JPH08281941A - Ink jet recorder - Google Patents

Abstract

PURPOSE: To quickly remove bubbles in ink that causes blurring of characters in an ink jet recorder utilizing an air flow and an electrostatic force. CONSTITUTION: While an air in an air supplying source 5 is spouted out from an air spouting hole 2 opposite an ink ejection nozzle 1, an ink is ejected by driving an ink electrode 8 and an air electrode 3 to execute recording. When bubbles are accumulated in the vicinity of the ink ejection nozzle 1 in an ink chamber 7, characters may blur so that good printing is not achieved. Therefore, a throttle valve 12 provided in a supplying passage to an air chamber 6 is closed so that an air pressure applied to the ink to in ink tank 4 from the air supplying source 5 is increased. Thereby, the bubbles are ejected along with the ink, then the bubbles are removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for ejecting ink from a minute opening to record characters, images, figures and the like on an object to be recorded by utilizing air flow and electrostatic force.

[0002]

2. Description of the Related Art A conventional ink jet recording apparatus will be described below. FIG. 3 shows an ink jet recording apparatus described in JP-A-57-12452.

In the figure, an ink ejection port 1 and an air ejection port 2 are perforated so as to face each other with a predetermined gap therebetween, and an ink electrode 8 is provided around the ink ejection port, and an air ejection port 2 is provided. An air electrode 3 is provided around the. The ink tank 4 fills the ink chamber 7 with ink via the ink supply passage 9. The air from the air supply source 5 flows into the air chamber 6 through the air supply passage 10, and then flows out from the air discharge port 2 with a sharp bend. On the other hand, the air from the air supply source 5 pressurizes the ink in the ink tank 4 through the pressure supply passage 11. The pressure of the air flowing through the gap and the pressure of the ink held in the ink ejection port 1 are set to be substantially equal to each other so that the ink is stably retained in the ink ejection port 1 when the ink is not ejected. It is set.

In the above configuration, when a potential difference is applied between the ink electrode 8 connected to the signal source and the air electrode 3, the ink charged to the potential of the ink electrode 8 has an electrostatic force generated by the potential difference from the air electrode 3. Be stretched by. The stretched ink flies through the air ejection port 2 by the air flow. Characters and figures can be recorded by intermittently ejecting ink droplets while moving the head.

[0005]

By the way, since air bubbles are originally mixed in the ink, or when the ink tank 4 is replaced, air bubbles are mixed while the ink is being supplied to the ink chamber 7. Will collect bubbles. When bubbles are present in the vicinity of the ink ejection port 1, the ink may not be ejected or the ink ejection amount may decrease even if a signal voltage is applied between the electrodes according to the image signal, so that characters may be blurred. is there. However, in the above-described conventional configuration, the mixed air bubbles have no choice but to continue recording in a faint state and wait until they are naturally removed.

In view of this, the present invention intends to promptly perform clear recording by forcibly removing the bubbles when the characters are blurred due to the inclusion of bubbles.

[0007]

In order to solve the above problems, an ink jet recording apparatus of the present invention is provided with an air valve in an air supply path from an air supply source to an air discharge port, and adjusts the air valve. As a result, compared with the air pressure applied to the ink in the ink tank, the pressure difference caused by reducing the pressure of the air flowing through the gap between the air ejection port and the ink ejection port causes the bubbles in the ink chamber to be ejected together with the ink. It is a thing.

[0008]

In the above structure, when air bubbles are accumulated in the vicinity of the ink ejection port and a character is blurred, the air pressure applied to the ink in the ink chamber is increased by closing the air valve or the like. Thereby, the bubbles are ejected together with the ink, and the bubbles can be forcibly removed.

[0009]

Embodiments of the ink jet recording apparatus of the present invention will be described below with reference to the drawings. FIG.
Shows an embodiment of the present invention. It should be noted that the same components as those of the related art are designated by the same reference numerals and the description thereof will be omitted. The air supply source 5 is different from the conventional configuration in the figure.
This is the point where the throttle valve 12 is provided in the air supply path 10 from the air chamber 6 to the air chamber 6.

Since a normal recording operation is similar to that of the above-mentioned conventional example, its explanation is omitted, and a bubble removing operation will be described below. When bubbles are mixed, the recording operation is stopped and the bubble removal operation is started. When the throttle valve 12 is throttled to a preset value, the amount of air supplied into the air chamber 6 decreases, and the pressure in the air chamber 6 decreases. At the same time, the total exhaust amount of air decreases, so the pressure of the air supply source 5 rises, and conversely the pressure in the ink chamber 7 rises. As a result, air bubbles are ejected along with the ink along with the air flow ejected from the air ejection port 2.

FIG. 2 shows another embodiment of the present invention. In the figure, the difference from the configuration of the above embodiment is that two supply passages to the air chamber 6 are provided, and the throttle valve 12 is provided in one of the supply passages. When removing air bubbles, the throttle valve 12 in the air supply passage 10 is closed. When the throttle valve 12 is closed, the amount of air supplied into the air chamber 6 decreases and the pressure in the air chamber decreases. At the same time, the total exhaust amount of air decreases, so that the pressure of the air supply source 5 rises and the pressure in the ink chamber 7 rises. Therefore, the bubbles are ejected along with the ink along with the air flow ejected from the air ejection port 2. In this embodiment, as compared with the embodiment of FIG. 1 described above,
Since the throttle valve 12 can be constituted by an electromagnetic valve, there is an advantage over the above-described embodiment that the throttle condition of the throttle valve need not be set in advance.

[0012]

As described above, according to the present invention, the throttle valve for adjusting the air pressure is provided instead of sucking the ink from the front surface of the ink discharge port or the air discharge port using a special device. With such a simple configuration, the bubbles can be removed easily and quickly.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the device.

FIG. 3 is a configuration diagram of a conventional inkjet recording device.

[Explanation of symbols]

 1 Ink ejection port 2 Air ejection port 3 Air electrode 4 Ink tank 6 Air chamber 7 Ink chamber 8 Ink electrode 9 Ink supply channel 10 Air supply channel 11 Pressure supply channel 12 Throttle valve

Claims (1)

[Claims] 1. An ink ejection port, one of which communicates with an ink chamber, is arranged so as to face the air ejection port with a predetermined gap, and air from an air supply source is continuously passed through the gap and continuously from the air ejection port. A pulse voltage is intermittently applied between the air discharge port and electrodes provided around the ink discharge port while the ink in the ink tank communicating with the ink chamber is pressurized by the air from the air supply source while flowing out. In the ink jet recording apparatus for intermittently ejecting the ink from the ink ejection port together with the air flow from the air ejection port to perform recording by applying the voltage, in an air supply path from the air supply source to the air ejection port. An air valve is provided on the air valve to reduce the pressure of the air flowing through the gap as compared with the air pressure applied to the ink in the ink tank. An ink jet recording apparatus characterized in that air bubbles in an ink chamber are ejected together with ink by a pressure difference caused by the pressure difference.