Straight fluorescent tube LED lamp

Abstract

To provide an LED lamp that achieves significant improvement in the width and luminescence intensity of a luminescence region in order to illuminate an advertisement plate from the inside of a signboard frame, and prevents cracks from occurring due to expansion or shrinkage of a cylindrical cover.SOLUTION: An LED lamp of straight fluorescent lamp type has a polygonal support in a longitudinal direction. On the support, LEDs are arrayed in three or more lines in the longitudinal direction. In the polygonal central cavity of the support, a power supply is provided.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a straight-tube fluorescent LED lamp (hereinafter referred to as "LED lamp") that uses an LED (light-emitting diode) as the light source. For example, the LED lamp is housed in a signboard frame that holds an acrylic resin advertising panel, and is suitable for illuminating an area (advertising panel) that is approximately 10 to 20 cm away. [Background technology]

[0002] Lamps using LED modules housed within sign frames to illuminate advertising panels have long been used in place of conventional mercury discharge fluorescent lamps (hereinafter referred to as "straight tube fluorescent lamps"). When using LED lamps, not only can the problem of the lifespan of conventional fluorescent lamps be solved by extending their service life semi-permanently, but they can also be installed directly in the frames of existing straight tube fluorescent lamps, dramatically improving their convenience as sign lamps.

[0003] However, LEDs generally have a higher degree of directionality than fluorescent lights, so for lighting devices using LEDs, efforts are being made to expand the illumination range in order to illuminate a wider area. For example, a straight-tube fluorescent LED lamp for signs is known that uses an LED module in which many LEDs are arranged in two longitudinal rows on two inclined support plates formed with a mountain-shaped cross section (Patent Document 1). This LED lamp has a wide illumination range because the two inclined support plates are formed with an acute mountain-shaped cross section, and when used as an advertising lamp, it is said to be able to illuminate the advertising panel evenly and brightly.

[0004] However, LED lamps up to now, including the straight-tube fluorescent LED lamps for signs mentioned above, have been used as replacements for straight-tube fluorescent lamps, and use the same frame as straight-tube fluorescent lamps. As a result, they have inherited many of the same shapes as conventional fluorescent lamps, and in the following respects, their characteristics as lighting lamps have not been fully utilized.

[0005] That is, conventional straight-tube fluorescent lamps require relatively large caps at both ends, but these portions do not emit light. For this reason, when fluorescent lamps are connected in series to illuminate a long advertising board, the portion of the advertising board where the fluorescent lamp caps are located becomes dark because the caps do not emit light. To avoid this, fluorescent lamps are sometimes connected in such a way that the ends of the lamps overlap, eliminating any non-emitting portions along the length.

[0006] This is because straight-tube fluorescent lamps are constructed by sealing a small amount of mercury vapor and argon gas in an evacuated glass tube (mercury discharge tube), applying a voltage to both ends to generate light through gas discharge. In other words, in conventional straight-tube fluorescent lamps, the mercury discharge tube must be sufficiently sealed with the bases on both ends. For this reason, straight-tube fluorescent lamps must be equipped with bases of a certain size, which inevitably results in non-light-emitting areas. Even in LED lamps that replace straight-tube fluorescent lamps, the inclusion of a non-emitting base has become a natural choice.

[0007] Apart from this issue, conventional LED lamps also had another issue that needed to be improved. In conventional LED lamps, the connection between the socket and the cylindrical cover was sealed with a simple silicone ring. However, this was unable to adequately absorb the expansion and contraction of the cylindrical cover, which could cause cracks to appear on both ends of the cylindrical cover as it expanded, or gaps to appear as it contracted, allowing water to seep inside. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5717095 Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an LED lamp having good illumination characteristics. In other words, the objective is to provide an LED lamp that significantly improves the width of the light-emitting area and the light-emitting intensity by reducing the dimensions of the base portion to expand the light-emitting area and making the cap of the base portion transparent. [Means for solving the problem]

[0010] In order to solve the above problems, the LED lamp of the present invention is a straight-tube fluorescent LED lamp having a support body with a polygonal cross-section and a hollow structure extending longitudinally within a light-transmitting cylindrical cover, wherein three or more rows of LEDs are arranged longitudinally on the support body, and a power supply is installed within the polygonal cavity of the support body. The polygon is preferably a polygon having more than one side, and the LEDs are preferably arranged in three or four rows. [Effects of the Invention]

[0011] The LED lamp of the present invention expands the light-emitting area by reducing the dimensions of the base that is provided in conventional LED lamps, providing a bright LED lamp for signboards. [Brief explanation of the drawings]

[0012] [Figure 1] Figure 1 shows the cross-sectional structure of a conventional LED lamp, where (a) is a longitudinal cross-sectional view and (b) is an enlarged cross-sectional view along line AA. [Figure 2] FIG. 2 shows the cross-sectional structure of the LED lamp of the present invention, where (a) is a longitudinal cross-sectional view, and (b) is an enlarged cross-sectional view taken along line BB. [Figure 3] Figure 3 is an enlarged cross-sectional view of the LED lamp of the present invention taken along line CC in Figure 2. There are K type (a) and R type (b). [Figure 4]FIG. 4 shows the cross-sectional structure of the end of an LED lamp, where (a) is that of a conventional LED lamp and (b) is that of the LED lamp of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following describes a specific embodiment of the LED lamp of the present invention, taking as an example an embodiment used as a lamp for illuminating the inside of a sign frame. However, the LED lamp of the present invention is not limited to use in signboards, and it goes without saying that it can be used for various lighting applications due to its excellent lighting characteristics.

[0014] (conventional LED lamp) Figure 1 shows an overview of the structure of a conventional LED lamp, where (a) is a longitudinal cross-sectional view and (b) is an enlarged cross-sectional view along line AA. The structure is such that a support 3 on which many LEDs 2 are mounted in series in the longitudinal direction is loaded into a light-transmitting cylindrical cover 1, and the bases on both ends have a power source 4 and metal pins 5 that are electrically connected to the power source. Because of this structure, in conventional LED lamps, the bases are the parts that do not emit light. Generally, the support 3 is made of an aluminum alloy molded material, and the light-transmitting cylindrical cover 1 is made of flame-retardant polycarbonate.

[0015] (Cross-sectional shape of support) FIG. 2 shows cross-sectional views of the LED lamp of the present invention, where (a) is an enlarged cross-sectional view taken along the longitudinal direction and (b) is an enlarged cross-sectional view taken along line BB. The LED lamp of the present invention uses a hollow support 3 with a polygonal (hexagonal) vertical cross section, with the opening diameter of the polygon enlarged. This is a major difference from conventional LED lamps. This allows the power source 4 to be inserted into the cavity connected to the opening, and the support 3 on which the LED is mounted can be extended to the area that would normally be used as the base in conventional LED lamps. In other words, the dimensions of the base can be reduced. Also, by making the caps 8 on both ends of the LED lamp translucent, the light transmittance can be further improved.

[0016] The opening diameter of the support 3 must be large enough to allow the power source 4 to be inserted into the support 3. However, it is preferable to make the opening diameter smaller. This is because by increasing the space between the LED light source and the cylindrical cover 1, the highly directional LED light can be diffused by the cylindrical cover 1 to produce uniform light. In the LED lamp of the present invention, the light-emitting area can be significantly expanded compared to conventional lamps by installing the power source 4 inside the support 3. This is the first feature of the LED lamp of the present invention.

[0017] Figure 3 shows an enlarged cross-sectional view of an LED lamp taken along line CC in Figure 2(a). (a) shows a type in which three rows of LEDs 2 are mounted longitudinally on a support 3 (hereinafter referred to as "K type"), while (b) shows a type in which four rows of LEDs 2 are mounted (hereinafter referred to as "R type"). In this way, LED lamps can be installed facing multiple directions, ensuring a light distribution angle of 300° for the K type and 360° for the R type. The LED lamp of the present invention has a wide light distribution angle, so even when used to illuminate a double-sided sign frame with advertising panels on both the front and back sides, it can brightly illuminate the advertising surface. Also, when used to illuminate a single-sided sign frame, the advertising surface can be brightly illuminated by the light reflected or diffused from the back side of the advertising board.

[0018] In addition, in Figure 3, all supports 3 have a hexagonal vertical cross section, but depending on the relationship between the diameter of the cylindrical cover 1 and the dimensions of the LED 2, a support 3 with a polygonal cross section up to an octagonal shape can also be used. In this case, the number of surfaces on which the LED 2 is actually measured can be increased to eight, providing an even brighter sign surface.

[0019] (Silicone sealing material) Next, we will explain the sealing structure at both ends of the LED lamp. This is the technical feature related to the base part (prior art) in Figure 1(a) and the cap part 8 (present invention) in Figure 2(a). Figures 4(a) and (b) show enlarged views of each. In conventional LED lamps (Fig. 4(a)), the support 3 inside the LED lamp is fixed in place by the socket 7, and metal pins 5 are connected to the internal power supply 4 to supply the power required for light emission. A silicon ring with a square cross section is placed at the connection between the socket 7 and the cylindrical cover 1 to maintain airtightness inside the LED lamp.

[0020] FIG. 4(b) shows the cross-sectional structure of both ends of the LED lamp of the present invention. The LED lamp of the present invention also has a socket 7 for fixing the support 3 and metal pins 5 for supplying power to the power supply unit. In this respect, it is no different from conventional LED lamps. However, the LED lamp of the present invention is characterized in that it has a silicone sealing member 6 with a specific shape, as shown in FIG. 4(b).

[0021] The silicone sealing member 6 at the end of the LED lamp of the present invention is sandwiched between the cylindrical cover 1 and the cap 8 in the socket 7 and is placed at the connection between them. The part that connects to the cylindrical cover 1 is bellows-shaped, and the part that connects to the cap 8 has a gap. Because of this shape, even if the cylindrical cover 1 contracts or expands due to changes in the surrounding environment, the airtightness inside the LED lamp can be maintained, and its durability can be significantly improved. This is the second feature of the LED lamp of the present invention.

[0022] Specifically, when the cylindrical cover 1 shrinks, a gap will form between the conventional silicon ring with a square cross section and the cylindrical cover 1. As a result, when the lamp is placed in a cold environment in winter, the cylindrical cover 1 will shrink significantly, and water will inevitably seep into the LED through the gap in the cylindrical cover 1. This significantly reduces the lifespan of the LED lamp. In the silicone sealing member 6 of the present invention, since the silicone sealing member 6 has a bellows portion, even if the cylindrical cover shrinks, the airtightness inside the cylindrical cover can be maintained. This completely prevents water from entering the LED lamp.

[0023] Furthermore, if the cylindrical cover 1 expands, the gap formed between the silicone sealing member 6 and the cap 8 serves to maintain the airtightness of the LED lamp. In other words, if the LED lamp is left emitting light for a long period of time or is exposed to direct sunlight in the summer, the cylindrical cover 1 will inevitably expand due to high temperatures. Even in such cases, the shape of the silicone sealing member is set so that a gap is formed between the cap 8 and the cylindrical cover 1, and this gap can absorb the expansion of the cylindrical cover 1.

[0024] In conventional LED lamps, cracks sometimes occur at the ends of the cylindrical cover 1 due to expansion of the cylindrical cover 1. In the present invention, the silicon sealing member 6 has a structure with gaps, which prevents cracks from occurring at the ends of the cylindrical cover 1, resulting in a durable, long-lasting LED lamp. [Industrial Applicability]

[0025] The LED lamp of the present invention can be well applied to both single-sided and double-sided signs, and can provide a uniformly bright advertising surface. [Explanation of symbols]

[0026] 1 Cylindrical cover 2 LED 3 Support 4 Power supply 4a power supply accessory circuit 5 metal pins 6 Silicone sealing material 7 sockets 8 Cap

Claims

[Claim 1] A straight-tube fluorescent LED lamp having a cylindrical cover that is light-transmitting and diffuses light to produce uniform light, and a support body having a hexagonal cross section and a hollow structure in the longitudinal direction. Three or four rows of LEDs are arranged on the support in the longitudinal direction, A power source is installed in the hexagonal cavity of the support, thereby expanding the light-emitting area. Straight tube fluorescent type LED lamp for signs.

Images