JPS58108167A - Deflection detector for charged ink particle - Google Patents

Abstract

PURPOSE:To obtain a deflection detector having a simplified structure for discharging stored ink and capable of being inspected and cleaned easily by providing a detachable hygroscopic material into an ink trap space with a cover. CONSTITUTION:In a deflection detector for charged ink droplets, a cover 47 is preferably provided in front, and the first hygroscopic material 48b is detachably inserted into the lower ink trap of a detection electrode 48a. Thus, the inside of the device can be cleaned by taking out the hygroscopic material. The second hygroscopic material 48c is fixed to the inside of the cover 47. When the cover is closed, part of the second hygroscopic material is contacted with the firs hygroscopic material 48b and ink in the second hygroscopic material is transferred to the first hydgroscopic material. The place facing the ink droplets entrance 49a of the deflection detector 49 is a waiting place. The ink-jet head is restored to the waiting place each time a given recording is made and before the beginning of recording, and the detection, adjusting, and setting of deflection are made.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a deflection control type inkjet recording apparatus, and particularly to a deflection detection device for the inkjet recording apparatus.

In this type of inkjet recording apparatus, pressurized ink is supplied to an ink ejection head, and a regular periodic pressure vibration is applied to the pressurized ink in the head. The ink ejected from the nozzle of the head separates into ink particles at regular intervals after advancing a predetermined distance from the nozzle.

A charging electrode is disposed at a position where the ink separates into particles in this way, and the ink particles are charged by applying a charging voltage to the charging electrode in accordance with the particle formation of the ink. The charged ink particles are deflected by the deflection electric field and impinge on the marking paper. Uncharged ink particles travel straight and are captured by the gutter and returned to the ink reservoir.

One of the problems in such inkjet recording is a recording position shift due to ink temperature or pressure, that is, a deflection shift of ink particles. Therefore, conventionally,
The charging voltage, ink temperature, ink pressure, etc. are adjusted by detecting the ink temperature, pressure, flying speed, charge amount, or deflection amount of ink particles (for example, Japanese Patent Application No. 53-165187, 4I). Gansho 54-14692
No. 6 and Japanese Patent Application No. 55-24303).

Although collision type or non-contact type deflection detection electrodes are used in the deflection detection device, the accuracy of their arrangement affects the printed dot distribution and dot misalignment.

In addition, it is difficult to arrange the electrodes neatly, and droplets of colliding ink may be scattered around, or the detection electrode itself may leak due to wetting due to the droplets, resulting in inaccurate detection. Furthermore, noise is likely to be induced in the detection electrode (by external noise or turning on/off of the charging voltage).

Therefore, the present inventor has developed a hollow electrode housing having an ink particle entry window and a space along the axis of the platen, a charge detection electrode disposed inside the electrode housing, a support frame for supporting the electrode housing, and an electrode housing. a spring means for biasing the electrode housing in the direction of deflection of the ink particles, and movement of the electrode housing is restrained against the biasing force of the spring means.

a charged ink particle deflection amount detector comprising an adjusting means;
At the standby position or retreat position of the recording head outside the printing recording range, the ink droplet entry window is opposed to the front of the flight trajectory of the ink droplets ejected from the nuclear recording head, and the platen axis is located at least in the space along the platen axis. In order to solve the problem, a deflection detection device was proposed in which the support frame was fixed to the base frame of the recording device (Japanese Patent Application No. 56-84183
No. 80736-80739).

The present invention relates to the improvement of this type of deflection detection device, and its primary purpose is to facilitate inspection and cleaning of the inside of the device.
The second objective is to simplify the structure for discharging the stored ink.
The purpose of

The deflection detection device disclosed in the patent application and utility model registration application has a structure in which the ink that enters the device reaches the ink reservoir at the bottom of the device and is returned to the ink recovery system through the discharge port. Although there is an opening at the front through which ink particles can enter, it is relatively small, making it difficult to inspect and clean the inside of the device.

Therefore, in the present invention, the deflection detection device is provided with an opening/closing lid, preferably provided on the front surface of the device, and the first moisture absorbing member is removably inserted into the ink reservoir below the detection electrode. This allows the user to easily inspect the inside of the device by opening the lid. The moisture absorbing member can be taken out to thoroughly clean the inside of the device. The ink liquid can be easily discharged by replacing the moisture absorbing member with a new one, or by squeezing the moisture absorbing member outside the apparatus to discharge the ink liquid, and then attaching the dazzling moisture absorbing member to the apparatus again. A gutter is mounted on the carriage along with the head, and non-recording ink particles are captured by the gutter during recording.A deflection detection device is placed outside the side edge of the platen, and the carriage is moved to the home position before or during recording. In an embodiment in which ink particles are captured by a deflection detection device and a proper deflection is detected (deflection detection), the amount of ink ejected in one deflection detection is, for example, 6.
It is approximately X10 oo, and can be sufficiently absorbed by a moisture absorbing member. While deflection detection is not being performed, the ink solvent evaporates from the moisture absorbing member, so ink will not overflow from the device even if the moisture absorbing member is not replaced for a long time. Further, since the moisture absorbing member can be replaced by opening the lid, in a preferred embodiment of the present invention, the deflection detection device and the ink discharge port are removed, and an ink recovery system such as a recovery pipe is omitted. Since the inside of the deflection detection device becomes dirty with spray mist caused by the collision of ink particles, a second moisture absorbing member is fixed to the inner surface of the opening/closing lid, and its shape and arrangement are adjusted so that the second moisture absorption member does not change when the opening/closing lid is closed.
At least a portion of the moisture absorbing member contacts the first moisture absorbing member, so that ink from the second moisture absorbing member is transferred to the first moisture absorbing member.

FIG. 1 shows the appearance of one embodiment of the present invention. In FIG. 1, 51 is a support frame of the deflection detection device 49.

The deflection detection device 49 is suspended from a support frame 51 by a tension coil spring 52. At the back of the support frame 51 and the deflection detection device 49, a semicircular platen axis space is formed, through which the platen axis 60 passes. As shown in the figure, the detection device is arranged so that the space is occupied by the platen shaft 60, and the support frame 51 is screwed to the base frame 61. The ink ejecting head on the carriage 63, which is driven to reciprocate and scan parallel to the platen 62, has a home position (standby position) at a position where the ink ejecting direction faces the ink droplet inlet 49a of the deflection detection device 49. It is returned to the home position at the start of recording and every predetermined recording, where the recording position (deflection amount) is detected and the deflection amount adjustment setting is performed.

64 is a paper guide, ssl, 6s is a carriage 63
66 is a platen knob.

FIG. 2 shows the front side of the deflection detection device 49, and FIG. 3 shows its I-
A 1-line cross section is shown. Referring to these drawings, legs 49b and 49c of deflection detection device 49 have beams.

Link arm 50. One end of the legs 49b and 49c has a link arm 50. One end of the link arm 50. and 50. The other end is pivotally connected to the support frame 51. This allows the deflection detection device 49 to move relative to the support frame 51 in the deflection direction Dd (vertical direction in the drawing).

One end of a tension coil spring 52 is coupled to the support frame 51, and the other end engages with a pin 53 fixed to the deflection detection device 49. Therefore, the deflection detection device 4
9, the tension of the coil spring 52 is constantly acting upward. An adjustment screw 54 is screwed into the support frame 51, and its tip abuts against the upper surface of the deflection detection device 49. Therefore, when the screw 54 is tightened, the deflection detection device 49
is pushed down against the tension of the spring 52, and when the screw 54 is loosened, the device 49 is pulled up by the tension of the spring 52. The support frame 51 has screw holes 51a*51b for attachment to the base frame.

After fixing the support frame 51 to the home position of the base frame of the inkjet recording apparatus, the deflection detection device 49 can be easily adjusted in the deflection direction Dd by tightening the screw 54.

With the above configuration, the deflection detection device can be easily attached to the base frame, and after attachment, the deflection reference position can be arbitrarily adjusted using the screw 54.

The deflection detection device 49 is connected to the case body 46. It is composed of an opening/closing lid 47, an electrode body 48a, a sponge (first moisture absorbing member) 48b, and a sponge plate (second moisture absorbing member) 48c. An enlarged perspective view of the deflection detection device 49 is shown in FIG. The opening/closing lid 47 is pivotally connected to the case body 46 with a pin 45.
A sponge plate 48c with an ink particle entrance opening 491 is joined to its inner surface. The opening/closing lid 47 is formed with an ink particle inlet that is slightly larger than the ink particle inlet 49m. A partition 46m is formed inside the case body 46, and the base of the electrode body 48m passes through the partition 46a and the wall of the case body 46.

FIG. 5 shows an enlarged perspective view of the electrode body 48m. Electrode body 48
A wedge-shaped detection end 48a is formed at the tip of m, a screw 48a3 is formed at the other end, and a flange 48a2 is formed between them. This electrode body 48m is fixed to the case body 46 by passing its screw 48a through the outer wall of the case body 46, screwing together a nut, and tightening the nut. As shown in FIG. 4, when the electrode body 48m is fixed to the case body 46, the flange 48a blocks the splash of ink particles colliding with the detection end 48a, causing ink stains between the flange 48m and the partition wall 46m. The partition wall 46m prevents ink stains on the base of the electrode body 48m. A sponge 48b (first moisture absorbing member) is inserted into the ink reservoir space below the partition wall 46m. sponge 4
The external appearance of 8b is shown in FIG.

This sponge 48b is sized so that when the sponge 48b is inserted into the ink reservoir space as shown by the two-dot chain line in FIG. 4, its front surface is slightly compressed by the inner surface of the lid 47 when the lid 47 is closed. When the lid 47 is closed as shown in FIGS. 1 and 2, the lower part of the sponge plate 48c is in contact with the sponge 48b, and both are slightly compressed.

In FIG. 4, an electrode plate 48 is attached to the side wall of the case body 46.
An opening 46b for insertion and removal is opened, and this opening 46 is normally closed by pushing the rubber plate 44 into it. There is no ink discharge port in either the case body 46 or the opening/closing lid 47.

With the deflection detection device 49 installed in the inkjet printer as shown in FIG. 1, and with the ink pressure and other parameters that affect the deflection of charged ink particles set to appropriate values, as described above, With screw 53,
The deflection detection device 49 is adjusted in the direction of the Dd force so that the charged ink particles collide with the upper edge of the detection end 48a of the electrode body 48m or slightly deviate from the edge. After completing this adjustment, prior to the start of recording and, if necessary, after each recording of a predetermined amount, ink particles with a predetermined charge are made to collide with the ridgeline or take a trajectory that slightly deviates from the ridgeline. Deflection detection and adjustment are performed.

During inspection and cleaning, open the lid 47 as shown in FIG. 4, remove the sponge 48b, and clean the inside of the case body 46. If necessary, remove the rubber plate 44 and remove the electrode body 48m. The electrode body 48m is attached again, the rubber plate 44 is press-fitted, the ink is washed out, the liquid is squeezed out, and a sponge 48b, preferably dried, is inserted into the case body 46, and the lid 47 is closed. Since the amount of ink that enters the case body 46 during deflection detection/adjustment is very small, and since the ink solvent in the sponge 48b evaporates during operations other than deflection detection/adjustment, it is usually not necessary to replace the sponge 48b.

According to the present invention as described above, the deflection detection device can be easily inspected and cleaned, and an ink recovery system (such as a drain pipe) can be omitted.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the external appearance of an embodiment of the present invention, and shows one manner of attachment to an inkjet printer. Second
The figure is a front view thereof, and FIG. 3 is a sectional view taken along line I-1 in FIG. 2. FIG. 4 is an enlarged perspective view showing a state in which the open/close lid 47 is removed from the printer and opened, FIG. 5 is an enlarged perspective view of the electrode body 48m, and FIG. 6 is an enlarged perspective view of the sponge 48b. 44: Rubber plate 45: Pin 46: Case body 47: Open/close lid 48a: Electrode body 48b = sponge (first moisture absorption member) 48c: Sponge plate (second moisture absorption member) 49: Deflection detection device 49a: Ink particle entry Mouths 49b, 49e: legs 50. ．． 50. : Link arm 51 : Support frame 52 : Tension coil spring

Claims (6)

[Claims] (1) In a charged ink particle deflection detection device comprising an opening through which ink particles can enter and at least one charge detection electrode facing the opening, and an ink reservoir space formed below the charge detection electrode, an ink reservoir is provided. A part of the case member surrounding the space is made into an opening/closing lid that can be opened and closed with respect to the main body,
A deflection detection device for charged ink particles, characterized in that a removable first moisture absorbing member is disposed in an ink reservoir space, and the moisture absorbing member is taken out by opening an opening/closing lid. (2) The charged ink particle deflection detecting device according to claim 11, wherein a second moisture absorbing member is fixed to at least a part of the inner surface of the opening/closing lid. (3) The second moisture-absorbing member is shaped and arranged such that a part thereof comes into contact with the first moisture-absorbing member occupying the ink reservoir space when the opening/closing lid is closed. Ink particle deflection detection device. (4) The device for detecting deflection of charged ink particles according to claim (1), wherein an opening through which ink particles can enter is formed in the opening/closing lid. (5) Deflection detection of charged ink particles according to claim (2), wherein openings through which ink particles can enter are formed in the opening/closing lid and the second moisture absorbing member, and these openings are overlapped. Device. (6) Claim (1) above, wherein there is no ink recovery hole in either the case member or the opening/closing lid. The device for detecting deflection of charged ink particles according to item (2), item (3), item (4), or item (5).