A method, device and equipment for nondestructive cutting and section sealing of liquid crystal display

Abstract

This invention relates to a method, apparatus, and equipment for non-destructive cutting and section sealing of liquid crystal displays. The method includes identifying and aligning a cutting path on a display panel; scanning and cutting along the cutting path using an ultra-short pulse laser beam; and applying a liquid sealing material to the cut section to form a sealing protective layer. This achieves integrated processing of flexible and irregularly shaped OLED displays from high-precision non-destructive cutting to high-reliability section sealing, fundamentally improving the cutting quality, long-term environmental stability, and production efficiency of the product.

Description

Technical Field

[0001] This invention relates to the field of display panel manufacturing technology, and in particular to a method, apparatus and equipment for non-destructive cutting and section sealing of a liquid crystal display screen. Background Technology

[0002] In the display panel manufacturing industry, especially for the precision processing of flexible OLEDs and irregularly shaped screens, cutting and encapsulation are key processes that determine product yield and reliability. Traditional mechanical cutting methods suffer from high stress, micro-cracks, and edge chipping, making it difficult to meet the high-precision requirements of cutting flexible and complex shapes. Laser cutting technology, especially the application of ultrashort pulse lasers, can effectively reduce mechanical stress, but still faces challenges such as heat-affected zone control, optimization of cut surface quality, and subsequent corrosion-resistant sealing. Existing processes treat cutting and sealing as discrete steps, but the cut surface is susceptible to environmental contamination, and subsequent sealing treatment suffers from weak interfacial bonding and cumbersome process flow, affecting the performance and lifespan of the final product. Summary of the Invention

[0003] The main objective of this invention is to provide a method, apparatus, and equipment for non-destructive cutting and section sealing of liquid crystal displays, so as to achieve integrated processing of flexible and irregularly shaped OLED displays from high-precision non-destructive cutting to high-reliability section sealing, fundamentally improving the cutting quality, long-term environmental stability, and production efficiency of the products.

[0004] To achieve the above objectives, the present invention provides a method for non-destructive cutting and section sealing of a liquid crystal display screen, comprising the following steps:

[0005] Identify and align the cutting paths on the display panel, which has a thickness of 0.2 mm to 1 mm;

[0006] The cutting path is scanned and cut using an ultrashort pulse laser beam, wherein the wavelength of the ultrashort pulse laser is in the infrared band and the output power is not less than 10W.

[0007] A liquid sealing material is applied to the cut surface to form a sealed protective layer.

[0008] Furthermore, prior to the step of identifying and aligning the cutting paths on the display panel, the following steps are included:

[0009] The display panel is adsorbed and fixed onto a vacuum adsorption platform with cooling function;

[0010] The vacuum hole array on the surface of the vacuum adsorption platform provides adsorption force, and the temperature of the display panel is controlled by circulating cooling medium through internal channels.

[0011] Further, the steps of identifying and aligning the cutting paths on the display panel include:

[0012] Obtain the original image of the display panel;

[0013] The original image is compared and registered with a preset standard path graphic;

[0014] Based on the comparison and registration results, the coordinate offset between the actual position of the display panel and the theoretical preset position is calculated;

[0015] The coordinate system of the cutting system is compensated and calibrated based on the coordinate offset to obtain the cutting path.

[0016] Further, the step of scanning and cutting along the cutting path using an ultrashort pulse laser beam includes:

[0017] The ultrashort pulse laser beam is processed by a beam shaping module to form a focused spot with uniform energy distribution;

[0018] The focused spot is controlled to perform multiple scans along the cutting path, and the cutting is completed layer by layer. In the multiple scans, the laser pulse energy used in the first scan is set to the lowest value, and the laser pulse energy of each subsequent scan is increased or kept higher than the level of the first scan.

[0019] Furthermore, the step of scanning and cutting along the cutting path using an ultrashort pulse laser beam also includes:

[0020] A peelable protective film is attached to the side of the display panel away from the laser incident side.

[0021] The laser cutting operation penetrates the display panel and terminates at the protective film.

[0022] Furthermore, prior to the step of applying a liquid sealing material to the cut surface, the following steps are included:

[0023] The cut surface is scanned using a plasma jet.

[0024] The plasma jet is used to remove microscopic contaminants from the cut surface and increase surface energy.

[0025] Furthermore, the step of applying a liquid sealing material to the cut surface to form a sealing protective layer includes:

[0026] The liquid sealing material is uniformly covered onto the plasma-treated cut surface in an atomized form;

[0027] Applying ultraviolet light to the area covered with liquid sealing material accelerates the cross-linking and curing reaction of the liquid sealing material, forming a sealing and protective layer that bonds with the cut surface.

[0028] The present invention also provides a non-destructive cutting and section sealing device for a liquid crystal display screen, comprising:

[0029] The recognition module is used to identify and align the cutting paths on the display panel;

[0030] A cutting module is used to scan and cut along the cutting path using an ultrashort pulse laser beam;

[0031] A sealing module is used to apply liquid sealing material to the cut surface to form a sealed protective layer.

[0032] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described non-destructive cutting and section sealing method for liquid crystal displays.

[0033] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-described method for non-destructive cutting and section sealing of a liquid crystal display screen.

[0034] The non-destructive cutting and cross-section sealing method, apparatus, and equipment for liquid crystal displays provided by this invention have the following beneficial effects: This invention utilizes a multi-channel laser scanning method with progressively increasing energy to achieve high-quality cold-working cutting with no taper and minimal chipping of the cut surface without damaging sensitive components, fundamentally ensuring the initial integrity of the cut surface. Furthermore, the fresh cut surface is instantly activated by plasma jet treatment, removing microscopic contaminants and increasing surface energy, providing an ideal bonding interface for subsequent sealing materials. Finally, the use of atomized spraying and ultraviolet rapid curing ensures that the sealing material can uniformly cover and rapidly form a dense protective layer tightly bonded to the cut surface. This invention effectively solves the problems of unstable cutting quality, susceptibility to secondary contamination of the cut surface, weak bonding force of the sealing interface, and low process efficiency in existing technologies through a complete process, improving the cutting yield, long-term environmental reliability, and production efficiency of flexible and irregularly shaped OLED displays. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating a non-destructive cutting and section sealing method for a liquid crystal display screen according to an embodiment of the present invention.

[0036] Figure 2 This is a structural block diagram of a non-destructive cutting and section sealing device for a liquid crystal display screen according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic block diagram of the structure of a computer device according to an embodiment of the present invention.

[0038] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] Reference Figure 1 This is a flowchart illustrating a non-destructive cutting and section sealing method for a liquid crystal display screen proposed in this invention, comprising the following steps:

[0041] S1, Identify and align the cutting paths on the display panel, the thickness of which is 0.2mm to 1mm;

[0042] S2, using an ultrashort pulse laser beam to scan and cut along the cutting path, wherein the wavelength of the ultrashort pulse laser is in the infrared band and the output power is not less than 10W;

[0043] S3, apply liquid sealing material to the cut surface to form a sealing and protective layer.

[0044] In one embodiment, prior to step S1,

[0045] Prior to the steps of identifying and aligning the cut paths on the display panel, the following steps are included:

[0046] The display panel is adsorbed and fixed onto a vacuum adsorption platform with cooling function;

[0047] The vacuum hole array on the surface of the vacuum adsorption platform provides adsorption force, and the temperature of the display panel is controlled by circulating cooling medium through internal channels.

[0048] In practice, before identifying and aligning the cutting path, a vacuum adsorption platform with cooling function is used to stably fix the display panel. This platform utilizes a precisely distributed array of vacuum holes on its surface to generate uniform adsorption force, fixing the display panel, especially flexible OLED panels, flat and stress-free onto the working plane. Compared to mechanical clamping, this fixing method effectively avoids microscopic deformation or panel damage caused by stress concentration at contact points, ensuring the stability of the reference surface for subsequent visual recognition and laser cutting, especially for flexible screens without rigid support and irregularly shaped screens with complex curvatures. Although the heat-affected zone of the subsequent ultra-short pulse laser cutting is extremely small, heat accumulation still occurs under high repetition frequency processing. Therefore, the vacuum adsorption platform also integrates cooling channels, which can actively control the temperature of the display panel adsorbed on it through circulating cooling media (such as deionized water). This promptly removes localized heat generated during processing, preventing performance degradation, changes in internal stress, or microstructural damage due to excessive temperature rise, providing a process environment guarantee for maintaining the physical and chemical properties of the panel during the entire cutting process.

[0049] In one embodiment, for step S1,

[0050] The steps for identifying and aligning the cut paths on the display panel include:

[0051] Obtain the original image of the display panel;

[0052] The original image is compared and registered with a preset standard path graphic;

[0053] Based on the comparison and registration results, the coordinate offset between the actual position of the display panel and the theoretical preset position is calculated;

[0054] The coordinate system of the cutting system is compensated and calibrated based on the coordinate offset to obtain the cutting path.

[0055] In practice, a high-resolution vision system acquires the original image of the display panel. Considering the potential for slight displacement, rotation, or deformation of flexible OLEDs and irregularly shaped screens (such as notch screens and curved screens) after clamping, directly using the preset cutting path would lead to deviations in the actual cutting trajectory. Therefore, the acquired original image is compared and digitally registered in real time with standard path graphics pre-stored in the database. This registration process is not a simple overlap, but rather uses advanced image processing algorithms to identify specific marker points or contour features on the panel and match them with the theoretical model, thereby accurately calculating the coordinate offsets in the X, Y, and θ (rotation) directions between the panel's current actual position and the theoretical preset position. Based on the calculated offsets, the motion coordinate system of the laser cutting head is digitally compensated and calibrated in real time. This eliminates systematic errors caused by clamping errors and material deformation, allowing the system to dynamically learn and understand the true cutting path for each panel.

[0056] In one embodiment, for step S2,

[0057] The ultrashort pulse laser beam is processed by a beam shaping module to form a focused spot with uniform energy distribution;

[0058] The focused spot is controlled to perform multiple scans along the cutting path, and the cutting is completed layer by layer. In the multiple scans, the laser pulse energy used in the first scan is set to the lowest value, and the laser pulse energy of each subsequent scan is increased or kept higher than the level of the first scan.

[0059] In practice, the raw laser beam emitted from the ultrashort pulse laser is processed by a dedicated beam shaping module. This module uses a series of high-quality optical elements (such as beam expanders and homogenizing lenses) to modulate the wavefront of the laser beam, reshaping the energy profile, which might otherwise have a Gaussian distribution, into a focused spot with a highly uniform energy distribution within the effective processing area. This ensures that any point on the cutting path receives consistent energy during subsequent scanning and cutting, resulting in a cut surface with good perpendicularity, no taper, and uniform roughness. This effectively avoids defects such as localized overburning or incomplete cutting caused by uneven beam energy. The focused spot with uniform energy is controlled to perform multiple scans along the calibrated cutting path, employing a layered, successive ablation strategy to complete the cutting. In this multi-pass scanning process, the laser pulse energy is precisely programmed and controlled: the first scan is set to a low energy level far below the material's complete vaporization threshold, not for direct cutting, but to perform a kind of "pretreatment" or "modification" of the material, i.e., to form a very shallow, controllable initial groove or weakening zone on the cutting path, while preheating and driving away any water vapor that may be adsorbed by organic materials in this area; based on this, subsequent scans use progressively increasing or stabilizing laser pulse energy at a higher level to deeply etch the pretreated path until complete separation. Through the "low-to-high" multi-pass energy control strategy, the problems of thermal stress concentration, microcrack propagation, and molten residue splashing caused by a single high-energy impact can be greatly suppressed, thus physically achieving a high-quality cutting section with "small chipping and no residue".

[0060] In one embodiment, the step of scanning and cutting along the cutting path using an ultrashort pulse laser beam further includes:

[0061] A peelable protective film is attached to the side of the display panel away from the laser incident side.

[0062] The laser cutting operation penetrates the display panel and terminates at the protective film.

[0063] In practical implementation, when using an ultrashort pulse laser beam for scanning and cutting, a key auxiliary process needs to be introduced: a peelable protective film is pre-attached to the side of the display panel away from the laser incident surface to solve the problems of edge chipping and back-side contamination during ultrashort pulse laser processing. When the high-energy laser beam penetrates the final microscopic barrier of the panel material, its energy release and material ejection on the light-emitting surface become extremely unstable, easily causing microscopic cracks or imperceptible microscopic molten particles to splash at the cut edge. For display panels with precision driving circuits or sensitive functional coatings on the back, such micro-damage can affect the appearance at best, and lead to short circuits or performance degradation at worst. The protective film attached in this invention has appropriate flexibility, adhesion, and high-temperature resistance properties, acting as a sacrificial layer and physical barrier, adhered to the back of the panel. After the laser cutting operation completely penetrates the display panel body, its residual energy is effectively absorbed and blocked by the protective film, and the cutting process terminates at this protective film layer. Potential back-side chipping, micro-cracks, or hot-melt residue are contained and left on the protective film without damaging the functional structure of the panel itself. After cutting, the protective film is smoothly peeled off to obtain a clean and flawless cut surface with neat back edges.

[0064] In one embodiment, prior to step S3...

[0065] Prior to the step of applying a liquid sealant to the cut surface, the following steps are included:

[0066] The cut surface is scanned using a plasma jet.

[0067] The plasma jet is used to remove microscopic contaminants from the cut surface and increase surface energy.

[0068] In practical implementation, pretreatment is required before applying the liquid sealing material: a plasma jet is used to comprehensively scan the newly formed cut surface. Although ultrashort pulse lasers minimize molten residue, the cut surface may still have extremely fine organic or inorganic contaminants attached at the microscopic scale, as well as a weak interface layer that forms rapidly due to contact with air; furthermore, the surface energy of the cut surface is usually low, resulting in poor wettability and spreadability of the liquid sealing material, making it difficult to form a strong adhesion. This embodiment uses atmospheric pressure plasma jet technology to generate low-temperature plasma rich in highly active particles (such as free radicals, electrons, excited-state molecules, etc.). When this jet scans the cut surface, on the one hand, through the sputtering and vaporization effect at the microscopic level, the nanoscale contaminants and weak boundary layers attached to the cut surface are effectively stripped and removed, exposing a clean surface of the bulk material; on the other hand, and more importantly, the high-energy particles in the plasma bombard the molecular chains on the material surface, causing them to break and form new polar functional groups, thereby significantly and persistently increasing the surface energy of the cut surface. After this process, the originally chemically inert cut surface is transformed into an "activated" state, fundamentally improving its physicochemical compatibility with the liquid sealing material. This allows the subsequently coated sealing material to fully spread and deeply penetrate into the micropores of the cut surface, forming a dense, gapless, and strongly bonded permanent sealing protective layer. This eliminates moisture and oxygen erosion channels caused by poor interfacial bonding, ensuring the stability and lifespan of OLED display devices during long-term use.

[0069] In one embodiment, for step S3,

[0070] The step of applying a liquid sealing material to the cut surface to form a sealing protective layer includes:

[0071] The liquid sealing material is uniformly covered onto the plasma-treated cut surface in an atomized form;

[0072] Applying ultraviolet light to the area covered with liquid sealing material accelerates the cross-linking and curing reaction of the liquid sealing material, forming a sealing and protective layer that bonds with the cut surface.

[0073] In practice, the cut surface is sealed using an integrated coating and rapid curing process. On the clean cut surface, which has undergone plasma jet activation treatment to achieve high surface energy, a precisely controlled atomizing spraying device transforms a specially formulated liquid sealing material (such as modified acrylate or epoxy resin photocurable materials) into a fine and uniform atomized form, covering the entire cut surface. Compared to traditional dispensing or brushing, this atomizing spraying method ensures that the liquid sealing material, with an extremely thin layer and extremely high uniformity, completely encapsulates all the complex microscopic contours and pores of the cut surface, including the micron-level rough structures formed by laser cutting, thus avoiding localized sealing weaknesses caused by uneven coating or air bubble entrainment. Immediately after coating, ultraviolet light of a specific wavelength and energy is applied to the area covered with the liquid sealing material. This ultraviolet light, as an external energy source, rapidly excites the photoinitiator in the liquid sealing material system, thereby accelerating the cross-linking and curing reaction between the material's molecular chains, transforming it from a liquid state into a dense solid polymer within seconds. To improve production efficiency, a stable chemical bond and mechanical interlock are established between the sealing material and the plasma-activated cut surface, ultimately forming a permanent sealing and protective layer that is integrated with the cut surface and possesses excellent anti-aging and barrier properties. This protective layer can prevent moisture and oxygen from the environment from penetrating the brittle OLED organic light-emitting layer and metal electrodes, ensuring the stable performance and extended lifespan of the display panel during long-term use.

[0074] Reference Figure 2 The diagram shows a structural block diagram of a non-destructive cutting and section sealing device for a liquid crystal display screen according to an embodiment of the present invention, comprising:

[0075] The recognition module is used to identify and align the cutting paths on the display panel;

[0076] A cutting module is used to scan and cut along the cutting path using an ultrashort pulse laser beam;

[0077] A sealing module is used to apply liquid sealing material to the cut surface to form a sealed protective layer.

[0078] For the specific implementation of each module in the above device example, please refer to the above method embodiments, which will not be repeated here.

[0079] Reference Figure 3 This invention also provides a computer device, which can be a server, and its internal structure can be as follows: Figure 3As shown, the computer device includes a processor, memory, display screen, input device, network interface, and database connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system, computer programs, and database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database stores the data corresponding to this embodiment. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements the above-described method.

[0080] Those skilled in the art will understand that Figure 3 The structures shown are merely block diagrams of some structures related to the present invention and do not constitute a limitation on the computer devices on which the present invention is applied.

[0081] An embodiment of the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method. It is understood that the computer-readable storage medium in this embodiment can be a volatile readable storage medium or a non-volatile readable storage medium.

[0082] In summary, this invention achieves a fully integrated process for flexible and irregularly shaped OLED displays, from high-precision non-destructive cutting to high-reliability section sealing, by identifying and aligning the cutting path on the display panel; scanning and cutting along the cutting path using an ultra-short pulse laser beam; and applying a liquid sealing material to the cut surface to form a sealing protective layer. This fundamentally improves the cutting quality, long-term environmental stability, and production efficiency of the product.

[0083] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the present invention and embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual-rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM, etc.

[0084] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0085] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for non-destructive cutting and section sealing of a liquid crystal display screen, characterized in that, Includes the following steps: The display panel is adsorbed and fixed onto a vacuum adsorption platform with cooling function, and the temperature of the display panel is controlled by circulating cooling medium through internal channels. Identify and align the cutting paths on the display panel, which has a thickness of 0.2 mm to 1 mm; The method involves scanning and cutting along the cutting path using an ultrashort pulse laser beam, including: processing the ultrashort pulse laser beam through a beam shaping module to form a focused spot with uniform energy distribution; controlling the focused spot to perform multiple scans along the cutting path, completing the cutting layer by layer; wherein, in the multiple scans, the laser pulse energy used in the first scan is set to a low energy level far below the material's complete vaporization threshold, in order to form a very shallow, controllable initial groove or weakened region on the cutting path, while preheating and driving away any water vapor that may be adsorbed by the organic material in this region; the laser pulse energy of subsequent scans gradually increases or remains higher than the level of the first scan; the wavelength of the ultrashort pulse laser is located in the infrared band, and the output power is not less than 10W. Plasma jets are used to scan the cut surface to remove microscopic contaminants and increase surface energy. Liquid sealing material is uniformly atomized and applied to the plasma-treated cut surface. Ultraviolet light is then applied to the area covered with the liquid sealing material to accelerate the cross-linking and curing reaction of the liquid sealing material, forming a sealing and protective layer that bonds with the cut surface.

2. The non-destructive cutting and section sealing method for a liquid crystal display screen according to claim 1, characterized in that, The step of identifying and aligning the cutting paths on the display panel includes: Obtain the original image of the display panel; The original image is compared and registered with a preset standard path graphic; Based on the comparison and registration results, the coordinate offset between the actual position of the display panel and the theoretical preset position is calculated; The coordinate system of the cutting system is compensated and calibrated based on the coordinate offset to obtain the cutting path.

3. The non-destructive cutting and section sealing method for a liquid crystal display screen according to claim 1, characterized in that, The step of scanning and cutting along the cutting path using an ultrashort pulse laser beam further includes: A peelable protective film is attached to the side of the display panel away from the laser incident side. The laser cutting operation penetrates the display panel and terminates at the protective film.

4. A non-destructive cutting and section sealing device for a liquid crystal display screen, characterized in that, include: The vacuum adsorption module is used to adsorb and fix the display panel onto a vacuum adsorption platform with cooling function, and to control the temperature of the display panel through the internal flow channel circulating cooling medium. The recognition module is used to identify and align the cutting paths on the display panel; The cutting module is used to scan and cut along the cutting path using an ultrashort pulse laser beam, including: processing the ultrashort pulse laser beam through a beam shaping module to form a focused spot with uniform energy distribution; controlling the focused spot to perform multiple scans along the cutting path, completing the cutting layer by layer; wherein, in the multiple scans, the laser pulse energy used in the first scan is set to a low energy level far below the material's complete vaporization threshold, so as to form a very shallow, controllable initial groove or weakening zone on the cutting path, while preheating and driving away any water vapor that may be adsorbed by the organic material in this area, and the laser pulse energy of subsequent scans gradually increases or remains higher than the level of the first scan; The plasma processing module is used to scan the cut surface with a plasma jet to remove microscopic contaminants from the cut surface and increase the surface energy. The sealing module is used to uniformly cover the plasma-treated cut surface with liquid sealing material in an atomized form, and to apply ultraviolet irradiation to the area covered with liquid sealing material to accelerate the cross-linking and curing reaction of the liquid sealing material, forming a sealing protective layer that is bonded to the cut surface.

5. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the non-destructive cutting and section sealing method for the liquid crystal display screen according to any one of claims 1 to 3.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the non-destructive cutting and section sealing method for the liquid crystal display screen as described in any one of claims 1 to 3.

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