JPS5942962A - Dilution of ink liquid - Google Patents

Abstract

PURPOSE:To prevent the lowering of the quality of recording due to the increase in the viscosity of ink with the vaporization of solvent in the ink by a method in which when non-recording time after throwing-in the power source is integrated and the accumulated time reaches a given value, display and alarm are commanded for the supply of fresh ink. CONSTITUTION:A signal to operate an integrating timer circuit 13 during non- recording time is sent out of a recording control circuit 12 by making the power source, and non-recording time is integrated and stored by the circuit 13. When the accumulated non-recording time of the circuit 13 reaches a preset limiting value Tlim, a signal to show an ink viscosity alarm is sent out to the displayer 14 and at the same time the ink supplier 15 is stopped. The integrating timer circuit 13 is then reset.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink liquid dilution method for a charge amount control type ink jet recording apparatus that prevents recording failures caused by an increase in ink viscosity due to evaporation of an ink solvent.

FIG. 1 shows a schematic diagram of the configuration of a charge amount control type inkjet recording apparatus, which is the object of the present invention. In this diagram,
1 is an ink tank, 2 is a pump for pressurizing ink, 3 is a solenoid valve, 4 is a nozzle, 5 is a piezoelectric vibrator closely connected to the nozzle 4, 6 is a load [T6° pole, 7a, Tb are constant voltages applied deflection electrode.

B is a gutter, 9 is an ink recovery pump, 10 is an ink droplet array, and 11 is a recording paper.

Next, let me explain how it works.

The ink in the ink tank 1 is pressurized by the ink pressurizing pump 2, and is supplied to the nozzle Ic via the solenoid valve 3.
It is sprayed from nozzle 4. The ejected inkjet flow is given vibration by a piezoelectric vibrator 5, and a regular array of ink droplets 10 having the same period as the vibration period is generated. Next, this ink droplet is selectively charged according to the recorded information, and is further charged by the deflection electrodes 7a, 7.
It is deflected by the constant sum 1 field 9 between b and strikes a predetermined position 1- on the recording paper 11 to record.

In addition, unused ink that is not used for recording is not unloaded at the j-th vertical column (6), but goes straight, is collected in the °C gutter 8, and is returned to the ink tank 1 by the ink recovery pump 9. and reused.

As mentioned above, the ink droplets used for recording are electrically charged!菟6
Since the ink droplets receive a predetermined charge and are deflected according to the charge Ty and amount, if the ejection speed of the ink droplet changes, the charge or deflection 1. changes, causing recording distortion.

In particular, in inkjet recording apparatuses that need to accurately record a plurality of ink droplets, such as color recording, it is necessary to control ink pressure, ink viscosity, etc. so as to maintain a constant jetting speed of ink droplets.

However, in the %Jt control type inkjet recording device, the ink viscosity does not only change due to temperature, but also the ink droplets are continuously ejected after the power is turned on regardless of whether or not printing is performed, so the ink is collected and reused. There is a problem in that while the droplets are flying in the air or are collecting in the gutter 8, the ink solvent evaporates and the viscosity of the ink gradually increases.

In order to solve this problem, we have installed an ink viscosity measuring device inside the ink tank or on the ink collection route to monitor the ink viscosity and display 7 lanes or new waste as necessary. A method for replenishing ink at the destination station has been proposed. However, there is a drawback that the installation of an ink viscosity measuring device causes the entire device to become smaller or larger.

In addition, as another method, a method has been proposed in which the ejection speed of ink droplets is detected and this is fed back to the force, etc., to obtain a constant flow of ink 3ir.★1. ing.

However, since the viscosity of the ink increases in proportion to the evaporation of the solvent, the pump that generates the ink pressure to compensate for this increases in size. In particular, in the case of color recording, ink supply devices for 2.3 or 4 colors are required, which has the disadvantage of increasing the size of the entire device.

In order to eliminate the first and other drawbacks, the present invention accumulates and stores the non-recording time after the power is turned on, and displays the replenishment of new ink when the cumulative non-recording time reaches a certain value. , 5K is added. The following is a detailed description of the invention based on the drawings 17).

FIG. 2 is a block diagram for explaining one embodiment of the present invention. In this figure, 124 is a recording control circuit, 13 is an integration timer circuit, 14 is a display device, and 15 is an ink supply device. Further, FIG. 3 is a time chart for explaining the operation of the integration timer circuit 13 in FIG. 2.

To explain the operation, after the power is turned on, the recording control circuit 12 uses the integration timer circuit 13 only during non-recording time.
A signal to activate the device is output. In response to this signal, the integration timer circuit 13 integrates only the non-recording time, and is stored so that continuous integration can be performed even if the power is repeatedly turned off and on. Therefore, the cumulative non-recording time of the integration timer circuit 13 increases as shown in FIG. When the cumulative non-recording time reaches the preset limit Tlim (see Figure 3), a signal indicating an ink viscosity alarm is output to the display device vt14, and at the same time the ink supply devices 6 to 15
is stopped, and the integration timer circuit 13 is reset.

In this way, when the ink viscosity alarm is displayed on the display device 141C, the ink viscosity can be returned to a normal value by replacing the ink in the ink tank 1 with new ink or diluted ink. In addition, the limit value T l i m of cumulative non-recording time '''C should be determined from the relationship between the increase in ink viscosity, which is determined by the performance of the ink pressurizing pump, the ink droplet generation conditions, etc., and the evaporation rate of the ink solvent. Can be done.

In the above embodiment, only the ink viscosity alarm is displayed, but if the device space allows, it is also possible to provide a means to automatically replenish fresh ink.
It is Noh.

As explained above, according to the present invention, it is possible to easily
The electric circuit pressure can prevent deterioration in recording quality due to an increase in ink viscosity due to evaporation of the solvent in the ink, and has the advantage of providing stable 1-length recording quality over a long period of time.

[Brief explanation of the drawing]

Claims (1)

[Claims] Ink supplied under pressure from an ink tank to a nozzle is ejected as ink droplets from the nozzle, and the ink droplets are selectively charged with heavy pressure according to recording information to perform recording, and ink droplets that are not used for recording are captured. In the inkjet recording device that collects the ink tank and reuses the temperature,
The non-recording time ta after the power is turned on is accumulated and memorized, and when the accumulated non-recording time force 1 reaches a constant value, new ink tj! :
An ink liquid dilution method characterized by providing a desired display or replenishing new ink.