Display device

Abstract

The purpose of this invention is to provide a display device that is imperceptible when the LED device is not emitting light, provides excellent display performance when the LED device is emitting light, and offers excellent design flexibility. Specifically, the display device includes: an LED device comprising a plurality of LED elements soldered to one side of a flexible substrate; and a non-porous material with a visible light transmittance of 5-80% covering at least a portion of the LED arrangement side of the LED device.

Description

Technical Field

[0001] The present invention relates to a display device having a flexible LED device and a non-porous material covering at least a portion of the LED configuration surface side of the LED device. Prior Technology

[0002] LED display devices, such as dot matrix display devices, are rapidly becoming widespread. These devices can display any text, symbols, patterns, or other information by selectively emitting light from LED elements. Previous LED display devices widely used methods that mounted LED elements on rigid substrates that were not inherently flexible. However, this limited the design freedom of such LED display devices, thus restricting their applications.

[0003] For flexible LED display devices that can be shaped into a target form, for example, the devices listed in Patent Documents 1 and 2 are known. Patent document 1 describes a device that can be rolled up onto pillars of underground shopping malls and function as a digital sign. Patent document 2 describes an auxiliary substrate being stacked on the surface of an LED element on which the flexible substrate is not mounted, in order to suppress wrinkles in the flexible substrate in a flexible LED display device. The LED display devices described in these patent documents exhibit excellent display performance when the LED elements are emitting light. However, since their presence is also noticeable when the LED elements are not emitting light, improvements are desired in terms of design. [Existing Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent No. 6738057 [Patent Document 2] Japanese Patent Application Publication No. 2017-157837 Summary of the Invention

[0005] [The problem the invention aims to solve] The technical problem to be solved by the present invention is to obtain a display device that is imperceptible when the LED device is not emitting light, but has excellent display effect when the LED device is emitting light, and has excellent design and flexibility.

[0006] [Technical means to solve the problem] In order to solve the above-mentioned problems, the inventors conducted in-depth research and discovered that the above-mentioned problems could be solved by adopting the following structure, and thus completed the present invention. The details are as follows. Project 1: A display device, characterized in that it comprises: an LED device having a plurality of LED elements soldered to one side of a flexible substrate; and a non-porous material with a visible light transmittance of 5 to 80% covering at least a portion of the LED configuration side of the LED device. Project 2: The display device according to Project 1, characterized in that the LED device comprises: a circuit disposed on one side of a flexible substrate; a circuit-side terminal disposed in the circuit; and an LED element soldered to the circuit-side terminal by electromagnetic induction heating. Project 3: The display device according to Project 1, characterized in that the LED device comprises: a circuit disposed on one side of a flexible substrate; a circuit-side terminal disposed in the circuit; a conductive pad disposed on the other side of the flexible substrate at a position corresponding to the circuit-side terminal; and an LED element soldered to the circuit-side terminal by electromagnetic induction heating. Item 4: The display device according to Item 2 or 3, characterized in that, The LED device satisfies at least one of the following main conditions (1) to (8): (1) The thickness of the flexible substrate is 0.001mm~5.0mm. (2) The number of LED components ranges from 1 per 100cm² to 4000 per 100cm². (3) The circuit is formed by printing with conductive ink. (4) The circuit is formed by electroplating after the anti-plating layer is formed. (5) The circuit is formed by electroplating the seed crystal layer after printing. (6) The width of the circuit is 0.01mm~3.0mm. (7) The thickness of the circuit is 0.001mm~0.3mm. (8) The LED device can be wound on a cylinder with a diameter of 1 cm or more. Item 5: The display device according to any one of Items 1 to 4, characterized in that the non-porous material satisfies at least one of the following main conditions (a) to (c). (a) has a decorative layer, (b) Haze value is 50%~95%. (c) The half-value angle is less than 5°. Item 6: A display device according to any one of Items 1 to 5, characterized in that at least a portion of the ends of two or more sheets are provided with: a plurality of LED elements soldered to one side of the flexible substrate; and a connecting portion for fitting at least a portion of the plurality of LED elements, wherein the LED device is formed by joining the two or more sheets together by fitting the connecting portion to the LED elements. Item 7: The display device according to any one of Items 1 to 6, characterized in that the LED device and the non-porous material are joined through a double-sided adhesive sheet, the double-sided adhesive sheet having a recess or hole corresponding to at least a portion of a plurality of LED elements soldered to one side of a flexible substrate.

[0007] [The effects of the invention] According to the present invention, a display device can be provided that is imperceptible when the LED device is not emitting light, and has excellent display effect when the LED device is emitting light, and also has excellent design flexibility. Because the display device of the present invention is imperceptible when the LED device is not emitting light, it does not detract from the aesthetics of buildings or the streetscape, making it a display device with excellent design capabilities. Furthermore, due to its excellent flexibility, it can be rolled up and installed on traffic sign poles and street trees, or on curtains, banners, billboards, etc. Moreover, since it can be used as a display device at any time and is imperceptible when not in use, it can harmonize with the landscape. Simple Explanation of the Diagram

[0008] Figure 1 is a schematic configuration diagram of a display device according to one embodiment of the present invention. Figure 2 is a schematic cross-sectional view of the display device in Figure 1. Figure 3 is a schematic diagram of another embodiment of the present invention, namely a display device. Figure 4 is a schematic cross-sectional view of the display device in Figure 3. Figure 5 is a schematic configuration diagram of the third embodiment of the present invention, namely, the display device. Figure 6 is a schematic unfolded view of the display device shown in Figure 5. Figure 7 is a schematic cross-sectional view of the display device shown in Figure 5. Implementation

[0009] A preferred embodiment of the display device according to the present invention will now be described with reference to the accompanying drawings, but the present invention is not limited to the following embodiment. Furthermore, appropriate modifications can be made without departing from the scope of the invention. Additionally, the use of the same reference numerals in different drawings indicates similar or identical items or features.

[0010] As shown in Figure 1, one embodiment of the present invention, namely the display device D, has an LED device L and a non-porous material 1. The LED device L is a device in which multiple LED elements 3 are soldered onto one side of a flexible substrate 2. As shown in Figure 3, another embodiment of the display device D of the present invention can also be formed by fitting the LED device connecting portion 22 with the LED element 3 and combining two LED devices La and Lb. The two LED devices La and Lb each have at least a portion of the ends of the flexible substrate 2 comprising: a plurality of LED elements 3 soldered to one side of the flexible substrate 2; and an LED device connecting portion 22 for fitting at least a portion of the plurality of LED elements 3. The connected LED devices can also be two or more. As shown in Figure 5, yet another embodiment of the display device D of the present invention can also be formed by combining the LED device L with the non-porous material 1 via a double-sided adhesive sheet 7, wherein the double-sided adhesive sheet 7 has an LED element fitting portion 71 corresponding to at least a portion of the plurality of LED elements 3 soldered to one side of the flexible substrate 2. The LED device L, the non-porous material 1, and the display device D will be described in detail below.

[0011] [LED device] Flexible substrates The flexible substrate 2 on the LED device L is made of an insulator. For example, it is not particularly limited as long as it is an insulator such as a resin film, paper, or cloth and is flexible. To facilitate the imparting of the desired physical properties, it is preferable to have a resin film. The resins used to form the resin film can be, for example, polyester resins, polyamide-imide resins, polyamide resins, polyether ether ketone resins, polyurethane resins, polyphenylene sulfide resins, polyether sulfide resins, fluoropolymers, ABS resins, polyphenylene ether resins, acrylic resins, polycarbonate resins, polybutadiene resins, polyurethane resins, polyolefin resins, polyvinyl chloride resins, polystyrene resins, etc., and there are no particular restrictions. In addition, it can be a mixture of these resins, and can also contain functional materials such as colorants, ultraviolet absorbers, infrared reflective materials, and light-scattering particles as needed. Furthermore, it can also be a laminate formed by arbitrarily combining these resin films, paper, and cloth.

[0012] As long as it is flexible, the thickness of the flexible substrate 2 is not particularly limited, for example, it can be 0.001 mm to 5.0 mm. From the point of view of strength and flexibility, it is preferably 0.01 mm to 3.0 mm, and more preferably 0.02 mm to 1.0 mm. The optical properties of the flexible substrate 2 are not particularly limited; it can be colorless and transparent, colored and transparent, translucent, or opaque. The appropriate type can be selected based on the application of the display device or its installation location. The shape of the flexible substrate 2 is not particularly limited; it can be polygonal or circular. In addition, it can also have a three-dimensional structure by combining the same or different shapes.

[0013] (Circuit and circuit-side terminals) On the side of the flexible substrate 2 where the LED element 3 is mounted by soldering, at least a circuit and a circuit-side terminal 21 provided in the circuit are formed (hereinafter, the circuit and the circuit-side terminal 21 are collectively referred to as wiring). Furthermore, the end of the circuit has a connection terminal for connecting to a power supply or control device. The wiring is made of one or more conductive materials selected from metals such as gold, silver, copper, aluminum, nickel, and chromium, conductive polymers, and conductive carbon. Wiring can be formed by one or more methods selected from screen printing, inkjet printing, gravure offset printing, flexographic printing, etching, metal vapor deposition, electroplating, silver halide, etc.

[0014] The preferred wiring, especially the circuit, has a width of 0.01mm to 3.0mm, more preferably 0.03mm to 2.0mm, and even more preferably 0.1mm to 1.0mm. When the width of the wiring is less than 0.01 mm, it may be difficult to manufacture the wiring. In addition, the wiring may break due to the stress generated when the display device D and / or the LED device L are deformed. When the width of the wiring exceeds 3.0 mm, the wiring may become very obvious and impair the design when the transparent substrate is used as the flexible substrate 2 to form the display device D.

[0015] The optimal wiring, especially circuitry, has a thickness of 0.001mm to 0.3mm. In the LED device L of the present invention, the solder joint 4 where the LED element 3 is soldered is rigid and inflexible, while the portion where the LED element 3 is not soldered exhibits flexibility through bending. Therefore, when the display device D and / or the LED device L of the present invention are bent, stress is applied to the solder joint 4 where the LED element 3 is soldered. Thus, when the thickness of the wiring is less than 0.001 mm, it may be unable to withstand the generated stress when the display device D and / or the LED device L are deformed, leading to peeling or damage between the flexible substrate 2 and the wiring near the solder joint 4 of the LED element 3. On the other hand, when the thickness of the wiring exceeds 0.3 mm, the wiring becomes more rigid, which may reduce the flexibility of the display device D and / or the LED device L. The thickness of the wiring is preferably 0.003mm~0.2mm, more preferably 0.003mm~0.1mm, more preferably 0.003mm~0.08mm, and most preferably 0.005mm~0.06mm.

[0016] In this invention, the wiring disposed on one side of the flexible substrate 2 can be formed by printing conductive ink. Preferably, the printing method is screen printing, inkjet printing, or gravure offset printing. By forming the circuit using printing, mass production can be achieved inexpensively and easily. Furthermore, in this invention, the wiring disposed on one side of the flexible substrate 2 can be formed by electroplating after forming an anti-plating layer using methods such as printing, or by electroplating a seed layer after printing. Even using this method, mass production can be carried out inexpensively and easily.

[0017] (LED components) The LED device L of the present invention has a plurality of LED elements 3 soldered on one side of a flexible substrate 2. The number of LED elements 3 is not particularly limited and can be appropriately determined according to the dot density required by the LED device L. For example, the number of LED elements 3 can be 1 to 4000 per 100cm², preferably 30 to 3000 per 100cm², more preferably 60 to 3000 per 100cm², and even more preferably 80 to 2500 per 100cm². These multiple LED elements 3 can be arranged at a certain spacing on one side of the flexible substrate 2. Alternatively, they can be arranged in any configuration on one side of the flexible substrate 2.

[0018] LED element 3 is not particularly limited and can be any element such as a monochrome LED element or a full-color LED element. In this invention, from the viewpoint of the display device D's performance, it is preferable to use a full-color LED with a built-in control unit. A full-color LED has at least three LED elements (red, green, and blue) and a control unit within a single LED element device. The control unit is configured to emit any hue by selectively emitting one or more of the LED elements of each color based on an external command signal. By sending signals generated by the external main control unit to the built-in full-color LEDs of each control unit for control, multiple LEDs can function as color displays. While more precise displays can be achieved by increasing the dot density of LEDs, this may lead to a decrease in flexibility.

[0019] Soldering In this invention, the method of soldering on one side of the flexible substrate is not particularly limited. It can be appropriately determined by taking into account the physical properties of the solder, such as its melting point, the heat resistance of the flexible substrate 2 or the LED element 3, and its workability. For example, the LED element can be placed on the circuit-side terminal via solder, and the solder can be melted by heating in this state to solder the circuit-side terminal to the electronic component-side terminal. Thus, as shown in Figures 2(a) and 2(b), the circuit-side terminal 21 provided in the circuit and the LED element-side terminal 31 of the LED element 3 are connected via the solder joint 4, and the circuit is formed on one side of the flexible substrate 2. The type of solder used in soldering is not particularly limited. In this invention, from an environmental perspective, lead-free solder is preferred. For example, high-temperature solder (SnAgCu type solder, melting point around 220°C, etc.) to low-temperature solder (SnBi type solder, melting point around 140°C, etc.) can be used.

[0020] Methods of soldering include, for example, flow soldering, reflow soldering, and soldering using electromagnetic induction heating technology (IH technology). In situations where many LED components are bonded together to increase dot density, workability can be improved by using a heat-resistant, flexible substrate such as polyimide resin and by using methods such as reflow soldering. Furthermore, when using polyester resins with relatively low heat resistance, such as polyethylene terephthalate (PET) resin, as the flexible substrate, a soldering method utilizing electromagnetic induction heating technology (IH technology) can be used. The soldering method utilizing electromagnetic induction heating technology (IH technology) involves passing eddy currents through a conductive material and generating Joule heat, thus causing the conductive material to heat up itself. As a soldering method utilizing electromagnetic induction heating technology (IH technology), the method described in the aforementioned Patent Document 1 can be used, for example.

[0021] For example, when using a flexible substrate 2 with relatively low heat resistance, as shown in Figure 2(b), the circuit is disposed on one side of the flexible substrate 2 relative to the circuit-side terminal 21 disposed in the circuit, while a conductive pad 5 is disposed on the other side of the flexible substrate 2 at a position corresponding to the circuit-side terminal 21. Therefore, the LED element 3 can be more securely soldered to the circuit-side terminal 21 using electromagnetic induction heating technology (IH technology). As a result, the LED element 3 can be conveniently disposed in any position. Because the conductive pad 5 on the other side of the flexible substrate 2 has a larger volume than the circuit-side terminal 21 and solder, it generates more heat through electromagnetic induction heating. The heat generated on the conductive pad 5 through electromagnetic induction heating is then transferred to the solder through the flexible substrate 2 and the circuit-side terminal 21, effectively heating and melting the solder. This melts the solder, forming the solder joint 4, and the LED element 3 is soldered. At this point, because the heat generated on the conductive pad 5 through electromagnetic induction heating quickly transfers to the solder with higher thermal conductivity, the temperature rise of the flexible substrate 2 is suppressed. Therefore, the flexible substrate 2 can be a non-heat-resistant material.

[0022] The conductive pad 5 is formed of a metallic material containing one or more metallic elements selected from gold, silver, copper, aluminum, nickel, palladium, chromium, etc. The conductive pad 5 can be formed using the same method as the wiring. The conductive pad 5 has dimensions including a circuit-side terminal 21 located on the opposite side of the flexible substrate 2. While its shape is not particularly limited, it can be circular, polygonal, etc. For example, it can be a circle with a diameter of 3 mm. Preferably, the thickness of the conductive pad 5 is the same as that of the wiring, ranging from 0.001 mm to 0.3 mm, more preferably from 0.003 mm to 0.2 mm, and even more preferably from 0.005 mm to 0.06 mm. The conductive pad 5 can increase the heat generated by electromagnetic induction heating technology. In particular, it can raise the temperature of the area where the conductive pad 5 is formed, thus enabling more reliable soldering.

[0023] In addition, even when, for example, as shown in (a) of FIG. 2, the flexible substrate 2 does not have the conductive pad 5 on the other side, it is also possible to perform soldering through the soldering portion 4 by using the heat generated inside the circuit-side terminal 21 and solder, etc. by electromagnetic induction heating, such as by extending the heating time, increasing the current, reducing the resistance, etc. In addition, when the flexible substrate 2 and the LED element 3 have heat resistance, it is also possible to use a reflow furnace, etc. to heat the whole for soldering.

[0024] <Features of the LED device> The LED device L constituting the display device D of the present invention has flexibility. For example, the LED device L can be wound around a cylinder with a diameter of 1 cm or more. Here, being wound means that even after being wound around the cylinder, there will be no damage to the LED device functions such as disconnection of the wiring or peeling and dropping of the LED element 3. In the present invention, it can be wound around a cylinder with a diameter of 1 cm or more, for example, 10 cm or more. In addition, it can also conform to a corrugated board, etc. connected to an arc with a diameter of 1 cm or more.

[0025] [Non-porous material] The non-porous material 1 on the display device is not particularly limited as long as the visible light transmittance is 5 to 80% and it has flexibility. For example, a resin film, etc. can be cited. As needed, the non-porous material 1 can be decorated by printing, etc. to improve its design.

[0026] In the present invention, it is preferred that the opening area ratio of the non-porous material 1 is less than 3%, preferably 2% or less, and more preferably 0%. The opening area ratio refers to the ratio of the area of the holes (openings) formed on the surface of the non-porous material 1. When the opening area ratio is 3% or more, it may lead to substantial exhibition of the characteristics of the porous material, thus causing problems in terms of waterproofness and dustproofness, etc. In addition, since the light from the LED element 3 directly passes through, softness, etc. is not felt during visual recognition, and the usage method, etc. may be restricted in terms of design.

[0027] In this invention, the visible light transmittance of the non-porous material 1 is 5-80%. In this invention, the wavelength range of visible light is 360 nm to 830 nm. The visible light transmittance is determined using a spectrophotometer and according to the test method specified in the international standard ISO 9050. For example, it can be determined according to Japanese Industrial Standard JIS S 3107 (although in Japanese Industrial Standard JIS S 3107 the resin film is adhered to glass for measurement, in this invention, the measurement is performed on the non-porous material 1 itself, without it being adhered to glass).

[0028] When the visible light transmittance is less than 5%, it may be difficult to visually identify the light emission of the LED element 3 on the LED device L through the non-porous material 1. When the visible light transmittance exceeds 80%, the presence of an LED device L in a non-porous material 1 can be easily identified by visual inspection, which may lead to a deterioration in design. In this invention, the visible light transmittance of the non-porous material 1 is preferably 7-75%, and more preferably 10-70%.

[0029] In this invention, the preferred non-porous material 1 has a haze value of 50% to 95%. The haze value can be determined in accordance with Japanese Industrial Standard JIS K 7136. When the haze value is less than 50%, the transparency is too high, and the presence of LED elements 3 under non-porous material 1 can be easily identified by visual inspection, which may lead to poor design performance. When the haze value exceeds 95%, it may make it difficult to visually identify the light emission of the LED element 3 on the LED device L through the non-porous material 1.

[0030] In this invention, the half-value angle of the preferred non-porous material 1 is 5° or less. More preferably, it is 4° or less, and even more preferably, it is 3° or less. The half-value angle is, for example, the angle at which the brightness is halved relative to the center brightness, obtained by measuring the brightness distribution using a luminance meter after a parallel light beam is incident through a collimator. When the half-value angle exceeds 5°, the light diffusion increases, making it difficult to perceive the light emitted by the LED element 3 as a point, which may lead to a decrease in the visual recognition and design of the display device.

[0031] [Composition and Application of Display Devices] In this invention, as shown in FIG3, by connecting two or more LED devices La, Lb, etc., a large-screen LED device L can be formed. These LED devices La, Lb, etc., for example, have at least a portion of the end of the flexible substrate 2 including: a plurality of LED elements 3, which are soldered to one side of the flexible substrate 2; and an LED device connecting portion 22, which can fit at least a portion of the aforementioned plurality of LED elements 3. For example, as shown in Figures 3 and 4, by soldering multiple LED elements 3 on one side of the first LED device La with LED device connecting parts 22 provided on the end of the flexible substrate 2 of the second LED device Lb, two or more LED devices La and Lb can be connected. By adopting this configuration, it is easy to form a large-screen display device D and an LED device L.

[0032] The shape of the LED device connector 22 is not particularly limited as long as it can accommodate the LED element 3; for example, it can be a hole or a recess. For example, since a hole is simpler, it is preferable that the LED device connector 22 be a hole. The shape of the hole is not particularly limited as long as it can accommodate the LED element 3; it can be a circle, a polygon, an ellipse, or other shapes. When connecting two or more LED devices La, Lb, etc., it is preferable to form an LED device connecting adhesive layer 6 that bonds the individual LED devices together. The LED device connecting adhesive layer 6 can be composed of adhesives, bonding agents, adhesive sheets, etc., to reliably achieve the connection between the LED devices in two or more LED devices La, Lb, etc. For example, adhesives such as polysiloxane resins, polyurethane resins, polyolefin resins, acrylic resins, rubbers, and epoxy resins can be used. By using elastic adhesives, the display device D can be installed even in locations subject to impact, such as on the ground. By forming an adhesive layer 6 for the LED device connection part by means of adhesive, bonding agent, adhesive sheet, etc., when connecting two or more LED devices La, Lb, etc., the LED element 3 will be fixed on the LED device connection part 22 and will be difficult to move. Therefore, it can prevent the arrangement of the LED element 3 from becoming disordered. In addition, it can reduce the discomfort of the display part associated with connecting two or more LED devices La, Lb, etc.

[0033] LED devices formed and enlarged through interconnection remain flexible even after interconnection, and can be used in the same way as large LED devices formed as a flexible substrate. Furthermore, when the adhesive layer 6 of the LED device connection is formed by a re-peelable adhesive, even if a defect occurs due to a failure of the LED element 3, only the LED device L with the corresponding LED element 3 needs to be replaced, thus providing excellent maintainability. As a re-peelable adhesive, polysiloxane resins, polyurethane resins, polyolefin resins, acrylic resins, etc., can be used, and there are no particular limitations.

[0034] In this invention, the LED device L and the non-porous material 1 can be fixed or not. Alternatively, the LED device 3 can be encapsulated within the non-porous material 1, which is formed in a bag-like shape. When fixing the LED device L and the non-porous material 1, adhesives, bonding agents, adhesive sheets, etc., can be used. In addition, methods such as sewing and fitting can be used. When fixing the LED device L and the non-porous material 1, either a portion of it or the entire surface can be fixed.

[0035] In this invention, as shown in Figures 5 to 7, when fixing the LED device L and the non-porous material 1, it is preferable to use a double-sided adhesive sheet 7, which has an LED element fitting portion 71 corresponding to at least a portion of a plurality of LED elements 3 soldered to one side of the flexible substrate 2. By using this double-sided adhesive sheet 7, contamination caused by adhesive or bonding agent spillage can be prevented. In addition, it can be easily fixed in a simple way.

[0036] When the LED device L and the non-porous material 1 are not fixed, they can simply be clamped. For example, when fixing the non-porous material 1, which is decorated with printing or other decorations as needed, to a wall or the like, the LED device L can be clamped between the non-porous material 1 and the wall. Furthermore, when the display device D of the present invention is used as a billboard or banner, it can be combined by hanging the non-porous material 1, which is decorated with printing or other decorations, and the LED device L. Furthermore, the two can be fixed by wrapping a non-porous material 1 with printed or other decorations and an LED device L around a column or the like, without needing to be fixed to each other.

[0037] The display device D of the present invention can be used as a conventionally known LED light-emitting device. Furthermore, similar to LED light-emitting devices, the display device D of the present invention can be used for a wide variety of applications. Moreover, the display device D of the present invention can be used for applications where its flexibility can be fully utilized. Examples of applications for the display device D of the present invention include banners, partitions, wall panels (wall coverings), interior materials, buildings, billboards, toys, amusement machines (pinball machines, slot machines, etc.), game machines, lighting fixtures, tiles, medical instruments, inspection devices, various industrial machinery, transportation equipment, electrical equipment, agricultural equipment, fishing gear, etc. In particular, the display device D of the present invention is imperceptible when the LED device L is not emitting light, thus blending into the landscape. In addition, display devices D (LED devices L) in vehicles, streets, and buildings can be used in emergencies, disasters such as accidents, fires, earthquakes, tsunamis, and floods, or during gatherings such as concerts and memorial services. Depending on the occasion, multiple display devices D (LED devices L) can be controlled and linked together to display information for purposes such as evacuation, guidance, or attracting attention, making them extremely useful.

[0038] The power source for the display device D of the present invention is not particularly limited, and can be a battery, household power supply, vehicle, etc. For example, dry cell batteries or lithium-ion batteries can be used as power sources. Since the power source can be repeatedly used through charging, lithium-ion batteries are particularly preferred. In this invention, the product can be further developed into one that includes a control device and a control program, which are used to display necessary text or symbols and other information, by incorporating a power source such as a battery.

[0039] While the present invention has been described in detail above, various modifications can be made to its structure without departing from the scope of the invention. Therefore, all matters included in the foregoing description or shown in the accompanying drawings should be interpreted as exemplary.

[0040] 1: Non-porous materials 2: Flexible substrate 3: LED components 4: Soldering section 5: Conductive solder pads 6: Adhesive layer at the connection point of LED device 7: Double-sided adhesive sheet 21: Circuit side terminals 22: LED device connection part 31: LED component side terminal 71: LED component fitting part La: First LED device Lb: Second LED device D: Display device L: LED device

Claims

1. A display device, characterized in that it comprises: an LED device having a plurality of LED elements soldered to one side of a flexible substrate; and a non-porous material with a visible light transmittance of 5-80% covering at least a portion of the LED arrangement side of the LED device, wherein two or more sheets have: a plurality of LED elements soldered to one side of the flexible substrate; and a connecting portion for fitting at least a portion of the plurality of LED elements, wherein the LED device is formed by joining the two or more sheets together by fitting the connecting portion to the LED elements.

2. A display device, characterized in that it comprises: an LED device having a plurality of LED elements soldered to one side of a flexible substrate; and a non-porous material with a visible light transmittance of 5-80% covering at least a portion of the LED arrangement side of the LED device, wherein the LED device and the non-porous material are joined by a double-sided adhesive sheet having recesses or holes corresponding to at least a portion of the plurality of LED elements soldered to one side of the flexible substrate.

3. The display device as claimed in claim 1 or claim 2, characterized in that the LED device comprises: a circuit disposed on one side of a flexible substrate; a circuit-side terminal disposed in the circuit; and an LED element soldered to the circuit-side terminal by electromagnetic induction heating.

4. The display device according to claim 1 or claim 2, characterized in that the LED device comprises: a circuit disposed on one side of a flexible substrate; a circuit-side terminal disposed in the circuit; a conductive pad disposed on the other side of the flexible substrate at a position corresponding to the circuit-side terminal; and an LED element soldered to the circuit-side terminal by electromagnetic induction heating.

5. The display device as claimed in claim 3, characterized in that the LED device satisfies at least one of the following main conditions (1) to (8): (1) the thickness of the flexible substrate is 0.001 mm to 5.0 mm; (2) the number of LED elements is 1 / 100 cm2 to 4000 / 100 cm2; (3) the circuit is formed by printing conductive ink; (4) the circuit is formed by electroplating after forming an anti-plating layer; (5) the circuit is formed by electroplating a seed crystal layer after printing; (6) the width of the circuit is 0.01 mm to 3.0 mm; (7) the thickness of the circuit is 0.001 mm to 0.3 mm; (8) the LED device can be wound on a cylinder with a diameter of 1 cm or more.

6. The display device as claimed in claim 1 or claim 2, characterized in that the non-porous material satisfies at least one of the following main conditions (a) to (c): (a) having a decorative layer, (b) having a haze value of 50% to 95%, and (c) having a half-value angle of 5° or less.

Images