Emitter and field emission assembly comprising same

Abstract

An emitter is provided. The emitter according to an aspect of the present specification has the form of a sheet including carbon nanotubes and includes at least any one of a portion curved to form a ridge in the direction of electron emission and a portion bent to form a ridge in the electron emission direction.

Description

Emitter and field emission assembly including the same

[0001] The present invention relates to an emitter, a field emission assembly, and an electromagnetic wave generating device including the same. More specifically, the present invention relates to a field emission assembly capable of increasing the amount of electrons emitted and uniformizing field emission characteristics through the structure of the emitter, and an electromagnetic wave generating device including the same.

[0002] Recently, with the development of carbon nanotube (CNT) technology, a technology is being developed to replace the cathode of existing X-ray tubes using thermionic emission filaments with a cold cathode using carbon nanotubes.

[0003] Typically, a carbon nanotube-based X-ray tube is composed of a cathode section containing an emitter made of carbon nanotubes, a gate that induces electron emission, a focusing electrode that improves electron focusing performance, and an anode section that generates electromagnetic waves (specifically, X-rays) by collision of the emitted electrons.

[0004] These electromagnetic wave generators may require different field emission characteristics depending on their intended use. For example, an electromagnetic wave generator used for breast cancer detection may require a high dose of X-rays, while other specific applications may require less intense X-ray emissions. This is because higher X-ray intensities can penetrate the target being detected, potentially rendering it undetectable.

[0005] The voltage, geometry, and position of each component of an electromagnetic wave generator determine the quantity of emitted electrons, their collision velocity, and the size of their focal spot. These factors, in turn, determine the resolution and image quality of radiographic images. In particular, for emitters made of carbon nanotubes, the shape and bonding structure of the emitter can influence the uniformity of the amount of electrons emitted and / or the field emission.

[0006] In conventional cold cathode X-ray tubes using carbon nanotubes, a field emission assembly is used in which a linear yarn is cut into a certain length and the yarn is secured to a holder with the cut surface facing the anode. When an electric field is generated in such an X-ray tube, electrons can be emitted from the cut surface of the yarn.

[0007] However, in the case of these conventional field emission assemblies, there was a problem that the amount of electron emission was insufficient because the area of ​​the cross-section of the linear yarn facing the anode was not large.

[0008] In addition, there was a problem that the cross-section of the linear yarn composed of carbon nanotube fibers was not always constant, and accordingly, there was a limitation in that the uniformity of the field emission characteristics and the lifespan of the electromagnetic wave generating device was low.

[0009] In addition, there were limitations in precisely adjusting the amount or intensity of electromagnetic waves generated as the uniformity of field emission characteristics decreased.

[0010] The problem to be solved by this specification is to provide an emitter, a field emission assembly, and an electromagnetic wave generating device including the same, which can generate stronger electromagnetic waves by improving the amount of electrons emitted.

[0011] In addition, the present invention provides an emitter, a field emission assembly, and an electromagnetic wave generating device including the same, which can improve the field emission characteristics of the emitter and the uniformity of the lifespan of the electromagnetic wave generating device.

[0012] In addition, the present invention provides an emitter, a field emission assembly, and an electromagnetic wave generating device including the same, which can more precisely adjust the amount or intensity of electromagnetic waves generated.

[0013] An emitter according to an aspect of the present disclosure for achieving the above task may be formed in a sheet shape including carbon nanotubes and may include at least one of a portion bent so as to form a ridge in the electron emission direction and a portion folded so as to form a ridge in the electron emission direction.

[0014] This can improve the electron emission of the emitter, enabling the generation of stronger electromagnetic waves.

[0015] Additionally, the field emission characteristics in the emitter and the uniformity of the life of the electromagnetic wave generating device can be improved.

[0016] Additionally, as the uniformity of field emission characteristics improves, the amount or intensity of electromagnetic waves generated can be adjusted more precisely.

[0017] Additionally, the ridge formed by the curved or folded portion may be single.

[0018] Additionally, based on the ridge, the two sides may get closer to each other as they move in the direction of electron emission, or they may get closer to each other but some areas may be parallel.

[0019] Additionally, it may be a shape in which the slope of the tangent line changes continuously.

[0020] Additionally, if the emitter includes a portion that is curved so that a ridge is formed in the direction of electron emission, the radius of curvature at the ridge can be formed to be smaller than the radius of curvature of other portions of the emitter, based on the cross-section intersecting the ridge.

[0021] Additionally, when the emitter includes a portion that is bent so that a ridge is formed in the direction of electron emission, each of the two side regions can form a concave portion sunken toward the center based on the ridge.

[0022] Additionally, it may include a plurality of yarns including carbon nanotube fibers.

[0023] Additionally, it may be a structure in which a plurality of yarns extending in the first direction are arranged in a second direction that intersects the first direction.

[0024] Additionally, the ridges can be formed parallel to the first direction.

[0025] Additionally, the ridges can be formed parallel to the second direction.

[0026] Additionally, the emitter can be formed by weaving multiple yarns.

[0027] According to one aspect of the present disclosure for achieving the above object, a field emission assembly comprises: a sheet-shaped emitter including carbon nanotubes; and a holder for fixing the emitter, wherein the sheet-shaped emitter may include at least one of a portion bent so as to form a ridge in the electron emission direction and a portion folded so as to form a ridge in the electron emission direction.

[0028] Additionally, the emitter can be electrically connected to the holder by at least one of a method including being pressed into the holder, a method including being welded, and a method including being bonded by an adhesive.

[0029] Additionally, the two ends of the emitter can be spaced apart from each other and fixed to the holder with respect to the ridge.

[0030] Additionally, the holder includes a body portion, and both ends of the emitter can be pressed against both sides of the body portion, respectively.

[0031] Additionally, the holder may include a first fixing part arranged on one side of the body part and a second fixing part arranged on the other side of the body part, and one end of the emitter may be arranged between the body part and the first fixing part, and the other end of the emitter may be arranged between the body part and the second fixing part.

[0032] Additionally, the two ends of the emitter can be fixed to the holder so that they are adjacent to each other with respect to the ridge.

[0033] Additionally, the holder includes a first body portion, and both ends of the emitter can be brought into close contact with one side of the first body portion.

[0034] Additionally, the holder includes a second body part arranged on one side of the first body part, and both ends of the emitter can be arranged between the first body part and the second body part.

[0035] Additionally, the length of the emitter in the ridge direction may be greater than the height at which the emitter protrudes from the holder.

[0036] Additionally, the angle formed by the tangents of the two sides of the emitter that begin to protrude from the holder can be between 0° and 180°.

[0037] Through this specification, the electron emission of the emitter can be improved, thereby enabling the generation of stronger electromagnetic waves.

[0038] Additionally, the field emission characteristics in the emitter and the uniformity of the life of the electromagnetic wave generating device can be improved.

[0039] Additionally, as the uniformity of field emission characteristics improves, the amount or intensity of electromagnetic waves generated can be adjusted more precisely.

[0040] FIG. 1 is a conceptual diagram of an electromagnetic wave generating device including a field emission assembly according to one embodiment of the present specification.

[0041] FIG. 2 is a perspective view illustrating an example of a field emission assembly according to one embodiment of the present specification.

[0042] FIG. 3 is a cross-sectional view illustrating an example of a field emission assembly according to one embodiment of the present specification.

[0043] FIG. 4 is a perspective view illustrating another example of a field emission assembly according to one embodiment of the present specification.

[0044] FIG. 5 is a cross-sectional view illustrating another example of a field emission assembly according to one embodiment of the present specification.

[0045] FIG. 6 illustrates various aspects of an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0046] FIG. 7 is an enlarged view of an example of an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0047] FIG. 8 is an enlarged view of another example of an emitter according to one embodiment of the present specification.

[0048] FIG. 9 illustrates an example of a method for manufacturing an emitter according to one embodiment of the present specification.

[0049] FIG. 10 illustrates another example of a method for manufacturing an emitter according to one embodiment of the present disclosure.

[0050] FIGS. 11 and 12 illustrate various aspects of an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0051] FIG. 13 illustrates another example of an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0052] Figure 14 is an enlarged view of the P region of the emitter illustrated in Figure 13.

[0053] FIG. 15 is a photograph of a yarn forming an emitter of a field emission assembly according to one embodiment of the present specification.

[0054] FIG. 16 illustrates a method for forming an emitter of a field emission assembly according to one embodiment of the present specification.

[0055] FIG. 17 is a graph showing field emission characteristics according to the exposure area of ​​an emitter of a field emission assembly according to one embodiment of the present specification.

[0056] FIG. 18 is a graph showing field emission characteristics according to the ridge formation direction of the emitter of a field emission assembly according to one embodiment of the present specification.

[0057] FIG. 19 is a perspective view illustrating an example of a field emission assembly according to another embodiment of the present specification.

[0058] FIG. 20 is a perspective view illustrating another example of a field emission assembly according to another embodiment of the present specification.

[0059] The terms used in the examples have been selected from widely used, current terms, taking into account the functions of the present disclosure. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description. Therefore, the terms used in this disclosure should not be defined simply as names, but rather based on the meanings of the terms and the overall content of the present disclosure.

[0060] The suffixes "module" and "part" used for components in the following description are given or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments included in the present disclosure, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments included in the present disclosure, the detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments included in the present disclosure, and the technical idea of ​​the present disclosure is not limited by the attached drawings, and it should be understood that they include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present disclosure.

[0061] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0062] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0063] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0064] It should be understood that terms such as “comprises” or “has” used throughout the specification are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0065] The expression "at least one of a, b, and c" described throughout the specification may encompass 'a alone', 'b alone', 'c alone', 'a and b', 'a and c', 'b and c', or 'all of a, b, and c'.

[0066] Below, embodiments of the present disclosure are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

[0067] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0068] FIG. 1 is a conceptual diagram of an electromagnetic wave generating device including a field emission assembly according to one embodiment of the present specification.

[0069] The electromagnetic wave generating device (100) according to the first embodiment of the present specification may include a housing (110), a field emission assembly (120), a gate electrode (130), a focusing portion (140), and an anode (150), but some of these components may be omitted and implemented, and additional components are not excluded.

[0070] Hereinafter, the electron emission direction (z) can be understood as the direction from the field emission assembly (120) toward the anode (150), i.e., the upward direction with reference to FIGS. 1 to 5.

[0071] Referring to FIG. 1, an electromagnetic wave generating device (100) may include a housing (110). The housing (110) may accommodate components such as a field emission assembly (120), a gate electrode (130), and an anode (150). The interior of the housing (110) may be maintained in a vacuum state or close to a vacuum state.

[0072] The housing (110) may be provided with an irradiation unit (111). The electromagnetic waves generated from the anode (150) may be emitted to the outside of the housing (110) through the irradiation unit (111). However, alternatively, the housing (110) may be formed entirely of a transparent material, such as glass, so that the electromagnetic waves generated from the anode (150) may pass through, and in this case, a separate irradiation unit (111) may not be provided. In addition, since the intensity of the generated electromagnetic waves may pass through opaque materials when the intensity is strong, the housing (110) may be formed of an opaque material without being provided with an irradiation unit (111).

[0073] An electromagnetic wave generating device (100) may include a field emission assembly (120). The field emission assembly (120) may be a part that emits electrons by an electric field. The field emission assembly (120) may serve as a cathode to which an anode is applied.

[0074] The field emission assembly (120) may include an emitter (121) that emits electrons and a holder (122) that secures the emitter. The specific structure of the field emission assembly (120) will be described in detail later with reference to FIGS. 2 to 5.

[0075] The field emission assembly (120) of the electromagnetic wave generating device (100) according to one embodiment of the present specification may be a cold cathode. Specifically, in the electromagnetic wave generating device (100) according to one embodiment of the present specification, electrons contained in the emitter (121) can be emitted by a voltage applied between the field emission assembly (120) and the gate electrode (130) without applying separate heat to the emitter (121).

[0076] The electromagnetic wave generating device (100) may include a gate electrode (130). The gate electrode (130) may be positioned between the emitter (121) and the anode (150). More specifically, the gate electrode (130) may be positioned closer to the emitter (121) between the emitter (121) and the anode (150).

[0077] The gate electrode (130) can induce electron emission from the emitter (121). Electrons contained in the emitter (121) can be emitted by a voltage applied between the gate electrode (130) and the emitter (121). The gate electrode (130) can primarily perform the role of drawing electrons out of the emitter (121).

[0078] However, the electromagnetic wave generating device (100) may not include a gate electrode (130). In this case, electrons included in the emitter (121) may be emitted by a voltage applied between the focusing unit (140) and the field emission assembly (120), or between the anode (150) and the field emission assembly (120), which will be described later.

[0079] The electromagnetic wave generating device (100) may include a focusing unit (140). The focusing unit (140) may be placed between the gate electrode (130) and the anode (150), or between the field emission assembly (120) and the anode (150).

[0080] The focusing unit (140) can focus an electron beam that has passed through the gate electrode (130) as voltage is applied. The focusing unit (140) can be referred to as a lens. In addition, the focusing unit (140) can further accelerate the electron beam that has passed through the gate electrode (130). Specifically, when a voltage is generated between the focusing unit (140) and the gate electrode (130), electrons that have passed through the gate electrode (130) can be accelerated by an electric field formed by the voltage applied between the focusing unit (140) and the gate electrode (130). An electromagnetic wave generating device (100) of the type in which the focusing unit (140) is provided in this manner can be referred to as a triode type.

[0081] However, the present invention is not limited thereto, and if the focusing performance of the gate electrode (130) itself is good or excellent, the focusing unit (140) may not be provided. In this way, an electromagnetic wave generating device (100) that is not provided with a focusing unit (140) may be referred to as a diode type.

[0082] The electromagnetic wave generating device (100) may include an anode (150). The anode (150) may be disposed on the opposite side of the field emission assembly (120) in the internal space of the housing (110). The anode (150) may be disposed behind the gate electrode (130) and / or the focusing unit (140) in the direction of travel of the electron beam. The anode (150) is a portion to which a positive voltage (+) is applied and may be referred to as an anode portion, or may be referred to as a target meaning an object on which the electron beam collides.

[0083] An electromagnetic wave can be formed at the anode (150). Specifically, an electron beam emitted from the emitter (121) can be accelerated while passing through the gate electrode (130) and / or the focusing unit (140) and then collide with the anode (150). At this time, the electron beam can excite the material constituting the anode (150) to an excited state and then return to its original state, thereby generating an electromagnetic wave.

[0084] The electromagnetic wave emitted by the electromagnetic wave generating device (100) may have a wavelength of 0.001 nm to 10 nm. For example, the electromagnetic wave generating device (100) may emit X-rays having a wavelength of 0.001 nm to 10 nm. More specifically, the electromagnetic wave generating device (100) may emit X-rays having a wavelength of 0.01 nm to 10 nm.

[0085] FIG. 2 is a perspective view illustrating an example of a field emission assembly according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view illustrating an example of a field emission assembly according to an embodiment of the present disclosure. FIG. 4 is a perspective view illustrating another example of a field emission assembly according to an embodiment of the present disclosure. FIG. 5 is a cross-sectional view illustrating another example of a field emission assembly according to an embodiment of the present disclosure. FIG. 6 illustrates various aspects of an emitter of a field emission assembly according to an embodiment of the present disclosure.

[0086] Referring to FIGS. 2 to 5, the field emission assembly (120) may include an emitter (121). The emitter (121) may be fixed to a holder (122). The emitter (121) may be electrically connected to the holder (122) by at least one of a method of being pressed against the holder (122), a method of being welded, and a method of being bonded with an adhesive. When an electric field is applied to the electromagnetic wave generating device (100), electrons may move to the emitter (121) through the holder (122) and then be emitted from the emitter (121). The emitter (121) may include a carbon nanotube fiber through which electrons can easily move. Without being limited thereto, the emitter (121) may be formed of various materials capable of emitting electrons.

[0087] A field emission assembly (120) according to one embodiment of the present specification may include an emitter (121) and a holder (122), but may be implemented excluding some of these, and additional configurations are not excluded.

[0088] The emitter (121) may be in the form of a sheet. Since the emitter (121) is in the form of a sheet, the area from which electrons can be emitted increases, thereby inducing a large amount of electron emission and, accordingly, generating a large amount of electromagnetic waves. Such a sheet-shaped emitter (121) can be particularly useful in specific fields requiring a large amount of electromagnetic waves, such as breast cancer detection.

[0089] The emitter (121) may include carbon nanotubes. Specifically, the emitter (121) may include a plurality of yarns (1211) including carbon nanotube fibers (CNTs). The yarn (1211) may be a linear material formed by gathering carbon nanotube single yarns. The yarn (1211) may be a non-twisted yarn formed by simply gathering a plurality of carbon nanotube single yarns, a twisted yarn, or a braided yarn. When the yarn (1211) is formed as a twisted yarn or a braided yarn, the formation method of the yarn (1211) will be described in detail with reference to FIGS. 15 and 16.

[0090] The plurality of yarns (1211) constituting the sheet-shaped emitter (121) may have various structures. For example, the emitter (121) may have a structure in which a plurality of yarns (1211) extending in one direction are arranged in parallel. In this case, it may be particularly preferable that each yarn (1211) is a twisted yarn, but it is not excluded that each yarn (1211) is a twisted yarn or a braided yarn, or a combination of at least any two of a twisted yarn, a twisted yarn, and a braided yarn.

[0091] Alternatively, the emitter (121) may have a structure in which a plurality of yarns (1211) are woven together. In this case, it may be particularly preferred that each yarn (1211) be a twisted yarn, a twisted yarn, or a braided yarn. However, each yarn (1211) may also be composed of a combination of at least two of the twisted yarns, the twisted yarns, and the braided yarns.

[0092] Alternatively, the emitter (121) may have a structure in which a plurality of yarns (1211) are randomly intertwined with each other. In this case, it may be particularly preferred that each yarn (1211) be a twisted yarn, a twisted yarn, or a braided yarn. However, each yarn (1211) may also be composed of a combination of at least two of the twisted yarns, the twisted yarns, and the braided yarns.

[0093] The emitter (121) having a structure in which a plurality of yarns (1211) extending in one direction are arranged in parallel will be described in detail later with reference to FIGS. 7 to 12. The emitter (121) having a structure in which a plurality of yarns (1211) are woven together will be described in detail later with reference to FIGS. 13 and 14.

[0094] The emitter (121) may include at least one of a curved portion so as to form a ridge (121a) in the electron emission direction (z) and a folded portion so as to form a ridge (121a) in the electron emission direction (z). In other words, the emitter (121) may include a portion that is curved so as to be convex in the electron emission direction (z), or may include a portion that is folded so as to protrude in the electron emission direction (z), or may include both such curved portions and folded portions. The ridge (121a) may be understood to mean a point that protrudes in the electron emission direction (z) relatively to the surrounding area.

[0095] When an electric field is applied to the emitter (121), electrons contained inside the emitter (121) and / or electrons transferred to the emitter (121) from the holder (122) are guided to a region (121b) near the ridge of a portion of the emitter (121) that protrudes in the electron emission direction (z), and then can be emitted to the outside of the emitter (121).

[0096] For example, the emitter (121) may have a shape in which the slope of the tangent line changes continuously. This may mean that the emitter (121) has a shape that is gently curved without any sharp bends. In this case, electron movement within the emitter (121) may become smoother, thereby enabling effective electron emission.

[0097] As another example, the emitter (121) may include a bent (i.e., sharply bent) portion. In this case, it may be desirable for the emitter (121) to be bent so that a ridge (121a) is formed in the electron emission direction (z). Specifically, when an electric field is applied to the emitter (121), electrons may be guided to a portion protruding from the emitter (121) in the electron emission direction (z) and then emitted to the outside of the emitter (121). In this case, if the emitter (121) includes a bent portion so that a ridge is formed in the electron emission direction (z), the electrons may be easily concentrated at the bent point of the emitter (121), and accordingly, the repulsive force between the electrons may increase, so that the electrons may be easily emitted to the outside of the emitter (121). In addition, since the electrons are concentrated and emitted at the bent point, the formation location of the electron emission point may be easily adjusted.

[0098] Hereinafter, a field emission assembly (120) according to one embodiment of the present specification will be described in detail.

[0099] Hereinafter, in the field emission assembly (120) according to one embodiment of the present specification, since the emitter (121) is formed with one ridge (121a), the ridge (121a) may be the same point as the frontmost point (hereinafter, “front end (121a)”) of the electron emission direction (z) of the emitter (121).

[0100] Referring to FIGS. 2 to 5, the emitter (121) of the field emission assembly (120) according to one embodiment of the present disclosure may be bent to form a ridge (121a) in the electron emission direction (z), or may be folded to form a ridge (121a) in the electron emission direction (z). With reference to FIG. 1, the emitter (121) may be bent to form a ridge (121a) toward the anode (150, illustrated in FIG. 1), or may be folded to form a ridge (121a) toward the anode (150, illustrated in FIG. 1). It may be understood that the emitter (121) of the field emission assembly (120) according to one embodiment of the present disclosure is bent to have one ridge (121a) or is folded to have one ridge (121a). The emitter (121) in the form of a single ridge (121a) has a simple shape, so that the field emission assembly (120) can be manufactured consistently, and through this, the uniformity of the field emission characteristics and the lifespan of the electromagnetic wave generating device (100) can be improved.

[0101] When an electric field is applied to the emitter (121), electrons contained inside the emitter (121) and / or electrons transferred to the emitter (121) from the holder (122) are guided to a region near the front end (121a) of the electron emission direction (z) of the emitter (121) (hereinafter, “front end (121b)”), and then can be emitted to the outside of the emitter (121) from the front end (121b).

[0102] Through this electron emission method, the non-uniformity caused by cutting of the emitter (121) can be eliminated, and accordingly, the uniformity of the field emission characteristics and the lifespan of the electromagnetic wave generating device (100) can be improved. In addition, the adjustment of the amount or intensity of electromagnetic waves generated can be performed more precisely due to the improved uniformity of the field emission characteristics. In addition, since electrons are emitted across the ridge (121a) and / or the area near the ridge (121b), the area from which electrons can be emitted can be expanded, and accordingly, a sufficient amount of electrons can be emitted.

[0103] Based on the ridge (121a) of the emitter (121), both sides of the emitter (121) may become closer as they go toward the electron emission direction (z). However, some areas may be parallel. Referring to Fig. 1, based on the front end (121a) of the emitter (121) in the electron emission direction (z), both sides of the emitter (121) may become closer to each other as they go toward the anode (150, shown in Fig. 1), or some areas may be parallel. That is, it can be understood that the emitter (121) does not form a part that becomes further away from each other as it goes toward the electron emission direction (z) based on both ends fixed to the holder (122). Through this, electrons contained inside the emitter (121) can be more easily guided to the front part (121b) of the emitter (121).

[0104] In contrast, based on the ridge (121a) of the emitter (121), both sides of the emitter (121) may include some portions that move away from each other in the electron emission direction (z) (for example, when viewed from the front of the emitter, the emitter is formed in a ring shape). For example, in a state where both ends of the emitter (121) are fixed, if the radius of curvature of the electron emission direction (z) front end (121a) of the emitter (121) increases to a certain level or more depending on the required field emission characteristics, or in a state where the radius of curvature of the electron emission direction (z) front end (121a) of the emitter (121) is fixed, if the gap between the two fixed parts (1222, 1223) narrows to a certain level or more due to structural constraints, a portion of the emitter (121) that protrudes further to both sides than the both ends of the emitter (121) may be formed, and in this case, the emitter (121) may include portions that become farther apart from each other as they go in the electron emission direction (z).

[0105] The emitter (121) may be formed symmetrically left and right. Specifically, the emitter (121) may be formed symmetrically with respect to the ridge (121a). Through this, the uniformity of the shape of the emitter (121) may be improved, which may in turn mean that the uniformity of the field emission characteristics and the lifespan of the electromagnetic wave generating device (100) may be improved.

[0106] The length (d) of the ridge (121a) of the emitter (121) in the direction of the ridge (121a) may be greater than the height (h) at which the emitter (121) protrudes from the holder (122). That is, when the field emission assembly (120) illustrated in FIG. 2 is viewed from the side, the width (d) of the emitter (121) may be greater than the height (h) of the emitter (121) protruding from the holder (122). Through this structure, the ridge (121a) from which electrons are emitted is sufficiently secured, so that electrons can be emitted smoothly, thereby improving the amount of electron emission. The amount of electron emission according to the width of the emitter (121) will be described in detail later with reference to FIG. 17.

[0107] The sheet-shaped emitter (121) can be bent or folded in various ways and fixed to the holder (122). For example, a person can directly apply force to the sheet-shaped emitter (121) or can apply force to the emitter (121) through a separately provided folding mechanism to bend or fold the emitter (121) into an appropriate shape and then fix it to the holder (122). As another example, the emitter (121) can be fixed to the holder (122) in such a way that one end of the flat emitter (121) is fixed to the holder (122), the emitter (121) is bent or folded into an appropriate shape by a person directly or through a separately provided folding mechanism, and then the other end of the emitter (121) is finally fixed to the holder (122).

[0108] Hereinafter, the radius of curvature (R) of the emitter (121) will be described in detail through Fig. 6 (a) and Fig. 6 (b).

[0109] It can be understood that Fig. 6 is a cross-sectional view of the emitter (121) cut along a plane intersecting the ridge (121a) of the emitter (121).

[0110] The emitter (121) can be bent or curved according to the required field emission characteristics, and when bent, the electron emission direction (z) shear (121a) of the emitter (121) can be formed with various radii of curvature (R).

[0111] For example, as shown in (a) of FIG. 6, when the electron emission direction (z) front end (121a) of the emitter (121) is bent with a large radius of curvature (R), the electron emission direction (z) front end (121b) of the emitter (121) can be formed into a blunt shape, and in this case, the threshold voltage value at which electrons start to be emitted and the maximum current (Max Current), which is the maximum value of the current formed due to the emitted electrons, can be increased.

[0112] On the other hand, when the electron emission direction (z) front end (121a) of the emitter (121) is bent with a small radius of curvature (R) or folded as shown in (b) of FIG. 6, the electron emission direction (z) front end (121b) of the emitter (121) can be formed into a more pointed shape, and in this case, the threshold voltage value at which electrons start to be emitted and the maximum current value, which is the maximum value of the current formed due to the emitted electrons, can be lowered.

[0113] The radius of curvature of the emitter (121) is not required to be the same across the region. That is, the emitter (121) may have different radii of curvature across the region. The curved shape of the emitter (121) may be determined by the thickness, size, distance between the fixed ends of the sheet-shaped emitter (121), the fixed angle of the fixed ends, and the type of sheet emitter (121) described in FIGS. 7 to 16. Furthermore, when permanent deformation occurs due to an external force, the emitter may have a shape corresponding thereto.

[0114] When the emitter (121) includes a portion that is bent so that a ridge (121a) is formed in the electron emission direction (z), the radius of curvature (R) of the ridge (121a) of the emitter (121) may be formed smaller than the radius of curvature of other portions of the emitter (121), based on the cross-section intersecting the ridge (121a) of the emitter (121). A smaller radius of curvature may mean that the ridge is bent sharply, but in order for electrons to be smoothly guided to the front portion (121b) of the emitter (121) by the electric field, it may be desirable for the portion other than the electron emission direction (z) front end (121a) of the emitter (121) to be bent as gently as possible compared to the electron emission direction (z) front end (121a) of the emitter (121).

[0115] Hereinafter, the bending angle (a) of the emitter (121) will be described in detail through (a) and (c) of FIG. 6.

[0116] Referring to Fig. 6, the emitter (121) can be formed with various bending angles (a) depending on how it is fixed to the holder. At this time, the bending angle (a) can be understood as the angle formed by the tangents of the two sides of the emitter (121) protruding from the holder. The bending angle (a) of the emitter (121) can be 0° to 180°, preferably 0° to 90°, and more preferably 0° to 45°.

[0117] For example, as shown in (a) of Fig. 6, when both ends of the emitter (121) are fixed to the holder with a sufficient distance from each other, the bending angle (a) can be increased.

[0118] Conversely, when the two ends of the emitter (121) are fixed to the holder so that they are close to each other and the gap between the two ends of the emitter (121) is narrow, the bending angle (a) can be reduced, and further, as shown in (c) of FIG. 6, the tangent lines of the two ends of the emitter (121) can be parallel to each other or close to parallel.

[0119] Meanwhile, referring to (d) of FIG. 6, when the emitter (121) includes a portion that is bent so that a ridge (121a) is formed in the electron emission direction (z), the regions on both sides of the ridge (121a) may each form a concave portion sunken toward the center. Through this structure, even when the two ends of the emitter (121) are spaced apart from each other and fixed to the holder (122), the area occupied by the emitter (121) can be reduced, thereby improving space efficiency. In addition, even though the two ends of the emitter (121) are spaced apart from each other, the ridge (121a) of the emitter (121) can be formed more pointed, so that the threshold voltage value at which electrons start to be emitted and the maximum current value, which is the maximum value of the current formed due to the emitted electrons, can be further lowered.

[0120] Hereinafter, the structure in which the emitter (121) is fixed to the holder (122) will be described in detail with reference to FIGS. 2 to 5.

[0121] The field emission assembly (120) may include a holder (122). The holder (122) may secure an emitter (121). According to one embodiment of the present disclosure, both ends of the emitter (121) of the field emission assembly (120) may be secured to the holder (122) while being spaced apart from each other with respect to a ridge (121a).

[0122] The holder (122) may be formed of an electrically conductive material capable of conducting current. Specifically, the holder (122) may be formed of a material that is electrically conductive and has mechanical strength sufficient to not be deformed by the repulsive force of electrons accumulated in the field emission assembly (120). For example, the holder (122) may be formed of one or more materials selected from the group consisting of tungsten, zinc, nickel, copper, silver, aluminum, gold, platinum, tin, stainless steel, and conductive ceramics. When an electric field is applied to the field emission assembly (120), electrons may move to the emitter (121) through the holder (122) formed of the electrically conductive material, and then be emitted to the outside of the emitter (121).

[0123] The holder (122) may include a body portion (1221). The two ends of the emitter (121) may be attached to two sides of the body portion (1221), respectively. The body portion (1221) may be provided in a box shape as illustrated in FIGS. 2 to 5, but may also be provided with a structure in which the middle portion is empty, or may be composed of two members, one of which is in contact with the inside of one of the two ends of the emitter (121), and the other of which is in contact with the inside of the other of the two ends of the emitter (121).

[0124] Referring to FIGS. 2 and 3, the holder (122) may include a first fixing portion (1222). The first fixing portion (1222) may be disposed on one side of the body portion (1221). The first fixing portion (1222) may be adjacent to one side of the body portion (1221) or may be closely coupled thereto. One end of the emitter (121) may be disposed between the body portion (1221) and the first fixing portion (1222).

[0125] The holder (122) may include a second fixing portion (1223). The second fixing portion (1223) may be positioned on the other side of the body portion (1221). The second fixing portion (1223) may be adjacent to or closely coupled to the other side of the body portion (1221). The other end of the emitter (121) may be positioned between the body portion (1221) and the second fixing portion (1223).

[0126] It can be understood that the sheet-shaped emitter (121) is bent or folded to form a ridge (121a) in the electron emission direction (z) and is coupled to the holder (122) in a structure that wraps around a portion of the body (1221).

[0127] The emitter (121) can be fixed to the holder (122) in various ways. For example, both ends of the emitter (121) can be directly pressed and fixed by the body part (1221) and the fixing parts (1222, 1223). For example, a connecting member (not shown) that penetrates the fixing parts (1222, 1223) and is fastened to the body part (1221) is provided, and as the connecting member is tightened, the gap between the body part (1221) and the fixing parts (1222, 1223) narrows, so that the emitter (121) can be compressed and fixed. As another example, both ends of the emitter (121) can be fixed to the holder (122) by being pressed by the ends of the connecting members that penetrate the fixing parts (1222, 1223) and the side surfaces of the body part (1221).

[0128] The body part (1221), the first fixing part (1222), and the second fixing part (1223) may each be provided as separate members. In this case, since the body part (1221) and the fixing parts (1222, 1223) may each be manufactured in a box shape, it may be easy to manufacture each member. On the other hand, the body part (1221) and the fixing parts (1222, 1223) may also be formed integrally. Even if the body part (1221) and the fixing parts (1222, 1223) are formed integrally, it may be understood that a gap in which the emitter (121) can be seated is still formed between the body part (1221) and the fixing parts (1222, 1223). In this case, the process of separately aligning the fixing portions (1222, 1223) with respect to the body portion (1221) may not be necessary, so the process of fixing the emitter (121) to the holder (122) may be facilitated.

[0129] Referring to FIGS. 4 and 5, unlike what was described above with respect to FIGS. 2 and 3, the holder (122) may not be provided with a first fixing portion (1222) and a second fixing portion (1223).

[0130] Specifically, both ends of the emitter (121) may be attached to both sides of the body portion (1221), respectively. For example, both ends of the emitter (121) may be welded to both sides of the body portion (1221) using a welding material (1224), respectively. For another example, both ends of the emitter (121) may be attached to both sides of the body portion (1221) using an adhesive (1224).

[0131] In addition, unlike what was described above with respect to FIGS. 2 to 5, it may be considered that the holder (122) does not include the first fixing portion (1222) and the second fixing portion (1223), and the coupling member is directly coupled to the side surface of the body portion (1221). In this case, the emitter (121) can be fixed to the holder (122) by coupling the coupling member to the side surface of the body portion (1221) by penetrating the both ends of the emitter (121) while the both ends of the emitter (121) are in close contact with the both sides of the body portion (1221).

[0132] FIG. 7 is an enlarged view of an example of an emitter of a field emission assembly according to one embodiment of the present disclosure. FIG. 8 is an enlarged view of another example of an emitter according to one embodiment of the present disclosure. FIG. 9 is an example of a method for manufacturing an emitter according to one embodiment of the present disclosure. FIG. 10 is an example of a method for manufacturing an emitter according to one embodiment of the present disclosure. FIGS. 11 and 12 illustrate various aspects of an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0133] Hereinafter, the first direction (x) can be understood as a direction in which each of the plurality of yarns (1211) extends, and the second direction (y) can be understood as a direction in which the plurality of yarns (1211) intersect the first direction (x) and are arranged.

[0134] Referring to FIGS. 7 and 8, the emitter (121) may have a structure in which a plurality of yarns (1211) extending in a first direction (x) are arranged in a second direction (y) that intersects the first direction (x).

[0135] The emitter (121) may be formed by at least one layer of an array structure of a plurality of yarns (1211). For example, as illustrated in FIG. 7, the emitter (121) may be a single-layer structure in which a plurality of yarns (1211) extending in a first direction (x) are arranged in a second direction (y). In addition, as illustrated in FIG. 8, the emitter (121) may be a double-layer structure in which a plurality of yarns (1211) extending in a first direction (x) are arranged in a second direction (y). The present invention is not limited thereto, and the emitter (121) may be provided with an array structure of a plurality of yarns (1211) in three or more layers.

[0136] The process for manufacturing the emitter (121) illustrated in FIGS. 7 and 8 is as follows.

[0137] Referring to FIG. 9, a method for manufacturing an emitter (121) may include a step of winding yarn (1211) around a winding means (160) having a cylindrical shape centered on an axis to form a sheet preform (170). Thereafter, the method for manufacturing an emitter (121) may include a step of separating the sheet preform (170) from the winding means (160). When the sheet preform (170) is separated from the winding means (160), the sheet preform (170) can roughly maintain a pipe shape.

[0138] When winding the yarn (1211) around the winding means (160), it may be wound in one layer along the outer circumference of the winding means (160), or in two or more layers. However, in order to realize uniformity of physical and electrical properties of the emitter (121), it may be preferable that the yarn (1211) be wound so as to be uniformly distributed over the entire winding area. That is, the gap between yarns (1211) that are continuously and adjacently wound in the sheet preform (170) may be substantially uniform, and the yarns (1211) may be wound in the same number of layers from the bottom to the top of the sheet preform (170).

[0139] The sheet preform (170) may be self-supporting in itself, which may be due to the π-π interaction of the tightly wound yarns (1211) with adjacent yarns (1211).

[0140] The sheet-shaped emitter (121) can be formed by cutting and / or pressing a sheet preform (170).

[0141] For example, referring to FIG. 9, when one side of a pipe-shaped sheet spare body (170) is cut vertically (for example, cut along A-A' shown in FIG. 9), the pipe-shaped sheet spare body (170) may be unrolled to form a sheet-shaped emitter (121). At this time, when the sheet spare body (170) has a structure in which yarns (1211) are wound in one layer, a sheet-shaped emitter (121) in which a plurality of yarns (1211) are arranged in one layer as shown in FIG. 7 may be formed, and when the sheet spare body (170) has a structure in which yarns (1211) are wound in two layers, a sheet-shaped emitter (121) in which a plurality of yarns (1211) are arranged in two layers as shown in FIG. 8 may be formed.

[0142] As another example, referring to FIG. 10, a sheet-shaped emitter (121) can be formed by laterally pressing a pipe-shaped sheet spare part (170). Pressing can be performed by, but is not limited to, placing the sheet spare part (170) between two plate-shaped members and then pressing the two plate-shaped members, or by passing the sheet spare part (170) between two adjacent rollers and rolling it. When the sheet spare part (170) has a structure in which yarns (1211) are wound in a single layer, a sheet-shaped emitter (121) can be formed in which a plurality of yarns (1211) are arranged in two layers, as illustrated in FIG. 8. In a structure in which the sheet reserve (170) is wound with two or more layers of yarn (1211), an emitter (121) in the form of a sheet in which the arrangement structure of multiple yarns (1211) is composed of four or more even layers can be formed.

[0143] Referring to FIG. 11, the emitter (121) illustrated in FIG. 7 or FIG. 8 may be bent so that a ridge (121a) is formed in the electron emission direction (z) or may be folded so that a ridge (121a) is formed in the electron emission direction (z). At this time, the emitter (121) may be bent or folded so that the ridge (121a) is formed parallel to the direction in which the plurality of yarns (1211) extend, i.e., the first direction (x). At this time, the first direction (x) may be referred to as a machine direction (MD). In this way, when the emitter (121) is bent or folded so that the ridge (121a) is formed along the MD, the ridge (121a) may be formed as a knot formed by the plurality of yarns (1211), so that it may be easy to bend or fold the sheet-shaped emitter (121) into more diverse shapes.

[0144] Alternatively, the ridge (121a) may be formed so that the emitter (121) is bent or folded so that it is formed in a direction that intersects the direction in which the plurality of yarns (1211) extend, i.e., parallel to the second direction (y). In this case, the second direction (y) may be referred to as a cross direction (CD).

[0145] In this way, when the emitter (121) is bent or folded so that a ridge (121a) is formed along the CD, the field emission characteristics of the emitter (121) can be improved. Specifically, electrons can be guided to the most forward point (E) of each yarn (1211) by the electric field and then emitted from the emitter (121). At this time, since the most forward point (E) of each yarn (1211) is formed narrowly as illustrated in FIG. 12, the electrons guided to the most forward point (E) by the electric field can be densely packed due to the narrow structure of the most forward point (E), so that the repulsive force between the electrons can increase, and due to this increase in repulsive force, the electrons can be more easily emitted from the emitter (121). The most forward point (E) may also be referred to as an electron emission point (E).

[0146] In addition, when the emitter (121) is bent or folded so that a ridge (121a) is formed along the CD as shown in FIG. 12, the durability of the sheet-shaped emitter (121) can be improved. Specifically, when the ridge (121a) is formed parallel to the second direction (y), the ridge (121a) is not formed along a line where a plurality of yarns (1211) are adjacent to each other, but is formed when each of the plurality of yarns (1211) is bent or folded, so that the emitter (121) in the sheet shape can be prevented from being damaged during the process of bending or folding the emitter (121).

[0147] The field emission characteristics according to the formation direction of the ridge (121a) will be described in detail later with reference to Fig. 18.

[0148] Fig. 13 illustrates another example of an emitter of a field emission assembly according to one embodiment of the present disclosure. Fig. 14 is an enlarged view of the P region of the emitter illustrated in Fig. 13.

[0149] The emitter (121) may be formed by weaving a plurality of yarns (1211). Specifically, the emitter (121) may be in the form of a sheet in which a plurality of linearly formed yarns (1211) are woven together. Through this, the uniformity of the electrical and mechanical properties of the emitter (121) may be improved, and further, the electrical and mechanical properties may be strengthened.

[0150] Specifically, when a plurality of yarns (1211) are woven, the sheet-shaped emitter (121) can have a certain texture, through which electron emission points (E) can be uniformly distributed on the sheet, so that the uniformity of field emission characteristics can be improved.

[0151] In addition, the electron emission point (E) can be formed at a portion where linear yarns (1211) intersect each other, and since a plurality of yarns (1211) are provided in a regularly woven sheet form, a factor that overlaps the electron emission point (E) in the electron emission direction (z) and interferes with electron emission can be removed. That is, since a plurality of yarns (1211) are regularly woven, the electron emission point (E), which is a portion where linear yarns (1211) intersect each other, can all be exposed forward in the electron emission direction (z). Through this, electron emission can be performed more smoothly.

[0152] In addition, when multiple yarns (1211) are woven, structural uniformity can be secured between the manufactured emitters (121), thereby improving the uniformity of the mechanical properties of the emitters (121). Through this, consistency in the lifespan of the field emission assembly (120) and the electromagnetic wave generating device (100) can be ensured. In addition, when manufacturing the field emission assembly (120), errors due to differences in mechanical properties can be reduced, thereby improving the uniformity of field emission characteristics.

[0153] In addition, when multiple yarns (1211) are woven, the structure of the emitter (121) can be strengthened, so that the durability of the emitter (121), the field emission assembly (120), and the electromagnetic wave generating device (100) can be improved.

[0154] The emitter (121) can be woven in various ways. For example, the emitter (121) can be woven in various ways, such as plain weaving, twill weaving, or satin weaving. That is, the emitter (121) can be formed without being limited to a specific weaving method as long as a regular texture can be formed. The emitter (121) formed by weaving can take the form of a thin and wide sheet, and the stiffness can slightly vary depending on the weaving method.

[0155] Weaving can mean that the structure of multiple yarns (1211) can take the form of a sheet without the addition of additional materials or physical / chemical processing. However, the sheet structure can be made more solid by adding additional materials or physical / chemical processing as needed.

[0156] The emitter (121) may include a point or region that is positioned relatively forward and a point or region that is positioned backward based on the electron emission direction (z) due to the characteristic of being woven. The point or region that is positioned relatively forward may include a peak, and the point or region that is positioned relatively backward may include a valley. These peaks and valleys may be formed at portions where yarns (1211) intersect each other. An electron emission point (E) may be formed at portions where yarns (1211) intersect each other, and this electron emission point (E) may be understood to coincide with a peak. The portion where the peak and valley are formed may be formed thicker than other portions, so that many electrons may be concentrated, and electron emission may be facilitated through the peak shape. By weaving multiple yarns (1211) into a regular texture, multiple peaks and valleys have a regular distribution, which can improve the uniformity of field emission characteristics.

[0157] Fig. 15 is a photograph of a yarn forming an emitter of a field emission assembly according to one embodiment of the present disclosure. Fig. 16 illustrates a method for forming an emitter of a field emission assembly according to one embodiment of the present disclosure.

[0158] Referring to Fig. 15, the emitter (121) may be composed of a plurality of linear yarns formed of carbon nanotube material. Referring to Fig. 15 (a), each of the plurality of yarns (1211) constituting the emitter (121) may be a twisted yarn. In this case, since the yarn (1211) can be manufactured more easily, manufacturing efficiency may be improved. In addition, referring to Fig. 15 (b), each of the plurality of yarns (1211) constituting the emitter (121) may be a braided yarn. In this case, since the mechanical and electrical properties of the yarn (1211) may be improved, the field emission characteristics may also be improved.

[0159] FIG. 16 specifically illustrates the process of forming an emitter (121) of a field emission assembly (120) according to one embodiment of the present specification.

[0160] Referring to (a) and (b) of Fig. 16, the yarn may be a twisted yarn. At this time, referring to (a) of Fig. 16, the twisted yarn constituting the yarn may be a primary twisted yarn formed by twisting a plurality of carbon nanotube fibers. In addition, referring to (b) of Fig. 12, the twisted yarn constituting the yarn may be a secondary twisted yarn formed by twisting primary twisted yarns with each other. At this time, the primary twisted yarn may be formed by twisting a plurality of carbon nanotube fibers.

[0161] Meanwhile, referring to (c) and (d) of FIG. 16, the yarn may be a braided yarn. At this time, referring to (c) of FIG. 16, the braided yarns constituting the yarn may be formed by braiding a plurality of primary twisted yarns with each other, and these primary twisted yarns may be formed by twisting a plurality of carbon nanotube single yarns. In addition, referring to (d) of FIG. 16, the braided yarns constituting the yarn may be formed by braiding a plurality of secondary twisted yarns with each other. At this time, the secondary twisted yarns may be formed by twisting a plurality of primary twisted yarns with each other, and these primary twisted yarns may be formed by twisting a plurality of carbon nanotube single yarns.

[0162] However, if it is possible to form linear yarns that can be woven to form sheet-shaped emitters, the manner in which the yarns constituting the emitters are formed is not limited to the manners described above in (a) to (d) of FIG. 16, and may be formed by various combinations of the manners described in (a) to (d) of FIG. 16, depending on the required field emission characteristics, or may be formed in a manner not described in (a) to (d) of FIG. 16.

[0163] FIG. 17 is a graph showing field emission characteristics according to the exposure area of ​​an emitter of a field emission assembly according to one embodiment of the present specification.

[0164] The graph of Fig. 17 shows the amount of electron emission in terms of current (Current) according to the voltage applied to the electrode for each case where the emitter width (d) is 1 mm, 4 mm, and 12 mm when the emitter is folded along the cross direction as shown in Fig. 12 and fixed to the holder so that the emitter protrudes 1 mm from the holder. It can be understood that the x-axis of Fig. 17 represents voltage and the y-axis represents current.

[0165] Referring to Fig. 17, it can be seen that even if the voltage is increased, the current is not detected up to a certain voltage, and that the current increases as the voltage increases beyond a certain voltage. At this time, when the width (d) of the emitter is 1 mm, the average value of the threshold voltage (hereinafter, Threshold.V) at which the detection current starts to be detected is 1.33 kV, when the width (d) of the emitter is 4 mm, the average value of Threshold.V is 1.10 kV, and when the width (d) of the emitter is 12 mm, the average value of Threshold.V is confirmed to be 0.80 kV.

[0166] In addition, it can be seen that the magnitude of the voltage applied to the electrode when a current of 3 mA is detected (hereinafter referred to as 'V@3mA') is different depending on the width (d) of the emitter. When the width (d) of the emitter is 1 mm, V@3mA is 2.42 kV, when the width (d) of the emitter is 4 mm, V@3mA is 2.06 kV, and when the width (d) of the emitter is 12 mm, V@3mA is confirmed to be 1.63 kV.

[0167] In addition, it can be confirmed that the slope of the current according to the voltage when the emitter width (d) is 4 mm is greater than the slope of the current according to the voltage when the emitter width (d) is 1 mm, and the slope of the current according to the voltage when the emitter width (d) is 12 mm is greater than the slope of the current according to the voltage when the emitter width (d) is 4 mm.

[0168] The field emission characteristics according to the exposure area of ​​the emitter illustrated in Fig. 17 are shown in Table 1 below.

[0169] Emitter width (d) V@3mA Threshold voltage (Threshold.V) Average (Avg) Standard deviation of population (std.p) 1mm2.42 kV 1.33 kV 0.05 4mm2.06 kV 1.10 kV 0.00 12mm1.63 kV 0.80 kV 0.00

[0170] Referring to Fig. 17 and [Table 1], it can be confirmed that V@3mA decreases as the emitter width (d) increases. This may mean that the wider the emitter width (d), the easier it is to reach a specific current. In other words, it can be confirmed that the wider the emitter width (d), the better the field emission characteristics.

[0171] Also, referring to FIG. 17 and [Table 1], it can be seen that Threshold.V decreases as the emitter width (d) increases. This may mean that as the emitter width (d) increases, electrons begin to be emitted even at a lower voltage. In other words, it can be confirmed that as the emitter width (d) increases, electrons are emitted more easily, thereby improving field emission characteristics.

[0172] FIG. 18 is a graph showing field emission characteristics according to the ridge formation direction of the emitter of a field emission assembly according to one embodiment of the present specification.

[0173] Specifically, FIG. 18 illustrates field emission characteristics when the emitter is folded so that the ridge of the emitter is formed along the Machine direction (MD), which is the direction in which the yarn extends, and when the emitter is folded so that the ridge of the emitter is formed along the Cross direction (CD), which is the direction intersecting the direction in which the yarn extends.

[0174] Referring to Fig. 18, it can be confirmed that V@3mA is 2.01 kV when the emitter ridge is formed along MD, and V@3mA is 1.68 kV when the emitter ridge is formed along CD.

[0175] Additionally, it can be confirmed that Threshold.V is 1.10 kV when the emitter ridge is formed along MD, and Threshold.V is 0.90 kV when the emitter ridge is formed along CD.

[0176] The field emission characteristics according to the ridge formation direction of the emitter illustrated in Fig. 18 are shown in Table 2 below.

[0177] Ridge formation direction V@3mA Threshold voltage (Threshold.V) Average (Avg) Standard deviation of the population (std.p) Machine direction (MD) 2.01 kV 1.10 kV 0.05 Cross direction (CD) 1.68 kV 0.90 kV 0.00

[0178] Referring to FIG. 18 and [Table 2], it can be confirmed that the V@3mA value when the emitter ridge is formed along the CD is smaller than the V@3mA value when the emitter ridge is formed along the MD. This may mean that it is easier to reach a specific current when the emitter ridge is formed along the CD compared to when the emitter ridge is formed along the MD.

[0179] Also, referring to FIG. 18 and [Table 2], it can be confirmed that the Threshold.V value when the emitter ridge is formed along the CD is smaller than the Threshold.V value when the emitter ridge is formed along the MD. This may mean that electrons start to be emitted at a lower voltage when the emitter ridge is formed along the CD compared to when the emitter ridge is formed along the MD.

[0180] These data confirm that sheet-shaped emitters exhibit superior field emission characteristics when the ridges are formed along the CD compared to when they are formed along the MD. The reason why field emission characteristics are improved when the emitter ridges are formed along the CD is as described above with reference to FIG. 12.

[0181] Fig. 19 is a perspective view illustrating an example of a field emission assembly according to another embodiment of the present disclosure. Fig. 20 is a perspective view illustrating another example of a field emission assembly according to another embodiment of the present disclosure.

[0182] The detailed configuration of the field emission assembly (220) according to another embodiment of the present specification that is not described below may be understood to be the same as the detailed configuration of the field emission assembly (120) according to one embodiment of the present specification described with reference to FIGS. 1 to 18.

[0183] Referring to FIGS. 19 and 20, the two ends of the emitter (221) can be fixed to the holder (222) while being adjacent to each other with the ridge (221a) as the center. That is, it can be understood that the two ends of the emitter (221) are fixed to the holder (222) in a state of being in close contact with each other.

[0184] The holder (222) may include a first body portion (2221). Both ends of the emitter (221) may be in close contact with one side of the first body portion (2221). The first body portion (2221) may be provided in a box shape as illustrated in FIGS. 19 and 20, but is not limited to a specific shape as long as both ends of the emitter (221) can be in close contact with one side of the first body portion (2221).

[0185] Referring to FIG. 19, the holder (222) may include a second body portion (2222). The second body portion (2222) may be disposed on one side of the first body portion (2221). The second body portion (2222) may be adjacent to one side of the first body portion (2221) or may be coupled in close contact with it. Both ends of the emitter (221) may be disposed between the first body portion (2221) and the second body portion (2222).

[0186] The emitter (221) can be fixed to the holder (222) in various ways. For example, both ends of the emitter (221) can be directly pressed and fixed by the first body part (2221) and the second body part (2222). For example, a case can be considered where a connecting member (not shown) is provided that penetrates the first body part (2221) and the second body part (2222) and is fastened, and the gap between the first body part (2221) and the second body part (2222) narrows as the connecting member is tightened, thereby compressing the emitter (221). As another example, both ends of the emitter (221) may be fixed to the holder (222) by being pressed by the end of a connecting member penetrating one of the first body part (2221) and the second body part (2222) and the side surface of the other one of the first body part (2221) and the second body part (2222).

[0187] The first body part (2221) and the second body part (2222) may be provided as separate members. In this case, since the first body part (2221) and the second body part (2222) may each be manufactured in a box shape, it may be easy to manufacture each member. On the other hand, the first body part (2221) and the second body part (2222) may be formed integrally. Even if the first body part (2221) and the second body part (2222) are formed integrally, it may be understood that a gap in which the emitter (221) can be installed is still formed between the first body part (2221) and the second body part (2222). In this case, the process of aligning the first body part (2221) and the second body part (2222) with each other may not be necessary, so the process of fixing the emitter (221) to the holder (222) may become easier.

[0188] Referring to FIG. 20, unlike what was described above with respect to FIG. 19, the holder (222) may not be provided with a second body portion (2222).

[0189] Specifically, both ends of the emitter (221) may be attached to one side of the first body portion (2221). For example, both ends of the emitter (221) may be welded to one side of the first body portion (2221) by a welding material (2224). For another example, both ends of the emitter (221) may be attached to one side of the first body portion (2221) by an adhesive (2224).

[0190] In addition, unlike what was described above with respect to FIGS. 19 and 20, it may be considered that the holder (222) does not include the second body portion (2222), and the coupling member is directly coupled to the side surface of the first body portion (2221). In this case, the emitter (221) can be fixed to the holder (222) by coupling the coupling member to the side surface of the first body portion (2221) by penetrating the both ends of the emitter (221) while the both ends of the emitter (221) are in close contact with the side surface of the first body portion (2221).

[0191] Any or all of the embodiments of this specification described above are not mutually exclusive or distinct. Any or all of the embodiments of this specification described above may have their respective components or functions combined or used together.

[0192] For example, it means that a configuration A described in a particular embodiment and / or drawing can be combined with a configuration B described in another embodiment and / or drawing. That is, even if a combination between configurations is not directly described, it means that a combination is possible, except in cases where a combination is described as impossible.

[0193] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of this specification should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of this specification are intended to be embraced therein.

Claims

1. As an emitter that emits electrons from an electromagnetic wave generating device, It is formed in the form of a sheet containing carbon nanotubes, An emitter comprising at least one of a curved portion so as to form a ridge in the direction of electron emission and a folded portion so as to form a ridge in the direction of electron emission.

2. In paragraph 1, The ridge formed by the above-mentioned curved or folded portion is a single emitter.

3. In paragraph 2, Emitters whose sides, based on the above ridge, become closer to each other as they go in the electron emission direction, or become closer to each other but have some areas that are parallel.

4. In paragraph 1, An emitter is a shape in which the slope of the tangent line changes continuously.

5. In paragraph 4, If the above emitter includes a portion that is curved so that a ridge is formed in the electron emission direction, An emitter formed with a radius of curvature at the ridge that is smaller than the radius of curvature of other parts, based on a cross-section intersecting the ridge.

6. In paragraph 1, If the above emitter includes a portion that is bent so that a ridge is formed in the electron emission direction, Based on the above ridge, each of the two side regions has an emitter that forms a concave portion sunken toward the center.

7. In paragraph 1, An emitter comprising a plurality of yarns comprising carbon nanotube fibers.

8. In paragraph 7, An emitter having a structure in which a plurality of yarns extending in a first direction are arranged in a second direction that intersects the first direction.

9. In paragraph 8, The above ridge is an emitter formed parallel to the first direction.

10. In paragraph 8, The above ridge is an emitter formed parallel to the second direction.

11. In paragraph 7, An emitter formed by weaving the above plurality of yarns.

12. Sheet-shaped emitter containing carbon nanotubes; and Including a holder for fixing the above emitter, A field emission assembly wherein the sheet-shaped emitter comprises at least one of a curved portion so as to form a ridge in the electron emission direction and a folded portion so as to form a ridge in the electron emission direction.

13. In paragraph 12, A field emission assembly electrically connected to the holder by at least one of a method including a method of being pressed into the holder, a method of being welded, and a method of being bonded by an adhesive.

14. In paragraph 12, A field emission assembly in which the two ends of the emitter are spaced apart from each other with the ridge as the center and are fixed to the holder.

15. In paragraph 14, The above holder includes a body portion, The two ends of the above emitter are each a field emission assembly that is in close contact with both sides of the body portion.

16. In paragraph 15, The holder includes a first fixing part arranged on one side of the body part and a second fixing part arranged on the other side of the body part, One end of the above emitter is disposed between the body part and the first fixed part, The other end of the above emitter is a field emission assembly disposed between the body part and the second fixed part.

17. In paragraph 12, A field emission assembly in which the two ends of the emitter are adjacent to each other and fixed to the holder with the ridge as the center.

18. In paragraph 17, The holder includes a first body portion, A field emission assembly in which both ends of the above emitter are in close contact with one side of the above first body part.

19. In paragraph 18, The holder includes a second body part arranged on one side of the first body part, A field emission assembly in which both ends of the above emitter are disposed between the first body portion and the second body portion.

20. In paragraph 12, A field emission assembly wherein the length of the emitter in the ridge direction is greater than the height at which the emitter protrudes from the holder.

21. In paragraph 12, A field emission assembly in which the angle formed by the tangent lines of the two sides of the emitter protruding from the holder is between 0° and 180°.

Images