JPS61134263A - Ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To make a charged amount of electrodes large, to expond the deflec tion values, and to prevent the ink particles charged on the different marks from being mixed by disposing a pair of deflection electrodes right behind a charged electrode, which impressing a voltage of different polarity to each electrode. CONSTITUTION:A charged electrode 21 which is impressed a recording signal voltage from a mono-signal source 20 is disposed adjacent to a nozzle 3, and a pair of deflection electrode 22a and 22b are provided in the position directly rear of this charged electrode 21. The voltage (+Vd/2) and (-Vd/2) are im pressed to the deflection electrodes 22a and 22b respectively, so as to make the potential zero on a line on which the ink drops advance straitly. In such a constitution, an annexation of the ink drops does not occur adjacent to an inlet of the deflection electrodes, since the deflection of the ink drops separated from an ink pillar 14 is started immediately after they leave the charged elec trode 21. Further, the charged amount can be made large, since the distance (d) between the charged electrodes can be made small, and in its turn, the deflection amount can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inkjet recording device that increases the amount of charge, expands the deflection width, and further prevents droplets charged with opposite signs from merging.

[Conventional technology]

As a conventional inkjet recording apparatus, for example, there is the one shown in JP-A No. 56-135079 shown in FIG. 2, which is equipped with an ink chamber 2 containing a piezoelectric vibrator,
A head l that flies an ink column 14 in response to the vibration of a vibrator, and charging and deflection electrodes 6a disposed above and below the course of passage of a group of ink droplets.

6, b, bias power supplies 8a, 8b which are connected in series with each of the recording signal sources 7a, 7b and apply voltages of mutually different polarities to each of the electrodes 6a, 6b, and the recording paper 10 of the charging/deflecting electrodes 6a, 6b. A pair of deflection electrodes 9a and 9b are arranged on the closer side and deflect the small-diameter particles 5 ejected from the nozzle according to the amount of electric charge (DC voltage is applied to 9a,
b is grounded), a DC power source 11 that applies a DC voltage to the deflection electrode 9a, and a gutter 13 that captures the large-diameter particles 4 and the small-diameter particles 12 that were not used for recording and prevents them from reaching the recording paper IO. It consists of

In the above configuration, since the recording signal voltage superimposed on the bias voltage is superimposed on the charging/deflecting electrodes 6a and 6b, there is a gap between the ink column 14 ejected from the nozzle 3 and the charging/deflecting electrodes 5a, 5b. Electric lines of force are generated. As a result, the ink column 14 is given a charge corresponding to the voltage of the recording signal sources 7a and 7b. The small diameter particles 5 separated from the ink column 14 are subjected to a deflection force by an electrostatic field (normally formed) generated by the voltage applied by the bias power supplies 8a and 8b. However, for small diameter particles and large diameter particles 4 that are not used for recording, the ink column 14 is connected to the electrodes 6a and 6b.
Since both bias voltages are set to be approximately the same and have opposite polarities, the battery moves straight toward the gutter 13 without being charged. The small-diameter particles 5 deflected by the electrodes 6a and 6b are further deflected by the deflection electrodes 9a and 9b, and adhere to the surface of the recording paper 10 at a position corresponding to the print signal.

In this way, by generating two types of ink particles, large and small, and charging and deflecting only the small diameter particles according to the recording signal, it is possible to apply a deflection force at the same time as the ink particles are generated, and the particles used for recording can be The flight trajectories of particles not used for recording can be separated and independent immediately after the ink particles are generated.

[Problem that the invention seeks to solve]

However, according to conventional inkjet recording devices, ink particles are deflected from the time they exist inside the charging/deflection electrode, so although it is possible to prevent ink droplets charged with opposite signs from merging, the electrodes of the charging/deflection electrode You need to make the spacing thicker. Therefore, the amount of charge on the ink droplets decreases, and the deflection width also becomes narrow.

[Means and effects for solving the problems] The present invention has the following features:
This was done in view of the above, and in order to increase the amount of charge and expand the deflection width, and to prevent ink particles charged with opposite signs from merging, a pair of deflection electrodes is placed immediately after the charging electrode. At the same time, it is an object of the present invention to provide an inkjet recording apparatus in which voltages of different polarities are applied to each of the inkjet recording apparatuses.

〔Example〕

Hereinafter, the inkjet recording apparatus according to the present invention will be explained in detail.

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIG. A charging electrode 21 is disposed close to the nozzle 3, and a pair of deflection electrodes 22a and 22b is arranged immediately after the charging electrode 21.
It has been established. The voltage applied to the deflection electrodes 22a and 22b is such that (+Vd/2) is applied to the electrode 22a so that the line along which the ink droplets travel straight is O potential.
(-Vd/2) is applied to 2b. Note that the deflection electrode 22a
The distance between and 22b is set to be sufficiently wide relative to the inner diameter d of the charging electrode 21 (the distance when a pair of flat electrodes is used), but the distance d of the charging electrode 21 is different from the case in FIG. Since there is no need to do this, it can be made smaller.

In the above configuration, the ink droplet 23 separated from the ink column 14 is charged by the charging electrode 21 and travels straight, and when passing between the deflection electrodes 22a and 22b, it is deflected according to the amount of charge. That is, the deflection starts immediately after leaving the charging electrode 21, and even if the ink droplets are charged with charges of opposite signs at the charging electrode 21, they approach each other due to the Coulomb force of adjacent ink droplets with charges of opposite signs. Since the trajectories are deflected and separated into individual trajectories before being deflected, merging near the entrance of the deflection electrode does not occur. Furthermore, since the amount of deflection on the exit side of the charging electrode 21 is O, no charge is induced in the ink droplet by the deflection electric field. Furthermore, since the distance d between the charging electrodes can be made smaller, the amount of charging can be increased compared to the case of the electrode structure shown in FIG. 2, and the amount of deflection can be increased. Therefore, when applied to a multi-nozzle inkjet printer that covers the paper width, the number of nozzles can be reduced.

〔Effect of the invention〕

As explained above, according to the inkjet recording device of the present invention, a pair of deflection electrodes are disposed immediately after the charging electrode, and deflection voltages of different polarities are applied to each electrode, so that the amount of charge is increased and the deflection is The width can be increased, and even if adjacent ink droplets are charged with opposite signs, there is no possibility of merging near the entrance of the deflection electrode.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional inkjet recording apparatus. Explanation of symbols 1--head, 3--1---nozzle. 10...-recording paper, 13-...-gutter. 20--signal source, 2 t-----
Charged electrode. 22a, 22b ---- one deflection electrode. Patent applicant Fuji Xerox Co., Ltd. Agent Patent attorney Shin Matsubara 2 Seiji Muraki Tadao Hirata Atsushi Ueshima - Same Lead powder Hitoshi 7IEI

Claims (1)

[Scope of Claims] Mechanical vibration is applied to ink in an ink chamber to cause ink particles to fly from a nozzle communicating with the ink chamber, and the ink particles are selectively charged by a charging electrode in accordance with a recording signal. , in an inkjet recording device that deflects by a pair of deflection electrodes according to the amount of charge, the deflection electrode is disposed adjacent to and immediately after the charged electrode, and substantially the same voltage is applied to each electrode with different polarity. An inkjet recording device characterized by: