CN116811439A - Optical ink-jet printing apparatus and method of ejecting the same - Google Patents

Abstract

The present application relates to an optical inkjet printing apparatus and an inkjet method thereof. The optical inkjet printing apparatus includes: a laser for outputting a modulated laser light; the optical system is positioned at the output end of the modulatable laser along the propagation direction of the optical path and is used for splitting the modulatable laser into parallel laser beams; the micro lens array is arranged at the output end of the optical system along the propagation direction of the optical path; the ink jet assembly comprises a plurality of vibrating plates and a plurality of ink chambers, each vibrating plate is arranged on the surface of the ink chamber corresponding to the micro lens array, and ink is contained in the ink chamber; the adjustable laser is split into parallel laser beams by an optical system, focused by a micro lens array, shaped and then injected into an ink jet assembly to excite a vibration plate, so that the vibration plate extrudes ink in an ink chamber to form micro-droplet ejection. The vibration plate is controlled to generate displacement in a non-contact mode to extrude, so that damage to the vibration plate is avoided, usability is guaranteed, and processing efficiency and productivity of the display screen are improved.

Description

Optical ink-jet printing apparatus and method of ejecting the same

Technical Field

The application relates to the technical field of ink-jet printing equipment, in particular to an optical ink-jet printing device and an injection method thereof.

Background

Organic light emitting diodes (Organic Light Emitting Diode, OLEDs), a novel display technology for achieving self-luminescence by means of power-up, have been increasingly applied to display fields and lighting markets such as mobile televisions, vehicle-mounted displays, smart wearable and VR devices.

With the advent of new age of OLED display, higher demands are put forward on the research on colorization and patterning of display screens. Compared with the traditional vacuum evaporation technology, the ink-jet printing technology is easier to realize colorization of large-area devices and patterning of composite functional materials, has simple process and low cost, and can process flexible devices.

Current inkjet printing technologies mainly include continuous inkjet technology and drop-on-demand technology. Among them, the most widely used drop-on-demand technology mainly includes acoustic, electrostatic, thermal bubble, piezoelectric, and the like. In the OLED display printing, a piezoelectric printhead is mainly used, and there are two manufacturing methods, namely a shared wall type and an independent cavity type. Wherein the shared wall mode is to spray ink drops through vibration of the shear type piezoelectric ceramic blocks; the independent cavity mainly comprises a squeezing type for vibrating and squeezing the ink cavity to jet ink in a normal direction to the piezoelectric ceramic block, and a bending type for sputtering the piezoelectric ceramic material to the top of the ink cavity generally through a Micro-Electro-mechanical system (MEMS) process, exciting the piezoelectric film to vibrate by applying electricity, squeezing the vibrating plate on the upper surface of the ink cavity, and driving the Micro ink drop to jet.

For the piezoelectric ceramic excitation method, the piezoelectric material is excited to vibrate through contact type electric excitation so as to extrude the ink cavity vibrating membrane, so that the problems of low excitation frequency, low display screen processing efficiency and productivity, high manufacturing difficulty of a printing head, material fatigue damage caused by contact resonance of the piezoelectric ceramic material layer and the vibrating plate material layer, and the like exist, and the usability is affected.

Disclosure of Invention

Accordingly, it is necessary to provide an optical inkjet printing apparatus and an inkjet method thereof capable of suppressing ink in a noncontact manner to ensure the excitation frequency and prevent damage, in order to solve the problems of low excitation frequency, and easiness in damaging a vibrating membrane, etc., which are caused by the conventional pressing of ink in a contact manner.

An optical inkjet printing apparatus comprising:

a laser for outputting a modulated laser light;

the optical system is positioned at the output end of the modulatable laser along the light path propagation direction and is used for splitting the modulatable laser into parallel laser beams;

the micro lens array is arranged at the output end of the optical system along the light path propagation direction; and

the ink jet assembly comprises a plurality of vibrating plates and a plurality of ink chambers, wherein each vibrating plate is arranged on the surface of the ink chamber corresponding to the micro lens array, and ink is contained in the ink chamber;

The adjustable laser is split into parallel laser beams through the optical system, focused and shaped through the micro lens array and then injected into the ink jet assembly to excite the vibrating plate, so that the vibrating plate extrudes the ink in the ink chamber to form micro liquid drop jet.

In an embodiment of the present application, the optical system includes a beam expanding lens and a beam splitting lens, where the beam expanding lens and the beam splitting lens are disposed between the laser and the microlens array at intervals along the propagation direction of the optical path;

the beam expanding lens is used for expanding the beam diameter of the modulated laser, and the beam dividing lens is used for dividing the modulated laser after beam expansion into parallel laser beams.

In an embodiment of the application, the microlens array includes a lens body and a plurality of focusing lenses, and the focusing lenses are disposed on a surface of the lens body facing the inkjet component, and each focusing lens is used for focusing and shaping one of the laser beams.

In an embodiment of the present application, each of the vibration plates is disposed corresponding to one of the focusing lenses.

In an embodiment of the present application, the ink jet assembly includes a nozzle housing, a plurality of ink chambers are disposed in at least one row in the nozzle housing, the nozzle housing has a nozzle, and a liquid outlet of the ink chambers is disposed in the nozzle;

The surface of the nozzle shell facing the micro lens array is provided with a plurality of mounting positions, each mounting position is provided with one vibrating plate and corresponds to one ink chamber, the vibrating plate is arranged in the mounting position, and the vibrating plate is attached to the end part of the ink chamber.

In an embodiment of the present application, the optical inkjet printing apparatus further includes a spatial light modulator, where the spatial light modulator is disposed at an output end of the optical system along a propagation direction of an optical path, and is configured to modulate a deflection angle of the laser beam, so that the laser beam is deflected or projected to the microlens array.

In an embodiment of the present application, the spatial light modulator is a reflective modulator, the optical system is disposed on a first optical path, the microlens array and the inkjet assembly are disposed on a second optical path, the first optical path is perpendicular to the second optical path, and the reflective modulator is disposed at a junction of the first optical path and the second optical path;

the reflective modulator comprises a digital micro-mirror device and a mask plate, wherein the digital micro-mirror device is arranged at the junction of the first light path and the second light path, and the mask plate is arranged on the second light path and is positioned at the output end of the digital micro-mirror device.

In an embodiment of the present application, the mask plate has a plurality of mask holes, and the mask holes penetrate through the mask plate along the second optical path, and the mask holes allow a beam of the laser beam to pass through, and each mask hole corresponds to one of the ink chambers.

In one embodiment of the application, the spatial light modulator is a transmissive modulator;

the optical system and the transmission type modulator are arranged on a first light path, the micro lens array and the ink jet assembly are arranged on a second light path, the first light path is perpendicular to the second light path, and the reflecting mirror is arranged at the junction of the first light path and the second light path.

An ejection method of an optical inkjet printing apparatus, the ejection method being applied to the optical inkjet printing apparatus according to any one of the technical features described above, the ejection method comprising the steps of:

controlling the laser to emit a modulated laser;

the modulated laser beam is injected into the optical system and split into parallel laser beams;

the parallel laser beams are injected into a micro lens array, and are focused and shaped by the micro lens array;

The laser beam passing through the micro lens array is injected into the ink jet assembly to excite the vibration plate of the ink jet assembly, so that the vibration plate is deformed to generate displacement to squeeze the ink in the ink chamber to form micro liquid drops to be sprayed to the substrate.

After the technical scheme is adopted, the application has at least the following technical effects:

in the optical ink-jet printing device and the injection method thereof, a laser, an optical system, a micro lens array and an ink-jet assembly are arranged at intervals along the propagation direction of an optical path, the laser is used for outputting a modulated laser, the optical system is used for expanding and splitting the modulated laser to form a parallel laser beam, and the micro lens array can focus and shape the laser beam. The laser beam emitted by the laser device can be expanded and split by the optical system to form parallel laser beams, the parallel laser beams are emitted into the micro lens array, the micro lens array focuses and shapes the laser beams and then emits the laser beams into the ink jet assembly, and the laser beams can excite the vibrating plate to vibrate and deform to generate displacement through the photo-thermal effect so as to squeeze ink in the ink chamber to form micro liquid drops to be sprayed to the substrate.

The optical ink-jet printing device excites the vibrating plate through the laser beam, so that the vibrating plate extrudes ink in the ink cavity to form micro-droplets for jetting, the vibrating plate is controlled to generate displacement for extrusion in a non-contact mode, extrusion is not needed in a contact mode, the problems of fatigue damage and the like of materials generated by contact resonance of the piezoelectric ceramic material layer and the vibrating plate material layer at present can be effectively solved, damage to the vibrating plate can be avoided, the manufacturing difficulty of the optical ink-jet printing device is reduced, and the usability is guaranteed. In addition, the laser can output the modulated laser, the excitation frequency of the modulated laser can be adjusted, and the processing efficiency and the productivity of the display screen are improved.

Drawings

Fig. 1 is a schematic structural diagram of an optical inkjet printing apparatus according to an embodiment of the present application.

Fig. 2 is a schematic structural view of an optical inkjet printing apparatus according to another embodiment of the present application.

Fig. 3 is a waveform diagram of the power of a modulated laser using TTL level modulation.

Fig. 4 is a schematic view of an optical system in the optical inkjet printing apparatus shown in fig. 1.

Fig. 5 is a schematic diagram illustrating the cooperation between a reticle and a microlens array in the optical inkjet printing apparatus shown in fig. 1.

FIG. 6 is a schematic diagram of one embodiment of a digital micromirror device for deflecting a laser beam in the optical inkjet printing apparatus shown in FIG. 1.

Fig. 7 is a schematic diagram of another embodiment of a digital micromirror device for deflecting a laser beam in the optical inkjet printing apparatus shown in fig. 1.

Wherein: 100. an optical inkjet printing device; 110. a laser; 120. an optical system; 121. a beam expanding lens; 122. a beam splitting lens; 130. a microlens array; 131. a lens body; 132. a focusing lens; 140. an inkjet assembly; 141. an ink chamber; 142. a vibration plate; 143. a spray head housing; 150. a digital micromirror device; 151. a micro mirror unit; 160. masking plate; 161. mask holes; 170. a transmissive modulator; 171. a liquid crystal cell; 200. a display panel; 300. and (3) ink.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

Referring to fig. 1 and 2, the present application provides an optical inkjet printing apparatus 100. The optical inkjet printing apparatus 100 is applied to the field of inkjet printing, so that the ink 300 is formed into micro droplets to be ejected, thereby realizing inkjet printing. Fig. 1 is a schematic structural diagram of an optical inkjet printing apparatus 100 according to an embodiment of the present application, and fig. 2 is a schematic structural diagram of an optical inkjet printing apparatus 100 according to another embodiment of the present application. In the present embodiment, the optical inkjet printing apparatus 100 prints the ink 300 in the pixel holes of the display panel 200, thereby forming a display screen. Of course, in other embodiments of the present application, the optical inkjet printing apparatus 100 may also print the ink 300 on other carriers to form corresponding patterns on the carriers. The optical inkjet printing apparatus 100 of the present application will be described by taking the example of ejecting ink 300 on the display panel 200.

It can be understood that when the piezoelectric ceramic excitation method is adopted to jet ink at present, the piezoelectric material is excited to vibrate through contact type electric excitation so as to extrude the ink cavity vibrating membrane, so that the problems of low excitation frequency, low display screen processing efficiency and productivity, high manufacturing difficulty of a printing head, material fatigue damage generated by contact resonance of the piezoelectric ceramic material layer and the vibrating plate material layer, and the like exist, and the usability is affected.

Therefore, the present application provides a novel optical inkjet printing apparatus 100, where the optical inkjet printing apparatus 100 extrudes in a non-contact manner to form micro droplets of ink 300 for spraying, and extrusion in a contact manner is not needed, so that the problems of fatigue damage of materials caused by contact resonance of a piezoelectric ceramic material layer and a vibrating plate material layer at present can be effectively solved, damage of the vibrating plate 142 can be avoided, manufacturing difficulty of the optical inkjet printing apparatus 100 is reduced, and usability is ensured. The optical inkjet printing apparatus 100 can also output a modulated laser beam, and can adjust the excitation frequency of the modulated laser beam, thereby improving the processing efficiency and productivity of the display screen. The following describes a specific structure of the optical inkjet printing apparatus 100 of an embodiment.

Referring to fig. 1 and 2, in one embodiment, an optical inkjet printing apparatus 100 includes a laser 110, an optical system 120, a microlens array 130, and an inkjet assembly 140. The laser 110 is used to output a modulated laser light. An optical system 120 is located at the output of the tunable laser 110 along the optical path propagation direction for splitting the tunable laser into parallel laser beams. The microlens array 130 is disposed at the output end of the optical system 120 along the propagation direction of the optical path. The ink jet assembly 140 includes a plurality of vibration plates 142 and a plurality of ink chambers 141, wherein each vibration plate 142 is disposed on a surface of the ink chamber 141 corresponding to the microlens array 130, and the ink chamber 141 holds the ink 300. The modulated laser beam is split into parallel laser beams by the optical system 120, focused and shaped by the micro lens array 130, and then injected into the ink jet assembly 140 to excite the vibration plate 142, so that the vibration plate 142 extrudes the ink 300 in the ink chamber 141 to form micro droplet ejection.

The laser 110 is a laser source of the optical inkjet printing apparatus 100, and the laser 110 emits a tunable laser, so that the tunable laser is injected into the inkjet assembly through the optical system 120 and the microlens array 130, so as to excite the inkjet assembly 140, and the inkjet assembly 140 extrudes the ink 300 to form micro droplets for ejection. Moreover, the laser output by the laser 110 is a tunable laser, and parameters of the tunable laser can be adjusted by the laser 110, so that the photo-thermal energy of exciting the inkjet assembly 140 can be adjusted, so that the inkjet assembly 140 extrudes different volumes of ink 300, thereby printing micro-droplets with different volumes to meet different printing requirements.

The laser 110, the optical system 120, the microlens array 130, the inkjet assembly 140, and the display panel 200 are disposed at intervals and in sequence along the direction of propagation of the optical path. It will be appreciated that the optical path may be one optical path or two optical paths. When the number of the light paths is two, the first light path and the second light path are respectively, the first light path is perpendicular to the second light path, the laser 110 and the optical system 120 are arranged on the first light path at intervals, the microlens array 130, the ink jet assembly 140 and the display panel 200 are arranged on the second light path at intervals, and a reflecting element is arranged between the first light path and the second light path, so that the reflection of the laser is realized, as shown in fig. 1. When the light paths are one, the laser 110, the optical system 120, the microlens array 130, the ink jet assembly 140 and the display panel 200 are disposed on the same light path at intervals, as shown in fig. 2.

It should be noted that the number of optical paths may be set according to a specific application scenario and specific components of the optical inkjet printing apparatus 100, for example, when the space used by the optical inkjet printing apparatus 100 is limited, two optical paths may be used, and of course, the number of reflective components may be increased, multiple optical paths may be used, and when the space used by the optical inkjet printing apparatus 100 is not limited, one optical path may be used. For another example, two light paths may be used when the optical inkjet printing apparatus 100 is provided with a reflective member. Specific quantitative use cases with respect to the optical paths are mentioned later. In the present application, the input and output directions refer to the transmission directions of laser light, the laser light is incident on a certain component along the input direction, the direction in which the laser light is emitted from the certain component is the output direction, and the side on which the laser light is located is the output end.

The optical system 120 is disposed at an output end of the laser 110 along the propagation direction of the optical path, and the modulated laser light output from the laser 110 is incident on the optical system 120. The optical system 120 is capable of modulating the laser light for beam expansion and splitting such that the modulated laser light is split into a plurality of parallel laser beams. The inkjet assemblies 140 are respectively excited by a plurality of parallel laser beams, so that the inkjet assemblies 140 spray the extrusion ink 300 correspondingly to form corresponding patterns on the display panel 200.

The microlens array 130 is located at the output end of the optical system 120 along the optical path propagation direction, i.e., the optical system 120 is located between the laser 110 and the microlens array 130 along the optical path propagation direction. A plurality of parallel laser beams emitted from the optical system 120 can be incident into the microlens array 130. The ink jet assembly 140 is disposed at an output end of the microlens array 130, i.e., along the propagation direction of the optical path, and the microlens array 130 is located between the optical system 120 and the ink jet assembly 140. The laser beam emitted from the microlens array 130 can be incident on the inkjet assembly 140, and the inkjet assembly 140 is excited by the photo-thermal effect to squeeze the ink 300 to form micro droplets for ejection.

It will be appreciated that after the optical system 120 performs the beam expanding and splitting operation, the shape of the laser beam may be irregular, and the energy may be relatively dispersed, so that the direct use of the laser beam to excite the inkjet assembly 140 may affect the excitation effect of the inkjet assembly 140, and the extrusion of the ink 300 may not be expected. Therefore, the micro lens array 130 is added at the input end of the ink jet assembly 140, and the micro lens array 130 can respectively restrict, focus and shape a plurality of parallel laser beams, so that the energy of the laser beams is concentrated, and the laser beams can accurately excite the ink jet assembly 140 after being injected into the ink jet assembly 140, thereby ensuring the ink jet effect of the ink jet assembly 140.

Specifically, the inkjet assembly 140 includes a plurality of vibration plates 142 and a plurality of ink chambers 141. The ink chamber 141 is hollow, the ink chamber 141 holds ink 300 therein, and the vibration plate 142 is disposed at an end of the ink chamber 141 and toward the microlens array 130. The ink chamber 141 has a liquid outlet at an end remote from the vibration plate 142, and the ink 300 is ejected as micro droplets through the liquid outlet. The laser beam emitted from the microlens array 130 can be focused on the vibration plate 142, and the vibration plate 142 is excited by the photo-thermal effect, so that the vibration plate 142 vibrates to generate deformation displacement, and the vibration plate 142 can squeeze the ink 300 in the ink chamber 141 to form micro droplets to be ejected into the pixel holes of the display panel 200, thereby forming a display screen.

The plurality of parallel laser beams correspond to the plurality of vibration plates 142, respectively, so that different laser beams can excite the corresponding vibration plates 142 to enable the corresponding ink chambers 141 to eject ink. Optionally, the inks 300 contained in the respective ink chambers 141 are the same and/or different in color. Illustratively, the inks 300 in the respective ink chambers 141 are partially identical in color and partially different in color to meet the actual ejection demands.

When the optical ink-jet printing device 100 of the present application is used, the laser 110 emits a modulatable laser beam and emits the modulatable laser beam into the optical system 120, the optical system 120 expands and splits the beam to form a plurality of parallel laser beams, and the parallel laser beams are emitted into the micro lens array 130, the micro lens array 130 is used for restraining, focusing and shaping the parallel laser beams and then emits the parallel laser beams into the ink-jet assembly 140, and the parallel laser beams can respectively excite the corresponding vibration plates 142 to vibrate and deform to generate displacement through the photo-thermal effect, so that the ink 300 in the ink cavity 141 is extruded to form micro droplets and jet the micro droplets into the pixel holes of the display panel 200, thereby forming the display screen on the display panel 200.

In the optical inkjet printing device 100 of the above embodiment, the vibration plate 142 is excited by the laser beam, so that the vibration plate 142 extrudes the ink 300 in the ink chamber 141 to form micro droplets for jetting, the vibration plate 142 is controlled to generate displacement for extrusion in a non-contact manner, and extrusion is not required in a contact manner, so that the problems of fatigue damage of materials and the like caused by contact resonance of the piezoelectric ceramic material layer and the vibration plate material layer at present can be effectively solved, damage to the vibration plate 142 can be avoided, the manufacturing difficulty of the optical inkjet printing device 100 is reduced, and the usability is ensured. In addition, the laser 110 can output the modulated laser, and can adjust the excitation frequency of the modulated laser, thereby improving the processing efficiency and productivity of the display screen.

In one embodiment, one or more of the parameters of power, waveform, phase, polarization, etc. of the modulated laser light output by the laser 110 are adjustable to adjust the frequency of the modulated laser light output by the laser 110. After the parameters of the modulated laser are adjusted, the purpose of adjusting the frequency of the modulated laser can be achieved, and then the frequency of ink-jet printing is adjusted, so that the frequency of the modulated laser can reach hundreds of kHz to MHz, and the frequency of ink-jet printing and the manufacturing efficiency of a display screen are greatly improved. Alternatively, the laser 110 is electrically connected to a controller of the optical inkjet printing apparatus 100, which controls the laser 110 to modulate corresponding parameters.

Alternatively, the laser 110 may modulate the power of the laser by high and low level adjustments. Illustratively, for a laser 110 using transistor-transistor logic integrated circuit (TTL) level modulation, as shown in FIG. 3, FIG. 3 is a waveform diagram of the power of a modulated laser using TTL level modulation. When the input is at a low level, the output power of the laser 110 is 0, and the laser 110 does not emit the modulatable laser light; when a high level is input, the output power of the laser 110 is Pmax, and the laser 110 can modulate the laser light according to the maximum power output. The level modulation frequency f controls the laser switch, the period is T, and the level modulation frequency f corresponds to the ink-jet printing frequency f. The modulation frequency of the modulated laser can reach hundreds of kHz to MHz, and the ink-jet printing frequency and the display screen manufacturing efficiency are greatly improved. For a continuously modulated laser 110, different laser powers can be output with different modulation voltages to print different volumes of ink droplets under conditions that meet the minimum laser energy. Of course, in other embodiments of the present application, other types of lasers 110 may be employed as long as they can output a modulated laser light.

As shown in fig. 4, in an embodiment, the optical system 120 includes a beam expander 121 and a beam splitter 122, where the beam expander 121 and the beam splitter 122 are disposed between the laser 110 and the microlens array 130 along the propagation direction of the optical path; the beam expander 121 expands the beam diameter of the modulated laser beam, and the beam splitter 122 splits the expanded modulated laser beam into parallel laser beams. Fig. 4 is a schematic diagram of an optical system 120 in the optical inkjet printing apparatus 100 shown in fig. 1.

The beam expander 121 and the beam splitter 122 are disposed at intervals along the propagation direction of the optical path, and the modulated laser light emitted by the laser 110 is first incident into the beam expander 121 for beam expansion, and then enters the beam splitter 122 for beam splitting. The beam expander 121 in the optical system 120 mainly expands the beam of the modulated laser beam emitted from the laser 110 to expand the spot diameter of the original laser beam. The expanded modulated laser beam is incident on the beam splitting lens 122, and the expanded modulated laser beam is split into a plurality of parallel laser beams by the beam splitting lens 122.

The optical system 120 can divide the modulatable laser into a plurality of parallel laser beams, and the parallel laser beams can be injected into the inkjet assembly 140 after passing through the microlens array 130, each laser beam can correspond to one vibration plate 142, so as to realize excitation of the corresponding vibration plate 142, and the vibration plate 142 can squeeze the ink chamber 141 to jet micro droplets. That is, the optical system 120 can cause the modulatable laser beams to form a plurality of optical excitation sources to excite the corresponding vibration plates 142, respectively, so that the corresponding ink chambers 141 eject micro droplets.

Referring to fig. 1, 2 and 5, in one embodiment, the microlens array 130 includes a lens body 131 and a plurality of focusing lenses 132, where the plurality of focusing lenses 132 are disposed on a surface of the lens body 131 facing the inkjet assembly 140, and each focusing lens 132 is used for focusing and shaping a laser beam. Fig. 5 is a schematic diagram illustrating the cooperation of the mask 160 and the microlens array 130 in the optical inkjet printing apparatus 100 shown in fig. 1.

The lens body 131 is a mounting motherboard of the microlens array 130, and the focusing lenses 132 are disposed on a surface of the lens body 131 away from the optical system 120, i.e., the focusing lenses 132 are located between the lens body 131 and the inkjet assembly 140. The plurality of focusing lenses 132 are supported by the lens body 131, so that the plurality of focusing lenses 132 form an integral structure, and the installation and the use are convenient. After the parallel laser beams emitted from the beam splitting lens 122 are incident on the microlens array 130, the parallel laser beams are incident on the focusing lens 132 through the lens body 131, and each focusing lens 132 can constrain, focus and shape one laser beam so that the laser beam forms a corresponding shape.

After the laser beam is split by the beam splitting lens 122, the laser beam exhibits a shape similar to a cylinder, and the energy of the laser beam is more dispersed. After the laser beam enters the focusing lens 132 through the lens body 131, the focusing lens 132 can constrain, shape and focus the laser beam so that the laser beam is emitted in a cone shape as shown in fig. 1, 2 and 5 and then enters the vibration plate 142. In this way, the energy of the laser beam is concentrated and the vibration plate 142 can be accurately excited, so that the vibration plate 142 is vibrated to deform to generate displacement to press the ink 300 in the ink chamber 141 to form micro droplets to be ejected into the pixel holes of the display panel 200.

Referring to fig. 1, 2 and 5, in one embodiment, each vibration plate 142 is disposed corresponding to one focusing lens 132. That is, one focusing lens 132 is disposed corresponding to one vibration plate 142 in the direction along the optical path propagation, and is further disposed corresponding to the ink chamber 141 through the vibration plate 142. In this way, the focusing lens 132 irradiates the focused and shaped laser beam into the vibration plate 142 to excite the corresponding vibration plate 142, and the ink chamber 141 can be pressed when the vibration plate 142 vibrates, so that the ink chamber 141 ejects micro droplets.

Referring to fig. 1 and 2, in an embodiment, the inkjet assembly 140 includes a nozzle housing 143, a plurality of ink chambers 141 are disposed in at least one row in the nozzle housing 143, the nozzle housing 143 has a nozzle, and a liquid outlet of the ink chambers 141 is disposed in the nozzle. The head housing 143 has a plurality of mounting positions on a surface facing the microlens array 130, each mounting position mounting one vibration plate 142 and corresponding to one ink chamber 141, and the vibration plate 142 is mounted in the mounting position, and the vibration plate 142 is attached to an end of the ink chamber 141.

The head housing 143 is a housing of the inkjet assembly 140, and a plurality of ink chambers 141 are spaced apart in the head housing 143. The plurality of ink chambers 141 are integrated by the head housing 143 such that the plurality of ink chambers 141 form an integral structure for easy assembly use. Alternatively, the head housing 143 is integrally formed with the ink chamber 141. That is, the head housing 143 is provided therein with a plurality of chambers for holding the ink 300, which corresponds to the ink chambers 141. Of course, in other embodiments of the present application, the head housing 143 may be provided separately from the ink chamber 141, and the ink chamber 141 is fixedly provided in the head housing 143.

Also, one end of the head housing 143 toward the microlens array 130 has a plurality of mounting positions, each of which faces the ink chamber 141, and the vibration plate 142 is mounted in the mounting position and abuts the ink chamber 141. In this way, when the vibration plate 142 is excited, vibration generated by the vibration plate 142 can press the ink 300 in the ink chamber 141 to eject micro droplets. Note that the vibration plate 142 is integrally formed at the mounting position of the head housing 143 by a micromachining process, and the ink chamber 142 is provided below the vibration plate 142.

The head housing 143 has a nozzle at an end remote from the microlens array 130, and after the ink chamber 141 is mounted to the head housing 143, a liquid outlet of the ink chamber 141 is located in the nozzle and communicates with the nozzle. When the vibration plate 142 is excited in this way, vibration generated by the vibration plate 142 can press the ink 300 in the ink chamber 141, and the ink 300 enters the nozzle through the liquid outlet, and the ink 300 is formed into micro droplets through the nozzle to be ejected.

Alternatively, the thickness of the vibration plate 142 is 1 μm to 3 μm. Optionally, a plurality of ink chambers 141 are arranged in a row. Of course, in other embodiments of the present application, a plurality of ink chambers 141 are arranged in rows and columns. That is, the ink chambers 141 are distributed in an array.

Referring to fig. 1, 2, 6 and 7, in an embodiment, the optical inkjet printing apparatus 100 further includes a spatial light modulator disposed at an output end of the optical system 120 along the propagation direction of the optical path, for modulating the deflection angle of the laser beam, so that the laser beam is deflected or projected to the microlens array 130. Fig. 6 is a schematic diagram of an embodiment of the digital micromirror device 150 in the optical inkjet printing apparatus 100 shown in fig. 1 for deflecting a laser beam, and fig. 7 is a schematic diagram of another embodiment of the digital micromirror device 150 in the optical inkjet printing apparatus 100 shown in fig. 1 for deflecting a laser beam.

A spatial light modulator is disposed between the optical system 120 and the microlens array 130, and the spatial light modulator is capable of modulating a deflection angle of a plurality of parallel laser beams such that the laser beams are deflected or projected to the microlens array 130, thereby controlling parameters such as laser intensity, phase, and polarization of the laser beams. After the spatial light modulator modulates the laser beam, the laser beam can be incident into the microlens array 130 or the laser beam is reflected to other positions and cannot enter into the microlens array 130. When the laser beam is incident on the microlens array 130, the laser beam can excite the corresponding vibration plate 142, and after the laser beam does not enter the microlens array 130, the vibration plate 142 at the corresponding position cannot be excited. In this way, the ink ejection of the corresponding ink chamber 141 can be controlled according to the pattern on the display panel 200, for example, so that the ink chamber 141 ejects ink, a part of the ink chamber 141 ejects ink, and all the ink chambers 141 do not eject ink.

Alternatively, the spatial light modulator is electrically connected to a controller of the optical inkjet printing apparatus 100, and the controller controls the spatial light modulator to deflect the laser beam. In this way, the controller can control whether the laser beam passes through the microlens array 130 according to the pattern molded on the display panel 200.

It is noted that the type of spatial light modulator is in principle not limited as long as modulation of the laser beam can be achieved. Alternatively, the spatial light modulator is a reflective modulator or a transmissive modulator, the spatial light modulator shown in fig. 1 is a reflective modulator, and the spatial light modulator shown in fig. 2 is a transmissive modulator. Of course, in other embodiments of the application, the spatial light modulator may be other projection or reflection type light modulators, such as electro-optic, acousto-optic, magneto-optic materials and devices, and the like.

Referring to fig. 1, 5 to 7, in an embodiment of the application, the spatial light modulator is a reflective modulator, the optical system 120 is disposed on a first optical path, the microlens array 130 and the inkjet assembly 140 are disposed on a second optical path, the first optical path is perpendicular to the second optical path, and the reflective modulator is disposed at the intersection of the first optical path and the second optical path. The reflective modulator includes a digital micromirror device 150 and a mask 160, where the digital micromirror device 150 is disposed at the junction of the first optical path and the second optical path, and the mask 160 is disposed on the second optical path and located at the output end of the digital micromirror device 150.

Since the spatial light modulator is a reflective modulator, the optical system 120 and the microlens array 130 cannot be in the same optical path, that is, the laser 110 and the optical system 120 are in a first optical path, the microlens array 130 and the inkjet assembly 140 are disposed in a second optical path, the reflective modulator is disposed at the intersection of the first optical path and the second optical path, and multiple parallel laser beams split by the optical system 120 are reflected into the microlens array 130 by the reflective modulator.

Specifically, the reflective modulator includes a digital micromirror device 150 and a mask 160, the digital micromirror device 150 is disposed at the intersection of the first optical path and the second optical path, and is used for deflecting the laser beam, and the mask 160 is disposed at the output end of the digital micromirror device 150 and is located at the input end of the microlens array 130, and the laser beam can selectively pass through the mask 160. After the digital micromirror device 150 deflects the laser beam in a direction along the second optical path, the laser beam can be directed into the microlens array 130 through the reticle 160, as shown in fig. 1, 2, and 6. After the digital micromirror device 150 deflects the laser beam in a direction inclined with respect to the second optical path, the laser beam is obliquely projected onto the reticle 160, and then the reticle 160 reflects the laser beam toward the optical system 120, and the laser beam cannot be injected into the microlens array 130, as shown in fig. 1, 2 and 7.

The digital micromirror device 150 is a micro-electro-mechanical system of electronic input and optical output, and is composed of a high-speed digital micromirror unit 151, and the imaging pattern and its characteristics are determined by controlling the rotation of the micromirror unit 151 around a fixed (yoke) and the time domain response (determining the reflection angle and dead time of light). The deflection control of the micromirror unit 151 in the digital micromirror device 150 can be performed by logic signals in the controller. As shown in fig. 6, the laser beam reflected by the micro-mirror directly reflects through the mask 160 to excite the vibration plate 142 to vibrate, and as shown in fig. 7, the laser beam is reflected through the mask 160 to deflect due to the deflection of the micro-mirror unit 151, so that the vibration plate 142 cannot be excited. It should be noted that the digital micromirror device 150 is a conventional structure, and the principle thereof is not described herein.

Alternatively, the digital micromirror device 150 has a plurality of micromirror units 151, and the plurality of micromirror units 151 are rotatably disposed and electrically connected to a controller capable of controlling the deflection of the plurality of micromirror units 151, respectively, so that the modulation units have different orientations. As shown in fig. 1, 2 and 6, when the controller controls the micro mirror unit 151 to be parallel to the surface of the digital micro mirror device 150, the micro mirror unit 151 can reflect the laser beam in the direction of the second optical path so that the laser beam can be injected into the micro lens array 130 through the reticle 160. As shown in fig. 1, 2 and 7, the controller controls the micro-mirror unit 151 to deflect and form an included angle with the surface of the digital micro-mirror device 150, and the micro-mirror unit 151 reflects the laser beam to incline with respect to the second optical path, at this time, the laser beam is reflected by the mask 160 and cannot be injected into the micro-lens array 130 after being injected into the mask 160.

Referring to fig. 1, 2 and 5, in one embodiment, the mask 160 has a plurality of mask holes 161, the mask holes 161 penetrating the mask 160 along the second optical path, the mask holes 161 allowing a laser beam to pass therethrough, each mask hole 161 corresponding to one of the ink chambers 141. The digital micromirror device 150 reflects the laser beam in a vertical direction, which can be aligned with the mask hole 161 and injected into the microlens array 130 through the mask hole 161.

Furthermore, there is a space between adjacent mask holes 161, and after the dmd 150 reflects the laser beam to a position between two mask holes 161, the laser beam is reflected by the mask 160 and cannot be emitted through the mask holes 161. That is, only the laser beam is injected into the mask holes 161, the laser beam can be injected into the microlens array 130 through the mask holes 161, and the laser beam cannot pass through when the laser beam is injected into the surface of the reticle 160 between the adjacent mask holes 161. The specific fabrication of reticle 160 may be performed using prior art techniques.

It should be noted that, each mask hole 161 is disposed in a one-to-one correspondence with each focusing lens 132 of the microlens array 130, so that the laser beam passing through the mask hole 161 can be incident into the focusing lens 132, and is confined, shaped and focused by the focusing lens 132. And, the distance between the adjacent mask holes 161 corresponds to the position of the micromirror unit 151 of the digital micromirror device 150 to ensure that the laser beam reflected by the micromirror unit 151 can be incident into the mask holes 161 or reflected by the reticle 160.

As shown in fig. 1, when the optical inkjet printing apparatus 100 is in operation, a laser 110 emits a modulated laser beam, and the modulated laser beam is incident on an optical system 120, and the optical system 120 performs beam expansion and beam splitting processing to output a plurality of parallel laser beams. A plurality of parallel laser beams are incident on the dmd 150, and the controller controls the deflection or non-deflection of a portion of the micromirror units 151 in the dmd 150. For the vibration plate 142 needing to be excited, the micro-mirror unit 151 in the digital micro-mirror device 150 does not deflect, the micro-mirror unit 151 reflects the laser beam to focus on the vibration plate 142 through the mask 160 and the micro-lens array 130, and the vibration plate 142 is excited to vibrate and deform, so that the ink chamber 141 is extruded to spray micro-droplets to the display panel 200, and a display screen is formed. For vibration plates 142 that do not require excitation, the micro mirror units 151 in the digital micromirror device 150 deflect, and the reflected laser beams from the micro mirror units 151 are reflected back through the reticle 160.

Referring to fig. 2, in another embodiment of the present application, the spatial light modulator is a transmissive modulator 170, and the transmissive modulator 170 is disposed between the optical system 120 and the microlens array 130. After a plurality of parallel laser beams emitted from the optical system 120 pass through the transmission modulator 170, the laser beams are selectively passed through the transmission modulator 170. In this way, the laser beam that can pass through the transmission modulator 170 can enter the microlens array 130, and the laser beam that cannot pass through the transmission modulator 170 is reflected away, and cannot enter the microlens array 130.

As shown in fig. 6, the transmissive modulator 170 is illustratively a transmissive liquid crystal spatial light modulator (LC-SLM), which is based on an optical phased array technology, and uses the electro-optic effect of liquid crystals to realize the intensity, phase and polarization state transformation of an optical wave. The refractive index of the liquid crystal layer is controlled by applying an electric field to the liquid crystal cells 171 in different areas, as desired to print a pattern of ink drop positions. When the laser beam passes through the liquid crystal cell 171 modulated by different electric fields, different phase depth profiles are generated, realizing different angle beam deflection. For the position where printing is not needed, the liquid crystal unit 171 is not deflected, and at this time, the liquid crystal unit 171 is arranged parallel to the surface of the transmission modulator 170, blocking the laser beam from passing through; for the position to be printed, an electric field is applied to deflect the liquid crystal unit 171, at this time, the liquid crystal unit 171 deflects at a certain angle relative to the surface of the transmission modulator 170, when the deflection angle is 90 degrees, the laser beam passes through completely, and when the deflection angle is other deflection angles, the laser beam passes through partially, so that parameters such as laser intensity, phase and polarization are controlled.

It should be noted that the transmissive modulator 170 is a prior art and is not described herein. Of course, in other embodiments of the present application, if the installation space of the optical inkjet printing apparatus 100 is limited, the optical inkjet printing apparatus 100 may further include a mirror, the optical system 120 and the transmissive modulator 170 are disposed on a first optical path, the microlens array 130 and the inkjet assembly 140 are disposed on a second optical path, the first optical path is perpendicular to the second optical path, and the mirror is disposed at the intersection of the first optical path and the second optical path.

Referring to fig. 1 and 2, the optical inkjet printing apparatus 100 according to the present application excites the vibration plate 142 by a photo-excitation method, has a wide light excitation frequency and a high excitation frequency, and is characterized in that the energy distribution is concentrated, the tunable laser is split by the optical system 120 to form a plurality of parallel laser beams, and after the parallel laser beams are processed by the spatial light modulator and constrained and focused by the microlens array 130, a photo-thermal effect is applied to the vibration plate 142 to excite the vibration plate 142 to vibrate, and at the same time, the micro-droplet ejection in the plurality of ink chambers 141 is controlled. In addition, the vibration plate 142 is excited by the photo-thermal effect and is in a non-contact method, so that the problems of material fatigue damage and the like caused by the contact resonance of the original piezoelectric ceramic material layer and the vibration plate material layer can be solved, and the processing efficiency and the productivity of the display screen are improved.

Referring to fig. 1 and 2, the present application also provides an ejection method of an optical inkjet printing apparatus 100, the ejection method being applied to the optical inkjet printing apparatus 100 according to any one of the embodiments described above, the ejection method including the steps of:

controlling the laser 110 to emit a modulated laser light;

the modulated laser light enters the optical system 120 and is split into parallel laser beams;

the parallel laser beams are injected into the micro lens array 130, and are focused and shaped by the micro lens array 130;

The laser beam passing through the microlens array 130 is injected into the ink jet assembly 140 to excite the vibration plate 142 of the ink jet assembly 140, so that the vibration plate 142 is deformed to generate displacement to squeeze the ink 300 in the ink chamber 141 to form micro droplets to be ejected to the substrate.

When the optical ink-jet printing device 100 of the present application is used, the laser 110 emits a modulatable laser beam and emits the modulatable laser beam into the optical system 120, the optical system 120 expands and splits the beam to form a plurality of parallel laser beams, and the parallel laser beams are emitted into the micro lens array 130, the micro lens array 130 is used for restraining, focusing and shaping the parallel laser beams and then emits the parallel laser beams into the ink-jet assembly 140, and the parallel laser beams can respectively excite the corresponding vibration plates 142 to vibrate and deform to generate displacement through the photo-thermal effect, so that the ink 300 in the ink cavity 141 is extruded to form micro droplets and jet the micro droplets into the pixel holes of the display panel 200, thereby forming the display screen on the display panel 200.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. An optical inkjet printing apparatus, comprising:

a laser for outputting a modulated laser light;

the optical system is positioned at the output end of the modulatable laser along the light path propagation direction and is used for splitting the modulatable laser into parallel laser beams;

the micro lens array is arranged at the output end of the optical system along the light path propagation direction; and

the ink jet assembly comprises a plurality of vibrating plates and a plurality of ink chambers, wherein each vibrating plate is arranged on the surface of the ink chamber corresponding to the micro lens array, and ink is contained in the ink chamber;

the adjustable laser is split into parallel laser beams through the optical system, focused and shaped through the micro lens array and then injected into the ink jet assembly to excite the vibrating plate, so that the vibrating plate extrudes the ink in the ink chamber to form micro liquid drop jet.

2. The optical inkjet printing apparatus of claim 1 wherein the optical system comprises a beam expanding lens and a beam splitting lens disposed between the laser and the microlens array at intervals along an optical path propagation direction;

the beam expanding lens is used for expanding the beam diameter of the modulated laser, and the beam dividing lens is used for dividing the modulated laser after beam expansion into parallel laser beams.

3. The optical inkjet printing apparatus of claim 1 wherein said microlens array comprises a lens body and a plurality of focusing lenses disposed on a surface of said lens body facing said inkjet assembly, each of said focusing lenses for focusing and shaping a beam of said laser beam.

4. An optical ink jet printing apparatus according to claim 3 wherein each of said vibration plates is provided corresponding to one of said focusing lenses.

5. The optical inkjet printing apparatus of claim 1 wherein said inkjet assembly comprises a jet housing in which a plurality of said ink chambers are disposed in at least one row, said jet housing having a nozzle, a liquid outlet of said ink chambers being disposed in said nozzle;

The surface of the nozzle shell facing the micro lens array is provided with a plurality of mounting positions, each mounting position is provided with one vibrating plate, and corresponds to one ink cavity, and the vibrating plate is attached to the end part of the ink cavity.

6. The apparatus according to any one of claims 1 to 5, further comprising a spatial light modulator disposed at an output end of the optical system in a light path propagation direction for modulating a deflection angle of the laser beam so that the laser beam is deflected or projected to the microlens array.

7. The optical inkjet printing apparatus of claim 6 wherein the spatial light modulator is a reflective modulator, the optical system is disposed in a first optical path, the microlens array and the inkjet assembly are disposed in a second optical path, the first optical path is perpendicular to the second optical path, and the reflective modulator is disposed at the intersection of the first optical path and the second optical path;

the reflective modulator comprises a digital micro-mirror device and a mask plate, wherein the digital micro-mirror device is arranged at the junction of the first light path and the second light path, and the mask plate is arranged on the second light path and is positioned at the output end of the digital micro-mirror device.

8. The optical inkjet printing apparatus of claim 7 wherein said mask plate has a plurality of mask apertures extending therethrough along said second optical path, said mask apertures allowing a beam of said laser beam to pass therethrough, each of said mask apertures corresponding to one of said ink chambers.

9. The optical inkjet printing apparatus of claim 6 wherein the spatial light modulator is a transmissive modulator;

the optical system and the transmission type modulator are arranged on a first light path, the micro lens array and the ink jet assembly are arranged on a second light path, the first light path is perpendicular to the second light path, and the reflecting mirror is arranged at the junction of the first light path and the second light path.

10. A jetting method of an optical inkjet printing apparatus, characterized in that the jetting method is applied to the optical inkjet printing apparatus according to any one of claims 1 to 9, the jetting method comprising the steps of:

controlling the laser to emit a modulated laser;

The modulated laser beam is injected into the optical system and split into parallel laser beams;

the parallel laser beams are injected into a micro lens array, and are focused and shaped by the micro lens array;

the laser beam passing through the micro lens array is injected into the ink jet assembly to excite the vibration plate of the ink jet assembly, so that the vibration plate is deformed to generate displacement to squeeze the ink in the ink chamber to form micro liquid drops to be sprayed to the substrate.