JPS60225759A - Chromaticity adjustor for ink - Google Patents

Abstract

PURPOSE:To keep constant the chromaticity of ink that is produced by mixing in a blending tank by controlling the supply of a dye solution to the blending tank from respective dye solution containers. CONSTITUTION:Chromaticity C1-C3 are measured with an analysis section 12 about individual dye solutions 2a-2c via a sampling section 9, an adjusting section 10 and a weighing/pouring section 11 and sent to a control section 14. A final controlling element sets the volume Vs of ink 4 to be produced, the allowable errors DELTAE of the chromaticity Co of the ink actually mixed ink from the chromaticity thereof Cs and mixing time with a blending tank 3. The control section 14 calculates the supply V1-V3 of dye solutions and controls a valve 5a by opening or closing for the supply thereof to reach V1 by a signal of a flowmeter 6a. It performs the same control for 5b and 5c. With the blending tank 3, ink 4 is produced by mixing with a sterring blade 8 by a set time with a operation timer. After the mixing, the chromaticity Co of the ink 4 in the tank is measured with the analysis section 12 in the same way as with the dye solutions to be compared with Cs and when the results exceed DELTAE, the supplies V1-V3 for correction are calculated. After a mixing for correction, if the results of the comparison between Co and Cs are withing DELTAE, the production will finish. Thus, the chromaticity of the ink can be kept almost constant by controlling the supply of individual dye solutions.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an ink chromaticity adjustment device that adjusts the chromaticity of ink to a desired level by mixing two or more types of dyes during the production of ink. The present invention can be used, for example, to manufacture ink for writing instruments such as felt pens and fountain pens, but is particularly applicable to inkjet recording methods, such as ejecting ink in a recording head from an ejection orifice using vibrations using a piezo vibrator. It is useful when used in the production of aqueous ink used in recording methods and the like.

[Prior Art] Generally, dyes are used to color ink, but it is rare for a single dye to achieve the desired chromaticity, so two or more types of dyes are mixed to adjust the desired chromaticity. In most cases. Ink chromaticity adjustment errors not only cause ink color unevenness, but also, especially in inkjet recording systems, fluctuations in the amount of dye contained due to errors cause small amounts of ink to be printed at high speeds thousands of times per second. This can clog the recording head, which has an extremely dense structure due to the fact that it ejects the liquid at a high speed, and cause a malfunction. Therefore, it is desired that the chromaticity adjustment of ink be both efficient and accurate.

Conventionally, to adjust the chromaticity of the ink, the dye is mixed with a solvent, etc. at a predetermined mixing ratio based on a test mixture, and then samples are taken to check whether the ink has the predetermined chromaticity. In some cases, this is done by repeatedly adding dye and testing.

However, when the dye is a solid (powder), it is difficult to control the weight of the dye, it is difficult to mix the dye accurately in a predetermined proportion, and it is even more difficult to automate this process.

Therefore, not only is the batch work largely dependent on manual labor, but also the dye supplementation and inspection must be repeated frequently, resulting in extremely low work efficiency. Also,
Since the dissolution time of solid dyes differs depending on the type of dye, the mixing and stirring time cannot be unambiguously determined, and it is even more difficult to automate the process from evaluating the dye to inspecting the chromaticity of the ink after mixing.

On the other hand, if the dye solution is a dye solution in which the dye is dissolved in a predetermined solvent, it is easy to ensure accurate weighing, and since the dye is already dissolved in the solvent, differences in the dissolution time of the dye do not pose a problem. Therefore, it is conceivable to use this dye solution to automate the process from weighing to testing the chromaticity of the ink after mixing.

However, in the case of dye solutions, the chromaticity of each unit is not necessarily constant, so if you simply mix them at a fixed ratio,
When the unit of the dye solution changes, the chromaticity of the resulting ink also changes. Therefore, it is necessary to carry out test mixing for each unit of dye solution and re-determine the blending ratio, which is often untenable. In addition, in order to maintain a constant chromaticity between units of dye solution, the amount of solid dye added to the solvent must be accurately weighed and rigorously inspected, making the procedure complicated and impractical. will be lost.

[Problems to be Solved by the Invention] The present invention solves the problem that when adjusting the chromaticity of ink using a dye solution, if there is a chromaticity error in each unit of the dye solution, the error occurs each time the unit of the dye solution changes. The problem to be solved is that the chromaticity of mixed and manufactured inks varies due to errors.

[Means for Solving the Problems] In the present invention, the means taken to solve the above problems include a plurality of dye solution containers and a mixing tank for mixing the dye solutions supplied from each dye solution container. The ink chromaticity adjustment device has the following features: and a control unit that controls the amount of dye solution supplied from each dye solution container to the mixing tank based on the chromaticity of each dye solution to be supplied to the mixing tank. .

[Function 1] According to the above means, the supply amount is controlled by the control unit according to the chromaticity of each dye solution to be mixed, so that the chromaticity of the dye solution charged into each dye solution container is controlled by the controller. Even if the chromaticity changes, it is possible to obtain a holding effect that keeps the chromaticity of the ink mixed and manufactured in the mixing tank almost constant.

[Example] In FIG. 1, 1a-1c are dye solution containers,
Dye solutions 2a to 2c of different colors are stored in each of the dye solution containers 1a to lc. Dye solution 2a-2
c is a dye dissolved in a predetermined solvent, and may be further added with other components necessary for the ink 4 mixed and manufactured in the mixing tank 3. The solvent is water or an organic solvent, and the above-mentioned components include glycols and additives for improving ink properties.

The dye solution containers 1a-1c are connected to the mixing tank 3 via pulps 5a-5c and flow meters 6a-6c, respectively.

The mixing tank 3 has a stirring blade 8 rotated by a motor 7.
It has become. Each dye solution 2a to 2c is supplied to the mixing tank 3 through valves 5a to 5c and flowmeters 6a to 6c.
The ink 4 is supplied to the mixing tank 3 and mixed by a stirring blade 5 in the mixing tank 3 to form an ink 4 having a desired chromaticity.

Meanwhile, the dye solution containers 1a-1c and the mixing tank 3 are also connected to a sampling section 9 for collecting samples in order to detect the chromaticity of each of the dye solutions 2a-2c and the ink 4. This sampling section 9 is for taking in each of the dye solutions 2a to 2c or ink 4 as a sample in an amount necessary for detecting chromaticity.

The sampling section 9 is connected to the adjustment section 10. This adjustment part
O adjusts the sample sent from the sampling section 9 into a sample solution suitable for analysis.

As shown in FIG. 2, the sample sent from the sampling section 9, which is, for example, a constant flow pump P, is mixed with the adjustment liquid 10b sent from the adjustment liquid tank 10a by, for example, a constant flow pump P2 in the adjustment section 1O. 10c, where they are mixed and diluted to form a sample solution suitable for chromaticity analysis. The concentration, composition, etc. of the sample solution are adjusted according to the analyzer by adjusting the flow rate of the constant flow pumps P1+P2, adjusting the concentration and composition of the adjustment liquid tab, etc.

The adjustment section IO is connected to the metering injection section 11 . This metering injection section 11 is for injecting a fixed amount of sample solution into the analysis section 12 connected thereto. As the measuring injection part 11, for example, a commonly used autosampler or the like can be used. The analysis section 12 analyzes the injected sample solution and detects the chromaticity of each of the dye solutions 2a to 2c or the ink 4, and uses, for example, a spectrophotometer.

The valves 5a to 5c, the flowmeters 6a to 8c, the sampling part 9,
The adjustment section 10, metering and injection section 11, and analysis section 12 are connected to a control section 14 that is connected to an operation section 13 equipped with various display sections, drive switches, and the like. Collection part 9, adjustment part lO
The operation of the one-meter injection unit 11 and the analysis unit 12 is controlled by this control unit 14. Further, the valves 58 to 5c are
Opening and closing are controlled by signals from a controller 14 based on signals from the flowmeters 6a to 8c and the analysis section 12.

FIG. 3 is a flow sheet for the control section 14, and the operation of the apparatus will be explained based on this flow sheet.

First, add the required dye solutions 2a to 2 to the dye solution containers 1a to 1c.
Fill with c and start operation.

Each of the dye solutions 2a to 2c is sequentially taken into the collection section 9, passes through the adjustment section lO2 metering and injection section 11, and then is measured in the analysis section 12 for its chromaticity C1 to C3. The measurement results are then sent to the control section 14.

Next, the amount of ink 4 to be produced Vs and its chromaticity Os
Furthermore, the allowable error ΔE between the chromaticity Go of the actually produced ink 4 and the set chromaticity Cs and the mixing time of the ink 4 in the mixing tank 3 are set using the operation unit 13.

The above-set chromaticity Cs of ink 4 and amount V of ink 4
s and the chromaticity C of each of the measured dye solutions 2a to 2C,
-Cs, the control unit 14 calculates the supply amounts of each of the dye solutions 2a to 2c, .about.v3. Next, the control unit 14 opens the valve 5a, reads the signal from the flowmeter 6a, and
When the amount of dye solution 2a supplied to the mixing tank 3 reaches Vl, the valve 5a is closed, and the valves 5b and 5c are sequentially controlled to open and close in the same manner.

After each dye solution 2a to 2C is supplied to the mixing tank 3 in this way, the operation timer of the motor 7 is reset, and the stirring blade 8 is rotated by the motor 7 for the set time T to mix the ink 4. Manufacture.

After mixing for a time T, the ink 4 in the mixing tank 3 is taken into the collection section 9, passes through the adjustment section 10 and the metering and injection section 11, and then the chromaticity CO is measured and set in the analysis section 12. It is compared with the chromaticity Cs. If the difference between the chromaticity Co of the ink 4 and the preset chromaticity Cs exceeds the set tolerance ΔE, supply of dye solutions 2a to 2c to be supplemented to adjust this difference. v1 to v3 are calculated. Then, based on this calculation result, necessary dye solutions 2a to 2c are supplemented and mixed in the same manner as described above, and then the chromaticities Co and Cs are compared again. If both chromaticities CO and Cs are within the allowable error ΔE, one cycle of chromaticity adjustment processing is completed.

[Effects of the Invention] According to the present invention, the supply amount is determined according to the chromaticity of each dye solution to be mixed, so even if the chromaticity of the dye solution changes from unit to unit, the color of the ink produced can be maintained. The temperature can be kept almost constant. Thereby, it is possible to automate everything from weighing to ink chromaticity inspection after mixing by using the dye solution, and it is possible to efficiently adjust the chromaticity of the ink. Furthermore, by knowing the chromaticity of each dye solution, it is easy to finely adjust the chromaticity of the manufactured ink.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the ink chromaticity adjustment device according to the present invention, FIG. 2 is a detailed diagram of the sampling section and adjustment section in FIG. 1, and FIG. 3 is a control section in FIG. 1. This is a flow sheet. Ia-1c: dye solution container, 2a-2c: dye solution,
3: Preparation tank, 4. 5a to 5c: Valve, 6a to 6c: Flow meter, 7: Motor, 8: Stirring blade, 8: Collection section, lo: Adjustment section, 11: Metering and injection section 12: Analysis section, Ia: Operation section 1.
14: Control unit. Applicant Canon Co., Ltd. Agent Yutaka 1) Yoshio

Claims (1)

[Claims] l) A plurality of dye solution containers, a mixing tank for mixing the dye solutions supplied from each dye solution container, and supplying each dye solution from each dye solution container to the mixing tank based on the chromaticity of each dye solution to be supplied to the mixing tank. 1. An ink chromaticity adjustment device, comprising: a control section that controls the amount of dye solution supplied.