JP2003063032A - Liquid adjusting device and ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid adjusting device which is small sized, inexpensive, and has a short measurement time and excellent measurement precision. SOLUTION: A viscosity measuring device 70 is provided with a cylinder 41 for introducing liquid stored in a container 1, a plunger 42 disposed movably in the cylinder 41, an electromagnetic coil 43 for moving the plunger 42, and a plunger detecting device 45 for detecting the position of the plunger 42. The viscosity measuring device 70 computes the time from the start of moving the plunger 42 driven by the electromagnetic coil 43 until the detection of the position of the plunger 42 with the plunger detecting device 45 and controls a condensed liquid supply device 81 or a diluted liquid supply device 82 to supply diluted liquid or condensed liquid to the container 1 based on the computed result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid adjusting device and an ink jet recording device, and more particularly to a liquid adjusting device and an ink jet recording device for measuring the viscosity of a liquid and adjusting the viscosity or the concentration.

[0002]

2. Description of the Related Art A conventional liquid adjusting device for measuring and adjusting a liquid viscosity is, for example, as shown in JP-A-5-60676 (Prior Art 1), in a vertically set cylindrical measuring pipe. Insert a cylindrical weight into the measuring tube, fill the measuring tube with the liquid to be measured, and install upper and lower detectors such as optical and magnetic sensors on the upper and lower outer circumferences in the middle of the measuring tube,
The upper detector and the lower detector are separated by a predetermined distance, and a physical signal such as a magnetic or optical signal is transmitted when the weight falls and passes through the upper detector and the lower detector. It is equipped with a viscometer equipped with a line that electrically transmits the to the measuring instrument. A bellows pump is composed of a bellows, a check valve, a spring, etc., and while the measuring pipe is filled with the liquid to be measured, the weight is positioned at the upper end of the measuring pipe by the bellows pump and allowed to fall freely into the pipe from the upper end. While passing through the viscous resistance of the liquid to be measured in the pipe, first passes the upper detector and then the lower detector, and then descends to the lower end position of the measuring pipe and stops. At this time, the passage time of the upper detector and the lower detector is detected and the viscosity of the liquid to be measured is measured from the difference, and the viscosity value measured is compared with the preset upper and lower viscosity limits. If it is higher than the upper limit value, the diluent is injected into the tank. Conversely, if the measured viscosity value is lower than the lower limit value, the concentrated liquid is injected into the tank, and the liquid viscosity in the tank is within the desired value range. Work to hold in.

Further, as a conventional ink jet recording apparatus, as shown in Japanese Utility Model Publication No. 6-7945 (Prior Art 2), the ink viscosity is corrected according to the flow rate of the ink ejected from the orifice, and the orifice is corrected. There is one that controls the speed of the ink droplets ejected from the device to be constant. This control is performed by providing two liquid level detectors arranged in a container for supplying to the orifice.

[0004]

However, the above-mentioned prior art 1 is to detect the time when the weight passes through the upper detector and the lower detector and measure the viscosity of the constant liquid to be measured from the difference. The weight must fall from above the upper detector to below the lower detector. Therefore, the prior art 1
Then, the falling distance of the falling weight needs to be extremely long, and there is a problem that the height dimension becomes particularly large. Therefore, it is conceivable to shorten the distance between the upper detector and the lower detector, but in this case, there arises a problem that the detection accuracy of the liquid viscosity decreases. In addition, in the related art 1, since the upper detector is required in addition to the lower detector, there is a problem that the height of the upper detector is increased and the cost is increased.

Further, in the prior art 1, a cylindrical weight is inserted into a cylindrical measuring tube and a detector such as an optical sensor or a magnetic sensor is provided on the outer circumference of the measuring tube. In such a case, there is a problem that the falling weight cannot be detected by the optical sensor with a liquid that does not transmit light such as ink. When the detection coil wound around the outer circumference of the measuring tube is used as the magnetic sensor, there is a problem that the detection accuracy decreases when the moving speed of the weight changes due to the viscosity of the liquid. When the detector of the method is used, the detection object becomes a curved surface with respect to the sensor surface, so that there is a problem that the detection accuracy is reduced.
In order to improve this accuracy, it is sufficient to increase the interval between the passage detectors, but there is a problem that the device becomes large.

Further, in the prior art 1, since the bellows pump having a complicated structure including the bellows, the check valve, the spring and the like is used, when different liquids are used as in the ink jet recording apparatus, the previous one is used. There is a problem that it is difficult to completely clean the existing liquid, and the amount of the cleaning liquid used increases.

On the other hand, in the prior art 2, since the liquid level detectors arranged in the container for supplying to the orifice are provided at two locations for control, it is impossible to perform accurate measurement in a state where the liquid shakes. There were challenges.
Furthermore, since the ink is ejected from the orifice to measure the viscosity, it is necessary to activate the entire apparatus. Therefore, there is a problem that it takes time to measure only the viscosity of the ink and adjust the viscosity based on the result.

Further, in the prior arts 1 and 2, there is no description about adjustment of viscosity by temperature change.

The first object of the present invention is to be compact and inexpensive,
Moreover, it is an object of the present invention to provide a liquid adjusting apparatus which has a short measuring time and a high measuring accuracy.

A second object of the present invention is that it is small and inexpensive.
Moreover, it is an object of the present invention to provide a liquid adjusting apparatus which has a short measurement time and has a high measurement accuracy even if the temperature changes.

A third object of the present invention is to be compact and inexpensive,
Moreover, it is an object of the present invention to provide an ink jet recording apparatus that has a short measurement time and high measurement accuracy.

[0012]

The first means of the present invention for achieving the above first object is a container for containing a liquid, and a viscosity measuring means for measuring the viscosity of the liquid in the container.
In a liquid adjusting device comprising an adjusting liquid supply means for supplying an adjusting liquid for adjusting the liquid viscosity to the container, and a controller for controlling the viscosity measuring means and the adjusting liquid supplying means, the viscosity measuring means is A cylinder for introducing the liquid contained in the container, a plunger movably arranged in the cylinder, a drive unit for moving the plunger, and a plunger detector for detecting the position of the plunger, and the control The means supplies the adjusted liquid to the container based on the result of measurement by the viscosity measuring means of the time from the start of movement of the plunger by the driving of the driving means to the detection of the position of the plunger by the plunger detector. The adjusting liquid supply means is controlled so as to do so.

A second means of the present invention for achieving the above second object is a container for containing a liquid, a viscosity measuring means for measuring the viscosity of the liquid in the container, and a liquid viscosity adjusting means. An adjusting liquid supply unit that supplies an adjusting liquid to the container, and a control device that controls the viscosity measuring unit and the adjusting liquid supplying unit, and the viscosity measuring unit includes a cylinder that introduces the liquid contained in the container. A plunger arranged movably in the cylinder, a driving unit for moving the plunger, a plunger detector for detecting the position of the plunger, and a temperature detector for detecting the temperature of the liquid to be measured, The control means corrects the measurement result of the moving time of the plunger by the temperature detected by the temperature detector, and supplies the adjusted liquid to the container based on the correction result. In that the arrangement for controlling the adjusting liquid supply means.

A third means of the present invention for achieving the above third object is a container for accommodating ink, a viscosity measuring means for measuring the viscosity of the ink in the container, and an ink viscosity adjusting means. Adjusting ink supplying means for supplying the adjusting ink to the container, an ink supplying device for supplying the ink of the container to the ink ejecting section, a controller for controlling the viscosity measuring means, the adjusting ink supplying means and the ink supplying means. In an ink jet recording apparatus comprising: a container, the viscosity measuring unit includes a cylinder for introducing the ink contained in the container, a plunger movably arranged in the cylinder, a driving unit for moving the plunger, and the plunger. A plunger detector for detecting the position of the ink supply means, and the control means, during the operation of the ink supply means,
Based on the result of measuring the time from the movement start of the plunger by the driving of the ink collecting means the driving means until the position of the plunger is detected by the plunger detector to the container, the adjusted ink is stored in the container. The adjustment ink supply unit is controlled to supply the adjustment ink.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

A liquid adjusting apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 8.

First, the circulation system of the liquid regulating apparatus of this embodiment will be described with reference to FIG. FIG. 1 shows the first of the present invention.
FIG. 3 is a schematic diagram of a circulation system of the liquid regulator of the embodiment.

The liquid adjusting apparatus 100 is used in, for example, an ink jet recording apparatus, and includes a container 1 and
The viscosity measuring device 70 and the adjusted liquid supply device 80 are provided. The container 1 is used to store a liquid such as ink with a predetermined viscosity and supply the liquid to other necessary places.

The viscosity measuring device 70 comprises a pump 32, a solenoid valve 18, a filter 34, a viscometer 17, and a viscosity measuring path 24. The container 1, the pump 32, the solenoid valve 18, the filter 34, and the cylinder 41 of the viscometer 17 are connected in this order via the viscosity measurement path 24, and as shown by the arrow,
The liquid in the container 1 is introduced through the inlet of the viscosity measuring path 24, and the liquid is led out into the container 1 through the outlet of the viscosity measuring path 24.

The pump 32 is operated when measuring the viscosity of the liquid in the container 1, sucks the liquid in the container 1 and supplies the liquid to the viscometer 17 via the electromagnetic valve 18 and the filter 34. . The solenoid valve 18 is opened and closed during the operation of the pump 32 to intermittently supply the liquid to the filter 34. The pump 32 and the solenoid valve 18 are controlled by the controller 35. The filter 34 removes dust and the like in the liquid in order to ensure the accuracy and reliability of the viscometer 17.

The viscometer 17 shown schematically in FIG.
41 that introduces the liquid, a plunger 42 that is movably arranged in the cylinder 41, and an electromagnetic coil 43 that constitutes a drive unit that moves the plunger 42.
And a plunger detector 45 for detecting the position of the plunger 42 as a main component. The electromagnetic coil 43 is controlled by the controller 35, and the signal measured by the plunger detector 45 is input to the controller 35. The details of the viscometer 17 will be described later.

A controller 35 which is an example of a control device.
Is based on the result of measuring the viscosity of the liquid by driving and controlling the pump 32, the electromagnetic valve 18, and the electromagnetic coil 43 of the viscometer 17 based on the measurement command signal and the like, and measuring the liquid viscosity by the measurement command signal and the signal from the plunger detector 45. Then, the pump 33 and the solenoid valve 27 of the concentrated liquid supply device 81 or the pump 31 and the solenoid valve 29 of the diluted liquid supply device 82 are drive-controlled.

The adjusted liquid supply device 80 includes a concentrated liquid supply device 81 for increasing the viscosity of the liquid in the container 1 and a diluting liquid supply device 82 for diluting the viscosity of the liquid in the container 1. The concentrated liquid supply device 81 includes a container 28, a pump 33, a solenoid valve 27, and a supply path 25.
The container 28, the pump 33, and the solenoid valve 27 are connected in this order through the replenishment path 25, and as shown by the arrow, the container 28
The concentrated liquid of 1 is supplied into the container 1.

The pump 33 is operated when the viscosity of the liquid in the container 1 is low, sucks the concentrated liquid in the container 28,
The concentrated liquid is supplied to the container 1 via the electromagnetic valve 27. The electromagnetic valve 27 is opened and closed during the operation of the pump 33 to intermittently supply the concentrated liquid to the container 1.
The pump 33 and the solenoid valve 27 are controlled by the controller 35.

The diluting liquid supply device 82 comprises a container 30, a pump 31, a solenoid valve 29, and a replenishing path 26.
The container 30, the pump 31, and the solenoid valve 29 are connected in this order via the replenishment path 26, and as shown by the arrow, the container 30
The diluted liquid of 1 is supplied into the container 1.

The pump 31 is operated when the viscosity of the liquid in the container 1 is high, sucks the diluted liquid in the container 30,
The diluted liquid is supplied to the container 1 via the electromagnetic valve 29. The electromagnetic valve 29 is opened and closed during the operation of the pump 31 to intermittently supply the diluted liquid to the container 1.
The pump 31 and the solenoid valve 29 are controlled by the controller 35.

Next, the structure of the viscometer 17 will be specifically described with reference to FIG. FIG. 2 is a vertical sectional view of the viscometer shown in FIG.

The cylinder 41 is made of SUS, which is a non-magnetic material.
It is made of 304 and has a vertically long cylinder chamber 62 in its center.
Are formed. The cylinder 41 is formed in a vertically long cylindrical shape, and a cylinder chamber 62 is concentrically formed in the cylinder. The lower surface of the cylinder 41 is open, a notch 41a for introduction is formed at the lower end, and a cylinder chamber 62 is provided at the upper part.
An outlet 41b is formed on the upper surface of the outlet 41b. A joint portion 52 for connecting to the viscosity measuring path 24 is formed at the opening of the outlet 41b.

The cylinder block 49 includes a cylinder 41.
A recess 49a to which the lower end of the cylinder 41 is attached is formed so as to close the lower open surface of the cylinder. Cylinder 41
An O-ring 63 is attached to the outer periphery of the lower end of the above for sealing with the recess 49a. Also, the cylinder block 4
An inlet port 49b, which communicates with the cylinder chamber 62 through the cutout portion 41a, is formed in the side wall 9 of the connector 9. In this way, since the inlet port 49b is provided so as to be opened to the side surface, the height dimension including the viscosity measurement path 24 and the like can be made smaller than in the case where the inlet port is opened to the lower surface. A joint portion 53 for connecting to the viscosity measuring path 24 is formed at the opening of the introduction port 49b.

In the structure of the cylinder 41 described above, the liquid from the container 1 is introduced from the liquid introduction port 49b,
The cylinder chamber 62 is filled.

The plunger detector 45 is composed of an eddy current type proximity sensor which is an example of a magnetic sensor, and is arranged in a recess 49c extending from the lower surface of the cylinder block 49, and its upper end surface is close to the bottom surface of the recess 49a. is set up. As a result, when the plunger 42 is dropped, the upper end surface of the cylinder block 49 is located close to the lower end surface thereof, and the plunger detector 45 is located below the lower end surface 51. The plunger detector 45 may be an ultrasonic sensor or a mechanical contact sensor, or may be an optical sensor when used for a transparent liquid.
If 2 is magnetized, it can be used as a Hall element.

The temperature sensor 54 is a thermistor for detecting the temperature of the liquid introduced into the cylinder 41, is installed in a hole 49d extending from the side surface of the cylinder block 49, and is in thermal contact with the lower end of the cylinder 41. Is provided. The temperature sensor 54 is connected to the controller 35 and is used for liquid viscosity calculation correction and concentration calculation correction based on the detected temperature.

The plunger 42 is made of a magnetic material such as SUS430 and has a vertically long cylindrical shape. The outer periphery of the plunger 42 is formed to be slightly smaller than the cylinder chamber 62. The plunger 42 is movably installed in the cylinder 41 in the axial direction of the cylinder 41. . The length of the plunger 42 is 35 mm in this embodiment.
A stopper 50 that narrows the cylinder chamber 62 is formed on the upper portion of the cylinder 41. This allows the plunger 4
2 is moved by the stopper 50 and the lower end surface 5 of the cylinder chamber 62.
1 and the moving distance is 2 in this embodiment.
It is 0 mm. Therefore, since the length of the plunger 42 is longer than the moving distance thereof, the cylinder 42 is small and the length thereof is small, and the plunger 42 can be stably moved, and the area of the portion receiving the viscous resistance is large. Can be increased and the detection accuracy can be improved.

A presser plate 44, a spacer 48, an electromagnetic coil 43, and a coil presser 47 are provided on the outer peripheral portion of the cylinder 41 from below.
Are installed in a stack. The pressing plate 44 is for pressing and fixing the cylinder 41 to the cylinder block 49 from above. The spacer 48 has a predetermined thickness dimension and is for adjusting the electromagnetic coil 43 to a predetermined position in the axial direction of the cylinder 41 (the same as the height direction in this embodiment). The electromagnetic coil 43 is installed corresponding to the upper part of the cylinder chamber 62 and is controlled by the controller 35. The coil retainer 47 is screwed and fixed to the outer periphery of the cylinder 41, and is held against the cylinder block 49 by the retainer plate 4.
4, the spacer 48 and the electromagnetic coil 43 are restrained and fixed.

The electromagnetic coil 43 generates an electromagnetic field when energized. The stopper 50 is provided in the electromagnetic field of the electromagnetic coil 43, and the plunger 42 is
It is arranged so that it is always contained in the electromagnetic field of. As a result, when the electromagnetic coil 42 is energized, the plunger 4
2 is reliably moved to and held at the position of the stopper 50.

As described above, the cylinder 41 is made of a cylindrical non-magnetic material, the plunger 42 is made of a cylindrical magnetic material, and the driving means of the plunger 42 is the electromagnetic coil 43 provided on the outer circumference of the cylinder 41. Since the plunger 42 is formed and is energized to move the plunger 42 to the position of the stopper 50, the plunger 42 is moved by a predetermined distance with a simple configuration and simple control to move the plunger 42 for a long time. Can be measured.

Since the plunger detector 45 is arranged close to the plunger 42 and the lower end of the plunger 42 is a flat surface, its detection accuracy can be made high. In this embodiment, the shortest distance between the plunger detector 45 and the plunger 42 is 0.5 mm, and the lower end of the plunger 42 is a flat surface, so the detection accuracy of the plunger detector 45 is ± 0.05 mm. Therefore, the ratio of the accuracy of the plunger detector 45 to the movement distance of the plunger 42 is as small as ± 0.05 mm / 20 mm × 100 = 0.25%, and accurate measurement is possible.

In this embodiment, the moving time (falling time) until the plunger 42 freely falls from the stopper 50 and reaches the lower end surface 51 of the cylinder chamber 62 is measured, but the lower end of the cylinder of the plunger 42 is measured. The moving time from 51 to the stopper 50 may be measured. At that time, the plunger detector 45 may be installed near the stopper 50. Further, by disposing a permanent magnet in the stopper 50 portion of the cylinder 41, the plunger 42 is held and a voltage reverse to that at the time of pulling is applied to the electromagnetic coil 43,
The plunger 42 may be dropped. This makes it possible to reduce the power consumption of the electromagnetic coil 43 while holding the plunger 42.

Next, the circuit configuration of the controller 35 of the liquid adjusting apparatus 100 will be described in detail with reference to FIG. FIG. 3 is a circuit configuration diagram of the liquid regulator of the present embodiment.

In FIG. 3, a CPU 300 is a central processing unit that controls the liquid adjusting apparatus 100 of this embodiment. The ROM 310 is a read-only memory that stores programs and control data necessary for the CPU 300 to operate. The RAM 305 is a rewritable memory that temporarily stores data and the like handled by the CPU 300 during program execution. Bus line 380 is CPU3
This is a signal line including all the data from 00, address signals, control signals, and the like. The interface circuit 315 mediates input / output of data, address signals, control signals, and the like.

The pump control circuit 320 includes the pumps 31, 3
Drive control of 2 and 33 is performed. Solenoid valve control circuit 340
Controls the opening / closing of the solenoid valves 18, 27, 29. The coil control circuit 330 controls ON / OFF of energization of the electromagnetic coil 43 of the viscometer 17.

The plunger detector 45 is connected to the plunger 42.
A signal indicating whether or not is detected is input to the CPU 300 via the interface circuit 315. Viscometer 17 temperature sensor 5
The signal No. 4 is input to the CPU 300 via the A / D converter 355 and the interface circuit 315.

The timer 370 is used by the clock generation circuit 37.
1, a frequency dividing circuit 372, and a counter circuit 373. The frequency divider circuit 372 divides the signal output from the clock generation circuit 371. The counter circuit 373 is a CPU
The signal frequency-divided by the frequency dividing circuit 372 is counted by the instruction of 300, and the movement time of the plunger 42 is obtained by the CPU 300. Further, it can be reset by an instruction of the CPU 300, and the frequency division ratio of the frequency dividing circuit 372 can be changed by an instruction of the CPU 300.

Next, the operation of the viscometer 17 will be described with reference to FIG. FIG. 4 is a flow chart showing the operation of the viscometer of the liquid adjusting apparatus of this embodiment.

In order to operate the viscometer 17, first, in step 400, the pump 32 is controlled by the pump control circuit 320.
Is driven, and in step 405, the solenoid valve control circuit 340 opens the solenoid valve 18, and the liquid in the container 1 is guided to the viscometer 17 through the pump 32, the solenoid valve 18, and the filter 34. The liquid is supplied in step 410, and when the predetermined time is reached, the electromagnetic valve 18 is closed in step 415 to stop the liquid supply to the viscometer 17. As a result, the cylinder 41 of the viscometer 17
The liquid to be measured is filled inside.

Next, at step 420, the coil control circuit 330 energizes the electromagnetic coil 43 of the viscometer 17 to pull up the plunger 42 of the viscometer 17 to a predetermined position (stopper 50). Cylinder 4 in step 425
Wait for the flow in 1 to stabilize (about 5 seconds). Step 4
At 30 the temperature of the liquid to be measured is measured by the temperature sensor 54 attached to the viscometer 17. Next, at step 435, the energization of the electromagnetic coil 43 is turned off, and at the same time, the timer 37
Start counting at 0. This causes the plunger 42 to start falling. In step 440, when the plunger 42 reaches the lower end 51 of the cylinder 41, the plunger detector 45
Is turned on and the counting by the timer 370 is stopped. In step 445, the measured value is set to C by the timer 370.
Input to the PU 300, the drop time of the plunger 42 is obtained. In step 450, the number of measurements of the drop time of the plunger 42 is determined, and the processing from step 435 is performed again until it reaches a predetermined number.

Next, a method of adjusting the liquid viscosity will be described with reference to FIGS. FIG. 5 is a flow chart showing the liquid viscosity adjusting method of the liquid viscosity adjusting device of this embodiment, and FIG. 6 is a characteristic diagram showing the relationship between the viscosity of the liquid and the drop time.

When the measurement of the falling time of the plunger 42 by the operation of the viscometer 17 is completed, step 500
Move to viscosity measurement process. In step 510, the average value tf of the results obtained by measuring the falling time of the plunger 42 a predetermined number of times is obtained. In this embodiment, the measurement is performed 15 times, and the average value of the measured values from the 6th time to the 15th time is used as the fall time tf.

Here, the relationship between the falling time of the plunger 42 and the viscosity is linear as shown in FIG.
The viscosity can be calculated by obtaining the falling time tf of the plunger 42. In addition, the falling time of the plunger 42 is several seconds, and the time for pulling up the plunger 42 is 1
Since it is about a second, the viscosity can be measured in a short time by using the dropping time or the pulling time of the plunger 42.

Next, at step 520, from the target viscosity,
The target fall time tf0 is determined. This target fall time tf0
Is obtained in advance as a data table and stored in the RAM 305 as a data table. Then, in step 530, a deviation δ between the fall time tf obtained by the measurement and the target fall time tf0 is obtained. In step 540, the magnitude of the deviation δ is judged (specifically, 0
Judgment) and select the viscosity correction method. When the deviation δ> 0, it is determined that the viscosity is high, the process proceeds to step 560, the electromagnetic valve 29 is opened for a predetermined time, and the diluting liquid is supplied to the container 1. When the deviation δ ≦ 0, it is determined that the viscosity is low, the process proceeds to step 550, the electromagnetic valve 27 is opened for a predetermined time, and the concentrated liquid is supplied to the container 1. By repeating the above steps, the viscosity of the container 1 can be maintained at a predetermined value.

The diluting liquid or the concentrated liquid means a liquid having a low viscosity or a high viscosity. However, when the liquid has a low viscosity or a high viscosity, it is desirable to control the concentration as well. When liquids with different concentrations are used as adjusting liquids for viscosity adjustment, for example, measure the viscosity at a low temperature, judge that the viscosity is high, and dilute it with a diluting liquid to make the viscosity constant. Then, the concentration of the liquid will decrease. This is because when the liquid is ink, the problem is that the print density decreases when the density decreases.

Next, a liquid concentration adjusting method will be described with reference to FIGS. 5 to 8 and 14. 7 is a characteristic diagram showing the relationship between temperature and viscosity, FIG. 8 is a characteristic diagram showing the relationship between temperature and target drop time, and FIG. 14 is a characteristic diagram showing the relationship between viscosity and concentration.

The relationship between the concentration and the viscosity of the liquid is as shown in FIG. 14, and even if the viscosity is the same, the concentration varies depending on the temperature. Therefore, when the temperature changes, the concentration cannot be made constant by merely controlling the drop time of the plunger 42 to be constant. Therefore, the relationship 85 between the temperature and the viscosity that achieves the target concentration (100% in this embodiment) as shown in FIG. 7 is obtained, and then the relationship between the target drop time tf0 and the temperature corresponding to the viscosity. Is calculated as shown in FIG. And the plunger 4 at the liquid temperature T
The drop time of 2 is compared with the target drop time tf0 at this temperature T to control the density. By controlling in this way, the concentration can be made constant even if the temperature changes.

The flow of the concentration control is the same as that of the viscosity control described with reference to FIG. 5, but only the method of obtaining the target drop time tf0 is different.

A method for controlling the density will be specifically described. When the measurement of the falling time of the plunger 42 by the operation of the viscometer 17 described above is completed, the viscosity measurement process is started in step 500. In step 510, the average value tf of the results obtained by measuring the falling time of the plunger 42 a predetermined number of times is obtained. here,
Since the relationship between the falling time of the plunger 42 and the viscosity is linear as shown in FIG. 6, the viscosity can be calculated by obtaining the falling time tf of the plunger 42. The falling time of the plunger 42 is several seconds, and the time for pulling up the plunger 42 is about 1 second. Therefore, by using the falling time or the pulling time of the plunger 42, the viscosity can be measured in a short time.

Next, at step 520, the temperature sensor 54
The target fall time tf
Decide 0. The target drop time tf0 is obtained in advance based on the relationship between the concentration and the viscosity shown in FIG. 14 and the relationship between the temperature and the viscosity shown in FIG. 7, as shown in FIG. RA as a data table
It is stored in M305. Then, in step 530, a deviation δ between the fall time tf obtained by measurement and the target fall time tf0 at the detection value T is obtained. In step 540, the magnitude of the deviation δ is determined (specifically, the determination is made by comparing with 0), and the viscosity correction method is selected. If the deviation δ> 0,
It is determined that the concentration is high, the process proceeds to step 560, the electromagnetic valve 29 is opened for a predetermined time, and the diluting liquid is replenished in the container 1. When the deviation δ ≦ 0, it is determined that the concentration is low, the process proceeds to step 550, the electromagnetic valve 27 is opened for a predetermined time, and the concentrated liquid is supplied to the container 1. By repeating the above steps, the concentration of the container 1 can be maintained at a predetermined value.

According to the present embodiment, the cylinder 41 for introducing the liquid stored in the container 1, the plunger 42 movably arranged in the cylinder 41, the electromagnetic coil 43 for moving the plunger 42, and the position of the plunger 42. Measuring device 70 including a plunger detector 45 for detecting
Then, the time from the start of movement of the plunger 42 by driving the electromagnetic coil 43 to the detection of the position of the plunger 42 by the plunger detector 45 is calculated, and the diluted liquid or the concentrated liquid is supplied to the container 1 based on the calculation result. As described above, since the control means controls the concentrated liquid supply device 81 or the diluted liquid supply device 82, the plunger 4
The moving time of the plunger 42 can be measured and the viscosity of the liquid can be adjusted without passing the No. 2 through the upper detector as in the related art 1. This eliminates the need for the upper detector as in the related art 1, and makes it possible to provide a small size and low cost, a short measurement time, and a high measurement accuracy.

Next, an ink jet recording apparatus according to the second embodiment of the present invention will be described with reference to FIGS. 9 to 13. This ink jet recording apparatus basically uses the above-described liquid adjusting apparatus, and duplicate description and illustration of common parts will be omitted. 9 to 12 of the present embodiment and FIGS. 1 to 8 of the first embodiment indicate the same or equivalent parts.

First, the overall structure of the ink jet recording apparatus 900 will be described with reference to FIGS. 9 and 10. Figure 9
FIG. 10 is an external perspective view of an inkjet recording apparatus according to a second embodiment of the present invention, and FIG. 10 is a schematic vertical sectional view of the inkjet recording apparatus.

As shown in FIG. 9, the ink jet recording apparatus 900 includes a main body 600 containing a control system and a circulation system,
The head unit 610 has a nozzle that ejects ink to generate particles, and a cable 620 that connects the main body 600 and the circulation system and control system of the head unit 610. Body 6
An input device 630 including a touch panel type liquid crystal panel that allows a user to input print contents, print specifications, etc., and display control contents, device operating conditions, etc., is provided on the upper inclined surface of 00. .

The internal structure of the main body 600 will be described. As shown in FIG. 10, electric system components such as a control board 640 are arranged in the upper portion of the main body 600. Body 60
A circulation system control component such as a solenoid valve 650 and a pump unit 655 is arranged in the rear part of the lower part of the 0, and a viscometer 17, a container storing ink, a container storing solvent, etc. in the front part thereof. Has been paid. The lid 670 can be opened and closed as shown in FIG. 10, and the ink container, the solvent container, the viscometer 1
7 can be pulled out forward. This allows
Ink and solvent replenishment, disposal, and maintenance of the viscometer 17 can be easily performed. Further, the viscometer 17 can be adjusted in mounting angle so that the falling time can be adjusted.

Next, the ink circulation system of the ink jet recording apparatus 900 will be described with reference to FIG. FIG. 11 is an ink circulation system diagram of the ink jet recording apparatus of this embodiment.

The ink supply device 83 has a pump 2 for pressure-feeding the ink in the container 1 for storing the ink, a pressure regulating valve 3 for adjusting the ink pressure, a pressure gauge 4 for displaying the pressure of the supplied ink, a filter 5, and a communication of these. Ink supply path 21
The ink (liquid) contained in the container 1 is supplied to the nozzle 6. 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 nozzle 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. Therefore, an electrostatic field is formed between the upper deflection electrode 9 and the lower deflection electrode 10, and the charged ink particles 8
Is deflected according to the amount of charge, and printing is performed. The ink recovery device 84 includes a play 11, a filter 12, a pump 14, and an ink recovery path 22 that connects them.
The ink particles 8 that are not charged by the charging electrode 7 and are not involved in recording are collected and returned to the container 1 for ink reuse.

As in the first embodiment, the viscosity measuring device 70 includes a pump 32, a solenoid valve 18, a filter 34, a viscometer 17, and a viscosity measuring path 24 that connects these components to each other. Ink is supplied through the filter 34 by opening the solenoid valve 18. The diluting liquid supply device 82 includes a container 30, which stores an ink solvent as a diluting liquid, a pump 31, a solenoid valve 29, and a replenishing path 26 that connects these components, and supplies the solvent to the container 1 by opening the solenoid valve 29. . In this embodiment, the reused ink has only a means for correcting the viscosity to a low value because the solvent volatilizes and returns with a high viscosity. However, when the solvent is mixed, the ink has a low viscosity. It is preferable to provide a means for increasing the viscosity, such as the concentrated liquid supply device 81 of the embodiment. Next, the circuit configuration of the controller 35 of the inkjet recording apparatus 900 will be described in detail with reference to FIG. FIG. 12 is a circuit configuration diagram of the ink jet recording apparatus of this embodiment.

In FIG. 12, a CPU 300 is a central processing unit that controls the ink jet recording apparatus 900 of this embodiment. The ROM 310 is a read-only memory that stores programs and control data necessary for the CPU 300 to operate. The RAM 305 is a rewritable memory that temporarily stores data and the like handled by the CPU 300 during program execution. Bus line 38
Reference numeral 0 is a signal line including all data, address signals, control signals, etc. from the CPU 300. The interface circuit 315 mediates input / output of data, address signals, control signals, and the like.

The pump control circuit 350 controls the driving of the pumps 2, 14, 31, 32 based on a command from the CPU 300. The solenoid valve control circuit 340 is the CPU 300.
The opening / closing operation control of the solenoid valves 18 and 29 is performed based on the command from.

The plunger detector 45 is connected to the plunger 42.
A signal indicating whether or not is detected is input to the CPU 300 via the interface circuit 315. Viscometer 17 temperature sensor 5
The signal No. 4 is input to the CPU 300 via the A / D converter 355 and the interface circuit 315.

The timer 370 is used by the clock generation circuit 37.
1, a frequency dividing circuit 372, and a counter circuit 373.
The frequency divider circuit 372 divides the signal output from the clock generation circuit 371. The counter circuit 373 is the frequency dividing circuit 3
The signals divided by 80 are counted. Counter circuit 370
Can be reset by an instruction of the CPU 300, and the frequency division ratio of the frequency dividing circuit 380 can be changed by an instruction of the CPU 300.

The excitation source 13 is for driving the nozzle 6, and inputs an excitation signal to the CPU via the interface circuit 315. Recording signal source 1
Reference numeral 6 is for supplying a recording signal to the charging electrode 7, and the recording signal is transferred to the C via the interface circuit 315.
Input to PU.

Next, a control method of the ink jet recording apparatus will be described with reference to FIG. FIG. 13 is a flowchart showing the method of controlling the inkjet recording apparatus according to this embodiment.

When CPU 300 receives a device activation command from input device 630, CPU 300 performs the process of step 100. In step 105, the viscosity measurement process described in FIG. 4 of the first embodiment is performed to measure the ink viscosity of the ink container 1. In step 110, it is determined whether the ink viscosity is the target value. If it is outside the proper range, step 11
5, the same process as the viscosity correction described in FIG. 5 of the first embodiment is performed to correct the ink viscosity. After the correction process is completed, step 105 is performed again, and step 1
Check whether the ink viscosity is appropriate at 10. In addition, step 1
Although the viscosity correction process is performed in No. 15, the ink abnormality may be displayed on the display 630 and the user may be instructed to replace or correct the ink.

If the ink viscosity is an appropriate value in step 110, the process proceeds to step 120 and it is determined whether or not ink is ejected. If there is no ink ejection in this determination, step 150
If there is ink ejection, the pump 14 and the pump 2 are started in step 130, the ink in the ink container 1 is supplied to the nozzle 6 from the ink supply path 21, and the ink is ejected from the nozzle 6. Then, the gutter 11 receives the ink particles that are not involved in the recording of the ejected ink, and collects them in the ink container 1 through the ink collecting path 23.

Next, at step 140, the excitation source 13
An exciting voltage is output from the device and is applied to a piezoelectric body attached to the nozzle 6 to vibrate the ink to regularly eject the ejected ink into particles. As a result, the ink particles 8 are ready for printing.

In step 150, the timer 370 for setting the ink viscosity measurement interval is reset and then started, and in step 160 it is judged whether or not the timer 370 has reached the set value. When the set value is reached, the process of step 170 is shifted. . In step 170, the inkjet recording device 90
It is judged whether or not there is a stop command of 0, and if there is no stop command, the process returns to the ink viscosity measurement of step 105 and the above steps are repeated. If there is a stop command in step 170, the stop processing of the inkjet recording apparatus 900 is performed.

As described above, by measuring the ink viscosity at the time of starting the apparatus and at the time of operating the apparatus, the ink viscosity can be appropriately maintained, and stable ink particle formation and printing can be performed.

[0076]

According to the present invention, it is possible to obtain a liquid adjusting apparatus which is small in size and inexpensive, has a short measuring time, and has a high measuring accuracy.

Further, according to the present invention, it is small and inexpensive,
In addition, it is possible to obtain a liquid adjusting apparatus which has a short measurement time and has high measurement accuracy even if the temperature changes.

Further, according to the present invention, it is small and inexpensive,
Moreover, it is possible to obtain an ink jet recording apparatus having a short measurement time and a high measurement accuracy.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a circulation system of a liquid regulator according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a viscometer used in the liquid adjusting apparatus.

FIG. 3 is a circuit configuration diagram of the liquid adjusting apparatus.

FIG. 4 is a flowchart showing the operation of the viscometer of the liquid adjusting apparatus.

FIG. 5 is a flowchart showing a liquid viscosity adjusting method of the liquid adjusting apparatus.

FIG. 6 is a characteristic diagram showing the relationship between the viscosity of liquid and the drop time.

FIG. 7 is a characteristic diagram showing a relationship between temperature and viscosity.

FIG. 8 is a characteristic diagram showing the relationship between temperature and target drop time.

FIG. 9 is an external perspective view of an inkjet recording apparatus according to a second embodiment of the present invention.

FIG. 10 is a schematic vertical cross-sectional view of the inkjet recording apparatus.

FIG. 11 is a schematic diagram of an ink circulation system of the inkjet recording apparatus.

FIG. 12 is a circuit configuration diagram of the ink jet recording apparatus.

FIG. 13 is a flowchart showing a control method of the inkjet recording apparatus.

FIG. 14 is a characteristic diagram showing a relationship between viscosity and concentration.

[Explanation of symbols]

1 ... Container, 2 ... Pump, 3 ... Pressure regulating valve, 4 ... Pressure gauge, 5 ...
Filter, 6 ... Nozzle, 7 ... Charging electrode, 8 ... Ink particles, 9 ... Upper deflection electrode, 10 ... Lower deflection electrode, 11 ... Gutter, 12 ... Filter, 14 ... Pump, 17 ... Viscometer,
18 ... Electromagnetic valve, 21 ... Ink supply path, 22 ... Ink recovery path, 24 ... Viscosity measurement path, 25 ... Replenishment path, 26 ...
Supply route, 27 ... Solenoid valve, 28 ... Container, 29 ... Solenoid valve,
30 ... Container, 31, 32, 33 ... Pump, 34 ... Filter, 35 ... Controller, 41 ... Cylinder, 42 ... Plunger, 43 ... Electromagnetic coil, 44 ... Press plate, 45 ... Plunger detector, 47 ... Coil press, 48 … Spacers, 4
9 ... Cylinder block, 50 ... Stopper, 51 ... Cylinder lower end surface, 53 ... Joint, 54 ... Temperature sensor, 62 ... Cylinder chamber, 70 ... Viscosity measuring device, 80 ... Adjusting liquid supply device, 81 ... Concentrated liquid supply device, 82 ... Diluting liquid supply device, 83 ... Ink supply device, 84 ... Ink recovery device, 1
00 ... Liquid adjusting device, 300 ... CPU, 305 ... RA
M, 310 ... ROM, 315 ... Interface circuit,
320 ... Pump control circuit, 330 ... Coil control circuit, 3
40 ... Solenoid valve control circuit, 355 ... A / D converter, 360
... Input device, 370 ... Timer, 371 ... Clock generation circuit, 372 ... Frequency divider circuit, 373 ... Counter circuit, 38
0 ... Bus line, 600 ... Main body, 610 ... Head part, 6
20 ... Cable, 640 ... Control board, 650 ... Solenoid valve,
655 ... Pump unit, 670 ... Lid, 900 ... Inkjet recording apparatus.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiharu Takizawa             1-1-1 Higashitaga-cho, Hitachi City, Ibaraki Prefecture             Inside the ceremony company Hitachi Taga Electronics (72) Inventor Akira Miyao             1-1-1 Higashitaga-cho, Hitachi City, Ibaraki Prefecture             Inside the ceremony company Hitachi Taga Electronics F-term (reference) 2C056 EA23 EA24 EB30 EB32 EC21                       EC43 KD06 KD10

Claims (12)

[Claims] 1. A container for containing a liquid, a viscosity measuring unit for measuring the viscosity of the liquid in the container, an adjusting liquid supplying unit for supplying an adjusting liquid for adjusting the liquid viscosity to the container, and the viscosity measuring unit. Means and a controller for controlling the adjusted liquid supply means, wherein the viscosity measuring means moves a cylinder for introducing the liquid stored in the container, a plunger movably arranged in the cylinder, and the plunger. Drive means for
A plunger detector that detects the position of the plunger, wherein the control means measures the time from the start of movement of the plunger by the driving of the driving means to the detection of the plunger position by the plunger detector. A liquid adjusting device characterized in that the adjusting liquid supply means is controlled so as to supply the adjusting liquid to the container based on the result measured by the means. 2. The liquid adjusting device according to claim 1, wherein the length of the plunger in the moving direction is longer than the moving distance from the predetermined position of the plunger to the detection by the plunger detector. 3. The cylinder according to claim 1, wherein the cylinder is formed of a cylindrical non-magnetic material, the plunger is formed of a cylindrical magnetic material, and the driving means is formed of an electromagnetic coil provided on the outer circumference of the cylinder. Then, the liquid adjustment device is characterized in that the plunger is moved by energizing the electromagnetic coil. 4. The plunger detector according to claim 3, wherein the plunger detector is formed by a magnetic sensor and is arranged on a plunger moving axis, and the plunger detector is installed so as to be close to an end face flat portion when the position of the plunger is detected. A liquid adjusting device characterized in that 5. The means according to claim 3, wherein the viscosity measuring means is vertically arranged, and the time from when the electromagnetic coil is de-energized and the plunger begins to fall until it is detected by the plunger detector is measured. Liquid adjusting device characterized by having. 6. A liquid adjusting apparatus according to claim 3, wherein at least a part of the plunger is always housed in the electromagnetic coil. 7. A container for containing a liquid, a viscosity measuring unit for measuring the viscosity of the liquid in the container, an adjusting liquid supplying unit for supplying an adjusting liquid for adjusting the liquid viscosity to the container, and the viscosity measuring unit. Means and a controller for controlling the adjusted liquid supply means, wherein the viscosity measuring means moves a cylinder for introducing the liquid stored in the container, a plunger movably arranged in the cylinder, and the plunger. Drive means for
A plunger detector for detecting the position of the plunger,
A temperature detector for detecting the temperature of the liquid to be measured, wherein the control means corrects the measurement result of the moving time of the plunger by the temperature detected by the temperature detector, and the adjusted liquid based on the correction result. A liquid adjusting device, wherein the adjusting liquid supply means is controlled so as to supply the liquid to the container. 8. The temperature detected by the temperature detector according to claim 7, wherein the temperature detected by the temperature detector is the result of measuring the time from the start of movement of the plunger by the driving of the drive means to the detection of the position of the plunger by the plunger detector. A liquid adjusting device, characterized in that the above-mentioned control means is used for correction. 9. The liquid adjusting device according to claim 7, wherein a target time for correcting the measurement result with temperature is stored in a storage device of the control device. 10. A means for comparing target drop time data with measured drop time according to claim 1 or 7, and replenishing with a diluting liquid for lowering the viscosity of the liquid when the drop time measured is longer than the target drop time. And a means for replenishing the concentrated liquid that increases the viscosity of the liquid when the measured fall time is shorter than the target fall time. 11. A container for storing ink, a viscosity measuring means for measuring the viscosity of the ink in the container, an adjusting ink supplying means for supplying the adjusting ink for adjusting the ink viscosity to the container, and An ink supply device that supplies ink to the ink ejecting unit, and a control device that controls the viscosity measurement unit, the adjustment ink supply unit, and the ink supply unit, the viscosity measurement unit, the ink stored in the container A cylinder to be introduced, a plunger movably arranged in the cylinder, a driving unit that moves the plunger, and a plunger detector that detects the position of the plunger, the control unit includes the ink supply unit. During operation, from the start of movement of the plunger by the drive of the ink collecting means and the driving means, the plunger detector starts the movement of the plunger. Ink jet recording, characterized in that the adjusting ink supply means is controlled so as to supply the adjusting ink to the container based on the result of measurement of the time until the position of the nozzle is detected by the viscosity measuring means. apparatus. 12. The ink jet system according to claim 11, wherein the adjusted ink is supplied from the adjusted ink supply unit based on the measurement by the viscosity measuring unit at a predetermined interval during the operation of the ink supply unit. Recording device.