KR100925655B1 - Led lamp - Google Patents

Abstract

Here, the lamp having both ends blocked and having a transmissive lamp tube having a longitudinal axis, at least one LED, the light emitting means provided to be accommodated in the lamp tube, and the wavelength of the light emitted from the light emitting means to convert the lamp. Disclosed is an LED lamp for a backlight comprising a phosphor formed on an inner circumferential surface or an outer circumferential surface of a tube. In this case, the light emitting means includes a UV LED or a blue LED, the phosphor is made of a combination to create a white light with the UV LED or the blue LED, the light emitting means further comprises a red LED for reinforcing the red wavelength band can do.

LED, backlight, phosphor, UV, lamp tube, blue, red, green,

Description

LED lamps {LED LAMP}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LED (Light Emitting Diode) lamp suitable for a backlight, and more particularly, to an LED lamp in which light emitting means including LEDs are accommodated in a transmissive lamp tube.

Conventionally, Cold Cathode Fluorescent Lamps (CCFLs) have been mainly used for the surface light source of backlights. However, since the cold cathode fluorescent lamp uses mercury gas, it is not environmentally friendly and has disadvantages such as slow response speed, low color reproducibility, and coarse structure.

On the other hand, an LED (Light Emitting Diode) has the advantage of being environmentally friendly, good response speed and color reproducibility, and the implementation of a relatively compact backlight unit. Therefore, the application of using LED as a light source of the backlight unit instead of the existing cold cathode fluorescent lamp is increasing trend.

The LED (Light Emitting Diode) is a device in which electrons and holes meet and emit light in a p-n semiconductor junction by a current application. Such LEDs are used in the form of bare chips or manufactured in a package structure. Often, a bare chip type LED is referred to as an LED chip, and a package structure LED is called an LED package.

Conventionally, a backlight unit in which a plurality of LED packages are disposed adjacent to a light guide plate or a diffusion plate is mainly used. In this case, each of the plurality of LED packages is used to produce white light using an RGB phosphor contained in a blue LED chip and an encapsulant encapsulating the blue LED chip. Therefore, the prior art has the hassle and difficulty of adjusting the white balance for each of the plurality of LED packages. For example, in an application using 54 LED packages in one backlight unit, the white balance should be adjusted for each of the 54 LED packages. Furthermore, despite the above-described adjustment of the white balance, as a whole, it was not easy to match the uniformity of the white light.

 In addition, the conventional technology has a problem that the use of the UV LED chip is not easy. The reason is that the UV LED chip generates high energy in the light emission process and discolors the encapsulant that encapsulates it.

Therefore, the technical problem of this invention is suitable for a backlight use, and can use the translucent lamp tube in which fluorescent substance was formed as a means for accommodating and protecting LED, and uniform color conversion of the light is possible over the whole path | route which light emits. In addition, to provide an LED lamp that minimizes the performance degradation due to high energy from the LED (especially UV).

According to an aspect of the present invention, there is provided a light-transmitting lamp tube having both ends closed and having a longitudinal axis, at least one LED, the light emitting means being provided to be accommodated in the lamp tube, and the light emitted from the light emitting means. To convert, there is provided an LED lamp comprising a phosphor formed on the inner circumferential surface or the outer circumferential surface of the lamp tube.

Preferably, the light emitting means comprises a UV LED or a blue LED, and the phosphor is made of a combination which produces white light together with the UV LED or the blue LED.

According to an embodiment of the present invention, the light emitting means includes a plurality of UV LEDs, and the phosphor may be composed of a red phosphor, a green phosphor, and a blue phosphor.

According to another embodiment of the present invention, the light emitting means includes a plurality of UV LEDs, and the phosphor may be composed of a blue phosphor and a yellow phosphor.

Preferably, the light emitting means may further include a red LED for reinforcing the red wavelength band. In addition, the light emitting means includes a plurality of LEDs arranged along the longitudinal axis, wherein the phosphor is disposed on the inner circumferential surface of the lamp tube in parallel with the longitudinal axis so as to correspond to the path of the light emitted from the light emitting means. The heat dissipation oil may be filled in the lamp tube, and in this case, the heat dissipation oil is preferably a paraffinic hydrocarbon oil, and the lamp tube avoids the direction of light emission from the light emitting means. Thermally conductive metals may be combined.

The above-described LED is preferably an LED chip mounted on a substrate (especially a PCB).

According to the present invention, since the wavelength conversion of the light emitted from the light emitting means including the LED is made in the lamp tube, color adjustment of the white light is easy, and in particular, in the case of using a plurality of LEDs, color adjustment for each of the plurality of LEDs is performed. It is not necessary, and it is easy to obtain uniform white light. In addition, since there is no resin causing color change by the energy of the LED around the LED (especially UV LED), the problem of performance degradation due to discoloration of the resin encapsulant, which is a problem of the backlight unit using the existing LED package, is solved. Can be.

In addition, when white light is produced by various combinations of UV LEDs or blue LEDs and phosphors, color reproducibility and color rendering can be greatly improved by reinforcing the red wavelength band with a red LED.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention can be fully conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a view for explaining a backlight LED lamp according to an embodiment of the present invention.

Referring to FIG. 1, the LED lamp 1 for backlight of this embodiment includes the LED array 10 as a light emitting means, and the hollow cylindrical translucent lamp tube 20. As shown in FIG. In addition, the LED lamp 1 may include, as an additional component, a transparent heat-radiating oil 40 (indicated by a dot hatch). The LED array 10 has a structure in which a plurality of LED chips 12a and 12b are arranged long on the upper surface of the long PCB 11. In this case, the plurality of LED chips 12a and 12b may be electrically connected to a plating pattern (not shown) formed on the PCB 11 by, for example, bonding wires (not shown). It is electrically connected to the connector 21 described below. Here, the LED array 10 preferably includes a plurality of LED chips, but may also include only one LED chip.

The translucent lamp tube 20 has a virtual longitudinal axis Y, the end of which is blocked by a cap-shaped connector 21 provided for supplying power to the LED array 10. In this case, both ends of the lamp tube 20 may be sealed with the connector 21. Alternatively, one end of the lamp tube 20 may be sealed by the connector 21 and the other end of the lamp tube 20 may be closed. It is also contemplated that the end is closed with other means, such as a portion of the lamp tube 20.

In this case, the light-transmitting lamp tube 20 may be a glass tube used for a conventional CCFL or fluorescent lamp, in this case, it is economically advantageous because it is possible to use the production equipment of the existing glass tube as it is to manufacture a lamp tube. . In addition, the connector 21 has a detachable structure, and the connector 21 is detached to release the seal in the translucent lamp tube 20, and then the components in the lamp tube 20, in particular, an LED array. It may also be considered to be able to replace (10).

Since the light-transmitting lamp tube 20 can transmit light through the entire length portion except the end where the connector 21 is installed, when the LED chips 12a and 12b are densely aligned in the longitudinal direction, the lamp tube 20 The surface light emitted over the entire length of) can be obtained. In addition, the light-transmitting lamp tube 20 serves to limit the space in which the heat dissipation oil 40 is filled. The heat dissipation oil 40 is entirely filled in the LED array 10, that is, the PCB 11 and the plurality of LED chips 12a and 12b mounted thereon while being filled in the transparent lamp tube 20.

The heat dissipation oil 40 is a liquid having fluidity at room temperature, and furthermore, under temperature conditions around the LED chips 12a and 12b, and has excellent thermal conductivity. The heat dissipation oil 40 can enclose the LED array 10 as a whole, thereby taking heat generated from each of the LED chips 12a and 12b of the LED array 10 in all directions.

According to a preferred embodiment of the present invention, the heat dissipation oil 40 is composed of a paraffinic hydrocarbon (C _n H _{2n +2} ) -based oil, most preferably an oil having a molecular formula of C ₁₀ H ₂₂ . Paraffinic hydrocarbon-based oils are transparent, have high moisture repelling properties, and have high thermal conductivity. Therefore, the heat radiation oil 40 of the paraffinic hydrocarbon system transmits the light from the LED array 10 toward the lamp tube 20, disperses and dissipates the heat from the LED array 10 widely, and at the same time, Moisture intrusion from the outside can be blocked in advance, thereby preventing the risk of various defects due to moisture infiltration, such as electric shorts.

As mentioned above, the LED array 10 includes a plurality of LED chips arranged long on the PCB 11 along the longitudinal axis Y, the plurality of LED chips are UV LED chips that emit ultraviolet light. 12a and a red LED chip 12b that emits red light.

In addition, a phosphor 30 for wavelength converting ultraviolet rays from the UV LED chip 12a is formed on the inner circumferential surface of the lamp tube 20. The phosphor 30 may be formed of red and green blue phosphors that convert ultraviolet rays into wavelengths of red, green, and blue. Alternatively, the phosphor 30 may be made of a yellow phosphor and a blue phosphor. The light whose wavelength is changed by the phosphor 30 is mixed with each other to produce white light. At this time, the phosphor 30 is formed long in the lamp tube 20 so as to cover the light, that is, the range through which the ultraviolet light as a whole, contributes to make a uniform white light as a whole.

On the other hand, when analyzing the white light produced by the phosphor 30 and the UV LED chip 12a, the red wavelength is insufficient compared to the other wavelength band, which causes the color reproducibility and color rendering of the light deteriorate. The red LED chip 12b enhances the red wavelength, thereby contributing to improving color reproducibility and color rendering of light. In the present embodiment, the red LED chip 12b is disposed adjacent to each of the UV LED chip 12a disposed at regular intervals along the longitudinal axis Y. Accordingly, the red LED chip 12b may also be disposed at regular intervals along the longitudinal axis Y, similarly to the UV LED chip 12a.

It is also conceivable to use a blue LED chip instead of the UV LED chip 12a. In this case, the phosphor 30 may be made of a yellow phosphor, or may be made of a green phosphor and a red phosphor. In addition, instead of the above-mentioned green, red, blue, and yellow phosphors, various kinds of phosphors capable of emitting colors of any other wavelength may be used. Here, the phosphor 30 may be formed by directly coating phosphor particles on the surface of the lamp tube 20 or by stacking at least one phosphor film including phosphor particles on the surface of the lamp tube 20.

 2 is a cross-sectional view showing an LED lamp for a backlight according to another embodiment of the present invention. Referring to FIG. 2, the LED lamp 1 of the present embodiment includes a translucent lamp tube 20 composed of a semicircular curved portion 202 and a flat portion 204, instead of a hollow cylindrical translucent lamp tube. The curved portion 202 is in a light emitting path (or light emitting direction) of the LED array 10, and the flat portion 204 is located facing the PCB bottom of the LED array 10. The shape of the translucent lamp tube 20 is to improve the heat dissipation performance by considering the directivity angle or the light emission efficiency in the light emitting direction of the LED array 10 and making the bottom surface of the LED array 10 a flat surface rather than the light emitting path. Here, it is preferable that the fluorescent substance 30 is formed in the surface of the said curved part 202, especially the inner peripheral surface of the curved part 202. As shown in FIG.

In addition, for better heat dissipation performance, a thermally conductive metal 205 such as copper is coupled to the outside of the planar portion 204 of the translucent lamp tube 20. At this time, the position where the thermally conductive metal 205 is coupled is not limited to the bottom plane portion of the transparent lamp tube 20, and any position of the transparent lamp tube 20 in which the light emitting direction of the LED array 10 is combed. Can be.

Without being limited to the above-described embodiments, the present invention can be applied in various ways, for example, air or other gas may be enclosed in the transparent lamp tube 20 instead of heat-radiating oil (see FIG. 3). ). In addition, the light-transmitting lamp tube 20 may be filled with other liquid than oil. In addition, oils or other liquids filled in the light-transmitting lamp tube 20 may include any material (eg, a diffusion material) that improves the performance of the LED lamp or is suitable for a specific application of the LED lamp. Further, in the above embodiment, although the phosphor is described as being formed in a coating method on the inner circumferential surface of the transparent lamp tube 20, for example, forming the phosphor on the outer circumferential surface of the transparent lamp tube 20 may also be considered. The method of forming the phosphor on the inner circumferential surface or the outer circumferential surface of the light transmitting lamp tube may be made in various ways. In addition, the light-transmitting lamp tube 20 may be formed in various geometries, for example, to increase light efficiency or to provide predetermined light emission characteristics.

1 is a perspective view showing an LED lamp for a backlight according to an embodiment of the present invention.

2 is a cross-sectional view showing an LED lamp for a backlight according to another embodiment of the present invention.

3 is a cross-sectional view showing an LED lamp for a backlight according to another embodiment of the present invention.

Claims (10)

delete delete A translucent lamp tube having both ends blocked and having a longitudinal axis; A light emitting means having a plurality of LEDs and installed to be accommodated in the lamp tube; It includes a phosphor consisting of a red phosphor, a green phosphor and a blue phosphor formed on the inner circumferential surface or outer circumferential surface of the lamp tube, so as to wavelength convert the light emitted from the light emitting means, The plurality of LEDs, a plurality of UV LEDs, and LED lamp, characterized in that it comprises a red LED for reinforcing the red wavelength band. A translucent lamp tube having both ends blocked and having a longitudinal axis; A light emitting means having a plurality of LEDs and installed to be accommodated in the lamp tube; It includes a phosphor consisting of a blue phosphor and a yellow phosphor formed on the inner circumferential surface or outer circumferential surface of the lamp tube, so as to convert the wavelength of the light emitted from the light emitting means, The plurality of LEDs include a plurality of UV LEDs, and a red LED for protecting the red wavelength band. delete 5. The lamp tube of claim 3, wherein the plurality of LEDs are disposed elongated along the longitudinal axis, and the phosphors correspond to the path of the lights emitted from the plurality of LEDs, parallel to the longitudinal axis of the lamp tube. LED lamp, characterized in that formed on the inner peripheral surface. The LED lamp according to claim 3 or 4, wherein heat dissipation oil is filled in the lamp tube. The LED lamp according to claim 7, wherein the heat dissipation oil is a paraffinic hydrocarbon oil. The LED lamp according to claim 3 or 4, wherein the lamp tube is coupled with a thermally conductive metal to avoid the direction of light emission from the light emitting means. The LED lamp according to claim 3 or 4, wherein each of the plurality of LEDs is an LED chip mounted on a substrate.

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