Laser cutting device and lens assembly

Abstract

A laser cutting apparatus and a lens assembly are provided. The laser cutting apparatus can include a light source generating a laser beam and a lens assembly converging the laser beam incident from the light source. The lens assembly can include a first housing including a first body, a second housing including a second body, a first lens group disposed in the first body, and a second lens group disposed in the second body. The second housing can be combined to the first housing, and the second body can be disposed below the first body. A first opening can be defined in the first body, and a second opening overlapping the first opening is defined in the second body.

Description

Technical Field

[0001] This disclosure relates to a laser cutting apparatus, and more specifically, to a laser cutting apparatus for manufacturing display devices. Background Technology

[0002] Laser devices are typically used in the manufacture of electrical or electronic devices (such as display devices). Specifically, laser devices can be used to perform cutting, cleaning, marking, scanning, or crystallization processes on target objects, or to alter the surface properties of target objects. Therefore, it is necessary to develop a technique for easily controlling the shape, size, and energy density of the laser beam emitted from the laser device. Summary of the Invention

[0003] Embodiments of the inventive concept provide a laser cutting apparatus that includes a lens assembly that can be easily manufactured, maintained, and repaired.

[0004] According to embodiments of the inventive concept, a laser cutting apparatus may include a light source for generating a laser beam and a lens assembly for converging the laser beam incident from the light source. The lens assembly may include: a first housing including a first body defining a first opening therein; a second housing assembled to the first housing, the second housing including a second body disposed below the first body and defining a second opening therein overlapping the first opening; a first lens group disposed in the first body; and a second lens group disposed in the second body.

[0005] According to an embodiment of the inventive concept, a lens assembly may include: a first housing including a first body defining a first opening therein; a second housing including a second body disposed below the first body and defining a second opening therein overlapping the first opening; a first lens group disposed in the first body; and a second lens group disposed in the second body. The second housing may be selectively combined with the first housing. Attached Figure Description

[0006] The exemplary embodiments will be more clearly understood from the following brief description taken in conjunction with the accompanying drawings. The drawings illustrate non-limiting exemplary embodiments as described herein.

[0007] Figure 1 This is a schematic diagram illustrating a laser cutting apparatus according to an embodiment of the inventive concept.

[0008] Figure 2 This is an example shown Figure 1 A perspective view of the lens assembly shown in the image.

[0009] Figure 3 This is an example shown Figure 2The image shows a cross-sectional view of the first housing, the second housing, and the assembly unit of the lens assembly.

[0010] Figure 4 It is shown Figure 3 Top view of the first shell, the second shell, and the combined unit.

[0011] Figure 5 This is an example shown Figure 2 The image shows a cross-sectional view of the lens assembly.

[0012] Figures 6 to 8 The diagrams show lens assemblies according to other embodiments of the inventive concept.

[0013] Figure 9 This is an example shown Figure 5 The diagram shows multiple lenses.

[0014] Figure 10A It shows from Figure 1 An image of the cross-sectional shape of a laser beam emitted by a laser cutting device and directed onto a target object.

[0015] Figure 10B It is an image showing the cross-sectional shape of a laser beam emitted from a laser cutting apparatus according to a comparative example and irradiating a target object.

[0016] Figure 11 and Figure 12 The diagrams illustrate, by way of example, lenses constituting a lens assembly according to embodiments of the inventive concept.

[0017] Figure 13 This is an example shown Figure 1 A diagram showing the optical components of the extended portion.

[0018] It should be noted that these figures are intended to illustrate the general characteristics of the methods, structures, and / or materials used in some exemplary embodiments and are intended to supplement the written description provided below. However, these figures are not to scale and may not accurately reflect the precise structural or performance characteristics of any given embodiment, and should not be construed as limiting or restricting the range of values ​​or properties contained in the exemplary embodiments. For example, for clarity, the relative thickness and location of molecules, layers, regions, and / or structural elements may be reduced or exaggerated. The use of similar or identical reference numerals in the various figures is intended to indicate the presence of similar or identical elements or features. Detailed Implementation

[0019] Example embodiments of the inventive concept will now be described more fully with reference to the accompanying drawings, which illustrate exemplary embodiments. However, example embodiments of the inventive concept can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. In the drawings, the thickness of layers and regions is exaggerated for clarity. The same reference numerals in the drawings denote the same elements, and therefore their description will be omitted.

[0020] It will be understood that when an element is referred to as “connected” or “joined” to another element, that element may be directly connected to or joined to the other element, or there may be intermediate elements. Conversely, when an element is referred to as “directly connected” or “directly joined” to another element, there are no intermediate elements. The same notation always refers to the same element. As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items. Other words used to describe relationships between elements or layers should be interpreted in the same way (e.g., “between” vs. “directly between”, “adjacent” vs. “directly adjacent”, “on” vs. “directly on”).

[0021] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion.

[0022] For ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” and “above” may be used herein to describe the relationship between one element or feature and another, as shown in the accompanying drawings. It will be understood that, in addition to the orientations depicted in the drawings, the spatial relative terms are also intended to encompass different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as “below” or “under” another element or feature will subsequently be oriented “above” said other element or feature. Thus, the exemplary term “below” can encompass both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein will be interpreted accordingly.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “an” are also intended to include the plural forms. It will also be understood that if the terms “comprising” and / or “including” are used herein, it indicates the presence of the stated features, integrals, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.

[0024] Example embodiments of the inventive concept are described herein with reference to schematic cross-sectional views of idealized embodiments (and intermediate structures) of the exemplary embodiments. Thus, variations in the shape of the illustrations, such as those caused by manufacturing techniques and / or tolerances, will be anticipated. Therefore, the example embodiments of the inventive concept should not be construed as limited to the specific shapes of the areas shown herein, but will include, for example, deviations in shape due to manufacturing processes.

[0025] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments of the inventive concept pertain. It will also be understood that terms (such as those defined in a general dictionary) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0026] Figure 1 This is a schematic diagram illustrating a laser cutting apparatus according to an embodiment of the inventive concept.

[0027] Reference Figure 1 The laser cutting apparatus LD according to embodiments of the inventive concept can be used in the manufacturing process of display devices. For example, the laser cutting apparatus LD can use a laser beam to cut a panel substrate. However, the inventive concept is not limited to this example. For example, the laser cutting apparatus LD can be used to perform scanning, cleaning, and marking processes on a target object.

[0028] A laser cutting apparatus LD may include a light source LS, an extension section EXP, a scanner SC, a lens assembly LA, and a stage ST. The light source LS may be configured to generate a laser beam LB. In this embodiment, the laser beam LB may be an ultra-high frequency pulsed laser. For example, the laser beam LB may be an ultra-high frequency pulsed laser beam from a femtosecond laser. The wavelength of the laser beam LB may be approximately 300 nm. However, the type of laser beam LB is not limited to this example.

[0029] The extension portion EXP can adjust the profile size of the laser beam LB. Here, the profile size is the size of the cross-section of the laser beam LB as observed in the incident (or emitted) direction. For example, the extension portion EXP can be a beam expander. The extension portion EXP can be positioned adjacent to the light source LS. For example, as... Figure 1 As shown, the extended portion EXP can be spaced apart from the light source LS in the first direction DR1. The first direction DR1 can represent the horizontal direction.

[0030] A laser beam LB emitted from the light source LS can be incident on the extension portion EXP. The cross-sectional size of the laser beam LB incident on the extension portion EXP can be smaller than the cross-sectional size of the laser beam LB emitted from the extension portion EXP. In other words, the laser beam LB passing through the extension portion EXP can have an increased cross-sectional size. For this purpose, the extension portion EXP can include at least one optical component. This will be described in more detail below.

[0031] The scanner SC can be configured to be spaced apart from the extension portion EXP. For example, the scanner SC can be spaced apart from the extension portion EXP in a first direction DR1. The laser beam LB emitted from the extension portion EXP can be incident on the scanner SC. The scanner SC can adjust the illumination direction of the laser beam LB. For example, the scanner SC can change the illumination direction of the laser beam LB from the first direction DR1 to a second direction DR2. The scanner SC can be configured to determine the position where the laser beam LB illuminates the panel substrate SUB. In this embodiment, the scanner SC can be a galvanometer including a reflector.

[0032] The lens assembly LA can be positioned below the scanner SC. For example, the lens assembly LA can be spaced apart from the scanner SC in a second direction DR2. The second direction DR2 can be a direction perpendicular to the first direction DR1 and can represent a vertical (e.g., upward and / or downward) direction.

[0033] The lens assembly LA can be configured to converge the laser beam LB incident from the scanner SC. In this embodiment, the lens assembly LA can be an F-θ lens. The lens assembly LA will be described in more detail below.

[0034] A laser beam LB can be directed through a lens assembly LA onto a target object placed on a stage ST. In this embodiment, the target object may be a panel substrate SUB. The laser cutting apparatus LD can use the laser beam LB to process the panel substrate SUB, thereby giving the panel substrate SUB the desired design.

[0035] Figure 2 This is an example shown Figure 1 The lens assembly shown is a perspective view. (Refer to...) Figure 2Describe the structure or appearance of the lens assembly LA in more detail.

[0036] According to an embodiment of the inventive concept, the lens assembly LA may include a first housing CA1, a second housing CA2 disposed below the first housing CA1, and a combination unit CU. The first housing CA1 may have a truncated conical shape in which its outer diameter increases in a downward direction (e.g., in a second direction DR2). In an embodiment, the first housing CA1 may include a first body BO1 and a first flange portion FL1.

[0037] The first body BO1 may include a first portion PP1, a second portion PP2, a third portion PP3, a fourth portion PP4, and a fifth portion PP5. The first portion PP1 may be the upper part of the first housing CA1. The first portion PP1 may have a cylindrical shape. A first opening OP1 may be defined within the first portion PP1. When viewed in a plan view, the first opening OP1 may be shaped to resemble a circle. From the scanner SC (e.g., see...) Figure 1 The reflected laser beam LB can be incident into the lens assembly LA through the first opening OP1.

[0038] The second part, PP2, can be positioned below the first part, PP1. The second part, PP2, can be cylindrical in shape. The outer diameter of the second part, PP2, can be larger than the outer diameter of the first part, PP1. The third part, PP3, can be positioned below the second part, PP2. The third part, PP3, can be cylindrical in shape. The outer diameter of the third part, PP3, can be larger than the outer diameter of the second part, PP2. The fourth part, PP4, can be positioned below the third part, PP3. The fourth part, PP4, can be cylindrical in shape. The outer diameter of the fourth part, PP4, can be larger than the outer diameter of the third part, PP3.

[0039] The fifth part, PP5, can be positioned below the fourth part, PP4. The fifth part, PP5, can be shaped like a truncated cone. For example... Figure 2 As shown, the outer diameter of the fifth part PP5 can gradually increase in the downward direction (e.g., in the second direction DR2).

[0040] However, the structure or shape of the first body BO1 is not limited to this example. For example, in an embodiment, the first body BO1 may be shaped like a circular cylinder or a polygonal cylinder, etc.

[0041] The first portion PP1 to the fifth portion PP5 of the first body BO1 can be configured as a single object. However, the inventive concept is not limited to this example. For example, the first portion PP1 to the fifth portion PP5 can be manufactured separately and then combined with each other.

[0042] The first body BO1 can be formed of a material with sufficiently high stiffness. For example, the first body BO1 can be formed of or include a metallic material. However, the material of the first body BO1 is not limited to this example.

[0043] The first flange portion FL1 can be configured as an outer surface surrounding the lower part of the first body BO1. The lower part of the first body BO1 can be the lower part of the fifth portion PP5. In other words, the first flange portion FL1 can be configured as an outer surface surrounding the lower part of the fifth portion PP5. Therefore, the first flange portion FL1 can protrude relative to the fifth portion PP5 in the horizontal direction (e.g., the radial direction).

[0044] The first flange portion FL1 may extend from the first body BO1. For example, the first body BO1 and the first flange portion FL1 may be configured as a single object. However, the inventive concept is not limited to this example. The first flange portion FL1 may be manufactured as an element different from the first body BO1 and then combined with the first body BO1.

[0045] According to an embodiment of the inventive concept, the second housing CA2 may be disposed below the first housing CA1. The first housing CA1 and the second housing CA2 may be combined with each other, but may also be separable from each other. The second housing CA2 may include a second body BO2 and a second flange portion FL2.

[0046] The second body BO2 can have a cylindrical shape. When measured in the first direction DR1, the second body BO2 can have a constant outer diameter. Although in Figure 2 The second opening OP2 is not shown in the perspective view, but it may be confined within the bottom of the second body BO2 (see, for example, see...). Figure 4 and Figure 5 The second opening OP2 can be circular. The diameter of the second opening OP2 can be larger than the diameter of the first opening OP1. The laser beam LB passing through the lens assembly LA can pass through the second opening OP2 (see, for example, [reference needed]). Figure 1 It is incident into the panel substrate SUB.

[0047] The second flange portion FL2 can be configured as the outer surface surrounding the upper part of the second body BO2. Therefore, the second flange portion FL2 can protrude relative to the second body BO2 in the horizontal direction (e.g., in the first direction DR1).

[0048] The second flange portion FL2 may extend from the second body BO2. For example, the second body BO2 and the second flange portion FL2 may be configured as a single object. However, the inventive concept is not limited to this example. The second flange portion FL2 may be manufactured as an element different from the second body BO2 and then incorporated into the second body BO2.

[0049] The assembly unit CU can be used to combine the first housing CA1 and the second housing CA2 with each other. For example... Figure 2 As shown, the assembly unit CU can be fastened to the first flange portion FL1 and the second flange portion FL2. The assembly unit CU will be described in more detail below.

[0050] Figure 3 This is an example shown Figure 2 The image shows a cross-sectional view of the first housing, the second housing, and the assembly unit of the lens assembly. Figure 4 It is shown Figure 3 Top plan view of the first shell, the second shell, and the combined unit. For ease of explanation, Figure 3 The disassembled structure of the first housing, the second housing, and the combined unit is shown.

[0051] Reference Figure 3 and Figure 4 The first support portion SE1, the second support portion SE2, and the third support portion SE3 can be confined within the first body BO1 of the first housing CA1.

[0052] The first support portion SE1 may be defined within the second portion PP2. The first support portion SE1 may be defined by a first support surface SF1 and a first fastening member FM1. Specifically, the first support surface SF1 may be formed by an inwardly projecting inner portion of the second portion PP2. The first support surface SF1 may point downwards. The diameter of the first support surface SF1 may be smaller than the diameter of the first opening OP1. The first fastening member FM1 may be disposed on the first support surface SF1. The first support portion SE1 may represent the space defined between the first fastening member FM1 and the first support surface SF1. The first fastening member FM1 may be detachably mounted to the inner circumferential surface of the second portion PP2.

[0053] The second support portion SE2 may be defined within the third portion PP3. Specifically, the second support portion SE2 may be defined by a second support surface SF2 and a second fastening member FM2. The second support surface SF2 may be formed by a stepped structure formed in the inner circumferential surface of the third portion PP3. The second support surface SF2 may point downwards. The second fastening member FM2 may be disposed below the second support surface SF2. The second support portion SE2 may represent the space defined between the second fastening member FM2 and the second support surface SF2. The second fastening member FM2 may be detachably mounted to the inner circumferential surface of the third portion PP3.

[0054] The third support portion SE3 may be defined within the fifth portion PP5. Specifically, the third support portion SE3 may be defined by a third support surface SF3 and a third fastening member FM3. The third support surface SF3 may be formed by a stepped structure formed in the inner circumferential surface of the fifth portion PP5. The third support surface SF3 may point upwards. The third fastening member FM3 may be disposed below the third support surface SF3. The third support portion SE3 may represent the space defined between the third fastening member FM3 and the third support surface SF3. The third fastening member FM3 may be detachably mounted to the inner circumferential surface of the fifth portion PP5.

[0055] like Figure 3 As shown, when measured in the first direction DR1, the width of the third support portion SE3 can be greater than the width of the second support portion SE2, and the width of the second support portion SE2 can be greater than the width of the first support portion SE1.

[0056] The fourth support portion SE4, the fifth support portion SE5, and the sixth support portion SE6 can be defined within the second body BO2. The fourth support portion SE4 can be defined in the upper part of the second body BO2. The fourth support portion SE4 can be defined by the fourth support surface SF4 and the fourth fastening member FM4. Specifically, the fourth support surface SF4 can be formed by a stepped structure formed in the inner circumferential surface of the second body BO2. The fourth support surface SF4 can point downwards. The fourth fastening member FM4 can be disposed below the fourth support surface SF4. The fourth support portion SE4 can represent the space defined between the fourth fastening member FM4 and the fourth support surface SF4. The fourth fastening member FM4 can be detachably mounted into the internal space of the second body BO2.

[0057] The fifth support portion SE5 may be defined below the fourth support portion SE4. Specifically, the fifth support portion SE5 may be defined by a fifth support surface SF5 and a fifth fastening member FM5. The fifth support surface SF5 may be formed by a stepped structure formed in the inner circumferential surface of the second body BO2. The fifth support surface SF5 may point upwards. The fifth fastening member FM5 may be disposed below the fifth support surface SF5. The fifth support portion SE5 may represent the space defined between the fifth fastening member FM5 and the fifth support surface SF5. The fifth fastening member FM5 may be detachably fitted into the internal space of the second body BO2.

[0058] The sixth support portion SE6 may be defined below the fifth support portion SE5. Specifically, the sixth support portion SE6 may be defined by a sixth support surface SF6 and a sixth fastening member FM6. The sixth support surface SF6 may be formed by a stepped structure formed in the inner circumferential surface of the second body BO2. The sixth support surface SF6 may be horizontally oriented. The sixth fastening member FM6 may be disposed below the sixth support surface SF6. The sixth support portion SE6 may represent the space defined between the sixth fastening member FM6 and the sixth support surface SF6. The sixth fastening member FM6 may be detachably mounted into the internal space of the second body BO2.

[0059] like Figure 3 As shown, when measured in the first direction DR1, the width of the sixth support portion SE6 can be greater than the width of the fifth support portion SE5, and the width of the fifth support portion SE5 can be greater than the width of the fourth support portion SE4.

[0060] Although not shown, the first fastening members FM1 to the sixth fastening members FM6 can be formed in a ring-like manner. The first fastening members FM1 to the sixth fastening members FM6 can be formed of or comprise a material with elastic restoring force. For example, the first fastening members FM1 to the sixth fastening members FM6 can be formed of or comprise rubber. The first fastening members FM1 to the sixth fastening members FM6 can contract when inserted into the first body BO1 or the second body BO2, and then, if they are placed in their predetermined positions, they can be secured by the elastic restoring force.

[0061] However, the materials used for the first fastening member FM1 to the sixth fastening member FM6 are not limited to this example. For example, the first fastening member FM1 to the sixth fastening member FM6 may be formed of or include at least one of plastic and metal materials. In addition, each of the first fastening member FM1 to the sixth fastening member FM6 may include a plurality of fastening rings.

[0062] The first housing CA1 may further include a guide portion GI. The guide portion GI may extend from the first body BO1 in a downward direction (e.g., in the second direction DR2). Specifically, the bottom surface of the fifth portion PP5 may face the top surface of the second body BO2. The outer and inner diameters of the bottom surface of the fifth portion PP5 may be smaller than the outer and inner diameters of the top surface of the second body BO2. The guide portion GI may extend from the bottom surface of the fifth portion PP5. The outer diameter of the guide portion GI may be smaller than the inner diameter of the second body BO2. Therefore, the guide portion GI can be inserted into the second body BO2. The guide portion GI can be used to guide the assembly between the first housing CA1 and the second housing CA2.

[0063] A first hole H1 may be defined in a first flange portion FL1. The first hole H1 may pass through the first flange portion FL1 in the thickness direction (e.g., in the second direction DR2). A second hole H2 may be defined in a second flange portion FL2. The second hole H2 may pass through the second flange portion FL2 in the thickness direction (e.g., in the second direction DR2). The second hole H2 may overlap with the first hole H1.

[0064] The assembly unit CU may include a bolt BO and a nut NU. The bolt BO may be inserted into a first hole H1 and a second hole H2 respectively defined in a first flange portion FL1 and a second flange portion FL2. The head of the bolt BO may contact the top surface of the first flange portion FL1. The nut NU may be assembled with the lower part of the bolt BO passing through the second hole H2.

[0065] However, the assembly unit CU is not limited to this example. For example, the assembly unit CU may be a screw having an outer circumferential surface on which threads are formed. Alternatively, the assembly unit CU may be a clamp that is coupled to the top surface of the first flange portion FL1 and the bottom surface of the second flange portion FL2.

[0066] In this embodiment, multiple combined units (CUs) can be provided. For example... Figure 4 As shown, the number of combination units CU can be six. However, the number of combination units CU is not limited to this example. The combination units CU can be arranged around the center of the first opening OP1 and can be spaced apart from each other in the circumferential direction. Although not shown, the first hole H1 and the second hole H2, respectively defined in the first flange portion FL1 and the second flange portion FL2, can be arranged to... Figure 4 The number and position of the combined unit CUs shown in the figure correspond (for example, see [reference]). Figure 3 ).

[0067] According to an embodiment of the inventive concept, a sealing member may be further disposed between the first flange portion FL1 and the second flange portion FL2. The sealing member can airtightly seal the internal spaces of the first housing CA1 and the second housing CA2 from the external environment.

[0068] Figure 5 This is an example shown Figure 2 The image shows a cross-sectional view of the lens assembly.

[0069] Reference Figure 5 The lens assembly LA may include a first lens group GU1 and a second lens group GU2. The first lens group GU1 may be disposed in a first body BO1. The second lens group GU2 may be disposed in a second body BO2. The first lens group GU1 and the second lens group GU2 may be configured to refract a laser beam incident on the lens assembly LA, and thereby diffuse and / or converge the laser beam.

[0070] The first lens group GU1 may include a first lens LE1, a second lens LE2, and a third lens LE3. Both the top and bottom surfaces of the first lens LE1 may have a convex shape. The first lens LE1 can be placed on the first support portion SE1. Specifically, the first lens LE1 can be inserted into the first body BO1 through the top opening of the first body BO1 and can be placed on the first support surface SF1. Thereafter, a first fastening member FM1 can be provided on the first lens LE1. The first fastening member FM1 can fasten the first lens LE1 to the first support portion SE1.

[0071] The second lens LE2 can be disposed below the first lens LE1. Both the top and bottom surfaces of the second lens LE2 can have concave shapes. The second lens LE2 can be placed in the second support portion SE2. Specifically, the second lens LE2 can be inserted into the first body BO1 through the bottom opening of the first body BO1 and can be placed on the second support surface SF2. Thereafter, the second fastening member FM2 can be disposed below the second lens LE2. The second fastening member FM2 can fasten the second lens LE2 to the second support portion SE2.

[0072] The third lens LE3 can be disposed below the second lens LE2. The top surface of the third lens LE3 can be convex, and the bottom surface of the third lens LE3 can be concave. The third lens LE3 can be placed on the third support portion SE3. Specifically, the third lens LE3 can be inserted into the first body BO1 through the bottom opening of the first body BO1, and then placed on the third support surface SF3. Thereafter, the third fastening member FM3 can fasten the third lens LE3 to the third support portion SE3.

[0073] like Figure 5 As shown, when measured in the first direction DR1, the width of the second lens LE2 can be greater than the width of the first lens LE1, and the width of the third lens LE3 can be greater than the width of the second lens LE2. The placement of the third lens LE3 on the third support portion SE3 can be performed after the second lens LE2 is placed on the second support portion SE2.

[0074] The second lens group GU2 can be disposed below the first lens group GU1. The second lens group GU2 may include a fourth lens LE4, a fifth lens LE5, and a window WIN. The top surface of the fourth lens LE4 may have a concave shape, and the bottom surface of the fourth lens LE4 may have a convex shape. The fourth lens LE4 can be placed on the fourth support portion SE4. Specifically, the fourth lens LE4 can be inserted into the second body BO2 through the bottom opening of the second body BO2, and then placed on the fourth support surface SF4. Thereafter, the fourth fastening member FM4 can be disposed below the fourth lens LE4. The fourth fastening member FM4 can fasten the fourth lens LE4 to the fourth support portion SE4.

[0075] The fifth lens LE5 can be positioned below the fourth lens LE4. The top surface of the fifth lens LE5 can be convex. The bottom surface of the fifth lens LE5 can be flat. The fifth lens LE5 can be placed on the fifth support portion SE5. Specifically, the fifth lens LE5 can be inserted into the second body BO2 through the bottom opening of the second body BO2, and then placed on the fifth support surface SF5. Subsequently, the fifth fastening member FM5 can be positioned below the fifth lens LE5. The fifth fastening member FM5 can fasten the fifth lens LE5 to the fifth support portion SE5.

[0076] The window WIN can be positioned below the fifth lens LE5. Both the top and bottom surfaces of the window WIN can be flat. The window WIN can be placed on the sixth support portion SE6. Specifically, the window WIN can be inserted into the second body BO2 through the bottom opening of the second body BO2, and then placed on the sixth support surface SF6. Subsequently, the sixth fastening member FM6 can be positioned below the window WIN. The sixth fastening member FM6 can fasten the window WIN.

[0077] like Figure 5 As shown, when measured in the first direction DR1, the width of window WIN can be greater than the width of the fifth lens LE5, and the width of the fifth lens LE5 can be greater than the width of the fourth lens LE4. The fifth lens LE5 can be placed on the fifth support portion SE5 after the fourth lens LE4 is placed on the fourth support portion SE4. The window WIN can be placed on the sixth support portion SE6 after the fifth lens LE5 is placed on the fifth support portion SE5.

[0078] The shapes of the first lens LE1 to the fifth lens LE5 are not limited to... Figure 5 The example shown is illustrated below. Considering the light-gathering characteristics of the lens assembly LA, the shapes of the first lens LE1 through the fifth lens LE5 can be altered.

[0079] According to embodiments of the inventive concept, the first housing CA1 and the second housing CA2, comprising the first lens group GU1 and the second lens group GU2, can be manufactured such that they are separable from each other. In this case, the lens assembly LA can be easily handled. Furthermore, the lens assembly LA can be easily maintained and repaired.

[0080] Figures 6 to 8 The diagrams show lens assemblies according to other embodiments of the inventive concept.

[0081] In the following text, reference will be made to Figures 6 to 8 Lens assemblies LA', LA”, and LA”' according to other embodiments of the inventive concept are described in more detail. Figures 6 to 8 In the following description, previously described elements may be identified by similar or the same reference numerals without repeating their descriptions.

[0082] Reference Figure 6 According to an embodiment of the inventive concept, the lens assembly LA' may include a first housing CA1', a second housing CA2, a first lens group GU1, a second lens group GU2, and a combination unit CU. The first housing CA1' may include a first body BO1' and a first flange portion FL1'.

[0083] The fifth portion PP5' may define the lower part of the first body BO1'. In this embodiment, the outer and inner diameters of the bottom surface of the fifth portion PP5' may be equal to the outer and inner diameters of the top surface of the second body BO2, respectively. The first housing CA1' may not include the guide portion GI of the first housing CA1 in the previously described embodiments (e.g., see...). Figure 5 ).

[0084] According to this embodiment, since the guide portion is omitted from the first housing CA1', the first housing CA1' can have a simplified structure, and therefore, the process for manufacturing the first housing CA1' can be easily performed.

[0085] Reference Figure 7 According to an embodiment of the inventive concept, the lens assembly LA may include a first housing CA1", a second housing CA2", a first lens group GU1, and a second lens group GU2. The first housing CA1 may include a first body BO1 and a first extension EP1. The first body BO1 may include a fifth portion PP5. The outer diameter and inner diameter of the bottom surface of the fifth portion PP5 may be equal to the outer diameter and inner diameter of the second body BO2, respectively.

[0086] The first extension EP1 may extend downwards (e.g., in the second direction DR2) from the bottom surface of the fifth portion PP5". When measured in the first direction DR1, the outer diameter of the first extension EP1 may be equal to the outer diameter of the bottom surface of the fifth portion PP5", and the inner diameter of the first extension EP1 may be greater than the inner diameter of the bottom surface of the fifth portion PP5". In other words, the first extension EP1 may extend downwards from the outer edge portion of the bottom surface of the fifth portion PP5". The first thread SC1 may be defined on the inner circumferential surface of the first extension EP1.

[0087] The second housing CA2 may include a second body BO2 and a second extension EP2. The second extension EP2 may extend from the top surface of the second body BO2. When measured in the first direction DR1, the inner diameter of the second extension EP2 may be equal to the inner diameter of the top surface of the second body BO2, and the outer diameter of the second extension EP2 may be smaller than the outer diameter of the top surface of the second body BO2. The second thread SC2 may be defined on the outer circumferential surface of the second extension EP2.

[0088] When viewed in a plan view, the first extension EP1 can be positioned outside the second extension EP2. When measured in the first direction DR1, the inner diameter of the first extension EP1 can be equal to the outer diameter of the second extension EP2. Therefore, the first extension EP1 can be fastened to the second extension EP2.

[0089] According to embodiments of the inventive concept, since the first housing CA1” and the second housing CA2” of the lens assembly LA” are constructed to be fastened to each other, the lens assembly LA” does not require additional assembly units. Therefore, it is possible to reduce the number of components constituting the lens assembly LA” and to reduce the weight of the lens assembly LA”.

[0090] Reference Figure 8 The lens assembly LA”' may include a first housing CA1, a second housing CA2”' disposed below the first housing CA1, a third housing CA3 disposed below the second housing CA2”', a first lens group GU1, a second lens group GU2”', a third lens group GU3, and a combination unit CU.

[0091] According to this embodiment, the housing and lens group constituting the lens assembly LA”' can be more numerous than the housing and lens group constituting the aforementioned lens assemblies LA, LA', and LA”. The first housing CA1 can be combined with the second housing CA2”', and the second housing CA2”' can be combined with the third housing CA3.

[0092] The first lens group GU1 can be set in the first housing CA1, the second lens group GU2”' can be set in the second housing CA2”', and the third lens group GU3 can be set in the third housing CA3.

[0093] The second lens group GU2”' may include the fourth lens LE4 and the fifth lens LE5. The third lens group GU3 may include the sixth lens LE6 and the window WIN. The top and bottom surfaces of the sixth lens LE6 may both have a convex shape.

[0094] Compared with the aforementioned embodiments, the sixth lens LE6 can be additionally disposed in the lens assembly LA”', and the setting position of the window WIN can be changed from the second housing CA2”' to the third housing CA3.

[0095] like Figure 8 As shown, the first housing CA1 and the second housing CA2”' can be combined with each other by bolts BO and nuts NU fastened to the first flange portion FL1 and the second flange portion FL2.

[0096] The second housing CA2”' may include a first extension EP1”' extending downward from the second body BO2. A first thread SC1”' may be defined on the inner circumferential surface of the first extension EP1”'. The third housing CA3 may include a third body BO3 and a second extension EP2”' extending upward from the third body BO3. A second thread SC2”' may be defined on the outer circumferential surface of the second extension EP2”'. Figure 8 In the middle, the second opening OP2”' can be confined to the bottom of the third body BO3.

[0097] The inner diameter of the first extension EP1”' can be equal to the outer diameter of the second extension EP2”'. The first extension EP1”' can be fastened to the second extension EP2”'. As a result, the second housing CA2”' can be assembled to the third housing CA3. However, the method of assembling the first housing CA1, the second housing CA2”', and the third housing CA3 is not limited to the aforementioned method.

[0098] According to embodiments of the inventive concept, the lens assembly LA”' may include multiple housings and multiple lenses, the housings being combined with each other but disassembled, and the lenses being disposed within the housings. Therefore, the lens assembly LA”' may include lenses combined in various ways, thereby increasing the degree of freedom in designing the lens assembly.

[0099] Figure 9 It shows the composition Figure 5 A diagram illustrating multiple lenses in a lens assembly. For ease of explanation, Figure 9The first housing CA1, the second housing CA2, and the combining unit CU are omitted. Additionally, in Figure 9 lenses LE1 to LE5 arranged in the horizontal direction are shown. Figure 9 The horizontal direction of Figure 5 may correspond to the vertical direction of

[0100] Referring to Figure 9 , each of the first lens LE1, the fourth lens LE4, and the fifth lens LE5 may have a positive refractive power. Each of the second lens LE2 and the third lens LE3 may have a negative refractive power. A lens having a positive refractive power may converge an incident laser beam by refraction. A lens having a negative refractive power may diverge an incident laser beam by refraction.

[0101] According to an embodiment of the inventive concept, the first lens LE1 to the fifth lens LE5 may be configured to satisfy the conditions given by Equation 1 and Equation 2 below.

[0102] [Equation 1]

[0103] 0.2 < f1 / f < 0.4, -0.4 < f2 / f < -0.2, -1.9 < f3 / f < -0.4, 1.2 < f4 / f < 2.0, and 0.7 < f5 / f < 1.6

[0104] In Equation 1 above, f1, f2, f3, f4, and f5 respectively represent the focal lengths of the first lens LE1, the second lens LE2, the third lens LE3, the fourth lens LE4, and the fifth lens LE5. Additionally, hereinafter, the total focal length f represents the combined focal length of the lens assembly LA including all the lenses from the first lens LE1 to the fifth lens LE5.

[0105] Referring to Figure 9 , when the focal length is negative, the focus of the lens (e.g., the second lens LE2 or the third lens LE3) is defined to be on the left side of the lens. When the focal length is positive, the focus of the lens (e.g., the first lens LE1, the fourth lens LE4, or the fifth lens LE5) is defined to be on the right side of the lens.

[0106] [Equation 2]

[0107] -0.3 < f23 / f < -0.1, and

[0108] 0.4 < f45 / f < 0.8.

[0109] In Equation 2 above, f23 represents the combined focal length of the lens structure including the second lens LE2 and the third lens LE3, f45 represents the combined focal length of the lens structure including the fourth lens LE4 and the fifth lens LE5, and the total focal length f represents the combined focal length of the lens assembly LA including all lenses from the first lens LE1 to the fifth lens LE5.

[0110] Table 1 shows Figure 9 The lens specifications (e.g., radius of curvature, thickness, refractive index). In Table 1, R1 represents... Figure 9 The radius of curvature of the left portion of each lens is shown in Table 1, and R2 represents the radius of curvature of the right portion of the lens. In Table 1, the radius of curvature and thickness of each lens can be expressed in mm.

[0111] [Table 1]

[0112]

[0113]

[0114] Reference Figure 9 According to Table 1, the first distance d1 represents the distance between the scanner SC and the first lens LE1. The second distance d2 represents the distance between the first lens LE1 and the second lens LE2. The third distance d3 represents the distance between the second lens LE2 and the third lens LE3. The fourth distance d4 represents the distance between the third lens LE3 and the fourth lens LE4. The fifth distance d5 represents the distance between the fourth lens LE4 and the fifth lens LE5. The sixth distance d6 represents the distance between the fifth lens LE5 and the window WIN. The seventh distance d7 represents the distance between the window WIN and the panel substrate SUB.

[0115] In this embodiment, the first distance d1 is 90mm, the second distance d2 is 70mm, the third distance d3 is 98mm, the fourth distance d4 is 185mm, the fifth distance d5 is 20mm, the sixth distance d6 is 30mm, and the seventh distance d7 is 400mm. The wavelength of the laser beam with a 343nm wavelength is used in the embodiments shown in Table 1.

[0116] When the first lens LE1 to the fifth lens LE5 have the specifications shown in Table 1, the first lens LE1 to the fifth lens LE5 satisfy the conditions given by Equations 1 and 2. Specifically, referring to the results in Table 1, f1 / f is 0.317, f2 / f is -0.327, f3 / f is -0.519, f4 / f is 1.529, and f5 / f is 0.849. Furthermore, f23 / f is -0.173, and f45 / f is 0.544. Therefore, the focal lengths f1, f2, f3, f4, and f5 of the first lens LE1 to the fifth lens LE5 shown in Table 1 satisfy all the conditions given by Equations 1 and 2.

[0117] Figure 10A It shows from Figure 1 An image of the cross-sectional shape of a laser beam emitted by a laser cutting device and directed onto a target object. Figure 10B This is an image showing the cross-sectional shape of a laser beam emitted from and irradiating a target object from a laser cutting apparatus according to the comparative example. It is assumed that the lens of the laser cutting apparatus according to the comparative example does not satisfy the conditions of Equation 1 or Equation 2.

[0118] Reference Figure 10A Illuminating the target object (e.g., Figure 10A The cross-sectional shape of the laser beam (in its central part) can be similar to a circle. Conversely, referring to... Figure 10B Illuminating the target object (e.g., Figure 10B The cross-sectional shape of the laser beam (in the central part) can resemble an ellipse elongated in the diagonal direction, rather than a circle.

[0119] like Figure 10B As shown, when the laser beam irradiating the target object has an elliptical shape instead of a circular shape, it causes localized energy non-uniformity in the irradiated area. This can lead to malfunctions in the cutting process of the target object.

[0120] On the contrary, such as Figure 10A As shown, when the laser beam irradiating the target object has a circular shape, the laser beam can uniformly provide energy to the irradiated area. Therefore, the cutting process can be performed on the target object in a reliable manner.

[0121] In summary, the laser cutting apparatus LD according to embodiments of the inventive concept may include a lens assembly configured to satisfy the conditions given by Formulas 1 and 2, thereby enabling the cutting process to be performed in a highly reliable manner.

[0122] Figure 11 and Figure 12 These are all diagrams illustrating lenses constituting a lens assembly according to embodiments of the inventive concept. Figure 11 and Figure 12The lens can be configured to satisfy the conditions given by Equations 1 and 2. Hereinafter, a lens assembly in which the lens is configured to have specifications different from those of the embodiments described above will be described.

[0123] Table 2 shows Figure 11 The specifications of the lens are shown in the image.

[0124] [Table 2]

[0125]

[0126] Reference Figure 11 Referring to Table 2, in this embodiment, the first distance d1 is 100mm, the second distance d2 is 90mm, the third distance d3 is 175mm, the fourth distance d4 is 83mm, the fifth distance d5 is 43mm, the sixth distance d6 is 15mm, and the seventh distance d7 is 320mm. A laser beam with a wavelength of 343nm is used in the example in Table 2.

[0127] According to this embodiment, when the first lens LE1-1 to the fifth lens LE5-1 have the specifications shown in Table 2, the first lens LE1-1 to the fifth lens LE5-1 satisfy the conditions given by Equations 1 and 2. Specifically, referring to Table 2, f1 / f is 0.351, f2 / f is -0.281, f3 / f is -1.784, f4 / f is 1.816, and f5 / f is 1.000. Furthermore, f23 / f is -0.227, and f45 / f is 0.654. ​​Therefore, the focal lengths f1, f2, f3, f4, and f5 of the first lens LE1-1 to the fifth lens LE5-1 shown in Table 2 satisfy all the conditions given by Equations 1 and 2.

[0128] The laser beam irradiated onto the target object by the laser cutting apparatus according to this embodiment has the same properties as... Figure 10A The cross-sectional shape of the laser beam is similar to that of the cross-section shape.

[0129] Table 3 shows... Figure 12 The specifications of the lens are shown in the image.

[0130] [Table 3]

[0131]

[0132] Reference Figure 12 According to Table 3, in this embodiment, the first distance d1 is 80mm, the second distance d2 is 90mm, the third distance d3 is 150mm, the fourth distance d4 is 150mm, the fifth distance d5 is 20mm, the sixth distance d6 is 15mm, and the seventh distance d7 is 340mm. In the embodiment shown in Table 3, a laser beam with a wavelength of 343nm is used.

[0133] According to this embodiment, when the first lens LE1-2 to the fifth lens LE5-2 have the specifications shown in Table 3, the first lens LE1-2 to the fifth lens LE5-2 can satisfy the conditions given by Equations 1 and 2. Specifically, referring to Table 3, f1 / f is 0.325, f2 / f is -0.268, f3 / f is -1.620, f4 / f is 1.341, and f5 / f is 1.487. Furthermore, f23 / f is -0.217, and f45 / f is 0.714. Therefore, the focal lengths f1, f2, f3, f4, and f5 of the first lens LE1-2 to the fifth lens LE5-2 shown in Table 3 satisfy all the conditions given by Equations 1 and 2.

[0134] The laser beam irradiated onto the target object by the laser cutting apparatus according to this embodiment has the same properties as... Figure 10A The cross-sectional shape of the laser beam is similar to that of the cross-section shape.

[0135] Figure 13 This is an example shown Figure 1 A diagram showing the optical components of the extended portion.

[0136] Reference Figure 13 The extended portion EXP may include a first optical component OM1, a second optical component OM2, a third optical component OM3, a fourth optical component OM4, and a fifth optical component OM5. The first optical component OM1 to the fifth optical component OM5 may be arranged sequentially in the first direction DR1.

[0137] In this embodiment, each of the first optical component OM1 to the fifth optical component OM5 may include a lens. For example, the first optical component OM1 and the third optical component OM3 may be concave lenses. Each of the second optical component OM2, the fourth optical component OM4, and the fifth optical component OM5 may be a convex lens. The types of the first optical component OM1 to the fifth optical component OM5 are not limited to this example.

[0138] According to embodiments of the inventive concept, the positions of the first optical component OM1 and the fifth optical component OM5 can be changed. For example, the first optical component OM1 can be configured to move toward or away from the second optical component OM2 in a first direction DR1. In other words, the first distance k1 can be changed. The first distance k1 can represent the distance between the first optical component OM1 and the second optical component OM2.

[0139] The fifth optical component OM5 can be configured to move toward or away from the fourth optical component OM4 in the first direction DR1. In other words, the second distance k2 can be changed. The second distance k2 can represent the distance between the fourth optical component OM4 and the fifth optical component OM5.

[0140] The extended portion EXP can be configured to increase the cross-sectional width of the laser beam incident through the first optical element OM1 to the fifth optical element OM5. Here, the cross-sectional size of the laser beam is the size of the cross-section of the laser beam as observed in the incident (or emitted) direction.

[0141] The profile width of the laser beam incident on the extension section EXP can be varied. For example, even when the profile width of the laser beam designed for the light source LS is 2.5 mm, the profile width of the laser beam actually emitted from the light source LS can be 2.5 ± 0.5 mm. Here, 0.5 mm can represent the error in the width of the laser beam incident on the extension section EXP.

[0142] When the extended section EXP has a fixed magnification, the error increases. For example, if the extended section EXP has a magnification of 5.4, the ideal profile width of the laser beam emitted from the extended section EXP is 13.5 mm, but the actual profile width of the laser beam emitted from the extended section EXP will be 13.5 ± 2.7 mm. Here, 2.7 mm can represent the error in the width of the laser beam emitted from the extended section EXP. In other words, the error also increases by a factor of 5.4.

[0143] In contrast, according to embodiments of the inventive concept, the extended portion EXP can have a variable magnification. For example, the magnification of the extended portion EXP can be controlled by a first distance k1 and a second distance K2. Therefore, even when the width of the laser beam incident on the extended portion EXP differs from the design value, the width of the laser beam emitted from the extended portion EXP can be uniformly controlled.

[0144] According to an embodiment of the inventive concept, the first housing and the second housing, which are respectively provided with a first lens group and a second lens group, can be combined with each other in a manner in which they can be easily disassembled, so that the lens assembly can be easily processed, maintained and repaired.

[0145] While exemplary embodiments of the inventive concept have been specifically shown and described, those skilled in the art will understand that variations in form and detail may be made therein without departing from the spirit and scope of the appended claims.

Claims

1. A laser cutting device, wherein, The laser cutting device includes: a light source that generates a laser beam; and a lens assembly that converges the laser beam incident from the light source, wherein the lens assembly includes: a first housing including a first body in which a first opening and a plurality of support portions are defined, at least one of the plurality of support portions being defined by a support surface and a detachable fastening member; a second housing detachably combined with the first housing, the second housing including a second body disposed below the first body and having a second opening overlapping the first opening and a plurality of support portions defined therein, at least one of the plurality of support portions being defined by a support surface and a detachable fastening member; a first lens group disposed in the first body and including a plurality of lenses respectively disposed on the plurality of support portions defined in the first body; and a second lens group disposed in the second body and including a plurality of lenses respectively disposed on the plurality of support portions defined in the second body, wherein at least one of the plurality of support portions defined in the first body enables a corresponding lens in the first lens group to be detachably disposed on at least one of the plurality of support portions defined in the first body, and at least one of the plurality of support portions defined in the second body enables a corresponding lens in the second lens group to be detachably disposed on at least one of the plurality of support portions defined in the second body, wherein the plurality of lenses in the first lens group include a first lens, a second lens disposed below the first lens, and a third lens disposed below the second lens, and the plurality of lenses in the second lens group include a fourth lens disposed below the third lens and a fifth lens disposed below the fourth lens, and wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are configured to satisfy the conditions given by the following formula: [Formula] 0.2 < f1 / f < 0.4, -0.4 < f2 / f < -0.2, -1.9 < f3 / f < -0.4, 1.2 < f4 / f < 2.0, and 0.7 < f5 / f < 1.6, where f1, f2, f3, f4, and f5 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, respectively, and f is the combined focal length of all the lenses from the first lens to the fifth lens.

2. The laser cutting apparatus according to claim 1, wherein, The first housing further includes a first flange portion that surrounds an outer surface of a lower portion of the first body, and the second housing further includes a second flange portion that surrounds an outer surface of an upper portion of the second body and is combined with the first flange portion.

3. The laser cutting device according to claim 2, wherein the laser cutting device further comprises a combination unit, and the combination unit is inserted into a first hole defined in the first flange portion and a second hole defined in the second flange portion.

4. The laser cutting apparatus according to claim 2, wherein, The first housing further comprises a guiding portion, which extends downward from the bottom of the first body and is inserted into the second body.

5. The laser cutting apparatus according to claim 1, wherein, The first housing further comprises a first extending portion, which extends downward from the bottom of the first body, and a first thread is defined on the first extending portion. The second housing further comprises a second extending portion, which extends upward from the top of the second body, and a second thread is defined on the second extending portion, and the first extending portion is fastened to the second extending portion.

6. The laser cutting apparatus according to claim 5, wherein, The first thread is defined on the inner circumferential surface of the first extending portion. The second thread is defined on the outer circumferential surface of the second extending portion, and when observed in a plan view, the first extending portion is disposed outside the second extending portion.

7. The laser cutting apparatus according to claim 1, wherein, The first lens, the second lens and the third lens are respectively placed on the first support portion, the second support portion and the third support portion of the plurality of support portions defined in the first body, and the fourth lens and the fifth lens are respectively placed on the fourth support portion and the fifth support portion of the plurality of support portions defined in the second body.

8. The laser cutting apparatus according to claim 1, wherein, The second lens, the third lens, the fourth lens and the fifth lens are configured to satisfy the conditions given by the following formula: [Formula] -0.3 < f23 / f < -0.1 and 0.4 < f45 / f < 0.8, where f23 is the combined focal length of the second lens and the third lens, and f45 is the combined focal length of the fourth lens and the fifth lens.

9. The laser cutting apparatus according to claim 1, wherein, The laser cutting device further comprises a third housing disposed below the second housing.

10. The laser cutting apparatus according to claim 9, wherein, The laser cutting device further comprises a third lens group disposed in the third housing.

11. The laser cutting device according to claim 1, wherein the laser cutting device further comprises an expanding portion disposed between the light source and the lens assembly.

12. The laser cutting apparatus according to claim 11, wherein, The expanding portion is configured to increase the width of the laser beam incident from the light source and emit the laser beam toward the lens assembly.

13. The laser cutting apparatus according to claim 11, wherein, The expanding portion comprises a first optical member, a second optical member, a third optical member, a fourth optical member and a fifth optical member.

14. The laser cutting apparatus according to claim 13, wherein, The first optical member is configured to move toward or away from the second optical member, and the fifth optical member is configured to move toward or away from the fourth optical member.

15. The laser cutting apparatus according to claim 1, wherein, The light source is an ultra-high frequency pulsed laser.

16. A lens assembly, the lens assembly comprising: a first housing, comprising a first body, in which a first opening and a plurality of support portions are defined, and at least one of the plurality of support portions is defined by a support surface and a detachable fastening member; A second housing, including a second main body, the second main body being disposed below the first main body, and a second opening and a plurality of support portions being defined in the second main body, the second opening being superimposed with the first opening, and at least one of the plurality of support portions being defined by a support surface and a detachable fastening member; A first lens group, disposed in the first main body and including a plurality of lenses, the plurality of lenses being respectively disposed on the plurality of support portions defined in the first main body; And A second lens group, disposed in the second main body and including a plurality of lenses, the plurality of lenses being respectively disposed on the plurality of support portions defined in the second main body, wherein the second housing is selectively combined with the first housing, wherein at least one of the plurality of support portions defined in the first main body enables a corresponding lens in the first lens group to be detachably disposed on at least one of the plurality of support portions defined in the first main body, and at least one of the plurality of support portions defined in the second main body enables a corresponding lens in the second lens group to be detachably disposed on at least one of the plurality of support portions defined in the second main body, wherein the plurality of lenses in the first lens group include a first lens, a second lens disposed below the first lens, and a third lens disposed below the second lens, and the plurality of lenses in the second lens group include a fourth lens disposed below the third lens and a fifth lens disposed below the fourth lens, and wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are configured to satisfy the conditions given by the following formula: [Formula] 0.2 < f1 / f < 0.4, -0.4 < f2 / f < -0.2, -1.9 < f3 / f < -0.4, 1.2 < f4 / f < 2.0, and 0.7 < f5 / f < 1.6, wherein f1, f2, f3, f4, and f5 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, respectively, and f is the combined focal length of all the lenses from the first lens to the fifth lens.

17. The lens assembly according to claim 16, wherein, The first housing further includes a first flange portion surrounding an outer surface of a lower portion of the first main body, The second housing further includes a second flange portion surrounding an outer surface of an upper portion of the second main body and combined with the first flange portion, and A combining unit inserted into a first hole defined in the first flange portion and a second hole defined in the second flange portion.

18. The lens assembly according to claim 16, wherein, The first housing further includes a first extension portion extending downward from a bottom of the first main body, and a first thread is defined on an inner circumferential surface of the first extension portion, The second housing further includes a second extension portion extending upward from a top of the second main body, and a second thread is defined on an outer circumferential surface of the second extension portion, The first extension portion is fastened to the second extension portion.

19. A laser cutting device, the laser cutting device comprising: a light source that generates a laser beam; and a lens assembly that converges the laser beam incident from the light source, wherein the lens assembly includes: a plurality of detachable housings that are combined with each other and include a main body in which an opening and a plurality of support portions are defined, at least one of the plurality of support portions being defined by a support surface and a detachable fastening member; at least one combination unit disposed between the housings; and a plurality of lenses disposed in the housings, the plurality of lenses being respectively disposed on the plurality of support portions defined in the main body, wherein at least one of the plurality of support portions defined in the main body enables a corresponding lens to be detachably disposed on at least one of the plurality of support portions defined in the main body, wherein the plurality of lenses include a first lens, a second lens disposed below the first lens, a third lens disposed below the second lens, a fourth lens disposed below the third lens, and a fifth lens disposed below the fourth lens, and wherein the first lens, the second lens, the third lens, the fourth lens, and the fifth lens are configured to satisfy the conditions given by the following formula: [Formula] 0.2 < f1 / f < 0.4, -0.4 < f2 / f < -0.2, -1.9 < f3 / f < -0.4, 1.2 < f4 / f < 2.0, and 0.7 < f5 / f < 1.6, where f1, f2, f3, f4, and f5 are the focal lengths of the first lens, the second lens, the third lens, the fourth lens, and the fifth lens, respectively, and f is the combined focal length of all the lenses from the first lens to the fifth lens.

Images