Optical inkjet printing apparatus and method of ejection thereof

Abstract

The application relates to an optical inkjet printing device and a jetting method thereof. The optical inkjet printing device comprises a laser for outputting modulatable laser; an optical system located at the output end of the modulatable laser along the light path propagation direction, for splitting the modulatable laser into parallel laser beams; a microlens array arranged at the output end of the optical system along the light path propagation direction; and an inkjet assembly comprising a plurality of vibration plates and a plurality of ink chambers, each vibration plate being arranged on the surface of the corresponding microlens array of the ink chamber, and ink being contained in the ink chamber; after the modulatable laser is split into parallel laser beams by the optical system, the laser beams are focused and shaped by the microlens array and then enter the inkjet assembly, so as to excite the vibration plates and make the vibration plates extrude the ink in the ink chamber to form micro-liquid drop jetting. The displacement of the vibration plates is controlled in a non-contact manner to avoid damage to the vibration plates, ensure the use performance, and improve the processing efficiency and productivity of the display screen.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inkjet printing equipment, in particular to an optical inkjet printing device and a jetting method thereof. BACKGROUND

[0002] As a new type of display technology that realizes self-luminous by power-on, the organic light emitting diode (OLED) has been increasingly applied to display fields such as mobile phones, televisions, vehicle displays, smart wearables and VR devices, and lighting markets.

[0003] With the advent of the OLED display era, higher requirements are put forward for the colorization and patterning of display screens. Compared with the traditional vacuum evaporation technology, the inkjet printing technology is easier to realize the colorization of large-area devices and the patterning of composite functional materials, and has the advantages of simple process, low cost and flexible device processing.

[0004] At present, the inkjet printing technology mainly includes continuous inkjet technology and drop-on-demand inkjet technology. Among them, the most widely used drop-on-demand inkjet technology mainly includes acoustic type, electrostatic type, thermal bubble type and piezoelectric type. Among them, in OLED display printing, the piezoelectric type print head is mainly used, which has two manufacturing methods, namely shared wall and independent cavity type. Among them, the shared wall method is to spray ink droplets by shearing piezoelectric ceramic block vibration; and the independent cavity mainly includes extrusion type and bending type, the extrusion type is normal piezoelectric ceramic block vibration extrusion ink cavity inkjet, and the bending type is generally to sputter piezoelectric ceramic material to the top of the ink cavity by micro-electro-mechanical system (MEMS) process, and to drive micro-ink droplet jetting by exciting piezoelectric film vibration, extruding ink cavity upper surface vibration plate.

[0005] For the piezoelectric ceramic excitation method, the piezoelectric material is excited to vibrate by contact type electric excitation to extrude the ink cavity vibration film, which has the problems of low excitation frequency, low display screen processing efficiency and production capacity, great difficulty in manufacturing the print head, material fatigue damage caused by the contact resonance of the piezoelectric ceramic material layer and the vibration plate material layer, and the like, which affect the use performance. SUMMARY

[0006] Therefore, it is necessary to provide an optical inkjet printing device and a jetting method thereof which can extrude ink in a non-contact manner to ensure excitation frequency and avoid damage, in view of the problems of low excitation frequency and easy damage of the vibration film caused by the current contact extrusion of ink.

[0007] An optical inkjet printing device, comprising:

[0008] a laser for outputting modulatable laser;

[0009] an optical system disposed at an output end of the modulated laser along a light path direction, for splitting the modulated laser into parallel laser beams;

[0010] a microlens array disposed at an output end of the optical system along the light path direction; and

[0011] an inkjet assembly comprising a plurality of vibration plates and a plurality of ink chambers, each of the vibration plates being disposed on a surface of the ink chamber corresponding to the microlens array, and the ink chambers containing ink;

[0012] After the modulated laser is split into parallel laser beams by the optical system, the laser beams are focused and shaped by the microlens array and then enter the inkjet assembly to excite the vibration plates, so that the vibration plates press the ink in the ink chambers to form micro-droplet ejection.

[0013] In an embodiment of the present application, the optical system comprises a beam expander and a beam splitter, and the beam expander and the beam splitter are disposed between the laser and the microlens array along the light path direction.

[0014] The beam expander is used to expand the beam diameter of the modulated laser, and the beam splitter is used to split the modulated laser after beam expansion into parallel laser beams.

[0015] In an embodiment of the present application, the microlens array comprises 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 assembly, and each of the focusing lenses is used to focus and shape a laser beam.

[0016] In an embodiment of the present application, each of the vibration plates is disposed corresponding to one of the focusing lenses.

[0017] In an embodiment of the present application, the inkjet assembly comprises a nozzle housing, and the ink chambers are disposed in the nozzle housing in at least one row, and the nozzle housing has a nozzle, and the liquid outlet of the ink chamber is disposed in the nozzle.

[0018] The surface of the nozzle housing facing the microlens array has a plurality of mounting positions, each of the mounting positions mounts one of the vibration plates and corresponds to one of the ink chambers, the vibration plate is mounted in the mounting position, and the vibration plate is attached to the end of the ink chamber.

[0019] In an embodiment of the present application, the optical inkjet printing device further comprises a spatial light modulator disposed at an output end of the optical system along the light path direction, for modulating the deflection angle of the laser beam, so that the laser beam is deflected or projected to the microlens array.

[0020] In an embodiment of the present application, the spatial light modulator is a reflective modulator, the optical system is arranged in a first light path, the microlens array and the inkjet assembly are arranged in a second light path, the first light path is perpendicular to the second light path, and the reflective modulator is arranged at the intersection of the first light path and the second light path.

[0021] The reflective modulator comprises a digital micromirror device and a mask, the digital micromirror device is arranged at the intersection of the first light path and the second light path, and the mask is arranged in the second light path and located at the output end of the digital micromirror device.

[0022] In an embodiment of the present application, the mask has a plurality of mask holes, the mask holes pass through the mask along the second light path, and the mask holes allow a bundle of the laser beams to pass through, each mask hole corresponding to one ink chamber.

[0023] In an embodiment of the present application, the spatial light modulator is a transmissive modulator.

[0024] The transmissive modulator is arranged between the optical system and the microlens array, or the optical inkjet printing device further comprises a mirror, the optical system and the transmissive modulator are arranged in a first light path, the microlens array and the inkjet assembly are arranged in a second light path, the first light path is perpendicular to the second light path, and the mirror is arranged at the intersection of the first light path and the second light path.

[0025] A jetting method of an optical inkjet printing device, the jetting method is applied to the optical inkjet printing device as described in any of the technical features above, and the jetting method comprises the following steps:

[0026] Controlling a laser to emit modulatable laser beams.

[0027] The modulatable laser beams are incident into an optical system and split into parallel laser beams.

[0028] The parallel laser beams are incident into a microlens array and focused and shaped by the microlens array.

[0029] The laser beams passing through the microlens array are incident into the inkjet assembly to excite a vibrating plate of the inkjet assembly, make the vibrating plate deform to generate displacement, extrude ink in an ink chamber to form micro-droplets and jet the micro-droplets to a substrate.

[0030] After the above technical solutions are adopted, the present application has at least the following technical effects:

[0031] The optical inkjet printing device and the jetting method thereof, in the optical inkjet printing device, a laser, an optical system, a microlens array and an inkjet assembly are arranged along the light path propagation direction, the laser is used to output modulated laser, the optical system is used to expand and split the modulated laser to form parallel laser beams, and the microlens array can focus and shape the laser beams. The modulated laser emitted by the laser forms parallel laser beams after being expanded and split by the optical system, and is injected into the microlens array. After being focused and shaped by the microlens array, the laser beams are injected into the inkjet assembly. Through the photothermal effect, the laser beams can excite the vibration plate to vibrate and deform to generate displacement, extrude the ink in the ink chamber to form micro-droplet jetting to the substrate.

[0032] The optical inkjet printing device excites the vibration plate by the laser beam, so that the vibration plate extrudes the ink in the ink chamber to form micro-droplet jetting. It adopts a non-contact mode to control the vibration plate to generate displacement for extrusion, without extruding by contact. This can effectively solve the problem of material fatigue damage caused by the contact resonance of the piezoelectric ceramic material layer and the vibration plate material layer, avoid damage to the vibration plate, reduce the manufacturing difficulty of the optical inkjet printing device, and ensure the use performance. Moreover, the laser can output modulated laser, which can adjust the excitation frequency of the modulated laser, improve the processing efficiency of the display screen and the production capacity. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The structure schematic diagram of the optical inkjet printing device of an embodiment of the present application.

[0034] Figure 2 The structure schematic diagram of the optical inkjet printing device of another embodiment of the present application.

[0035] Figure 3 The waveform diagram of the power of the modulated laser modulated by the TTL level.

[0036] Figure 4 The Figure 1 The schematic diagram of the optical system in the optical inkjet printing device shown in the figure.

[0037] Figure 5 The Figure 1 The schematic diagram of the mask and the microlens array cooperation in the optical inkjet printing device shown in the figure.

[0038] Figure 6 The Figure 1 The schematic diagram of the digital micromirror device deflecting the laser beam in an embodiment of the optical inkjet printing device shown in the figure.

[0039] Figure 7 The Figure 1Schematic diagram of another embodiment of the digital micromirror device deflecting the laser beam in the optical inkjet printing device shown.

[0040] 100, optical inkjet printing device; 110, laser; 120, optical system; 121, beam expander lens; 122, beam splitter lens; 130, microlens array; 131, lens body; 132, focusing lens; 140, inkjet assembly; 141, ink chamber; 142, vibrating plate; 143, nozzle housing; 150, digital micromirror device; 151, micro-mirror unit; 160, mask; 161, mask hole; 170, transmissive modulator; 171, liquid crystal unit; 200, display panel; 300, ink. DETAILED DESCRIPTION

[0041] In order to make the above objectives, features and advantages of the present application more apparent, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. It will be apparent, however, to one skilled in the art that the present application can be practiced without using some or all of these specific details, and that the present application is not limited to the specific embodiments disclosed below.

[0042] In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0043] In addition, if the terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implying the number of technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, if the term "multiple" appears, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0044] In the present application, unless specifically defined otherwise and limited, if there are terms such as "mount", "connect", "connect", "fix", etc., these terms should be broadly understood. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0045] In the present application, unless specifically defined otherwise and limited, if there are similar descriptions such as "first feature on" or "second feature", the meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0046] It should be noted that if an element is referred to as "fixed to" or "provided to" another element, it can be directly on another element or there can be a middle element. If an element is considered to be "connected" to another element, it can be directly connected to another element or there can be a middle element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are for illustrative purposes only and are not the only embodiment.

[0047] Referring to Figure 1 and Figure 2 , the present application provides an optical inkjet printing device 100. The optical inkjet printing device 100 is applied to the field of inkjet printing to make ink 300 form microdroplets for ejection, realizing inkjet printing. Figure 1 The structure diagram of the optical inkjet printing device 100 of an embodiment of the present application is shown in the figure, Figure 2 The structure diagram of the optical inkjet printing device 100 of another embodiment of the present application is shown in the figure. In the present embodiment, the optical inkjet printing device 100 prints the ink 300 in the pixel hole of the display panel 200, thereby forming a display screen. Of course, in other embodiments of the present application, the optical inkjet printing device 100 can also print the ink 300 on other carriers to form corresponding patterns on the carriers. The optical inkjet printing device 100 of the present application is only taken as an example of ejecting the ink 300 on the display panel 200 for description.

[0048] It can be understood that, at present, when inkjet is carried out by piezoelectric ceramic excitation method, the piezoelectric material is excited to vibrate by contact electric excitation to extrude the vibration diaphragm of the ink chamber, which has the problems of low excitation frequency, low processing efficiency and production capacity of the display screen, great difficulty in manufacturing the print head, material fatigue damage caused by the contact resonance of the piezoelectric ceramic material layer and the vibration plate material layer, and the like, which affect the use performance.

[0049] Therefore, the present application provides a novel optical inkjet printing device 100, which extrudes the ink 300 to form microdroplets for jetting in a non-contact manner, without extruding in a contact manner, which can effectively solve the problems of material fatigue damage caused by the contact resonance of the piezoelectric ceramic material layer and the vibration plate material layer, avoid damage to the vibration plate 142, reduce the manufacturing difficulty of the optical inkjet printing device 100, and ensure the use performance. Moreover, the optical inkjet printing device 100 can also output modulated laser, which can adjust the excitation frequency of the modulated laser, improve the processing efficiency and production capacity of the display screen. The specific structure of an embodiment of the optical inkjet printing device 100 is introduced below.

[0050] Referring to Figure 1 and Figure 2 In an embodiment, the optical inkjet printing device 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 modulated laser. The optical system 120 is located at the output end of the modulated laser 110 along the light path propagation direction, and is used to split the modulated laser into parallel laser beams. The microlens array 130 is arranged at the output end of the optical system 120 along the light path propagation direction. The inkjet assembly 140 includes a plurality of vibration plates 142 and a plurality of ink chambers 141, each vibration plate 142 is arranged on the surface of the ink chamber 141 corresponding to the microlens array 130, and the ink chamber 141 contains ink 300. After the modulated laser is split into parallel laser beams by the optical system 120, it is focused and shaped by the microlens array 130 and then enters the inkjet 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 microdroplets for jetting.

[0051] The laser 110 is a laser source of the optical inkjet printing device 100. The laser 110 emits modulated laser light, so that the modulated laser light passes through the optical system 120 and the microlens array 130 and then enters the inkjet assembly to excite the inkjet assembly 140, so that the inkjet assembly 140 extrudes the ink 300 to form and eject microdroplets. Moreover, the laser light output by the laser 110 is modulated laser light, and the parameters of the modulated laser light can be adjusted by the laser 110. In this way, the optical and thermal energy for exciting the inkjet assembly 140 can be adjusted, so that the inkjet assembly 140 extrudes ink 300 of different volumes, thereby printing microdroplets of different volumes to meet different printing requirements.

[0052] The laser 110, the optical system 120, the microlens array 130, the inkjet assembly 140, and the display panel 200 are arranged in sequence along the direction of the light path. It can be understood that the light path herein can be one light path or two light paths. When the light path is two, the first light path and the second light path are perpendicular to each other, the laser 110 and the optical system 120 are arranged in the first light path, and the microlens array 130, the inkjet assembly 140, and the display panel 200 are arranged in the second light path. A reflecting element is arranged between the first light path and the second light path to reflect the laser light, as shown in FIG. 2B. Figure 1 When the light path is one, the laser 110, the optical system 120, the microlens array 130, the inkjet assembly 140, and the display panel 200 are arranged in the same light path, as shown in FIG. 2A. Figure 2

[0053] It is worth noting that the number of light paths depends on the specific application scenario and the specific components of the optical inkjet printing device 100. For example, when the space used by the optical inkjet printing device 100 is limited, two light paths can be used, and the number of reflecting components can also be increased to use multiple light paths. When the space used by the optical inkjet printing device 100 is not limited, one light path can be used. For example, when the optical inkjet printing device 100 has reflecting components, two light paths can be used. The specific number of light paths will be mentioned later. Moreover, the input and output directions mentioned in the present application refer to the transmission direction of the laser light. The direction in which the laser light enters a component is the input direction, and the direction in which the laser light exits a component is the output direction.

[0054] The optical system 120 is arranged at the output end of the laser 110 along the direction of the light path, and the modulated laser light output by the laser 110 enters the optical system 120. The optical system 120 can expand and split the modulated laser light, so that the modulated laser light is divided into multiple parallel laser beams. The multiple parallel laser beams excite the inkjet assembly 140 respectively, so that the inkjet assembly 140 extrudes and ejects the ink 300 to form corresponding patterns on the display panel 200.​

[0055] The microlens array 130 is located at the output end of the optical system 120 along the light path propagation direction, that is, the optical system 120 is located between the laser 110 and the microlens array 130 along the light path propagation direction. The multiple parallel laser beams emitted by the optical system 120 can enter the microlens array 130. The inkjet assembly 140 is arranged at the output end of the microlens array 130 along the light path propagation direction, that is, the microlens array 130 is located between the optical system 120 and the inkjet assembly 140 along the light path propagation direction. The laser beams emitted by the microlens array 130 can enter the inkjet assembly 140, and the inkjet assembly 140 is excited by the photothermal effect to squeeze the ink 300 to form and eject microdroplets.

[0056] It can be understood that after the optical system 120 expands and divides the light beams, the shape of the laser beams will appear irregular, and the energy will be relatively dispersed. If the laser beams are directly used to excite the inkjet assembly 140, the excitation effect of the inkjet assembly 140 will be affected, and the squeezing of the ink 300 cannot meet the expectation. Therefore, the microlens array 130 is added at the input end of the inkjet assembly 140. The microlens array 130 can constrain, focus and shape the multiple parallel laser beams respectively, so that the energy of the laser beams is concentrated. In this way, after the laser beams enter the inkjet assembly 140, the laser beams can accurately excite the inkjet assembly 140, and the inkjet effect of the inkjet assembly 140 is ensured.

[0057] Specifically, the inkjet assembly 140 includes multiple vibrating plates 142 and multiple ink chambers 141. The ink chamber 141 is hollow, the ink 300 is contained in the ink chamber 141, and the vibrating plate 142 is arranged at the end of the ink chamber 141 and faces the microlens array 130. The end of the ink chamber 141 away from the vibrating plate 142 has a liquid outlet, and the ink 300 is ejected in the form of microdroplets through the liquid outlet. The laser beams emitted by the microlens array 130 can be focused on the vibrating plate 142, and the vibrating plate 142 is excited by the photothermal effect, so that the vibrating plate 142 vibrates to produce a deformation displacement, and then the vibrating plate 142 can squeeze the ink 300 in the ink chamber 141 to form microdroplets and eject them into the pixel hole of the display panel 200, thereby forming a display screen.

[0058] The multiple parallel laser beams correspond to the multiple vibrating plates 142 respectively, so that different laser beams can excite corresponding vibrating plates 142, so that the corresponding ink chambers 141 can eject ink. Alternatively, the ink 300 contained in each ink chamber 141 is the same color and / or different color. Exemplarily, the ink 300 in each ink chamber 141 is partially the same color and partially different color to meet the actual ejection requirements.

[0059] The optical inkjet printing device 100 of the present application is used, the laser 110 emits modulated laser and enters the optical system 120, and after beam expansion and beam splitting by the optical system 120, a plurality of parallel laser beams are formed and enter the microlens array 130, and after the plurality of parallel laser beams are constrained, focused and shaped by the microlens array 130, they enter the inkjet assembly 140, and through the photothermal effect, the plurality of parallel laser beams can respectively excite the corresponding vibration plate 142 to vibrate and deform to generate displacement, extrude the ink 300 in the ink chamber 141 to form micro-droplet ejection to the pixel hole of the display panel 200, so that the display panel 200 forms a display screen.

[0060] The optical inkjet printing device 100 of the above embodiment excites the vibration plate 142 by laser beam, so that the vibration plate 142 extrudes the ink 300 in the ink chamber 141 to form micro-droplet ejection, which uses a non-contact method to control the vibration plate 142 to generate displacement for extrusion, without extrusion by contact, which can effectively solve the problem of material fatigue damage caused by contact resonance between the piezoelectric ceramic material layer and the vibration plate material layer, avoid damage to the vibration plate 142, and reduce the manufacturing difficulty of the optical inkjet printing device 100, ensure the use performance. Moreover, the laser 110 can output modulated laser, which can adjust the excitation frequency of the modulated laser, improve the processing efficiency and capacity of the display screen.

[0061] In an embodiment, one or more of the power, waveform, phase, polarization and other parameters of the modulated laser output by the laser 110 can be adjusted to adjust the frequency of the modulated laser output by the laser 110. After adjusting the parameters of the modulated laser, the purpose of adjusting the frequency of the modulated laser can be achieved, and the frequency of the modulated laser can reach several hundred kHz to MHz, greatly improving the inkjet printing frequency and display screen manufacturing efficiency. Alternatively, the laser 110 is electrically connected with the controller of the optical inkjet printing device 100, and the controller controls the laser 110 to modulate the corresponding parameters.

[0062] Alternatively, the laser 110 adjusts the power of the modulated laser by high and low levels. For example, for the laser 110 modulated by transistor-transistor logic integrated circuit (TTL) level, as shown in Figure 3 , the laser 110 is connected with the controller of the optical inkjet printing device 100, and the controller controls the laser 110 to modulate the corresponding parameters. Figure 3The waveform diagram of the power of the modulated laser is shown. When the input is low, the output power of the laser 110 is 0, and the laser 110 does not emit the modulated laser; when the input is high, the output power of the laser 110 is Pmax, and the laser 110 outputs the modulated laser at the maximum power. The frequency f of the level modulation controls the laser switch, and the period is T, which corresponds to the inkjet printing frequency f. The modulation frequency of the modulated laser can reach hundreds of kHz to MHz, greatly improving the inkjet printing frequency and the manufacturing efficiency of the display screen. For the continuously modulated laser 110, different laser powers can be output by different modulation voltages, and under the condition of meeting the minimum laser energy, micro-ink droplets of different volumes can be printed. Of course, in other embodiments of the present application, other types of lasers 110 can also be used as long as they can output modulated lasers.

[0063] As shown in Figure 4 , in an embodiment, the optical system 120 includes a beam expander lens 121 and a beam splitter lens 122, which are arranged in sequence along the propagation direction of the light path between the laser 110 and the microlens array 130; the beam expander lens 121 is used to expand the beam diameter of the modulated laser, and the beam splitter lens 122 is used to split the expanded modulated laser into parallel laser beams. Figure 4 As shown in Figure 1 , a schematic diagram of the optical system 120 in the optical inkjet printing device 100 is shown.

[0064] The beam expander lens 121 and the beam splitter lens 122 are arranged in sequence along the propagation direction of the light path, and the modulated laser emitted by the laser 110 first enters the beam expander lens 121 for beam expansion and then enters the beam splitter lens 122 for beam splitting. The beam expander lens 121 in the optical system 120 is mainly used to expand the modulated laser emitted by the laser 110 to expand the original laser spot diameter. The expanded modulated laser enters the beam splitter lens 122, which splits the expanded modulated laser into multiple parallel laser beams.

[0065] The optical system 120 can split the modulated laser into multiple parallel laser beams, and the multiple parallel laser beams can enter the inkjet assembly 140 after passing through the microlens array 130. Each laser beam can correspond to a vibrating plate 142, realize the excitation of the corresponding vibrating plate 142, and the vibration of the vibrating plate 142 can squeeze the ink chamber 141 to jet micro-liquid droplets. That is, the optical system 120 can form multiple optical excitation sources from the modulated laser beams to excite the corresponding vibrating plates 142 respectively, so that the corresponding ink chambers 141 jet micro-liquid droplets.

[0066] As shown in Figure 1 , Figure 2 , and Figure 5In an embodiment, the microlens array 130 includes a lens body 131 and a plurality of focusing lenses 132 disposed on a surface of the lens body 131 facing the inkjet assembly 140, each focusing lens 132 being configured to focus and shape a laser beam. Figure 5 For Figure 1 A schematic view of the cooperation between the mask 160 and the microlens array 130 in the optical inkjet printing device 100 is shown.

[0067] The lens body 131 is a mounting main plate of the microlens array 130, and the plurality of 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 to form an integrated structure, which is convenient for installation and use. After the plurality of parallel laser beams emitted from the beam splitter lens 122 enter the microlens array 130, the plurality of parallel laser beams will enter the focusing lenses 132 through the lens body 131, and each focusing lens 132 can constrain, focus and shape a laser beam, so that the laser beam forms a corresponding shape.

[0068] After the laser beams are split by the beam splitter lens 122, the laser beams present a shape similar to a cylinder, and the energy of the laser beams is relatively dispersed. After the laser beams pass through the lens body 131 and enter the focusing lenses 132, the focusing lenses 132 can constrain, shape and focus the laser beams, so that the laser beams are emitted in a conical shape, as shown in Figure 1 、 Figure 2 and Figure 5 , and then enter the vibration plate 142. In this way, the energy of the laser beams is concentrated, and the vibration plate 142 can be accurately excited, so that the vibration plate 142 vibrates and deforms to generate displacement to extrude the ink 300 in the ink chamber 141 to form micro-droplets to be sprayed into the pixel hole of the display panel 200.

[0069] Referring to Figure 1 、 Figure 2 and Figure 5 , in an embodiment, each vibration plate 142 is disposed in correspondence with one focusing lens 132. That is, in the direction of the light path propagation, one focusing lens 132 is disposed in correspondence with one vibration plate 142, and then the ink chamber 141 is disposed in correspondence with the vibration plate 142. In this way, the focusing lens 132 emits the focused and shaped laser beam into the vibration plate 142 to excite the corresponding vibration plate 142, and then the vibration plate 142 can extrude the ink chamber 141 when vibrating, so that the ink chamber 141 sprays micro-droplets.

[0070] Referring to Figure 1 and Figure 2In an embodiment, the inkjet assembly 140 comprises a nozzle housing 143, a plurality of ink chambers 141 are arranged in at least one row in the nozzle housing 143, the nozzle housing 143 has a nozzle, and the outlet of the ink chamber 141 is arranged in the nozzle. The nozzle housing 143 has a plurality of mounting positions towards the surface of the microlens array 130, each mounting position is mounted with a vibration plate 142, and each mounting position corresponds to an ink chamber 141. The vibration plate 142 is mounted in the mounting position, and the vibration plate 142 abuts the end of the ink chamber 141.

[0071] The nozzle housing 143 is a shell of the inkjet assembly 140, and the plurality of ink chambers 141 are arranged in the nozzle housing 143 in a spaced manner. By integrating the plurality of ink chambers 141 in the nozzle housing 143, the plurality of ink chambers 141 form an integral structure, which is convenient for assembly and use. Optionally, the nozzle housing 143 and the ink chamber 141 are an integral structure. That is, a plurality of chambers are arranged in the nozzle housing 143, and the chambers are used to contain the ink 300, which is equivalent to the ink chamber 141. Of course, in other embodiments of the present application, the nozzle housing 143 and the ink chamber 141 can be arranged separately, and the ink chamber 141 is fixedly arranged in the nozzle housing 143.

[0072] Moreover, the nozzle housing 143 has a plurality of mounting positions towards one end of the microlens array 130, each mounting position is opposite to the ink chamber 141, the vibration plate 142 is mounted in the mounting position, and the vibration plate 142 abuts the ink chamber 141. In this way, after the vibration plate 142 is excited, the vibration generated by the vibration plate 142 can press the ink 300 in the ink chamber 141 to eject the microdroplet. It is worth noting that the vibration plate 142 is integrally processed in the mounting position of the nozzle housing 143 by a micro-processing process, and the vibration plate 142 is below the ink chamber 141.

[0073] The nozzle housing 143 has a nozzle away from the microlens array 130, and the outlet of the ink chamber 141 is located in the nozzle and communicates with the nozzle after the ink chamber 141 is mounted to the nozzle housing 143. In this way, after the vibration plate 142 is excited, the vibration generated by the vibration plate 142 can press the ink 300 in the ink chamber 141, the ink 300 enters the nozzle through the outlet, and the ink 300 is formed into a microdroplet by the nozzle to be ejected.

[0074] Optionally, the thickness of the vibration plate 142 is 1 μm-3 μm. Optionally, the plurality of ink chambers 141 are arranged in a row. Of course, in other embodiments of the present application, the plurality of ink chambers 141 are arranged in rows and columns. That is, the ink chambers 141 are distributed in an array.

[0075] Referring to Figure 1 , Figure 2 , Figure 6 and Figure 7In an embodiment, the optical inkjet printing device 100 further comprises a spatial light modulator disposed at an output end of the optical system 120 along the light path propagation direction, for modulating the deflection angle of the laser beam so that the laser beam is deflected or projected to the microlens array 130. Figure 6 As shown in the optical inkjet printing device 100 in which the digital micromirror device 150 deflects the laser beam, Figure 1 As shown in the optical inkjet printing device 100 in which the digital micromirror device 150 deflects the laser beam, Figure 7 As shown in the optical inkjet printing device 100 in which the digital micromirror device 150 deflects the laser beam, Figure 1 As shown in the optical inkjet printing device 100 in which the digital micromirror device 150 deflects the laser beam.

[0076] The spatial light modulator is disposed between the optical system 120 and the microlens array 130, and is capable of modulating the deflection angle of the multiple parallel laser beams so that the laser beams are deflected or projected to the microlens array 130, thereby controlling the laser intensity, phase, polarization and other parameters of the laser beams. After the spatial light modulator modulates the laser beams, the laser beams can be injected into the microlens array 130, or the laser beams are reflected to other positions and cannot enter the microlens array 130. When the laser beams enter the microlens array 130, the corresponding vibration plate 142 can be excited, and when the laser beams do not enter the microlens array 130, the vibration plate 142 at the corresponding position cannot be excited. In this way, the corresponding ink chambers 141 can be controlled to eject ink according to the pattern on the display panel 200, for example, some ink chambers 141 eject ink, some ink chambers 141 eject ink and some ink chambers 141 do not eject ink.

[0077] Optionally, the spatial light modulator is electrically connected to the controller of the optical inkjet printing device 100, and the controller controls the spatial light modulator to deflect the laser beams. In this way, the controller can control whether the laser beams pass through the microlens array 130 according to the pattern formed on the display panel 200.

[0078] It is worth noting that the type of spatial light modulator is not limited in principle as long as it can modulate the laser beams. Optionally, the spatial light modulator is a reflective modulator or a transmissive modulator, Figure 1 As shown in the spatial light modulator is a reflective modulator, Figure 2 As shown in the spatial light modulator is a transmissive modulator. Of course, in other embodiments of the present application, the spatial light modulator can also be other types of light modulators such as electro-optical, acousto-optical, magneto-optical materials and devices, etc.

[0079] Referring to Figure 1 , Figure 5 to Figure 7In an embodiment of the present application, the spatial light modulator is a reflective modulator, the optical system 120 is disposed in a first optical path, the microlens array 130 and the inkjet assembly 140 are disposed in a second optical path, the first optical path and the second optical path are perpendicular, 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, the digital micromirror device 150 is disposed at the intersection of the first optical path and the second optical path, and the mask 160 is disposed in the second optical path and located at the output end of the digital micromirror device 150.

[0080] 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, i.e., 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, and the reflective modulator is disposed at the intersection of the first optical path and the second optical path. The reflective modulator reflects the multiple parallel laser beams split by the optical system 120 into the microlens array 130.

[0081] Specifically, the reflective modulator includes the digital micromirror device 150 and the 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 to deflect the laser beams, and the mask 160 is disposed at the output end of the digital micromirror device 150 and located at the input end of the microlens array 130. The laser beams can selectively pass through the mask 160. After the digital micromirror device 150 deflects the laser beams in the direction along the second optical path, the laser beams can pass through the mask 160 and enter the microlens array 130, as shown in Figure 1 、 Figure 2 and Figure 6 After the digital micromirror device 150 deflects the laser beams in the direction oblique to the second optical path, the laser beams are obliquely projected onto the mask 160, and then the mask 160 reflects the laser beams in the direction of the optical system 120. The laser beams cannot enter the microlens array 130, as shown in Figure 1 、 Figure 2 and Figure 7 .

[0082] The digital micromirror device 150 is a micro-electro-mechanical system with electronic input and optical output, which is composed of high-speed digital micro-mirror units 151. The imaging pattern and its characteristics are determined by controlling the rotation of the micro-mirror units 151 around the fixed yoke and the time-domain response (determining the reflection angle and dwell time of the light). The deflection of the micro-mirror units 151 in the digital micromirror device 150 can be controlled by logic signals in the controller. As shown in Figure 6 The laser beams reflected by the micro-mirror directly reflect the vibration of the vibrating plate 142 through the mask 160, as shown in Figure 7As shown, due to the deflection of the micro-mirror unit 151, the laser beam is reflected and deflected by the mask 160, and the vibrating plate 142 cannot be excited. It should be noted that the digital micro-mirror device 150 is a prior art structure, and its principle will not be described here.

[0083] Optionally, the digital micro-mirror device 150 has a plurality of micro-mirror units 151, which are rotatably arranged and electrically connected to the controller. The controller can control the deflection of each micro-mirror unit 151, so that the modulation unit has different orientations. As shown in Figure 1 、 Figure 2 and Figure 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 to the direction of the second light path, so that the laser beam can pass through the mask 160 and enter the microlens array 130. As shown in Figure 1 、 Figure 2 and Figure 7 When the controller controls the micro-mirror unit 151 to be deflected and form an angle with the surface of the digital micro-mirror device 150, the micro-mirror unit 151 reflects the laser beam to be inclined relative to the second light path. At this time, the laser beam is reflected by the mask 160 and cannot enter the microlens array 130 after being reflected by the mask 160.

[0084] Referring to Figure 1 、 Figure 2 and Figure 5 In an embodiment, the mask 160 has a plurality of mask holes 161, which pass through the mask 160 along the second light path. The mask hole 161 allows a laser beam to pass through, and each mask hole 161 corresponds to one ink chamber 141. The digital micro-mirror device 150 reflects the laser beam in the vertical direction, and the laser beam can be aligned with the mask hole 161 and pass through the mask hole 161 to enter the microlens array 130.

[0085] Moreover, there is a spacing between adjacent mask holes 161. When the digital micro-mirror device 150 reflects the laser beam to a position between two mask holes 161, the laser beam is reflected by the mask 160 and cannot pass through the mask hole 161. That is, only when the laser beam enters the mask hole 161, the laser beam can pass through the mask hole 161 and enter the microlens array 130. When the laser beam enters the surface of the mask 160 between the adjacent mask holes 161, the laser beam cannot pass through. The specific manufacturing of the mask 160 can adopt the prior art.

[0086] It is worth mentioning that each mask hole 161 is arranged one-to-one corresponding to each focusing lens 132 of the microlens array 130, so that the laser beam passing through the mask hole 161 can be injected into the focusing lens 132 and be constrained, shaped and focused by the focusing lens 132. Moreover, the distance between adjacent mask holes 161 corresponds to the position of the micro-mirror unit 151 of the digital micro-mirror device 150, so as to ensure that the laser beam reflected by the micro-mirror unit 151 can be injected into the mask hole 161 or be reflected by the mask plate 160.

[0087] As shown in Figure 1 , when the optical inkjet printing device 100 works, the laser 110 emits modulatable laser and injects into the optical system 120, and the optical system 120 performs beam expansion and beam splitting processing to output multiple parallel laser beams. The multiple parallel laser beams are injected into the digital micro-mirror device 150, and the controller controls part of the micro-mirror units 151 in the digital micro-mirror device 150 to deflect or not to deflect. For the vibration plate 142 that needs to be excited, the micro-mirror units 151 in the digital micro-mirror device 150 do not deflect, and the micro-mirror units 151 reflect the laser beams to be focused on the vibration plate 142 through the mask plate 160 and the microlens array 130, so as to excite the vibration plate 142 to vibrate and deform, thereby extruding the ink chamber 141 to spray micro-droplets to the display panel 200 to form a display screen. For the vibration plate 142 that does not need to be excited, the micro-mirror units 151 in the digital micro-mirror device 150 deflect, and the micro-mirror units 151 reflect the laser beams back through the mask plate 160.

[0088] Referring to Figure 2 , in another embodiment of the present application, the spatial light modulator is a transmissive modulator 170 arranged between the optical system 120 and the microlens array 130. The multiple parallel laser beams emitted by the optical system 120 pass through the transmissive modulator 170 and are selectively passed by the transmissive modulator 170. In this way, the laser beams that can pass through the transmissive modulator 170 can be injected into the microlens array 130, and the laser beams that cannot pass through the transmissive modulator 170 are reflected away and cannot be injected into the microlens array 130.

[0089] As shown in Figure 6As shown, the exemplary transmissive modulator 170 is a transmissive liquid crystal spatial light modulator (LC-SLM), which is based on optical phased array technology and uses the electro-optic effect of liquid crystals to achieve intensity, phase and polarization state transformation of light waves. According to the pattern of the required printing ink drop position, the refractive index of the liquid crystal layer is controlled by applying an electric field to the liquid crystal cells 171 in different regions. When the laser beam passes through the liquid crystal cells 171 modulated by different electric fields, different phase depth topographies are generated, realizing different angle beam deflection. For positions that do not need to be printed, the liquid crystal cells 171 are not deflected, and at this time the liquid crystal cells 171 are arranged parallel to the surface of the transmissive modulator 170, blocking the laser beam from passing through; for positions that need to be printed, an electric field is applied to deflect the liquid crystal cells 171, and at this time the liquid crystal cells 171 produce a certain angle of deflection relative to the surface of the transmissive modulator 170, when the deflection angle is 90 degrees, the laser beam passes through completely, and when it is other deflection angles, the laser beam passes through partially, thereby controlling the laser intensity, phase and polarization and other parameters.

[0090] It is worth noting that the transmissive modulator 170 described above is prior art and will not be described again here. Of course, in other embodiments of the present application, if the installation space of the optical inkjet printing device 100 is limited, the optical inkjet printing device 100 can also include a mirror, the optical system 120 and the transmissive modulator 170 are arranged in a first light path, the microlens array 130 and the inkjet assembly 140 are arranged in a second light path, the first light path and the second light path are perpendicular, and the mirror is arranged at the intersection of the first light path and the second light path.

[0091] Referring to Figure 1 and Figure 2 , the optical inkjet printing device 100 of the present application excites the vibration plate 142 by a light excitation method, which has a wide adjustable range of light excitation frequency, high excitation frequency and concentrated energy distribution. The modulatable laser is split by the optical system 120 to form multiple parallel lasers, which are then processed by the spatial light modulator, constrained and focused by the microlens array 130, and then the photothermal effect is applied to the vibration plate 142 to excite the vibration plate 142 to vibrate, while the microdroplet ejection in the multiple ink chambers 141 is controlled. Moreover, since the vibration plate 142 is excited by the photothermal effect, which is a non-contact method, it can solve the problem of material fatigue damage caused by the contact resonance between the piezoelectric ceramic material layer and the vibration plate material layer, and improve the processing efficiency and productivity of the display screen.

[0092] Referring to Figure 1 and Figure 2 , the present application also provides a jetting method of an optical inkjet printing device 100, which is applied to the optical inkjet printing device 100 of any of the above embodiments, and the jetting method comprises the following steps:

[0093] controlling the laser 110 to emit modulatable laser;

[0094] The modulated laser is incident into the optical system 120 and is split into parallel laser beams;

[0095] The parallel laser beams are incident into the microlens array 130 and are focused and shaped by the microlens array 130;

[0096] The laser beams passing through the microlens array 130 are incident into the inkjet assembly 140 to excite the vibration plate 142 of the inkjet assembly 140 to deform and displace the vibration plate 142 to squeeze the ink 300 in the ink chamber 141 to form micro-droplets to be ejected to the substrate.

[0097] When the optical inkjet printing device 100 is in use, the laser 110 emits modulated laser and is incident into the optical system 120. After being expanded and split by the optical system 120, a plurality of parallel laser beams are formed and are incident into the microlens array 130. After being constrained, focused and shaped by the microlens array 130, the plurality of parallel laser beams are incident into the inkjet assembly 140. Through the photo-thermal effect, the plurality of parallel laser beams can respectively excite the corresponding vibration plate 142 to vibrate and deform to displace, squeeze the ink 300 in the ink chamber 141 to form micro-droplets to be ejected to the pixel hole of the display panel 200, so that the display panel 200 forms a display screen.

[0098] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0099] The above-described embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. An optical inkjet printing apparatus characterized by comprising: The application relates to an optical inkjet printing device. The device comprises a laser for outputting modulated laser light, an optical system for splitting the modulated laser light into parallel laser beams, a microlens array, and an inkjet assembly. The inkjet assembly comprises a plurality of vibrating plates, a plurality of ink chambers, and a nozzle housing. Each vibrating plate is arranged on the surface of a corresponding ink chamber of the microlens array. The ink chambers contain ink, and a plurality of ink chambers are arranged in at least one row in the nozzle housing. The nozzle housing has a plurality of mounting positions on the surface facing the microlens array. Each mounting position is provided with a vibrating plate and a corresponding ink chamber.

2. The optical inkjet printing device of claim 1, wherein, The vibrating plate is attached to the end of the ink chamber. The modulated laser light is split into parallel laser beams by the optical system, focused and shaped by the microlens array, and then injected into the inkjet assembly.

3. The optical inkjet printing device of claim 1, wherein, Through the photo-thermal effect, a plurality of parallel laser beams can respectively excite corresponding vibrating plates to vibrate and deform to generate displacement.

4. The optical inkjet printing device of claim 3, wherein The vibrating plates press the ink in the ink chambers to form micro-droplets, which are sprayed into the pixel holes of a display panel to form a display screen.

5. The optical inkjet printing device according to any one of claims 1 to 4, characterized in that The optical system comprises an expander lens and a beam splitter lens.

6. The optical inkjet printing device of claim 5, wherein, The expander lens is used to expand the beam diameter of the modulated laser light. The beam splitter lens is used to split the expanded modulated laser light into parallel laser beams.

7. The optical inkjet printing device of claim 6, wherein, The microlens array comprises a lens body and a plurality of focusing lenses.

8. The optical inkjet printing device of claim 5, wherein, Each focusing lens is arranged on the surface of the lens body facing the inkjet assembly. Each vibrating plate is arranged corresponding to a focusing lens. The optical inkjet printing device further comprises a spatial light modulator. The spatial light modulator is arranged on the output end of the optical system along the light propagation direction. The spatial light modulator is used to modulate the deflection angle of the laser beams. The laser beams are deflected or projected to the microlens array. The spatial light modulator is a reflective modulator. The optical system is arranged in a first light path. The microlens array and the inkjet assembly are arranged in a second light path. The first light path and the second light path are perpendicular. The reflective modulator is arranged at the intersection of the first light path and the second light path. The reflective modulator comprises a digital micromirror device and a mask. The digital micromirror device is arranged at the intersection of the first light path and the second light path. The mask is arranged in the second light path and located at the output end of the digital micromirror device. The mask has a plurality of mask holes. Each mask hole corresponds to an ink chamber. The spatial light modulator is a transmissive modulator. The transmissive modulator is arranged between the optical system and the microlens array, or the optical inkjet printing device further comprises a mirror, the optical system and the transmissive modulator are arranged in a first light path, the microlens array and the inkjet assembly are arranged in a second light path, the first light path is perpendicular to the second light path, and the mirror is arranged at the intersection of the first light path and the second light path.

9. A method of ejection of an optical inkjet printing device, characterized by, The jetting method is applied to the optical inkjet printing device according to any one of claims 1 to 5, and the jetting method comprises the following steps: controlling a laser to emit modulatable laser; the modulatable laser is incident into an optical system and is split into parallel laser beams; the parallel laser beams are incident into a microlens array and are focused and shaped by the microlens array; the laser beams passing through the microlens array are incident into the inkjet assembly to excite a vibrating plate of the inkjet assembly, so that the vibrating plate is deformed to generate displacement, so as to squeeze ink in an ink chamber to form micro-droplet ejection to a substrate.

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