Optical system for measuring ink droplets

Abstract

An optical system for measuring ink droplets is disclosed. The optical system for measuring ink droplets disclosed in the present invention comprises: a chamber; an optical measuring unit, which is arranged outside the chamber and irradiates light toward a substrate to measure the state of the ink droplets; an optical unit, which is arranged inside the chamber and located on the light path; and a protection module, which comprises a moving unit and a roller unit, wherein the moving unit is arranged around the optical unit and performs lifting and lowering motion, and the roller unit supplies a film between the optical unit and the substrate.

Description

Technical Field

[0001] The present disclosure relates to optical systems for measuring ink droplets. Background Art

[0002] In order to provide an image, the display device may have various functional layers. Methods for forming the functional layer may include a printing process, an evaporation process, a laser-induced thermal imaging (LITI) process, etc. For example, the light-emitting layer may be formed by a nozzle printing method. An inkjet head is a device that can form an image by ejecting ink droplets at desired positions on a printing medium through a plurality of nozzles.

[0003] Recently, the application range of inkjet heads is widely expanding to display devices such as liquid crystal display devices and organic light emitting display devices. Summary of the invention

[0004] The ink droplets ejected onto the substrate undergo a drying process. After the drying process, an ink layer of a desired size can be formed on the substrate. However, a measuring system for measuring the state of the ink is required in the ink drying device.

[0005] An embodiment of the present disclosure is to provide an optical system for measuring ink droplets that can easily measure the state of ink droplets ejected onto a substrate.

[0006] According to one aspect of the present disclosure, an optical system for measuring ink droplets includes: a chamber, on which a substrate from which ink droplets are ejected is installed; an optical measuring unit, which is arranged outside the chamber and irradiates light toward the substrate to measure the state of the ink droplets; an optical unit, which is arranged inside the chamber and located on the light path; and a protection module, which has a moving unit and a roller unit, wherein the moving unit is configured around the optical unit and performs a lifting motion, and the roller unit supplies a film between the optical unit and the substrate.

[0007] In one embodiment, the chamber may be provided with a transparent window so that light irradiated from the optical measurement unit provided outside the chamber can travel along an optical path toward the optical unit provided inside the chamber.

[0008] In one embodiment, the optical measurement unit, the transparent window, and the optical unit may be arranged in a vertical direction.

[0009] In one embodiment, the moving part may surround the optical part, and perform a lifting motion with the help of a driving part to selectively contact the upper surface of the film.

[0010] In one embodiment, an attachment portion may be further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the membrane are in close contact with each other, and the attachment portion includes a plurality of wirings, and the plurality of wirings are provided in the moving portion and are powered so that the membrane is pulled relative to the moving portion by electrostatic force.

[0011] In one embodiment, an attachment portion may be further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the film are in close contact with each other, and the attachment portion includes an adhesive portion, which is arranged on the bottom surface of the moving portion and adheres the film relative to the moving portion.

[0012] In one embodiment, an attachment portion may be further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the membrane are in close contact with each other, and the attachment portion includes an O-ring, which is arranged on the bottom surface of the moving portion and pressurizes the top surface of the membrane.

[0013] In one embodiment, a protective portion surrounding the optical portion may be further disposed around the optical portion, and a lower end of the protective portion is coupled to the moving portion to seal a space where the optical portion is disposed.

[0014] In one embodiment, the roller portion may include: a first roller disposed on a first side of the optical portion; and a second roller disposed on a second side of the optical portion, and the film is interposed between the first roller and the second roller and moves toward the bottom of the optical portion.

[0015] In one embodiment, at least one of the optical measurement unit and the optical unit may be provided over the entire area on the substrate.

[0016] (Effect of Publicity)

[0017] The optical system for measuring ink droplets according to one aspect of the present disclosure can easily measure the shape, volume, crystallization, etc. of ink during the drying process of ink by position on a substrate. Therefore, the drying quality of ink can be improved by position on the substrate.

[0018] Furthermore, since the measurement can be performed during or before or after the ink is dried, there is no need to spend extra time on the measurement, thereby improving productivity.

[0019] Of course, the effects of the present disclosure can be derived from the contents described below with reference to the drawings in addition to the above-mentioned contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 1 is a diagram showing the structure of a chamber to which an optical system for measuring ink droplets according to an embodiment of the present disclosure is applied.

[0021] Figure 2 It is extraction Figure 1 An exploded perspective view showing the main parts of the optical system.

[0022] Figure 3a is a schematic diagram showing the settings Figure 1 A cross-sectional view of the electrostatic chuck in the moving portion.

[0023] Figure 3b is a schematic diagram showing the settings Figure 1 A cross-sectional view of the adhesive suction cup in the moving part.

[0024] Figure 3c is a schematic diagram showing the settings Figure 1 Top view of the O-ring in the moving part.

[0025] Figure 4 1 is a sequence diagram showing a method for measuring ink droplets using an optical system according to an embodiment of the present disclosure.

[0026] Figure 5a and Figure 5b It shows the use of Figure 1 A structural diagram showing a state in which the shape of an ink droplet is measured by an optical measuring unit.

[0027] Figure 5c It shows the use of Figure 1 A structural diagram showing a state in which the volume of an ink droplet is measured by an optical measuring unit.

[0028] Figure 5d It shows the use of Figure 1 A graph showing the curing degree of ink droplets measured by an optical measuring unit.

[0029] Figure 6 FIG. 1 is a diagram showing the configuration of a chamber to which an optical system for measuring ink droplets according to another embodiment of the present disclosure is applied.

[0030] Figure 7 This is a cross-sectional view showing one sub-pixel of a display device including a light-emitting layer from which ink droplets are ejected according to the present disclosure.

[0031] (Explanation of Reference Numerals)

[0032] 110: Chamber 120: Substrate

[0033] 140: ink droplets 200: optical system

[0034] 210: Optical measurement unit 220: Optical unit

[0035] 230: Window 240: Protection module

[0036] 250: Moving part 260: Roller part

[0037] 261: First roller 262: Second roller

[0038] 270: Film 310, 320, 330: Adhesion part

[0039] 312: Wiring 322: Adhesive part

[0040] 332: O-ring DETAILED DESCRIPTION

[0041] The present disclosure may be subjected to various modifications and may have various embodiments. Specific embodiments are illustrated in the accompanying drawings and described in detail in the detailed description. The effects, features and methods of achieving the ... Figure 1 This will become clear from the following detailed embodiments. However, the present disclosure is not limited to the embodiments disclosed below, and can be implemented in various forms.

[0042] In the following embodiments, when various constituent elements such as layers, films, regions, and plates are referred to as being "on" another constituent element, it includes not only the case where it is "directly" "on" another constituent element, but also the case where other constituent elements are interposed therebetween. In addition, for the convenience of explanation, the size of the constituent elements may be enlarged or reduced in the drawings. For example, the size and thickness of each constituent shown in the drawings are arbitrarily shown for the convenience of explanation, and therefore the present disclosure is not necessarily limited to the drawings.

[0043] In the following embodiments, the x-axis, y-axis and z-axis are not limited to the three axes on the rectangular coordinate system, but can be interpreted as including a broad meaning thereof. For example, the x-axis, y-axis and z-axis can be orthogonal to each other, but can also refer to different directions that are not orthogonal to each other.

[0044] In the following embodiments, the terms "first" and "second" are used for the purpose of distinguishing one constituent element from another constituent element and are not intended to be limiting.

[0045] In the following embodiments, a singular expression includes a plural expression unless it is clearly indicated as having a different meaning in the context.

[0046] In the following embodiments, the terms including or having refer to the existence of features or constituent elements recorded in the specification, and do not preclude the possibility of the addition of one or more other features or constituent elements.

[0047] In the following embodiments, when a certain embodiment can be implemented differently, a specific process sequence can also be performed differently from the described sequence. For example, two processes described successively can be performed substantially simultaneously or in a sequence opposite to the described sequence.

[0048] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing with reference to the drawings, the same or corresponding components will be given the same reference numerals, and repeated description thereof will be omitted.

[0049] In the following embodiments, when a film, region, component, etc. is referred to as being connected, it includes not only the case where the film, region, component, etc. is directly connected, but also the case where the film, region, component, etc. is indirectly connected with other films, regions, components, etc. in the middle. For example, when a film, region, component, etc. is referred to as being connected or electrically connected in this specification, it includes not only the case where the film, region, component, etc. is directly connected or electrically connected, but also the case where the film, region, component, etc. is indirectly connected or electrically connected with other films, regions, components, etc. in the middle.

[0050] Figure 1 1 is a diagram showing the structure of a chamber 110 to which an optical system 200 for measuring ink droplets 140 according to an embodiment of the present disclosure is applied. Figure 2 It is extraction Figure 1 An exploded perspective view showing the main parts of the optical system 200.

[0051] Reference Figure 1 and Figure 2 , the substrate 120 may be located in the chamber 110. The substrate 120 may be mounted on a substrate stage 130. The substrate 120 may move along a conveyor belt. In another embodiment, the substrate 120 may move with the aid of a robot mechanism. Ink droplets 140 may be formed on the substrate 120. The ink droplets 140 may be ejected from an inkjet head and formed in a desired area of ​​the substrate 120, such as a pixel area. For example, the ink droplets 140 may be a substance for forming a light-emitting layer of an organic light-emitting display device, or a substance for forming an organic layer of a color filter.

[0052] The ink droplets 140 ejected by the ink ejection process undergo a drying process. Here, the drying process may also include a hardening process. The drying of the ink droplets 140 may mean that the solvent contained in the ink evaporates. The chamber 110 may be a drying chamber. Although not shown in the figure, a device capable of drying the ink droplets 140 ejected on the substrate 120 may be provided in the chamber 110. When drying the ink droplets 140, it is necessary to measure the state of the ink droplets 140, such as the shape, volume, degree of hardening, crystallization, etc. of the ink droplets 140. How the state of the ink droplets 140 differs according to the position on the substrate 120 is measured and reflected when the droplets are ejected later.

[0053] An optical system 200 for measuring the state of the ink droplet 140 may be provided in the chamber 110. The optical system 200 includes an optical measuring unit 210 provided outside the chamber 110 and an optical unit 220 provided inside the chamber 110.

[0054] The optical measuring unit 210 can irradiate light toward the substrate 120 to measure the state of the ink droplet 140. In order to measure the state of the ink droplet 140, the optical measuring unit 210 can include various measuring devices. For example, the optical measuring unit 210 can include a confocal microscope, a chromatic confocal microscope, a CCD camera (charge-coupled device camera), a spectroscope, etc. The optical measuring unit 210 can select and use various optical devices according to the purpose of use. The optical measuring unit 210 can be connected to the control unit 211 to analyze the measured state of the ink droplet 140.

[0055] In one embodiment, in order to irradiate light onto the substrate 120 , the optical measuring unit 210 may include a light source such as a laser.

[0056] In one embodiment, in order to accurately align, the optical measuring unit 210 may include a driving mechanism capable of micro-movement along the X-axis, the Y-axis, and the Z-axis.

[0057] The optical measuring unit 210 may be disposed outside the chamber 110 so as to be protected from heat or fume generated when the ink droplets 140 are dried by an ink drying device disposed in the chamber 110. The optical measuring unit 210 may be fixed outside the chamber 110.

[0058] The optical part 220 may be located on the path of the light irradiated from the optical measuring part 210. The optical part 220 may be composed of various lens groups 221 according to the type of the optical measuring part 210. The optical part 220 may be arranged inside the chamber 110. The optical part 220 is not limited to any structure as long as it can be fixed inside the chamber 110, or fixed to an additional fixing mechanism, or fixed to a transparent window 230 described later, etc., which is arranged inside the chamber 110. In one embodiment, a driving mechanism capable of moving in the X-axis, the Y-axis, and the Z-axis may be included inside the optical part 220.

[0059] A transparent window 230 may be provided in the chamber 110. The transparent window 230 provides a path for light irradiated from outside the chamber 110 to travel toward the optical unit 220 provided inside the chamber. Light required for measuring the ink droplet 140 may travel toward the inside of the chamber 110 through the transparent window 230. The transparent window 230 may be made of glass or quartz.

[0060] The optical measurement unit 210, the optical unit 220 and the transparent window 230 may be disposed in a vertical direction (Z direction) of the chamber 110. The optical measurement unit 210 and the optical unit 220 may align their optical axes using X-axis, Y-axis and Z-axis drive mechanisms disposed inside the respective devices.

[0061] The optical part 220 is disposed inside the chamber 110 , so a protective module 240 may be required to prevent the optical part 220 from being contaminated by smoke or the like that may be generated during the drying process of the ink droplets 140 . The protective module 240 includes a moving part 250 and a roller part 260 .

[0062] A movable portion 250 capable of lifting and lowering motion may be provided around the optical portion 220. The movable portion 250 may surround the optical portion 220. The movable portion 250 may be in the shape of a four-sided frame. The optical portion 220 may be located at an opening 251 formed in the center of the movable portion 250. The movable portion 250 is not limited to any shape as long as it is a structure capable of surrounding the optical portion 220. The movable portion 250 is not limited to any one of metal materials, ceramic materials, polymer materials, rubber materials, etc. The movable portion 250 may move in a vertical direction (Z direction). The movable portion 250 is connected to a driving portion 252 and may be lifted and lowered. The driving portion 252 may be an actuator or a driving motor. The movable portion 250 may surround the optical portion 220 when performing a lifting and lowering motion.

[0063] In one embodiment, a protective part 280 surrounding the optical part 220 may be further provided around the optical part 220. The protective part 280 may be disposed above the interior of the chamber 110. The protective part 280 may be cylindrical and may accommodate the optical part 220. The protective part 280 may be made of metal material, glass, or quartz. The lower end of the protective part 280 may be combined with the moving part 250 to seal the space where the optical part 220 is provided.

[0064] When the moving part 250 and the protection part 280 are combined, the moving part 250 that performs lifting motion can move in the vertical direction (Z direction) along the outer surface of the protection part 280. In one embodiment, the moving part 250 can replace the function of the protection part 280 in the absence of the protection part 280. As long as the moving part 250 performs lifting motion and can seal the space where the optical part 220 is provided, it is not limited to any one structure.

[0065] A roller portion 260 for supplying a film 270 may be provided between the optical portion 220 and the substrate 120. The roller portion 260 includes a first roller 261 disposed on a first side of the optical portion 220 and a second roller 262 disposed on a second side of the optical portion 220 opposite to the first side. A plurality of guide rollers 263 may also be provided on the roller portion 260. The film 270 may be interposed between the first roller 261 and the second roller 262. The film 270 may travel in a roll-to-roll manner. The film 270 unwound from the first roller 261 may be rolled to the second roller 262 through the bottom of the optical portion 220.

[0066] The moving part 250 can be lowered by the driving part 252 to contact the upper surface of the film 270. When the moving part 250 contacts the film 270, the lower part of the optical part 220 can be sealed from the outside. Thus, smoke that may be generated during or before and after drying of the ink droplet 140 can be prevented from penetrating into the optical part 220.

[0067] In order to strengthen the adhesion between the bottom surface of the moving part 250 and the top surface of the film 270 , attachment parts 310 , 320 , and 330 may be further provided below the moving part 250 .

[0068] Reference Figure 3a The attachment part 310 may be an electrostatic chuck. The attachment part 310 includes a moving part body 311 and a plurality of wirings 312 disposed inside the moving part body 311. The moving part body 311 may be Figure 1 The moving part 250. The moving part body 311 may be a dielectric. In another embodiment, the moving part body 311 may be separately disposed below the moving part 250. The plurality of wirings 312 may be electrically connected to a power source 313.

[0069] By applying a DC voltage to the wiring 312, an electrostatic force acts between the wiring 312 and the film 270, and the film 270 can be attracted to the bottom of the moving part body 311 by the electrostatic force. Thus, the bottom of the optical part 220 can be sealed from the outside.

[0070] Reference Figure 3b The attachment part 320 may be a physical sticking chuck. The attachment part 320 includes a moving part body 321 and a plurality of sticking parts 322 disposed below the moving part body 321. The moving part body 321 may be Figure 1 In another embodiment, the moving part body 321 can be separately disposed below the moving part 250.

[0071] The adhesive portion 322 may be disposed in a groove 323 disposed below the moving portion body 321. The adhesive portion 322 may have adhesiveness. The adhesive portion 322 may include an adhesive film, or rubber having adhesiveness, an ionized film, etc. If the moving portion body 321 descends toward the film 270, the adhesive portion 322 may adhere to the top of the film 270. If the moving portion body 321 ascends, the adhesive portion 322 may be easily detached from the film 270. Thus, the lower portion of the optical portion 220 may be sealed from the outside.

[0072] Reference Figure 3c The attachment part 330 includes a moving part body 331 and an O-ring 332 disposed below the moving part body 331. The moving part body 331 may be Figure 1 In another embodiment, the moving part body 321 may be separately disposed below the moving part 250. The O-ring 332 may be configured to surround the opening 333 of the moving part body 331. Figure 1 The optical portion 220 may be located at the opening 333. The O-ring 332 may also be located at Figure 3a The attachment portion 310 and Figure 3b The attachment portion 320.

[0073] When the moving part body 331 descends toward the membrane 270, the O-ring 332 may be located on the membrane 270. When a predetermined pressure is applied to the moving part body 331, the O-ring 332 may be closely attached to the membrane 270 by the pressure.

[0074] Thus, by providing the attachment parts 310, 320, 330 below the moving part 250, the bottom surface of the moving part 250 and the top surface of the film 270 can be more firmly in contact with each other. Thus, the bottom of the optical part 220 can be sealed from the outside.

[0075] Reference Figures 1 to 4 The following describes a process of measuring the state of the ink droplet 140 using the optical system 200 having the above-described configuration.

[0076] The optical system 200 installed in the chamber 110 is prepared (S100).

[0077] The chamber 110 may be a drying chamber for drying the ink droplets 140 ejected onto the substrate 120 .

[0078] An optical measurement unit 210 is provided outside the chamber 110. The optical measurement unit 210 may be fixed outside the chamber 110. The optical measurement unit 210 may include a confocal microscopy, a chromatic confocal microscopy, a CCD camera (charge-coupled device camera), a spectroscope, etc. The optical measurement unit 210 may include a light source such as a laser.

[0079] The optical part 220 is disposed inside the chamber 110. The optical part 220 may be located on a path of light irradiated from the optical measuring part 210. The optical part 220 may be fixed to the chamber 110, or fixed to an additional fixing mechanism, or fixed to the transparent window 230.

[0080] A transparent window 230 may be provided in the chamber 110 on a light path so that light irradiated from the optical measurement unit 210 can travel toward the optical unit 220 .

[0081] A moving part 250 is disposed around the optical part 220 and is movable up and down in a vertical direction (Z direction) of the chamber 110 . The optical part 220 is located at an opening 251 formed at the center of the moving part 250 .

[0082] A roller part 260 supplying a film 270 is disposed between the optical part 220 and the substrate 120 .

[0083] After the chamber 110 is provided with the optical system 200 , the first region of the film 270 is positioned below the optical portion 220 ( S200 ).

[0084] The film 270 unwound from the first roller 261 passes under the optical part 220 and is rolled up to the second roller 262. If the first area of ​​the film 270 is located under the optical part 220, the winding operation of the roller part 260 is stopped.

[0085] Thereafter, the moving part 250 and the film 270 are brought into contact with each other (S300).

[0086] The moving part 250 is lowered by the driving part 252 and contacts the upper surface of the film 270. Figure 3a to Figure 3cThe attachment parts 310, 320, 330 shown in the figure can further strengthen the adhesion between the bottom surface of the moving part 250 and the top surface of the film 270. The attachment parts 310, 320, 330 can include any one of an electrostatic chuck, an adhesive chuck, and an O-ring. In another embodiment, the bonding device can include a vacuum chuck that uses a pressure difference to fix the film 270.

[0087] Next, the substrate 120 on which the ink droplets 140 are ejected is moved toward the lower side of the optical portion 220 ( S400 ).

[0088] At this time, the ink droplet 140 may be in any state before drying, during drying, or after drying. During the drying process, smoke may be generated from the ink droplet 140 in the chamber 110. If the smoke penetrates into the optical part 220, the optical part 220 is contaminated, which may cause poor measurement of the ink droplet 140.

[0089] Since the protection module 240 including the moving part 250 and the roller part 260 for protecting the optical part 220 is disposed below the optical part 220 , the smoke generated during the drying process can be blocked from penetrating into the optical part 220 at the source.

[0090] Thereafter, light is irradiated from the optical measuring unit 210 toward the substrate 120 to measure the state of the ink droplets 140 on the substrate 120 ( S500 ).

[0091] Light irradiated from the optical measurement unit 210 disposed outside the chamber 110 passes through a transparent window 230 disposed above the chamber 110. The light passing through the transparent window 230 travels toward the optical unit 220 disposed inside the chamber 110. The light passing through the optical unit 220 passes through the film 270 and irradiates the ink droplets 140 on the substrate 120.

[0092] The optical measuring unit 210 may measure the state of the ink droplet 140 using various optical devices.

[0093] When the optical measurement unit 210 is provided with a confocal microscope, Figure 5a As shown, by raising and lowering the optical measuring unit 210 in the vertical direction (Z direction) while changing the focus, the cross-sections of the first part ①, the second part ②, and the third part ③ of the ink droplet 140 ejected on the substrate 120 are extracted, and the cross-sectional size of the ink droplet 140 is calculated from the control unit 211, thereby measuring the shape of the ink droplet 140.

[0094] When the optical measurement unit 210 is equipped with a color confocal microscope, Figure 5bAs shown, while the substrate 120 is moved in the horizontal direction (X direction), the longitudinal sections of the first part ①, the second part ②, the third part ③, and the fourth part ④ of the ink droplet 140 ejected on the substrate 120 are extracted, and the size of the longitudinal section of the ink droplet 140 is calculated from the control unit 211, thereby measuring the shape of the ink droplet 140. In another embodiment, the optical measuring unit 210 may be moved in the horizontal direction (X direction) instead of the substrate 120.

[0095] When the optical measuring unit 210 includes a CCD camera, Figure 5c As shown, the planar shape of the ink droplet 140 ejected onto the substrate 120 is detected, and the area of ​​the ink droplet 140 and the previously known angle of the ink droplet 140 are calculated, thereby measuring the volume of the ink droplet 140.

[0096] When the optical measuring unit 210 includes a spectrometer, Figure 5d As shown, a specific peak of the ink droplet 140 is detected according to the wavelength or frequency, so as to determine the hardening degree of the ink droplet 140.

[0097] After the state of the ink droplets 140 on the substrate 120 is measured through the above-described process, the substrate 120 that has finished the measurement is discharged to the outside of the chamber 110. Next, before a new substrate 120 is moved under the optical part 220, the second area of ​​the film 270 is supplied under the optical part 220, thereby repeating the adhesion process and the measurement process.

[0098] The example shows that the chamber 110 is provided with a Figure 1 However, the optical system 200 may be provided in plurality across the entire area on the substrate 120. Figure 6 As shown, a plurality of optical systems 200 may be provided according to positions on the substrate 120 where measurements are desired.

[0099] Figure 7 1 is a cross-sectional view showing a sub-pixel of a display device 700 including a light-emitting layer from which ink droplets are ejected according to the present disclosure.

[0100] Here, the sub-pixel has at least one thin film transistor TFT and an organic light emitting element OLED. The thin film transistor TFT does not necessarily have to be Figure 7 The number and structure of the structure can be variously modified.

[0101] Referring to the drawings, the display device 700 is provided with a substrate 711. The substrate 711 includes a glass substrate, a plastic substrate, or a flexible film substrate. The substrate 711 may be transparent, semi-transparent, or opaque.

[0102] A buffer layer 712 may be disposed on the substrate 711. The buffer layer 712 may cover the upper surface of the substrate 711. The buffer layer 712 may be formed of an inorganic film or an organic film. The buffer layer 712 may be a single-layer film or a multi-layer film.

[0103] A thin film transistor (TFT) may be formed on the buffer layer 712. The thin film transistor TFT according to this embodiment exemplifies a top gate thin film transistor, but of course, a thin film transistor with other structures such as a bottom gate thin film transistor may be provided.

[0104] A semiconductor layer 713 may be disposed on the buffer layer 712. The semiconductor layer 713 may be doped with N-type or P-type impurity ions to form a source region 714 and a drain region 715. The region between the source region 714 and the drain region 715 may be a channel region 716 that is not doped with impurities.

[0105] The semiconductor layer 713 may be an organic semiconductor, an inorganic semiconductor, or amorphous silicon. In another embodiment, the semiconductor layer 713 may be an oxide semiconductor.

[0106] A gate insulating film 717 may be evaporated on the semiconductor layer 713. The gate insulating film 717 may be formed of an inorganic film. The gate insulating film 717 may be a single-layer film or a multi-layer film.

[0107] A gate electrode 718 may be disposed on the gate insulating film 717. The gate electrode 718 may include a single layer or a multilayer film of Au, Ag, Cu, Ni, Pt, Pd, Al, Mo, Cr, etc., or an alloy such as Al:Nd or Mo:W.

[0108] An interlayer insulating film 719 may be disposed on the gate electrode 718. The interlayer insulating film 719 may be formed of an inorganic film such as silicon oxide or silicon nitride.

[0109] A source electrode 720 and a drain electrode 721 may be disposed on the interlayer insulating film 719. A portion of the gate insulating film 717 and a portion of the interlayer insulating film 719 may be removed to form a contact hole, through which the source electrode 720 may be electrically connected to the source region 714, and the drain electrode 721 may be electrically connected to the drain region 715.

[0110] A passivation film 722 may be formed on the source electrode 720 and the drain electrode 721. The passivation film 722 may be formed of an inorganic film or an organic film.

[0111] A planarization film 723 may be formed on the passivation film 722. The planarization film 723 includes an organic film of acryl, polyimide, benzocyclobutene (BCB), etc. In one embodiment, the passivation film 722 and the planarization film 723 may be formed as a single layer or multiple layers.

[0112] An organic light emitting element OLED may be disposed above the thin film transistor TFT.

[0113] The organic light emitting element OLED includes a pixel electrode 725 , an opposite electrode 727 , and an intermediate layer 726 between the pixel electrode 725 and the opposite electrode 727 .

[0114] The pixel electrode 725 may be electrically connected to any one of the source electrode 720 and the drain electrode 721 through a contact hole.

[0115] The pixel electrode 725 functions as an anode and can be formed of various conductive materials. The pixel electrode 725 can be formed as a transparent electrode or a reflective electrode.

[0116] A pixel definition layer (PDL) 724 covering the edge of the pixel electrode 725 may be disposed on the planarization film 723 . The pixel definition layer 724 defines the light emitting region of each sub-pixel by surrounding the edge of the pixel electrode 725 .

[0117] The pixel definition film 724 may be formed of an organic film.

[0118] By etching a portion of the pixel definition film 724 on the pixel electrode 725, an intermediate layer 726 may be disposed on the exposed region. The intermediate layer 726 may be formed by an evaporation process.

[0119] The intermediate layer 726 may be made of low molecular weight organic matter or high molecular weight organic matter.

[0120] The intermediate layer 726 may include an emissive layer (EML). As another selective example, the intermediate layer 726 includes an emissive layer, and in addition, may also include at least one of a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL). In this embodiment, this is not limited to this, and the intermediate layer 726 may include an organic emissive layer and other various functional layers.

[0121] An opposite electrode 727 may be disposed on the intermediate layer 726. The opposite electrode 727 may correspond to the common electrode. The opposite electrode 727 may be formed as a transparent electrode or a reflective electrode similar to the pixel electrode 725.

[0122] The pixel electrode 725 and the counter electrode 727 may be insulated from each other by an intermediate layer 726. When a voltage is applied to the pixel electrode 725 and the counter electrode 727, visible light is emitted from the intermediate layer 726 to realize an image that can be recognized by a user.

[0123] A sealing portion 740 (encapsulation) may be disposed above the organic light emitting element OLED.

[0124] The sealing part 740 may be a plurality of organic films 741, 742 and a plurality of inorganic films 743, 744, 745 alternately stacked. In one embodiment, the sealing part 740 may have a structure in which the organic films 741, 742 are at least one layer and the inorganic films 743, 744, 745 are at least two layers. In order to prevent moisture permeation to the organic light emitting element OLED, the uppermost layer 745 exposed to the outside of the sealing part 740 may be formed of an inorganic film.

Claims

1. An optical system for measuring ink droplets, wherein: include: a chamber, mounting a substrate from which ink droplets are ejected; an optical measuring unit, disposed outside the chamber and irradiating light toward the substrate to measure the state of the ink droplets; an optical part, disposed inside the chamber and located on the light path; as well as The protection module comprises a moving part and a roller part, wherein the moving part is arranged around the optical part and performs lifting and lowering motion, and the roller part supplies a film between the optical part and the substrate. The moving part surrounds the optical part, and is moved up and down by the driving part to selectively contact the upper surface of the film.

2. The optical system for measuring ink droplets according to claim 1, wherein: The chamber is provided with a transparent window so that light irradiated from the optical measurement unit provided outside the chamber can travel along an optical path toward the optical unit provided inside the chamber.

3. The optical system for measuring ink droplets according to claim 2, wherein: The optical measurement unit, the transparent window, and the optical unit are arranged in a vertical direction.

4. The optical system for measuring ink droplets according to claim 1, wherein: An attachment portion is further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the film are in close contact with each other. The attachment portion includes a plurality of wirings that are provided in the moving portion and to which power is applied so that the film is pulled with electrostatic force relative to the moving portion.

5. The optical system for measuring ink droplets according to claim 1, wherein: An attachment portion is further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the film are in close contact with each other. The attachment portion includes an adhesive portion that is disposed on a bottom surface of the moving portion and adheres the film to the moving portion.

6. The optical system for measuring ink droplets according to claim 1, wherein: An attachment portion is further provided below the moving portion so that the bottom surface of the moving portion and the top surface of the film are in close contact with each other. The attachment portion includes an O-ring, and the O-ring is disposed on a bottom surface of the moving portion and pressurizes an upper surface of the film.

7. The optical system for measuring ink droplets according to claim 1, wherein: A protective part surrounding the optical part is also provided around the optical part. The lower end of the protection part is combined with the moving part to seal the space where the optical part is arranged.

8. The optical system for measuring ink droplets according to claim 1, wherein: The roller portion comprises: A first roller disposed on a first side of the optical portion; and a second roller, disposed on a second side of the optical portion, The film is interposed between the first roller and the second roller and moves below the optical portion.

9. The optical system for measuring ink droplets according to claim 1, wherein: At least one of the optical measurement units and at least one of the optical units are provided over the entire area on the substrate.

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