KR102455499B1 - Display device - Google Patents

Abstract

The present specification discloses a display device. The display device includes: a display area having a pixel circuit associated with one or more pixels; and a non-display area having a power line connected to the pixel circuit, wherein the non-display area includes a reinforcement layer covering a side surface of the power line.

Description

display device {DISPLAY DEVICE}

This specification relates to a display device.

A video display device that implements various information on a screen is a key technology in the information and communication era, and is developing in the direction of thinner, lighter, more portable and high-performance. Accordingly, an organic light emitting display device that displays an image by controlling the amount of light emitted from the organic light emitting diode is in the spotlight.

The organic light emitting device is a self-luminous device using a thin light emitting layer between electrodes, and has the advantage that it can be thinned. A typical organic light emitting display device has a structure in which a pixel driving circuit and an organic light emitting device are formed on a substrate, and an image is displayed while light emitted from the organic light emitting device passes through a substrate or a barrier layer.

In various display devices including organic light emitting display devices, when moisture permeation occurs, performance such as long-term reliability may be deteriorated, and thus, penetration and/or propagation of moisture is blocked in various ways. In particular, various structures are being studied/applied to prevent moisture from penetrating along the wiring in the outer part.

An object of the present specification is to propose a structure for preventing moisture permeation of a display device. The tasks of the present specification are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present specification, a display device is provided. The display device includes: a display area having a pixel circuit associated with one or more pixels; and a non-display area having a power line connected to the pixel circuit, wherein the non-display area may include a reinforcement layer covering a side surface of the power line.

Specific details of other embodiments are included in the detailed description and drawings.

Embodiments of the present specification may provide a display device in which reliability degradation due to wiring damage is improved. In addition, embodiments of the present specification may provide a structure for preventing a moisture permeation path through a wiring part outside the display device. Effects according to the embodiments of the present specification are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 illustrates an exemplary display device that may be included in an electronic device.
2A and 2B are cross-sectional views schematically illustrating a display area and a non-display area of a display device according to an exemplary embodiment of the present specification.
3A to 3C are exemplary views illustrating wiring arrangement of a display device.
4A to 4C are diagrams illustrating a display device according to an exemplary embodiment of the present specification.

Advantages and features of the present specification and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present specification are exemplary, and thus the present specification is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless specifically stated otherwise. In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between two parts unless 'directly' is used. Reference to a device or layer “on” another device or layer includes any intervening layer or other device directly on or in the middle of another device. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected,” “coupled,” or “connected” through another component.

Although first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not necessarily limited to the size and thickness of the illustrated component. Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 illustrates an exemplary display device that may be included in an electronic device.

Referring to FIG. 1 , the display device 100 includes at least one active area, and an array of pixels is formed in the display area. One or more inactive areas may be disposed around the display area. That is, the non-display area may be adjacent to one or more side surfaces of the display area. In FIG. 1 , the non-display area surrounds the rectangular display area. However, the shape of the display area and the shape/arrangement of the non-display area adjacent to the display area are not limited to the example illustrated in FIG. 1 . The display area and the non-display area may have a shape suitable for designing an electronic device on which the display device 100 is mounted. Exemplary shapes of the display area are pentagonal, hexagonal, circular, oval, and the like.

Each pixel in the display area may be associated with a pixel circuit. The pixel circuit may include one or more switching transistors and one or more driving transistors on a backplane. Each pixel circuit may be electrically connected to a gate line and a data line to communicate with one or more driving circuits such as a gate driver and a data driver located in the non-display area.

As shown in FIG. 1 , the driving circuit may be implemented as a thin film transistor (TFT) in the non-display area. Such a driving circuit may be referred to as a gate-in-panel (GIP). In addition, some components such as data driver IC are mounted on a separate printed circuit board, and circuit films such as FPCB (flexible printed circuit board), COF (chip-on-film), TCP (tape-carrier-package), etc. It may be combined with a connection interface (pad/bump, pin, etc.) disposed in the non-display area by using the . The non-display area may be bent together with the connection interface, so that the printed circuit (COF, PCB, etc.) may be located behind the display device 100 .

The display device 100 may include various additional elements for generating various signals or driving pixels in the display area. Additional elements for driving the pixel may include an inverter circuit, a multiplexer, an electrostatic discharge circuit, and the like. The display device 100 may also include additional elements related to functions other than pixel driving. For example, the display device 100 may include additional elements that provide a touch sensing function, a user authentication function (eg, fingerprint recognition), a multi-level pressure sensing function, a tactile feedback function, and the like. The above-mentioned additional elements may be located in the non-display area and/or in an external circuit connected to the connection interface.

One or more edges of the display device 100 may be bent away from a central portion 101 . Since one or more portions of the display device 100 may be bent, the display device 100 may be defined as a substantially flat portion and a bent portion. That is, a portion of the display device 100 (eg, a wiring portion between the pad PAD and the display area) is bent at a predetermined angle, and this portion may be referred to as a curved portion. The bent section includes a bent section that is actually bent to a predetermined radius of curvature. Although not always, the central portion of the display device 100 may be substantially flat, and the corner portions may be curved portions.

When the non-display area is bent, the non-display area is invisible or minimally visible from the front side of the display device. A portion of the non-display area visible from the front side of the display device may be covered with a bezel. The bezel may be formed as a stand-alone structure, or as a housing or other suitable element. Some of the non-display area visible from the front of the display may be hidden under an opaque mask layer such as black ink (eg, a polymer filled with carbon black). Such an opaque mask layer may be provided on various layers (a touch sensor layer, a polarization layer, a cover layer, etc.) included in the display device 100 .

The bend portion 102 may be bent outwardly from the central portion with a bend angle θ and a bend radius R with respect to the bend axis. The size of each of the bent portions need not be the same. Further, the angle of curvature θ around the flexion axis and the radius of curvature R from the flexion axis may be different for each bent portion.

2A and 2B are cross-sectional views schematically illustrating a display area and a non-display area of a display device according to an exemplary embodiment of the present specification.

The illustrated display area and non-display area may be applied to at least a portion of the display area A/A and the non-display area A/A-2 described in FIG. 1 . Hereinafter, the display device will be described using an organic light emitting display device as an example.

In the case of an organic light emitting diode display, thin film transistors 112 , 114 , 116 , 118 , organic light emitting devices 122 , 124 , 126 and various functional layers are positioned on the base layer 111 in the display area. . Meanwhile, various driving circuits, electrodes, wirings, functional structures, etc. may be positioned on the base layer 111 in the non-display area.

The base layer 111 supports various components of the organic light emitting diode display 100 . The base layer 111 may be formed of a transparent insulating material, for example, an insulating material such as glass or plastic. A substrate (array substrate) is also referred to as a concept including an element and a functional layer formed thereon, for example, a switching TFT, a driving TFT, an organic light emitting element, a protective film, and the like.

A buffer layer may be disposed on the base layer 111 . The buffer layer is a functional layer for protecting a thin film transistor (TFT) from impurities such as alkali ions leaking from the base layer 111 or the underlying layers. The buffer layer may be formed of silicon oxide (SiOx), silicon nitride (SiNx), or a multilayer thereof.

A thin film transistor is placed on the base layer 111 or the buffer layer. The thin film transistor may have a form in which a semiconductor layer 112 , a gate insulating layer 113 , a gate electrode 114 , an interlayer insulating layer 115 , and source and drain electrodes 116 and 118 are sequentially disposed. The semiconductor layer 112 is positioned on the base layer 111 or the buffer layer. The semiconductor layer 112 may be made of polysilicon (p-Si), and in this case, a predetermined region may be doped with an impurity. In addition, the semiconductor layer 112 may be made of amorphous silicon (a-Si) or various organic semiconductor materials such as pentacene. Furthermore, the semiconductor layer 112 may be made of oxide. The gate insulating layer 113 may be formed of an insulating inorganic material such as silicon oxide (SiOx) or silicon nitride (SiNx), or may be formed of an insulating organic material or the like. The gate electrode 114 may be formed of various conductive materials, for example, magnesium (Mg), aluminum (Al), nickel (Ni), chromium (Cr), molybdenum (Mo), tungsten (W), gold (Au), or an alloy thereof. and the like.

The interlayer insulating layer 115 may be formed of an insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx), and may also be formed of an insulating organic material. A contact hole through which the source and drain regions are exposed may be formed by selectively removing the interlayer insulating layer 115 and the gate insulating layer 113 .

The source and drain electrodes 116 and 118 are formed on the interlayer insulating film 115 in the form of a single layer or a multi-layered electrode material.

A planarization layer 117 may be disposed on the thin film transistor. The planarization layer 117 protects the thin film transistor and planarizes the top thereof. The planarization layer 117 may be configured in various forms, and may be formed of an organic insulating film such as BCB (Benzocyclobutene) or acrylic (Acryl), or an inorganic insulating film such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), Various modifications are possible, such as being formed in a single layer or may be configured in double or multiple layers.

The organic light emitting device may have a form in which the first electrode 122 , the organic light emitting layer 124 , and the second electrode 126 are sequentially disposed. That is, the organic light emitting diode includes a first electrode 122 formed on the planarization layer 117 , an organic light emitting layer 124 positioned on the first electrode 122 , and a second electrode ( ) positioned on the organic light emitting layer 124 . 126) can be configured.

The first electrode 122 is electrically connected to the drain electrode 118 of the driving TFT through a contact hole. When the organic light emitting diode display 100 is a top emission type, the first electrode 122 may be made of an opaque conductive material having high reflectance. For example, the first electrode 122 may be formed of silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), tungsten (W), chromium (Cr), or an alloy thereof. .

The bank 120 is formed in the remaining area except for the light emitting area. Accordingly, the bank 120 has a bank hole exposing the first electrode 122 corresponding to the emission region. The bank 120 may be made of an inorganic insulating material such as a silicon nitride film (SiNx) or a silicon oxide film (SiOx), or an organic insulating material such as BCB, an acrylic resin, or an imide resin.

An organic light emitting layer 124 is located on the first electrode 122 exposed by the bank 120 . The organic light emitting layer 124 may include an emission layer, an electron injection layer, an electron transport layer, a hole transport layer, a hole injection layer, and the like. The organic light emitting layer may have a structure of a single light emitting layer emitting one light, or a structure of emitting white light by being composed of a plurality of light emitting layers.

The second electrode 126 is positioned on the organic light emitting layer 124 . When the organic light emitting diode display 100 is a top emission type, the second electrode 126 is a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). By being formed of a material, light generated from the organic light emitting layer 124 is emitted to the upper portion of the second electrode 126 .

A protective layer 128 and an encapsulation layer 130 are disposed on the second electrode 126 . The protective layer 128 and the encapsulation layer 130 prevent the penetration of oxygen and moisture from the outside in order to prevent oxidation of the light emitting material and the electrode material. When the organic light emitting device is exposed to moisture or oxygen, a pixel shrinkage phenomenon in which the light emitting area is reduced may occur or a dark spot may occur in the light emitting area. The passivation layer and/or the encapsulation layer may be formed of an inorganic film made of glass, metal, aluminum oxide (AlOx) or silicon (Si)-based material, or an organic film and an inorganic film are alternately formed. It may have a laminated structure. The inorganic film serves to block the penetration of moisture or oxygen, and the organic film serves to planarize the surface of the inorganic film. The reason for forming the encapsulation layer as a multi-layered thin film layer is to make the movement path of moisture or oxygen longer and more complicated than that of a single layer, making it difficult to penetrate moisture/oxygen to the organic light emitting device.

The organic light emitting display device 100 may further include a touch layer, a polarization layer 160 , a cover layer 170 , and the like on the encapsulation layer 130 . A touch panel/touch sensing electrode may be provided on an upper surface of the organic light emitting diode (eg, an upper surface of an encapsulation layer) for sensing a user's touch input. If necessary, an independent layer provided with a touch sensing electrode and/or other components related to sensing a touch input may be provided in the display device 100 . The touch sensing electrode (eg, a touch driving/sensing electrode) is made of indium tin oxide, a carbon-based material such as graphene, carbon nanotubes, a conductive polymer, a hybrid material made of a mixture of various conductive/non-conductive materials, etc. It may be formed of a transparent conductive material. In addition, a metal mesh, for example, an aluminum mesh, a silver mesh, etc. may be used as the touch sensing electrode.

The display device 100 may include a polarization layer 160 to control display characteristics (eg, external light reflection, color accuracy, luminance, etc.). The cover layer 170 may be used to protect the display device 100 and may be, for example, cover glass.

In order to increase strength and/or rigidity in a specific portion of the display device 100 , one or more support layers 180 may be provided under the base layer 111 . The support layer 180 is attached to a surface (second surface) opposite to the surface (first surface) on which the organic light emitting device is located among both surfaces of the base layer 111 . The support layer 180 may include polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, and poly It may be made of a thin plastic film composed of a combination of polyether imide, polyether sulfonate, polyimide, polyacrylate, and other suitable polymers. Other suitable materials that may be used to form the support layer 180 may be thin glass, a dielectric shielded metal foil, a multilayer polymer, a polymer film containing a polymeric material in combination with nanoparticles or microparticles, etc. have.

For easier bending and improved reliability of the display device 100 , the configuration of components in the curved portion 102 may be different from that of the flat central portion 101 . Some components present in the central portion 101 are not disposed in the bent portion 102 or are provided in different thicknesses. For example, the support layer 180 , the polarization layer 160 , the touch sensor layer, the color filter layer, and/or other components that interfere with the bending of the display device 100 may not be present in the curved portion 102 . have. In addition, in consideration of the viewing angle characteristics of the curved portion 102 , the organic light emitting diodes may be provided in a shape different from that of the flat portion 101 .

A pixel circuit is not disposed in the non-display area I/A, but the base layer 111 and the organic/inorganic functional layers 113 , 115 , 117 128 , 130 , etc. may exist. In addition, materials used to form the display area A/A may be disposed in the non-display area I/A for different purposes. For example, as shown in FIG. 2B , a metal 114 ′ used as a gate electrode of the display region TFT or a metal 118 ′ used as a source/drain electrode is used for wiring and electrodes in the non-display region I/A. ) can be placed in Furthermore, the metal 122 ′ used as one electrode (eg, an anode) of the organic light emitting diode may be disposed in the non-display area I/A for wiring and electrodes.

3A to 3C are exemplary views illustrating wiring arrangement of a display device.

FIG. 3A is an enlarged view of part B of FIG. 1 . 3B is a cross-sectional view taken along 1-1' of FIG. 3A, and 3C is a cross-sectional view taken along 2-2' of FIG. 3A. For convenience of explanation, only the pad region P, the wiring layers 118' and 114', and the planarization layer 117 of the display device are illustrated in FIG. 3A for simplicity, and the planarization layer 117 and the wiring layer 118' are illustrated in FIG. , 114') on the encapsulation layer has been omitted. The encapsulation layer 130 is illustrated in FIGS. 3B and 3C . The encapsulation layer 130 may cover the entire area except for the pad area P or only a partial area.

The wiring layer 118 ′ may be formed of the same metal (a first metal layer) on the same layer as the source or drain electrode of the TFT in the display region. 3A-3C show the planarization layer 117 over the wiring layer 118', this is only one implementation and other insulating layers may overlie the wiring layer 118'. The wiring layer 118' and the planarization layer 117 have the positional relationship shown in FIG. 2B.

In the wiring part design of FIG. 3A , a planarization layer 117 that eliminates a step difference depending on the presence or absence of wiring is applied to some areas. That is, in some areas, the planarization layer 117 covers the upper portion of the wiring layer 118 ′, so that the level difference according to the presence or absence of the wiring layer disappears. Therefore, cracks due to the step difference can be prevented when the upper part of the structure is covered with an inorganic layer such as an encapsulation layer. On the other hand, there is no planarization layer 117 in a specific region, which is to prevent moisture transfer by breaking the planarization layer 117 because moisture may propagate along the organic layer constituting the planarization layer 117 . In this case, in a specific section where the planarization layer is not present, the second metal layer 114 ′ forms a jumping structure with the first metal layer 118 ′ and functions as one wiring.

The second metal layer 114' is provided on a different layer from the first metal layer 118'. In addition, the second metal layer 114' is connected to the first metal layer 118' through a contact hole or a direct connection method. Accordingly, the driving voltage. An electrical signal or the like is applied to a connection interface (such as a pad) of the pad region P, and is transmitted along the first metal layer 118 ′, and is transmitted along the second metal layer 114 ′ in a specific section.

However, several weaknesses have been found in the structure of the wiring unit described above. One of them is that the wiring metal (eg, multi-layer metal such as Ti/Al/Ti, etc.) in the portion without the planarization layer is partially eroded by other etching processes (eg, anode patterning process). Such erosion may create inorganic layer cracks and/or moisture permeation pathways. The inventors of the present invention have recognized such a problem and have devised a structure for preventing erosion of wiring metal and moisture permeation therefrom.

4A to 4C are diagrams illustrating a display device according to an exemplary embodiment of the present specification.

FIG. 4A is an enlarged view of part B of FIG. 1 , and shows an embodiment to which a wiring part robust structure is applied. 4B is a cross-sectional view taken along 1-1' of FIG. 4A, and 4C is a cross-sectional view taken along 2-2' of FIG. 4A. For convenience of explanation, only the pad region P, the wiring 119, the organic layer 117, and the reinforcement layer 123 of the display device are shown in FIG. 4A for simplicity, and the organic layer 117 and the reinforcement layer ( 123) the upper functional layer (eg encapsulation layer) is omitted. A reinforcement layer 123 covering a portion of a side surface of the power wiring 119 is provided in the non-display area.

4A to 4C illustrate the organic material layer 117 on the wiring 119, this is only an example, and other insulating layers may be used. The wiring 119 and the organic layer 117 have the positional relationship shown in FIG. 2B . Here, the wiring is a path through which power or various signals are transmitted, and is made of a conductive material such as metal. Hereinafter, an embodiment in which the wiring 119 is a power wiring will be described. The spirit of the present invention is not limited thereto. When the wiring 119 is a power supply wiring, the wiring illustrated in FIG. 4A may be a V _SS , V _REF , and V _DD wiring from the left. Meanwhile, the organic layer 117 may be a planarization layer.

The display device of FIG. 4A includes an active area with a pixel circuit associated with one or more pixels and an inactive area with a power supply wiring 119 connected to the pixel circuit. may include The non-display area may be disposed around the display area. That is, the non-display area may be adjacent to one or more side surfaces of the display area.

The non-display area may include a first portion S1 covered with the organic material layer 117 and a second portion S2 not covered with the organic material layer. In the first portion S1 , the organic material layer 117 may cover the entire upper surface of the wiring 119 , or may cover only an edge portion of the wiring 119 .

The display device may further include an encapsulation layer covering upper portions of the display area and the non-display area to prevent penetration of moisture, oxygen, and the like. Accordingly, the encapsulation layer 130 may be positioned on the power wiring 119 and the planarization layer 117 . The encapsulation layer 130 may not completely cover the outer edge of the display device in an embodiment. In this case, the encapsulation layer 130 may cover only the lower side of the specific line E. In this case, the portion above the specific line E (the portion not covered by the encapsulation layer) may be a curved portion. The encapsulation layer 130 is illustrated in FIGS. 4B and 4C , and covers at least a portion of the power wiring 119 .

The wiring 119 extends from a connection interface (such as a pad) of the pad area P in the direction of the display area. In this case, the power wiring 119 may be a metal layer formed on a single layer. Furthermore, the power wiring 119 may be made of the same material, for example, the same material (source/drain metal) as a source electrode or a drain electrode of a thin film transistor (TFT) included in the pixel circuit. In this case, the power wiring 119 may be a metal layer (so-called Ti/Al/Ti) having a multilayer structure stacked in the order of titanium (Ti), aluminum (Al), and titanium (Ti).

The reinforcing layer 123 is provided to prevent damage (eg, corrosion, etching, etc.) of the power wiring 119 . In particular, when the power wiring has a Ti/Al/Ti structure, it may be provided to prevent erosion of aluminum in the middle. In this case, the reinforcing layer 123 may be disposed over the first part S1 and the second part S2 as shown in FIG. 4A . Referring to FIG. 4B , the reinforcement layer 123 covers the wiring edges not covered with the organic layer 117 so as not to expose them. The reflective layer 123 disposed in this way protects the wiring metal 119 from another process (eg, anode patterning).

If the structure for reinforcing the weak part of the power wiring is adopted as described above, the wiring 119 can receive sufficient protection even in the portion S2 without the organic layer, so that the wiring 119 is a single unit without a jumping structure as shown in FIG. 4C . It can be formed only in layers.

The reinforcement layer 123 may be made of the same material as the anode electrode included in the pixel circuit. In this case, the reinforcement layer 123 may be formed together in the process of patterning the anode electrode.

Although the embodiments of the present specification have been described in detail with reference to the accompanying drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit thereof. Accordingly, the embodiments disclosed in the present specification are for explanation rather than limiting the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and may be technically variously linked and operated by those skilled in the art, and each embodiment may be implemented independently of each other or together in a related relationship. may be carried out. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (10)

a display area having pixel circuitry associated with one or more pixels; and
a non-display area having a power supply line connected to the pixel circuit;
A reinforcing layer covering a side surface of the power wiring is provided in the non-display area;
the reinforcing layer comprises a first portion covered with the planarization layer and a second portion not covered with the planarization layer;
and the reinforcing layer extends from an upper portion of the planarization layer and is disposed over the first portion and the second portion by covering an edge of the power wiring not covered with the planarization layer from being exposed. The method of claim 1,
The power wiring is a metal layer formed on a single layer. The method of claim 1,
The power wiring is made of the same material as a source electrode or a drain electrode of a thin film transistor (TFT) included in the pixel circuit. 4. The method of claim 3,
The power wiring is a display device having a multilayer structure in which titanium (Ti), aluminum (Al), and titanium (Ti) are sequentially stacked. 5. The method of claim 4,
The reinforcing layer is provided to prevent the aluminum of the power wiring from being eroded. The method of claim 1,
The reinforcement layer is made of the same material as the anode electrode of the organic light emitting diode included in the pixel circuit. delete delete The method of claim 1,
and an encapsulation layer covering at least a portion of the power wiring. 10. The method of claim 9,
The portion not covered by the encapsulation layer is a curved portion.

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