CN110587884B

CN110587884B - Adjusting mechanism, printing head module and ink-jet printing device

Info

Publication number: CN110587884B
Application number: CN201910939811.0A
Authority: CN
Inventors: 郝鹏
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2021-07-06
Anticipated expiration: 2039-09-30
Also published as: CN110587884A

Abstract

The invention provides an adjusting mechanism, a printing head module and an ink-jet printing device, wherein the ink-jet printing device comprises a printing head, and the adjusting mechanism comprises: the charging channel assembly is connected with the liquid outlet of the printing head and is used for charging the liquid drops flowing out of the liquid outlet; the deflection channel assembly is arranged at one end of the charging channel assembly, which is far away from the printing head, and is communicated with the charging channel assembly, and is used for applying a deflection electric field to the charged droplets so as to deflect the charged droplets passing through the deflection channel assembly; a recovery assembly disposed below the deflection channel assembly for recovering deflected droplets and offset from the outlet of the deflection channel assembly by a distance to avoid obstruction of undeflected droplets; a control assembly electrically connected to the charging channel assembly and the deflection channel assembly for controlling the power-up and power-down of the charging channel assembly and the deflection channel assembly.

Description

Adjusting mechanism, printing head module and ink-jet printing device

Technical Field

The invention relates to the technical field of display, in particular to an adjusting mechanism, a printing head module and an ink-jet printing device.

Background

Organic electroluminescent devices (OLEDs) have been a promising new type of display device in recent years due to their advantages of self-luminescence, all solid state, high contrast, and the like. The method for preparing the OLED device by using the evaporation equipment is a mainstream mode of the current production, but the defects of low material utilization rate and poor uniformity of the evaporation process are always lack of an effective solution. The solution method for preparing the OLED film has the advantages of high material utilization rate, low equipment cost and the like, and shows obvious advantages.

The solution process includes spin coating, Printing, etc., wherein a solution containing a light-emitting (or functional) material is dropped onto a predetermined position in the form of micro droplets (pico-upgrade), and then the solvent is evaporated to remove the solvent, leaving only a thin film formed by a solute (light-emitting or functional material), which is abbreviated as IJP (Ink-Jet Printing), and is currently the most suitable process for the current OLED light-emitting device.

The major steps of IJP in preparing OLED include:

(1) a precise volume of the droplet is dropped into a specified location, i.e., a sub-pixel opening of the panel.

(2) The droplets were dried to a film by vacuum drying under reduced pressure.

(3) And (4) heating and annealing treatment to improve the quality of the obtained OLED film.

In order to ensure the uniformity of the entire light-emitting area of the screen, the organic film thickness of each sub-pixel is required to be the same. That is, in the printing process, it is required to accurately ensure that the volumes of the organic solvents injected into the openings of the sub-pixels are the same, so that no film thickness difference is generated after the dry film is formed. This presents a significant challenge to the stability of the print head. In particular, to eliminate errors between different print nozzles due to machining accuracy, an algorithm is currently used that causes ink falling into the same sub-pixel opening to come from different nozzles as much as possible. That is, each nozzle is individually driven and controlled by a random algorithm and not a continuous jetting of ink. Before and after each print start, the nozzles also stop ejecting ink to avoid ejecting ink at locations outside the sub-pixel openings. The current print heads for IJP all use piezoelectric ceramics as triggers, which can realize independent driving of each nozzle and control of droplet speed and volume by adjusting the waveform of voltage.

However, with the current ink characteristics, when printing is resumed after each nozzle has been suspended for a while, the drop velocity of the ejected droplets is reduced to some extent, and then gradually returns to the original velocity. This causes a drop of a relatively slow velocity to land at a position other than the predetermined landing point, causing a printing deviation and a printing defect.

Therefore, the prior art has defects and needs to be improved urgently.

Disclosure of Invention

The invention provides an adjusting mechanism, a printing head module and an ink-jet printing device, which can improve the quality of a printed OLED film.

The invention provides an adjusting mechanism, which is applied to an ink-jet printing device, wherein the ink-jet printing device comprises a printing head, and the adjusting mechanism comprises:

the charging channel assembly is connected with the liquid outlet of the printing head and is used for charging the liquid drops flowing out of the liquid outlet;

the deflection channel assembly is arranged at one end of the charging channel assembly, which is far away from the printing head, and is communicated with the charging channel assembly, and is used for applying a deflection electric field to the charged droplets so as to deflect the charged droplets passing through the deflection channel assembly;

a recovery assembly disposed below the deflection channel assembly for recovering deflected droplets and offset from the outlet of the deflection channel assembly by a distance to avoid obstruction of undeflected droplets;

a control assembly electrically connected to the charging channel assembly and the deflection channel assembly for controlling the power-up and power-down of the charging channel assembly and the deflection channel assembly.

In the adjusting mechanism of the present invention, the charging channel assembly includes a first channel tube, and a first electrode layer and a second electrode layer disposed on an inner sidewall of the first channel tube.

In the adjusting mechanism of the present invention, the deflection channel assembly includes a first deflection electrode plate and a second deflection electrode plate that are disposed opposite to each other, and the first deflection electrode plate and the second deflection electrode plate are disposed at a predetermined distance apart at an end of the charging channel assembly that is far away from the print head.

In the adjusting mechanism of the present invention, the deflection channel assembly further includes a support tube connected below the first channel tube, and the first deflection electrode plate and the second deflection electrode plate are oppositely disposed on a sidewall of the support tube.

In the adjusting mechanism, the recovery assembly is arranged at the lower end of the support tube and deviates from the axis of the support tube by a preset distance, and the support tube and the first channel tube are coaxially arranged.

In the adjusting mechanism of the present invention, the control unit is configured to control the charging channel unit and the deflecting channel unit to be powered on for a preset time period each time the printhead starts ejecting liquid.

In the adjustment mechanism of the present invention, the control unit controls the charging path unit and the deflection path unit to be powered up before the printhead finishes ejecting a predetermined number of droplets each time ejection is started.

In the adjusting mechanism of the present invention, the adjusting mechanism further includes a droplet number detecting assembly, and the droplet number detecting assembly is disposed on a side wall of the charging channel assembly.

A printing head module comprises a printing head and an adjusting mechanism connected to a liquid outlet of the printing head, wherein the adjusting mechanism is any one of the adjusting mechanisms.

An ink jet printing device comprises the printing head module.

An ink jet printing control method comprising the steps of:

the charging channel assembly charges the liquid drops flowing out of the liquid outlet for a preset time period, and is powered off after the preset time period;

the deflecting channel assembly applies a deflecting electric field to the charged droplets so as to deflect the charged droplets passing through the deflecting channel assembly;

the recovery assembly recovers deflected droplets and deflects away from the outlet of the deflection channel assembly by a distance to avoid obstruction of undeflected droplets.

The invention can deflect the liquid drops with the lower drop falling speed to the recovery component through the charging channel component and the deflection channel component, thereby improving the quality of the printed OLED film.

Drawings

In order to illustrate the embodiments or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the invention, and it is obvious for a person skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a first block diagram of an adjustment mechanism in some embodiments of the invention.

FIG. 2 is a second block diagram of an adjustment mechanism in some embodiments of the invention.

FIG. 3 is a third block diagram of an adjustment mechanism in some embodiments of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an adjusting mechanism according to some embodiments of the present invention. The ink-jet printing device comprises a printing head, and an adjusting mechanism is arranged at the lower end of the printing head.

Wherein, this guiding mechanism includes: a charging tunnel assembly 10, a deflection tunnel assembly 20, a recovery assembly 30, and a control assembly 40.

The charging channel assembly 10 is connected to the outlet of the printhead and is commonly used to charge droplets flowing from the outlet. The deflection channel assembly 20 is disposed at an end of the charging channel assembly away from the print head and is in communication with the charging channel assembly, and is configured to apply a deflection electric field to the charged droplets so as to deflect the charged droplets passing therethrough. The recovery assembly 30 is disposed below the deflection channel assembly 20 for recovering deflected droplets and is offset from the outlet of the deflection channel assembly by a distance to avoid obstruction of undeflected droplets. A control assembly is electrically connected to the charging channel assembly 10 and the deflection channel assembly 20 for controlling the power-up and power-down of the charging channel assembly 10 and the deflection channel assembly 20.

Specifically, the charging channel assembly 10 includes a first channel tube 11, and a first electrode layer 12 and a second electrode layer 13 disposed on an inner sidewall of the first channel tube. The first electrode layer 12 and the second electrode layer 13 are isolated from each other. The control unit 40 charges the droplets passing through the first electrode layer 12 and the second electrode layer 13 after the first electrode layer and the second electrode layer are electrically charged.

Specifically, the deflection channel assembly 20 includes a first deflection electrode plate 21 and a second deflection electrode plate 22, which are oppositely disposed, and the first deflection electrode plate 21 and the second deflection electrode plate 22 are disposed at one end of the charging channel assembly 10 away from the print head and spaced apart by a predetermined distance.

Referring to fig. 2, in some embodiments, the deflection channel assembly 20 further includes a support tube 23, the support tube 23 is connected below the first channel tube 11, and the first deflection electrode plate 21 and the second deflection electrode plate 22 are oppositely disposed on a side wall of the support tube 23. The support tube 23 and the first channel tube 11 may be connected by means of insertion, screw connection, etc., and the joint is sealed by sealant.

It is understood that, in some embodiments, the support tube 23 and the first channel tube 11 may be an integrally formed structure, and the inner diameter of the support tube 23 is greater than the inner diameter of the first channel tube 11.

Referring to fig. 3, the recycling assembly 30 is disposed at the lower end of the support tube 23 and deviates from the axis of the support tube 23 by a preset distance, and the support tube 23 and the first channel tube 11 are coaxially disposed. The recovery unit 30 is connected to the outer side wall of the bracket tube by a connection ring 31. The connection ring 31 is connected to the recovery assembly 30, which is a container with a handle. The connecting ring 31 can be mounted on the outer side wall of the lower end of the support tube 23 by clamping, screwing or sleeving.

In some embodiments, the control assembly 40 is configured to control the charging channel assembly and the deflection channel assembly to power up for a preset period of time each time the printhead initiates ejection of liquid. The specific value of the preset time period is an empirical value obtained by adopting a plurality of tests, and the empirical value is only required to be stored in the control component.

In some embodiments, the control assembly controls the charging channel assembly and the deflection channel assembly to power up before the printhead finishes ejecting a predetermined number of drops each time ejection is initiated. The adjusting mechanism further comprises a liquid drop quantity detection assembly, and the liquid drop quantity detection assembly is arranged on the side wall of the charging channel assembly. The drop number detection assembly may employ a detection element known in the art. The number of droplets is an empirical value obtained by a plurality of experiments, and the empirical value is stored in the control unit.

The invention also provides a printing head module, which comprises a printing head and an adjusting mechanism connected to the liquid outlet of the printing head, wherein the adjusting mechanism is the adjusting mechanism in any embodiment.

The invention also provides an ink-jet printing device which comprises the printing head module in any embodiment.

The invention also provides an ink-jet printing control method, which comprises the following steps:

s1, the charging channel assembly charges the liquid drops flowing out of the liquid outlet for a preset time period, and the power is cut off after the preset time period;

s2, applying a deflection electric field to the charged droplets by the deflection channel assembly to deflect the charged droplets passing through the deflection channel assembly;

s3, the recovery assembly recovers the deflected droplets and deflects the outlet of the deflection channel assembly a distance to avoid obstructing the undeflected droplets.

In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, therefore, the scope of the present invention shall be determined by the appended claims.

Claims

1. An adjustment mechanism for use in an inkjet printing apparatus, the inkjet printing apparatus including a printhead, the adjustment mechanism comprising:

a control assembly electrically connected to the charging channel assembly and the deflection channel assembly for controlling the powering up and powering down of the charging channel assembly and the deflection channel assembly,

wherein the control assembly is used for controlling the charging channel assembly and the deflection channel assembly to be electrified for a preset time period each time the printing head starts to spray liquid; or before the printing head finishes spraying the preset number of liquid drops every time the printing head starts spraying, the control component controls the charging channel component and the deflection channel component to be electrified.

2. The adjustment mechanism of claim 1, wherein the charge tunnel assembly comprises a first tunnel tube and first and second electrode layers disposed on an inner sidewall of the first tunnel tube.

3. The adjustment mechanism of claim 2, wherein the deflection channel assembly comprises a first deflection electrode plate and a second deflection electrode plate disposed opposite to each other, and the first deflection electrode plate and the second deflection electrode plate are disposed at an end of the charging channel assembly away from the print head and spaced apart by a predetermined distance.

4. The adjustment mechanism of claim 3, wherein said deflection channel assembly further comprises a support tube connected below said first channel tube, said first and second deflection electrode plates being oppositely disposed on a sidewall of said support tube.

5. The adjustment mechanism of claim 4, wherein the retraction assembly is disposed at a lower end of the support tube and offset from an axis of the support tube by a predetermined distance, the support tube being disposed coaxially with the first passage tube.

6. The adjustment mechanism of claim 1, further comprising a drop number detection assembly disposed on a sidewall of the charge tunnel assembly.

7. A printhead module comprising a printhead and an adjustment mechanism connected to a fluid outlet of the printhead, the adjustment mechanism being as claimed in any one of claims 1 to 6.

8. An inkjet printing apparatus comprising the printhead module of claim 7.