JP2004130577A - Inkjet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem where a viscosity value cannot be correctly detected due to a difference of measurement conditions from conventional ones when parts are replaced in a viscosity measuring device incorporated in an inkjet recording apparatus for measuring a viscosity of ink used in the inkjet recording apparatus. <P>SOLUTION: The viscosity measuring device constituted inside the inkjet recording apparatus is enabled to be calibrated, and moreover enabled to be operated by users while it is kept mounted on an inkjet recording apparatus body. Thus the viscosity measuring device is calibrated arbitrarily. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus for continuously ejecting ink particles, and more particularly to an ink jet printer having an ink physical property control device for measuring the viscosity of ink and adjusting the viscosity or density of the ink.
[0002]
[Prior art]
Some ink jet recording apparatuses that continuously eject ink particles have a function of measuring the viscosity of ink and controlling the viscosity or density. Examples of the device for measuring the viscosity include a device for measuring the viscosity by dropping a ball, and a device using a cylindrical member as a falling object instead of the ball. In these, a falling object is allowed to freely fall from above in a cylinder filled with ink, and the time required for the falling is detected by a sensor or the like. The viscosity value is calculated based on the time of the fall. (For example, see Patent Document 1)
[Patent Document 1]
JP-A-5-60676 (page 4, FIG. 1)
[0003]
[Problems to be solved by the invention]
In the above prior art, it is the falling time of a falling object that determines the viscosity value. When the falling speed is large and the falling time is short, the accuracy is deteriorated because the amount of change in the detected value with respect to the actual change in ink viscosity is small. Therefore, in order to reduce the falling time to some extent, a measure is taken to reduce the dimensional gap between the falling object and the cylinder that guides the falling object to increase the resistance of the ink and reduce the falling speed.
[0004]
However, when the dimensional gap is reduced, the drop time is greatly affected by the difference in the size of the gap. Therefore, the gap between the falling object and the cylinder is desired to be kept constant, but when continuously dropped, the dimension changes due to abrasion, and the gap dimension may increase with time. In addition, when repair is performed due to a failure or the like, if the parts are replaced, the gap size differs from the conventional one, which may affect the drop time. In addition, individual differences in the dimensional gap between the falling object and the cylinder are inevitable.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an ink jet recording apparatus which addresses the above problems, performs ink viscosity with high accuracy, and can stably perform good printing.
[0006]
[Means for Solving the Problems]
The above-mentioned problem can be arbitrarily calibrated if the viscosity measuring device configured inside the ink jet recording device can be calibrated and further operated by a user while being mounted on the main body of the ink jet recording device. Can be done. Further, operability is good if the operation can be performed by key input.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0008]
First, FIG. 2 shows an overview of the ink jet recording apparatus. It comprises a main body 600 containing a control system and a circulation system, a head unit 610 having nozzles for ejecting ink and creating particles, and a cable 620 connecting the circulation system of the main body 600 and the head unit 610 to the control system. The touch panel type liquid crystal display 630 having a liquid crystal display / touch panel 630 on the upper part of the main body 600 displays a control content, an operation state of the apparatus, and the like, and allows a user to input a print content, a print specification, and the like.
[0009]
Next, the internal configuration of the main body 600 will be described with reference to FIG. Electrical components such as a control board 640 are arranged on the upper part of the main body 600. In the lower part A of the main body 600, circulating system control parts such as an electromagnetic valve 650 and a pump unit 655 are arranged, and in the lower part B, a viscosity measuring device 17, a container storing ink, a container storing solvent. Is stored. The door 670 can be opened and closed as shown in FIG. 3 so that the ink container, the solvent container, and the viscosity measuring device 17 can be pulled out to the door 670 side. Can be easily done.
[0010]
Next, a schematic configuration of the ink circulation system will be described with reference to FIG. The ink supply path 21 includes a container 1 for storing ink, a pump 2 for pumping ink, a pressure regulating valve 3 for adjusting ink pressure, a pressure gauge 4 for displaying the pressure of the supplied ink, and a filter 5. Supply. A recording signal source (not shown) is connected to the charging electrode 7, and by applying a recording signal voltage to the charging electrode 7, the ink particles 8 ejected regularly from the nozzles 6 are charged. A high voltage source (not shown) is applied to the upper deflection electrode 9, and the lower deflection electrode 10 is grounded. For this reason, an electrostatic field is formed between the upper deflection electrode 9 and the lower deflection electrode 10, and the charged ink particles 8 are deflected according to the charge amount, and printing is performed. The ink recovery path 22 includes a backlash 11, a filter 12, and a pump 14. The ink recovery path 22 recovers the ink particles 8 that are not charged by the charging electrode 7 and are not involved in recording, and return the ink particles 8 to the container 1 for reuse of the ink.
[0011]
The viscosity measuring device ink path 24 includes a pump 32, an electromagnetic valve 18, a filter 34, and a viscosity measuring device 17, and supplies the liquid in the container 1 to the viscosity measuring device 17 through the filter 34 by opening the electromagnetic valve 18. I do. The solvent supply path 26a includes a container 30a storing a solvent for ink as a diluting liquid, a pump 31a, and a solenoid valve 29a. By opening the solenoid valve 29a, the solvent is supplied to the container 1 to dilute the ink concentration in the container 1. . The ink supply path 26b includes a container 30b storing 100% concentration ink or concentrated ink, a pump 31b, and a solenoid valve 29b. The ink in the container 30b is supplied to the container 1 by opening the solenoid valve 29b. The ink density of the container 1 is increased. Since the concentration can be increased only by volatilization of the solvent, the ink supply path 26a may not be provided.
[0012]
Next, an embodiment of the configuration and operation principle of the viscosity measuring device 17 will be described with reference to FIG. The plunger 700 is made of a magnetic material, such as SUS430. The plunger 700 can move inside the cylinder 701 in the axial direction of the cylinder 701. The cylinder 701 is made of a non-magnetic material and is, for example, SUS304. The cylinder 701 is filled with ink, and both ends are connected to the ink path 24 for the viscosity measuring device. An electromagnetic coil 702 is provided on the outer periphery of the cylinder 701. The electromagnetic coil 702 can generate an electromagnetic field when energized, and can raise the plunger 700. When the raised plunger 700 contacts the end of the stopper 703, it is held at that position. When the energization of the electromagnetic coil 702 is cut off, the plunger 700 falls and reaches the lowermost lower surface 704. A plunger detector 705 that can detect the lower end of the plunger 700 is located below the lowermost lower surface 704. The time from when the power supply to the electromagnetic coil 702 is cut off to when the plunger detector 705 detects the plunger 700 is measured, and this time is defined as a fall time.
[0013]
As described above, since the ink is filled in the cylinder 701, the ink exists in the gap formed between the outer periphery of the plunger 700 and the inner surface of the cylinder 701, and the plunger 700 falls while receiving the resistance of the ink. If the viscosity of the ink is different, the resistance is different and a difference is generated in the drop time, so that the viscosity difference can be measured. Further, a temperature sensor 706 is installed to detect the ink temperature in the cylinder 701, and the ink temperature at the time of measuring the falling time is detected.
[0014]
Although the operation of measuring the falling time has been described above, it can also be detected by measuring the pulling time. At this time, the time from when the electromagnetic coil 702 is energized to when it reaches the stopper 703 is measured. The plunger detector 705 may be installed near the stopper 703.
[0015]
Next, a circuit configuration of a controller (not shown) of the ink adjustment control device will be described with reference to FIG. The CPU 300 is a central processing unit that controls the inkjet recording apparatus of the present embodiment. The ROM 310 is a read-only memory that stores programs and control data necessary for the operation of the CPU 300. The RAM 305 is a memory that can temporarily replace data and the like handled by the CPU 300 during execution of a program. The bus line 380 is a signal line including all data, address signals, and control signals from the CPU 300. The interface circuit 315 mediates input and output of data, address signals, control signals, and the like. The pump control circuit 320 controls the driving of the pumps 31a, 31b, 32. The solenoid valve control circuit 340 controls the operation of opening and closing the solenoid valves 18, 29a, 29b. The electromagnetic coil control circuit 330 controls on / off of energization of the electromagnetic coil 702 of the ink viscosity measuring device 17. The plunger detector 705 inputs a signal indicating whether or not the plunger 700 has been detected to the CPU 300 via the interface circuit 315. The signal of the temperature sensor 706 of the ink viscosity meter 17 is input to the CPU 300 via the A / D converter 355 and the interface circuit 315. The signal of the level sensor 40 for detecting the liquid level of the ink container 1 is input to the CPU 300 via the interface circuit 315. The timer 370 includes a clock generator 371, a frequency dividing circuit 372, and a counter circuit 373. The frequency divider 372 divides the signal output from the clock generator 371. The counter circuit 373 counts the signal divided by the frequency dividing circuit 372 in accordance with the instruction of the CPU 300, and obtains the moving time of the plunger 700 by the CPU 300. Further, the frequency can be reset by an instruction from the CPU 300, and the frequency division ratio of the frequency dividing circuit 372 can be changed by an instruction from the CPU 300.
[0016]
Next, calibration of the viscosity meter 17 will be described with reference to FIG. The calibration of the viscosity measuring device 17 starts with the key input of the calibration key 100 displayed on the liquid crystal display / touch panel 630 on the main body 600. The operator's operation is only this key input. When the key input is received, the operation shifts to the ink viscosity measuring operation.
[0017]
At this time, the ink used for the measurement is a new ink when the ink jet recording apparatus is installed. In calibration performed at the time of installation, new ink becomes the reference ink 101. If the ink temperature is known for a new ink, the viscosity value is determined. Since the ink temperature is detected by the temperature sensor 706, the current viscosity value of the reference ink 101 can be calculated, and this is referred to as a reference ink viscosity value. Then, a coefficient is calculated by dividing the reference ink viscosity value by the drop time data t ₀ according to the drop time data t ₀ 102 of the ink viscosity measuring device 17 and the reference viscosity value.
[0018]
The ink viscosity measurement during the operation of the ink jet recording apparatus is performed when a measurement command 103 is issued from the control unit, and the current time is obtained by multiplying the drop time data t105 of the main body ink 104 at that time by the coefficient determined above. Calculate the viscosity value. The calculated current viscosity value is compared with the reference ink viscosity value at the time of calibration, the level of ink viscosity is determined, and the pump 31a and the solenoid valve 29a or the pump 31b and the solenoid valve 29b are controlled to approach the reference ink viscosity value. are doing. According to this control, the ink always tries to match the physical properties with the ink used at the time of calibration.
[0019]
The plunger 700 and the cylinder 701 of the ink viscosity measuring device 17 have a dimensional tolerance, and if a plurality of ink viscosity measuring devices 17 are manufactured, the gap between the outer periphery of the plunger 700 and the inner surface of the cylinder 701 naturally has a dimensional variation. Since this gap affects the drop time, the dimensional variation directly leads to the variation in the viscosity measurement value. However, if the calibration is performed as described above, even if the ink viscosity measuring device 17 has individual differences at the time of manufacture, the coefficient is determined for each individual, so that the individual difference does not matter. In addition, since the actual ink used in the ink jet recording apparatus to be operated is calibrated in an unused state and is used as a reference, the ink properties are always controlled so that the initial good printing can be performed.
[0020]
Up to this point, the case where the calibration has been performed on the site of the inkjet recording apparatus has been described, but the calibration can be arbitrarily performed at any time. For example, when the viscosity measuring device 17 is repaired and some parts are replaced, if the calibration is performed at that time, there is no problem even if the gap size changes. At this time, if the ink is replaced with a new one, the calibration can be performed accurately. However, when the calibration is performed with the ink in use in the inkjet recording apparatus, the used ink becomes the reference ink 101, There is a possibility that there is a difference between the original reference ink viscosity value and the actual viscosity value of the ink used for calibration, but if good printing can be performed with that ink, control the ink physical properties so that There is no problem because it goes. If calibration is performed every time a certain period of time has elapsed in the operation of the inkjet recording apparatus, even if there is a dimensional change with time of the plunger 700, the cylinder 701, and the stopper 703, the coefficient in the ink viscometer after the dimensional change is obtained. There is no problem at all.
[0021]
As described above, since the calibration can be performed only by inputting the calibration key 100 of the touch panel 630 while the ink viscosity measuring device 17 is mounted on the ink jet recording apparatus, the operation at the time of on-site installation and subsequent operation by a user or a service person are also easy. Yes, it can be executed in a short time.
[0022]
If the means for calibrating the ink viscosity measuring device 17 as described above is provided, the ink viscosity can be accurately detected and controlled, and good printing can be stably performed.
[0023]
【The invention's effect】
As described above, according to the present invention, the calibration of the ink viscosity measuring device can be easily performed, the ink viscosity can be accurately detected and controlled, and good printing can be stably performed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing calibration of a viscosity measuring device according to one embodiment of the present invention.
FIG. 2 is an external view of an inkjet recording apparatus according to one embodiment of the present invention.
FIG. 3 is a configuration diagram of an ink jet recording apparatus main body according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of a circulation system of the ink jet recording apparatus according to one embodiment of the present invention. FIG. 5 is a configuration diagram of a viscosity measuring device according to one embodiment of the present invention.
FIG. 6 is a circuit configuration diagram of an ink adjustment device according to one embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Pump, 3 ... Pressure regulating valve, 4 ... Pressure gauge, 5 ... Filter, 6 ... Nozzle, 7 ... Charging electrode, 8 ... Ink particle, 9 ... Upper deflection electrode, 10 ... Lower deflection electrode, 11 ... Gutter, 12: Filter, 14: Pump, 17: Viscometer, 21: Ink supply path, 22: Ink recovery path, 24: Ink path for viscosity measuring device, 26a: Solvent supply path, 26b: Ink supply path, 29a ... solenoid valves, 29 b ... solenoid valves, 30a ... vessel, 30b ... container, 31a ... pumps, 31b ... pump, 40 ... level sensor, 100 ... calibration key 101 ... reference ink, 102 ... dropping time data _t 0, 103 ... Measurement command, 104: body ink, 105: fall time data t, 300: CPU, 305: RAM, 310: ROM, 315: interface circuit, 320: pump control cycle , 330: electromagnetic coil control circuit, 340: electromagnetic valve control circuit, 355: A / D converter, 370: timer, 371: clock generator, 372: frequency dividing circuit, 373: counter circuit, 600: main body, 610: Head part, 620 cable, 640 control board, 650 solenoid valve, 655 pump unit, 670 door, 700 plunger, 701 cylinder, 702 electromagnetic coil, 703 stopper, 704 lowermost lower surface, 705 … Plunger detector, 706… Temperature sensor

Claims (5)

In an ink jet recording apparatus which performs recording by applying vibration to an ejected ink to generate ink particles, and charging and deflecting the ink particles, the ink particles reach a predetermined place on a recording medium and perform recording. An ink jet recording apparatus comprising: means for managing the viscosity of the ink; a viscosity measuring device for measuring the viscosity of the ink; and calibrating means for calibrating the viscosity. In claim 1,
An ink jet recording apparatus comprising means capable of calibrating an ink viscosity measuring device by a user of the ink jet recording apparatus. In claim 1 or 2,
An ink jet recording apparatus characterized in that calibration of an ink viscosity measuring device is performed while the ink viscometer is mounted on an ink jet recording apparatus main body. In any one of claims 1 to 3,
An ink jet recording apparatus, wherein calibration of the ink viscosity meter is performed by key input from an operation panel of the ink jet recording apparatus. In any one of claims 1 to 4,
A coefficient for calculating a viscosity value from a measured value of an ink viscosity meter is determined based on a measured value obtained when the ink viscosity meter is operated with a reference ink filled therein. apparatus.

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