JPH01500341A - Inkjet printer head and industrial recording device equipped with the head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Inkjet printer head and industrial recording device equipped with the head The present invention relates to an inkjet printer head. In particular, in industrial recording equipment, related to the use of the pad.

Industrial recording devices exist in various forms, but all of them consist of a recording receiving sheet (supporting material). ) and a part that supports one or more styli. , these two parts can be moved by sheet movement or stylus movement or both. It moves relatively.

In such industrial recording devices, the ink stylus is often replaced by a ballpoint pen or is the shape of a felt-tip pen or a coronoid for special ink such as shojiru.

These styluses have a number of drawbacks, especially when printing on a printing support and a stylus. It is necessary to make contact with the illustration.

Therefore, depending on the stylus technique and the quality of the printing support surface, the quality of the recording may vary. and not necessarily of good quality, especially when the printing support is surface abrasive (paper). Regardless of the stylus technology, its lifespan is extremely shortened.

Another drawback is that the stylus must be raised so that no printing occurs during the movement of the printing support. is necessary. For this reason, there is a large amount of time lost during recording work, and The ink in the stylus does not always flow instantly when restarting A mark will be placed at the beginning of the record.

Another issue is the apparent compatibility of ink and stylus technology with the quality of the printing support. The reason is that it is not. As a result, the quality and lifespan of the trajectory on the support is greatly affected. Ru. Generally, on various supports (paper, mylar, polyester film of various qualities) Using different types of styli (ballpoint, felt-ben, coracoid) It is preferable to

The purpose of the present invention is to replace existing styli with continuous inkjet printers in response to industrial recording needs. The various drawbacks mentioned above can be corrected by replacing the printer head with a print head. That is.

More particularly, the present invention provides a continuous ink flow system coupled to an ink circulation system including a collection gutter. related to jet printer heads.

The head mainly includes a modulation system, an injection nozzle, a droplet charging electrode, and a deflection system. A feature of the head of the present invention, which includes a stem, is that the deflection system is arranged via an electronic circuit. It includes a set of deflection plates placed and powered, and the deflection electric field E of the droplet varies from 0 to 1800 It can be oriented at a range of different angles.

The present invention will be more fully understood from the following description based on the accompanying drawings.

FIG. 1 is a schematic illustration of conventional inkjet technology.

Figure 2 is an explanatory diagram showing the various line thicknesses obtained using inkjet technology. be.

Figures 3a and 3b are front views of the printer head of the present invention and the printer head. FIG. 3 is a plan view of the deflection plate of FIG.

Figures 4a, 4b and 4c illustrate the operation of a pair of deflection plates in the first embodiment of the invention. show.

FIG. 5 shows the markings made on the support according to the orientation of the dot frame.

Figure 6 shows the trajectory of the modified head-support relative movement at the radius of rotation of the point frame. Shown as a function.

Figures 7a and 7b are front views of a second embodiment of the printer/rad of the present invention, respectively. FIG. 3 is a plan view of a combination of an adapted recovery gutter and a set of deflection plates that cooperate with each other.

FIG. 8 shows the trajectory of the droplet in this second specific example.

Figures 9a, 9b and 9c show the operation of the deflection plate of this second embodiment.

Figure 10 shows the capacity of the modified collection gutter.

FIG. 11 shows a third specific example of a set of deflection plates of the present invention.

FIG. 12 shows a specific example of an electronic control circuit for deflection voltage.

Figures 13 and 14 show graphs of the control parameters for these voltages.

For clarity, the same elements are designated by the same reference numerals in all figures.

FIG. 1 shows a known inkjet printing technique.

According to FIG. A continuous jet of droplets is provided.

At the jet splitting point at the exit of the injection nozzle 81, the droplet is electrostatically charged by the charging electrode 7. Power up. A deflection plate 35 generating an electric field deflects the droplet from its trajectory. these An assembly of modulation means, ejection means, charging means and deflection means drives the printer head T. Configure. The recording receiving support S and the printer head T move relative to each other, and the printing dot matrix ( e+atrice) is formed. In the written example, the letter H is printed. not used All the droplets are collected in the gutter 1 and then recycled in the ink circulation system 2.

As shown in Figure 2, lines of various thickness can be created by arranging multiple droplets in parallel. can get. The line thickness is shown as e=0.1.0.2.0.3.0.4.0.5 Ru. These are the number n of droplets that give the support an impact of the order of diameter 130J11, respectively. Indicates that b is from 1 to 5.

Therefore, there are no contact points between the printer head and the support, so The main drawbacks due to touch, namely the use of a stylus to form a record on the support. This eliminates the disadvantages of You can also print different thicknesses using only one printer head. You can record the lines of Conventional recording devices record one line for each thickness of the line. One stylus was required.

Inkjet printers replace the writing methods commonly used in industrial recording devices. The advantages obtained by using the computer head are clear from the description in this specification. Well, let's discuss the advantages of inkjet technology in the field of industrial recording. Nor.

It is also an object of the invention to provide a new printer particularly suited for these applications. It is to provide the head. In conventional inkjet technology, Figure 1 shows The jet prints a sequence of dots as described in the following. Support on industrial recording equipment The holder can move in all directions relative to the stylus.

However, the known deflection continuous jet technology, which prints a series of dots (frames), The sequence of points always lies in the same plane, and this plane is generally defined by the movement of the object receiving the record. (see Figure 1).

Therefore, one of the important features of the present invention is that the droplets are deflected by the novel elliptical structure of the deflection plate. The direction of the electric field is freely adjustable.

Under these conditions, a point array (the example in Figure 2) consisting of a deflected droplet set (frame) is (in which the dot arrays each contain from 1 to 5 dots) are determined by the direction of movement relative to the printing support. It can always be maintained in a plane perpendicular to the direction of movement, regardless of the direction. Ru. An electronic control circuit cooperates with this novel set of deflection plates of the present invention. Regarding this circuit will be described later. Additionally, in some implementations, it may be possible to use modified gutters. The efficiency of the method is improved by

A first specific example of the printer head of the present invention is shown in a plan view in the third perspective view. A new set of deflection plates of the head is shown in plan view in plane 3b.

Figure 3a shows a modulating body 8 receiving pressurized ink, which body an ink ejection nozzle forming a jet and a droplet load coupled to a droplet passage detector 6; It was connected to the electrode and vacuum ink collection tube 2 and was not used for printing. a gutter 1 for collecting ink droplets (in the direction of arrow f).

According to the invention, this printer head is oriented at an angle ranging from 0° to 180°. combination of three deflection plates 3, 4.5 for generating a deflection electric field for charged droplets that can be The two deflection plates 3.5 are parallel to each other, and the third deflection plate 4 is According to another feature of the invention, these three deflections are arranged in a plane perpendicular to The combination of electrodes 3, 4.5 cooperates with the special structure of the ink collection gutter 1 to deflect the The droplets are oriented in a range of 0° to 180°. The droplets form a shallow gutter 1 It falls into the circular opening 1a provided in the pincer extension 1b of the reservoir. This opening is head T. is located within the axis of

Figures 4a, 4b and 4c show three examples of droplet deflection angles, viz. The following cases are shown below.

The electric field E generated by the combination of high voltages supplied to each of the three deflection plates is Corresponds to the deflection angle.

When β is O#, only the deflection plate 5 is supplied with power.

When β is 45°, power is supplied to deflection plates 4 and 5 at the same time.

When β is 180°, only the deflection plate 3 is supplied with power.

Figures 4a, 4b and 4c illustrate the case where one frame t consists of four droplets. This shows an example of such a deflection state when the jet is not deflected. It is indicated by a white dot X. Change the number of droplets per frame as shown in Figure 2. The line thickness of the recording can be selected by: by adjusting the direction of the deflection electric field. The thickness of the line is maintained regardless of the direction of movement of the support. Deflection electric field is the recording head oriented perpendicular to the direction of movement of the support.

Figure 5 shows that different numbers of point frames are arranged at different points to maintain a constant line thickness Diagram when the orientation is maintained at (j9=180” 135@90°45°o@) (not shown) shows a recording 100 on a support.

Depending on the deflection angle at that point with respect to the fixed point of the printer head, the point frame will be the same The point that does not fall into place is therefore maintained and is marked as a function of the deflection angle of the frame. Correct the trajectory by moving the print head relative to the print support There is a need.

Figure 6 shows the rotation of the point frame around the axis of the gutter to record the given curve tc. An inkjet diagram showing the relative trajectory of the head-support tr modified according to the radius R. In this variant of the printer head for recording by A trajectory correction program for curve recording is required in consideration of the beam deflection radius.

The second specific example of the printer head of the present invention is shown in sections 7a, 7b, 8, and 9a. The explanation will be made based on FIGS. 9b, 9c, and 9d. Similar to the previous example, FIG. 7a is a schematic front view of the printer head, and FIG. 7b is a plan view of a set of deflection plates. It is a diagram. The ink collection gutter 1 has a unique shape adapted to this specific example. In the example, three deflection plates are also deployed, and the same elements as in the previous example are deployed. . In this example, only the shape of the gutter is deformed and therefore the way the printing droplets are used is different. Become. That is, in this case, droplets not used for printing are systematically deflected into the gutter 1. be done. The gutter 1 has a semicircular receiving opening 111 according to the characteristics of the invention, and is used for printing. The used droplets are printed on a printed dot frame regardless of the number of dots per frame. The center of the beam is located within the axis of the head and therefore in the center of the semicircular mouth 111 of the gutter 1. It is deflected as follows. Figure 8 shows an example in which one frame consists of five points. Only the modulation system and the gutter 1 with the semicircular mouth 111 are shown.

Figures 9a, 9b, 9c and 9d illustrate several orientations of the deflection electric field, viz. The orientations of 0045°90° and 18o0 are shown by a frame of four points, respectively. There is. Droplets that were not used for printing are located at the mouth of ink collection gutter 1, as shown by the white dot x. 111.

The advantage of this structure is that the support is By adjusting the number of droplets without requiring correction of the relative trajectory of the head It is possible to record lines of programmed thickness and the relative trajectory of the head and printing support. It is possible to maintain the thickness of this line.

Another advantage of this second embodiment is that the special structure of the collection gutter 1 allows the printer head to It must be able to withstand certain accelerations.

That is, as shown in Figure 10, the direction of the vector (V, ), that is, perpendicular to the deflection plane of the drop During the acceleration (and deceleration) phase of the head in the direction of There is a slight deviation within the axis (Fig. 10). Therefore, the droplets that were not used for printing are recycled. There is a danger of not being able to fall into the collection gutter. Proposed with specific examples in Figures 7 to 10 According to the structure of the gutter, the arc formed by the mouth part 111 is This drawback can be corrected by making the dimensions of the gutter in the direction (vl) extremely large. It will be done.

There are two advantages of this second embodiment: no orbit correction is required, and high altitude. Being able to withstand acceleration is extremely advantageous for applications that require high-speed recording.

FIG. 11 shows a third specific example of the printer head of the present invention.

In this example, four deflection plates 3, 4, 5.9 are provided.

The deflection plate 9 is parallel to the deflection plate 4 and perpendicular to the remaining two deflection plates 3.5. In the specific example, a voltage is applied to the deflection plates 4,5. Distance a between deflection plates and b will be described later.

The fourth deflection plate can be freely retracted due to the need for maintenance of the printer head.

As described above, according to the present invention, the high voltage deflection control circuit C controls the deflection direction according to the present invention. Collaborate with printers and printers that can be adjusted freely.

The plane of deflection of a droplet is the axis of relative movement of the printing support with respect to the printer head at any moment. Positioned perpendicularly to the line, the high voltage deflection control circuit C connects the three electrodes 3, 4.5 (or three or four deflection electrodes 3, 4, 5 in the embodiments of FIGS. 7 to 11) ．． 9) performs the function of giving an appropriate potential to the! The voltages of the poles are V, , V, respectively.

Vs, indicated by V fist.

In the particular embodiment shown in FIG. The angle β of the relative movement is transmitted to the control device 200. This control device 200 at each moment The voltage to be applied to the electrodes (V!, V This circuit 200 also searches for the value of 4°Vs, Vs) in the memory 30. The voltage supply device 201 for the poles is constantly controlled. These voltages are for a given printer This is the characteristic value of the head. An example of calculating the values of these voltages is shown below.

The voltage on the deflection electrode is perpendicular to the axis of relative movement of the printing support to the printer head. is adjusted so that an electric field E of a given strength oriented in a plane is generated at the droplet. .

Voltage calculation v,,v4. v,,v,depends on the geometry of the head in question; Physical analysis of the potential distribution within the printer head, taking into account the geometrical details of the head. Requires exact solution of problem. This solution can be solved in various ways, including calculation of numerical solutions by computer. It can be obtained by the following method. Align the droplet position to the electrode and compare it to the frame dimensions. Using electrodes of comparatively large dimensions, an electric field of value E oriented at the desired angle β can be This gives an approximation of the deflection voltage needed to obtain the desired deflection voltage.

In this case, use the following formula:

The values of Ex　Ex×Ey, and tan(β)=Ey/ExEx and E are given below. Calculate using the obtained formula.

In a specific embodiment of the variant shown in FIG. 11, the spacing between the electrodes a=b= 5+s-, and the potential of the electrode 9 is 0 port.

Figure 13 shows that the value of the electric field obtained from point j on the axis of the undeflected jet is E = 0.2. The relationship between the voltages V, , V, , V, required to achieve 5 MV/- is shown.

For example, if we consider the case of angle β = 60°, then according to Fig. 14, vs = 750 volts and and V, = O volts. Therefore, V in Figure 3.

= 1300 volts. In this case, the value of the electric field obtained is 0.25MY/- equal.

It is also possible to use combinations of other values of voltage to achieve this result. child These combinations yield the same equation.

In the given example, the ink was sprayed to obtain a line of desired thickness (0.1-0.4 m5). The inner diameter of the exit nozzle is 25μ, and the voltage applied to the charging electrode is approximately 150 volts at maximum. It is.

As explained above, advantageous applications of continuous jet printer heads, especially directional A particularly advantageous application of printer heads with adjustable deflection plates is in the field of industrial recording equipment. It is in. Significant advantages are obtained as there is no need for any contact between the marking means and the support to be marked. Ru. Furthermore, the thickness of the line can be selected regardless of the axis of movement of the head relative to the support. can be selected and kept constant. Finally, place an ink collection gutter with a suitable geometry. Collecting unused ink droplets also during the acceleration (deceleration) phase is possible.

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Claims (15)

[Claims] (1) at least one modulation system (8), an injection nozzle (81) and a charging system; (7) and a charged droplet deflection system, and includes a collection gutter (1). Preparation by a continuous jet (je) of metered droplets coupled to a circulation system (80) a computer head, wherein the charged droplet deflection system has a droplet deflection electric field (E) of 0; An electronic circuit (C ) a set of deflection plates (3,4,5) (3.4.5,9) arranged and powered via A printer head comprising: (2) the deflection system has two electrodes (3, 5) arranged in two parallel planes; ) and a third electrode (4) placed in a plane perpendicular to the first two electrodes (3,5) The printer head according to claim 1, further comprising: (3) The claim further includes a fourth electrode (9) parallel to the third electrode (4). The printer head according to claim 2. (4) The fourth electrode (9) is retractable. printer head. (5) At each instant, the deflection plane of the charged droplet shifts relative to the printing support with respect to the printer head. The control circuit (C) is properly connected to the electrodes (3, 4, 5, 9) so that they are perpendicular to the axis of motion. 5. According to any one of claims 1 to 4, the device functions to provide four potentials. Printer head listed. (6) Respective bias voltages (V3, V4, V5, V6) is a value such that the electric field value (E) obtained at point j is constant. 6. The printer head according to claim 5, characterized in that: (7) The constant electric field (E 7. The printer head according to claim 6, wherein: ) is 0.25 MV/m. (8) The first one showing the changes in voltage (V3) and voltage (V5) as a function of cuticle (β). Based on the graph, select one angle (β) and one of the voltages (V3) or (V5) After determining the appropriate value of (E) = 0.25 MV/m, shows the change in voltage V4 as a function of voltage V3 and shows the change in voltage Vs as a function of voltage V4. Calculate the value V4 of the voltage to be applied to the third deflection plate from the second graph shown as a function. The printer head according to claim 6, characterized in that: (9) When angle (β) = 60°, (V5) is 750 volts and (V3) is 0 volts. 9. The preamp of claim 8, wherein V and (V4) are equal to 1300 volts. head. (10) The collection gutter 1 has a circular checkpoint (1a) aligned with the axis of the head. The printer head according to any one of claims 1 to 9, characterized in that: (11) The collection gutter (1) has a semi-circular mouth ( 111), the liquid is deflected towards the mouth, and the droplet fin used for printing is The center of the frame is itself aligned with the axis of the semicircular mouth (111). 10. Any one of claims 1 to 9, characterized in that the head is located on the axis of the head. Printer head described in. (12) comprising a record-receiving support and a writing means, the two parts being free from relative movement; An industrial recording device according to claim 1, wherein the entry means is according to any one of claims 1 to 11. An industrial recording device characterized by being the printer head as described above. (13) The orientation of the axis of relative movement of the support body with respect to the printer head with respect to the head a set of deflection currents configured and biased such that the direction of the electric field E can be adjusted according to 13. Industrial recording device according to claim 12, characterized in that it comprises poles (3, 4, 5, 9). . (14) A circle in which the printer head collection gutter 1 is aligned with the axis of the head Industrial recording device according to claim 12 or 13, characterized in that it comprises a shaped aperture (la). Place. (15) The collection gutter (1) includes a semicircular mouth (111) and the unused droplets is deflected to said mouth (111), and the center of the droplet frame used for filling is itself on the axis of the head aligned with the mouth (111). The industrial recording device according to claim 12 or 13, characterized in that: .