in a process associated with a known flushing process in the maintenance process. The electrode member 78 immersed in the ink L can be exposed. The suction pump 16 is driven by the PF motor M via a driving force switching mechanism (not shown).

The voltage application circuit 75 is electrically connected via a direct current power source (for example, 400 V) and a resistance element (for example, 1 MΩ) so that the electrode member 78 is a positive electrode and the nozzle substrate 43 of the recording head 3 is a negative electrode. ing.
The voltage detection circuit 76 amplifies the voltage signal of the electrode member 78 and outputs it, and A / D converts the signal output from the amplification circuit 81 and outputs it to the printer controller (not shown). D conversion circuit 82 is provided. The amplifier circuit 81 amplifies and outputs the voltage signal of the electrode member 78 at a predetermined amplification factor. The A / D conversion circuit 82 is configured to convert the analog signal output from the amplifier circuit 81 into a digital signal and output it as a detection signal to the control unit 60.

Next, the operation of the ink droplet sensor 7 will be described.
FIG. 6 is a schematic diagram for explaining the principle in which the ink droplet sensor 7 of the printer 1 according to the present embodiment generates an induced voltage by electrostatic induction. FIG. 6A is a diagram illustrating a state immediately after the ink droplet D is ejected. (B) is a diagram showing a state in which the ink droplet D has landed on the inspection region 74 of the cap member 15.
FIG. 7 is a diagram illustrating a waveform example of a detection signal output from the ink droplet sensor 7 of the printer 1 according to the present embodiment. In FIG. 7, the horizontal axis is time [μs], the vertical axis is the sensor detection value [V] output from the sensor 7, A is the peak value [V] that is positively correlated with the size of the ink droplet D, and the rise time of the waveform H. B1 indicating the landing time [μs] when the ejection speed of the ink droplet D is fast, and B2 indicating the rising time of the waveform (detection signal) G is the landing time [μs] when the ejection speed of the ink droplet D is slow, C Indicates a standard landing time [μs] defined as a specified value (design value).

First, when print data (see FIG. 4) is transmitted from the external device to the printer 1, the control unit 60 transmits ejection data (see FIG. 4) developed so as to correspond to the dot pattern to the recording head 3. The recording head 3 executes a recording (printing / printing) process, that is, the ejection of the ink droplet D onto the recording paper, based on the received ejection data.
When a preset time (periodic flushing time interval) elapses during the recording process, the recording process is interrupted and the periodic flushing process is started.

Next, the initial setting of the platen gap PG and / or the carriage speed in the printer 1 will be described with reference to FIG. 8 and other drawings.
FIG. 8 is a flowchart illustrating a process of initially setting the platen gap PG and / or the carriage speed in the printer 1 according to this embodiment.
In the printer 1 according to the present embodiment, the initial setting is automatically executed at the first operation after the assembly is completed, or at the first operation after the non-use period of a predetermined length has elapsed. Is done.

  First, at the first operation after the printer 1 is assembled at the factory, or after a non-use period of a predetermined length has passed by the user, that is, when the printer 1 is in a non-energized state, for example, a power plug is connected. When the power is turned on for the first time after being plugged into the outlet (hereinafter simply referred to as “first operation after manufacture”), the control unit 60 issues a signal for starting the initial setting to each unit (step S1). Note that all the operations are controls based on the execution of the computer program in the control unit 60, but description thereof is omitted in the following detailed description.

The operation following (Step S1) will be briefly described as follows.
In response to the signal for starting the initial setting, the recording head (nozzle opening surface 43a) 3 and the inspection area 74 are opposed to each other in a non-contact state (step S2). Next, a voltage is applied between the nozzle substrate and the electrode member (step S3). Then, an ink droplet is ejected from the nozzle (step S4). Then, a voltage change (detection waveform) is detected by the ink droplet sensor (step S5). A fluid ejection speed is obtained based on the detected waveform (step S6). Based on the fluid ejection speed, an optimum value of the platen gap PG and / or the carriage (CR) speed is calculated (step S7). Based on the optimum value, the platen gap PG and / or the carriage speed are initialized (step S8). After the initial setting, the process shifts to the normal printing mode (step S9).

Here, the operation after (step S2) will be described in detail.
First, the carriage 4 is driven, the recording head 3 is moved to the home position, and is positioned above the cap member 15. Next, the cap member 15 is raised by an unillustrated lifting mechanism, and the nozzle opening surface 43a of the recording head 3 and the inspection region 74 (electrode member 78) are brought close to each other in a non-contact state (step S2).
Then, a voltage is applied between the nozzle substrate 43 and the electrode member 78 by the voltage application circuit 75 (step S3).
Next, in a state where a voltage is applied between the nozzle substrate 43 and the electrode member 78, the piezoelectric vibrator 38 is driven, and the ink droplet D is discharged from any one of the nozzles 47 (for example, # 1). Discharge (step S4).

  At this time, since the nozzle substrate 43 is a negative electrode, as shown in FIG. 6A, a part of the negative charge of the nozzle substrate 43 moves to the ink droplet D, and the discharged ink droplet D becomes negative. Charge. As the ink droplet D approaches the inspection region 74 of the cap member 15, the positive charge increases in the inspection region 74 (the surface of the electrode member 78) due to electrostatic induction. Thereby, the voltage between the nozzle substrate 43 and the electrode member 78 becomes higher than the initial voltage value in the state where the ink droplet D is not ejected due to the induced voltage generated by electrostatic induction.

Thereafter, as shown in FIG. 6B, when the ink droplet D lands on the electrode member 78, the positive charge of the electrode member 78 is neutralized by the negative charge of the ink droplet D. For this reason, the voltage between the nozzle substrate 43 and the electrode member 78 is lower than the initial voltage value.
Thereafter, the voltage between the nozzle substrate 43 and the electrode member 78 returns to the initial voltage value.
Therefore, as shown in FIG. 7, the detection waveform output from the ink droplet sensor 7 is a waveform that once rises, then falls to below the initial voltage value, and then returns to the original voltage value.
In this manner, the ink droplet sensor 7 detects a voltage change (detection waveform) when the ink droplet D is ejected from the nozzle 47 (for example, # 1) (step S5).

The landing time of the ink droplet D corresponds to times B1 and B2 from when the voltage starts to rise (when a voltage change occurs) in the detection waveform until it reaches a peak.
Since the ejection speed of the ink droplet D is a value obtained by dividing the ejection distance by the landing times B1 and B2, the distance from the nozzle opening surface 43a to the electrode member 78 is known as the ejection distance. The ejection speed of the ink droplet D is calculated by dividing by the landing times B1 and B2 (step S6).
In FIG. 7, the waveform (detection signal) H indicates that the ejection speed of the ink droplet D is fast because the landing time B1 is shorter than the specified value C. The waveform (detection signal) G indicates that the ejection speed of the ink droplet D is slow because the landing time B2 is longer than the specified value C.
The ink droplet sensor 7 constitutes an ejection speed detection means for detecting the fluid ejection speed from the nozzle 47, and calculates the fluid ejection speed based on the landing times B1 and B2 and the ejection distance (step S7). Regarding these specific calculation processes, the digital signal output from the A / D conversion circuit 82 is calculated by a calculation program provided in the control unit 60.

Next, platen gap control for adjusting the platen gap PG based on the ejection speed of the ink droplet D will be described (step S8).
By the way, even if the printer 1 is supposed to be mass-produced by initially setting the ejection time of the ink droplets D according to the specified value C, the variation for each recording head 3 mounted for each printer 1 actually produced. Since the ejection speed of the ink droplets D differs depending on the type, there is a problem that the accuracy of the landing position cannot be increased.

Therefore, the platen gap PG is adjusted in the direction shown below based on the ejection speed of the ink droplet D during the initial operation after the printer 1 is manufactured so as to absorb the variation. As a result, the landing time B is adjusted to match the specified value C.
As described above, the first operation after manufacturing is, for example, in an operation test immediately after assembly of the printer 1 is completed in a production factory, or is used for the first time after a user purchases a new printer 1. It means time. Furthermore, for example, after a non-use period of 100 days has elapsed at the user's hand, the timing when it is reused may be detected by a calendar and a clock incorporated in a microcomputer provided in the control unit 60. .

Here, with respect to the platen gap PG with respect to the ejection speed of the ink droplet D, the platen gap calculation means 97 having the following control direction and the platen gap control means 91 that has started other programs control the platen gap adjustment mechanism 130. As a result, the setting of the platen gap PG is changed.
In the case of the waveform H in FIG. 7, since B1 <C and the ejection speed of the ink droplet D is faster than the specified value C, the direction is adjusted so as to widen the platen gap PG so that B1 = C.
In the case of the waveform G in FIG. 7, since B2> C and the ejection speed of the ink droplet D is slower than the specified value C, adjustment is made with a directionality that narrows the platen gap PG so that B2 = C (step) S8).

Next, carriage speed control for adjusting the movement speed of the carriage CR based on the ejection speed of the ink droplet D will be described (step S8).
Further, regarding the moving speed of the carriage CR with respect to the ejection speed of the ink droplet D, the relationship between the speed X before the change and the speed Y after the change is a carriage speed calculating means 94 means having a control direction as shown in the following equation. The carriage speed control means 93 that has started this program controls the carriage movement mechanism 65 to change the setting of the movement speed of the carriage CR.
B is a general value of B1 and B2 in FIG.
Y = (C / B) X

In the case of the waveform H in FIG. 7, B1 <C, and in the above equation Y = (C / B1) X, Y> X, that is, the ejection speed of the ink droplet D is faster than the specified value C. This means that the setting is changed so that the speed is increased from the speed X to the speed Y.
In the case of the waveform G in FIG. 7, B2> C, and in the above formula Y = (C / B2) X, Y <X, that is, the ejection speed of the ink droplet D is slower than the specified value C. This means that the setting is changed so that the speed is decreased from the speed X to the speed Y.

Thus, based on the ejection speed of the ink droplet D during the initial operation after the manufacture of the printer 1 so as to absorb the variation for each printer, the moving speed of the carriage CR is changed to the speed before the change as shown in the above equation. The setting is changed from X to the changed speed Y (step S8).
The platen gap calculating means 96 and the carriage speed calculating means 94 are realized by executing a calculation program stored in the microcomputer of the control unit 60 constituted by a one-chip microcomputer or the like.

  In (Step S8), the technical significance of changing the setting of the carriage CR moving speed based on the ejection speed of the ink droplets D during the initial operation after the manufacture of the printer 1 is different for each mass-produced printer 1. By accurately measuring the individual injection speeds with slight variations, the carriage CR movement speed corresponding to the measured actual injection speed is set.

  Further, after the printer 1 is manufactured, the platen gap PG is set to change the direction so that the landing time B matches the specified value C based on the ejection speed of the ink droplet D at the first operation, and the carriage CR is moved. Both speeds may be set simultaneously so that the speed is changed from the speed X to the optimum speed Y. Alternatively, a printer is provided with mode selection means 96 (see FIG. 4) in which the user can select either the speed priority mode in which only the carriage speed can be controlled or the platen gap priority mode in which only the platen gap PG can be controlled. 1 may be set at any time to suit the user's preference.

Next, the user can select one or both of the speed priority mode (CR priority mode) and the platen gap priority mode (PG priority mode) by the mode selection unit 96 included in the printer 1 according to the present embodiment. Explain that there is.
First, it is determined whether or not the ejection speed of the ink droplet D is detected along with the operation of the printer 1. In this detection determination, the user selects either the CR priority mode or the PG priority mode. In response to the user selection, the initial setting of the printer 1 is executed. The mode selection means 96 allows the user to arbitrarily select one of the CR priority mode and the PG priority mode according to the status of the paper used by the user, a request regarding usability, and other preferences. A mode may be provided in which both the platen gap PG and the carriage CR moving speed are simultaneously changed based on the injection speed.

  In the above embodiment, the so-called longitudinal vibration mode piezoelectric vibrator 38 is exemplified as the pressure generating source in the present invention, but the present invention is not limited to this. For example, a piezoelectric vibrator that can vibrate in the electric field direction (the stacking direction of the piezoelectric body and the internal electrode) may be used. Moreover, it is not limited to a unit formed for each nozzle row, and may be provided for each pressure chamber like a so-called flexural vibration mode piezoelectric vibrator. Further, not only the piezoelectric vibrator but also other pressure generating elements such as a heating element can be used.

In the above-described embodiment, the fluid ejecting apparatus is embodied as an ink jet printer (recording apparatus). However, the present invention is not limited to this, and liquids other than ink (such as liquid or gel in which functional material particles are dispersed) are used. It is also possible to embody the present invention in a fluid ejecting apparatus that ejects or ejects a fluid body.
For example, a liquid material injection device for injecting a liquid material in the form of dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays, and biochip manufacturing It may be a fluid ejecting apparatus that ejects a bio-organic substance used in the above, or a fluid ejecting apparatus that ejects a liquid as a sample that is used as a precision pipette.
In addition, transparent resin liquids such as UV curable resins to form fluid injection devices that inject lubricating oil onto precision machines such as watches and cameras, micro hemispherical lenses (optical lenses) used in optical communication elements, etc. May be a fluid ejecting apparatus that ejects a liquid onto the substrate, a fluid ejecting apparatus that ejects an etching solution such as acid or alkali to etch the substrate, or a fluid ejecting apparatus that ejects gel.
Then, in any one of these fluid ejecting apparatuses, the present invention can be applied if there is a possibility that the liquid to be ejected (liquid or fluid) is thickened by drying or the like.

FIG. 2 is a partially exploded view illustrating a schematic configuration of a main part of the printer according to the embodiment. It is the side view which showed the example of the platen gap adjustment mechanism of the printer which concerns on this embodiment. FIG. 3 is a side view showing a state in which the gap is largely adjusted in the platen gap adjusting mechanism shown in FIG. 2. FIG. 2 is a schematic diagram illustrating a schematic configuration of a recording head, an ink cartridge, an ink droplet sensor, and a control unit of the printer according to the embodiment. FIG. 3 is a cross-sectional view illustrating a configuration of a recording head of the printer according to the embodiment. It is a schematic diagram explaining the principle which the ink drop sensor of the printer which concerns on this embodiment produces an induced voltage by an electrostatic induction. It is a figure which shows the example of a waveform of the detection signal output from the ink drop sensor of the printer which concerns on this embodiment. 6 is a flowchart illustrating a process of initially setting a platen gap and / or a carriage speed in the printer according to the present embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer (fluid ejecting apparatus), 3 ... Recording head (fluid ejecting head), 7 ... Ink drop sensor (ejection speed detection means), 43a ... Nozzle opening surface, 47 ... Nozzle, 60 ... Control part, 65 ... Carriage movement 75: Voltage application circuit (voltage application unit), 76: Voltage detection circuit (detection unit), 92 ... Platen gap initial setting means, 93 ... Carriage speed control means, 94 ... Carriage speed calculation means, 95 ... Initial carriage speed Setting means 96 ... Mode selection means 97 ... Platen gap calculation means 130 ... Platen gap adjustment mechanism L ... Ink (fluid) D ... Ink droplet (fluid) G, H ... Detection waveform (detection signal), PG ... Platen gap

Claims (8)

A fluid ejecting head having a nozzle opening surface on which a plurality of nozzles ejecting fluid are formed;
An ejection speed detecting means for detecting a fluid ejection speed from the nozzle;
A platen gap adjusting mechanism for adjusting a platen gap between the surface of the platen on which the fluid injection target is placed and the nozzle opening surface;
A platen gap control means for adjusting the platen gap to be widened when the fluid ejection speed detected by the ejection speed detecting means is faster than a prescribed value, and to narrow the platen gap when the fluid ejection speed is slower than a prescribed value;
A fluid ejecting apparatus comprising: A platen gap calculating means for calculating an optimum value of the platen gap based on the fluid ejection speed at the time of the first operation after completion of the assembly or the first operation after the non-use period of a predetermined length;
Platen gap initial setting means for initially setting the optimum value;
The fluid ejecting apparatus according to claim 1, further comprising: A fluid ejecting head having a nozzle opening surface in which a nozzle for ejecting fluid is formed;
An ejection speed detecting means for detecting the fluid ejection speed from the nozzle;
A carriage mounted with the fluid ejecting head for scanning;
A carriage moving mechanism for reciprocating the carriage at a predetermined carriage speed;
If the fluid ejection speed detected by the ejection speed detection means is faster than a specified value, increase the carriage speed,
A carriage speed control means for controlling the carriage speed so as to reduce the carriage speed when the fluid ejection speed is slower than a specified value;
A fluid ejecting apparatus comprising: A carriage speed calculation means for calculating an optimum value of the carriage speed based on the fluid ejection speed at the time of the first operation after completion of the assembly or at the time of the first operation after a non-use period of a predetermined length;
Carriage speed initial setting means for initially setting the optimum value;
The fluid ejecting apparatus according to claim 3, further comprising: A fluid ejecting head having a nozzle opening surface on which a plurality of nozzles ejecting fluid are formed;
An ejection speed detecting means for detecting a fluid ejection speed from the nozzle;
A platen gap adjusting mechanism for adjusting a platen gap between the surface of the platen on which the fluid injection target is placed and the nozzle;
A platen gap control means for adjusting the platen gap to be widened when the fluid ejection speed detected by the ejection speed detecting means is faster than a prescribed value, and to narrow the platen gap when the fluid ejection speed is slower than a prescribed value;
A carriage moving mechanism that reciprocally moves a carriage that scans by mounting the fluid ejecting head at a predetermined carriage speed;
If the fluid ejection speed is faster than a specified value, increase the carriage speed,
A carriage speed control means for controlling the carriage speed so as to reduce the carriage speed when the fluid ejection speed is slower than a specified value;
With
A fluid ejecting apparatus that controls at least one of the platen gap and the carriage speed. The fluid ejection device according to claim 5, wherein
A fluid comprising mode selection means that allows a user to select one of a speed priority mode in which only the carriage speed can be controlled and a platen gap priority mode in which only the platen gap can be controlled. Injection device. The fluid ejection device according to claim 5, wherein
A fluid ejecting apparatus that simultaneously controls both the platen gap and the carriage speed. The injection speed detecting means is
A detection unit arranged to face the nozzle opening surface with a predetermined gap therebetween;
A voltage application unit for applying an electric field between the detection unit and the nozzle opening surface;
A voltage detection unit that outputs, as the detection signal, a change in the voltage value of the detection unit based on electrostatic induction when the fluid moves from the nozzle to the detection unit;
The fluid ejecting apparatus according to claim 1, further comprising:

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