HK1227081A - Belt-like led light - Google Patents

Description

Belt-shaped LED lamp

Technical Field

The invention relates to a ribbon-shaped LED lamp.

Background

When turning on a plurality of LEDs (light emitting diodes) of an SMD (surface mount device) type linearly mounted on a circuit substrate, the light emitting direction is generally a direction perpendicular to the circuit substrate. If the circuit substrate is manufactured using a band-shaped FPC (flexible printed circuit) which is easily bent, the light emitting module itself may be bent with respect to the light emitting direction. Such goods have been manufactured and are commercially available as "tape lights".

According to this structure, unless the band-shaped light emitting module is twisted, it is difficult to bend the module in a direction perpendicular to the light emitting direction of the LED (the lateral direction of the band-shaped FPC). The FPC must have a width of not less than 7 mm to mount components thereon to form a circuit. Therefore, the module cannot be bent in the lateral direction.

In order to bend the FPC substrate in a lateral direction perpendicular to the light emitting direction, a side emission type or a bullet type LED may be used. When the side emission type LED is used, since the light emitting direction of the LED is the width direction of the substrate, the tape substrate of the FPC may be bent in the lateral direction perpendicular to the light emitting direction. This is the same as a bullet LED. Examples of flexible light emitting modules using bullet-type LEDs are disclosed in reference 1 (japanese unexamined patent application publication (translation of PCT application) No.2004-526185), reference 2 (registered japanese utility model No.3098840), and reference 3 (registered japanese patent No. 3897260).

As an example in which no FPC is used, reference 4 (japanese patent application laid-open No. 9-297549) describes a flexible linear light emitting module configured as follows. That is, two or more pairs of positive and negative power feeding lines are arranged in a spiral or crossing state. A plurality of LEDs and a current limiting resistor are connected in series between the pairs to configure a series circuit. One or more of the series circuits are connected in parallel. Then, the feeder wirings and the like are covered with soft translucent synthetic resin to configure a flexible linear light emitting module.

Reference 5(USP No.7377787) proposes a lighting device comprising:

an electronic component (LED);

a tab circuit substrate having an operatively connected LED mounted thereon; and

a light diffusion member for receiving light emitted from the LED, wherein:

the tab circuit substrate includes:

a flexible substrate of a predetermined length;

a conductive trace formed on the flexible substrate; and

a tab disposed along a lateral edge of the flexible substrate,

one or more of the electronic components are connected to the conductive traces at each tab, an

The tab may be bent from a first position where the tab is aligned with the remainder of the base plate to a second position where the tab is oriented at an angle (90 degrees) relative to the remainder of the base plate.

As described above, even if the surface mounting type LED has been mounted on the FPC, light is always emitted in a lateral direction perpendicular to the surface of the FPC. That is, light is not always emitted in a shape in which the FPC is bent.

On the contrary, when the side emitting or bullet type LED is used, light is always radiated in a shape that the FPC is bent. However, such LEDs have little variation in brightness and color, and thus cannot satisfy various customer needs. This is because side-emitting or bullet-type LEDs are not used except for certain applications.

Reference 4 discloses a flexible linear light emitting module without using an FPC. Thus, a step of mounting the LED thereon and another step of twisting the feeder line are required. Therefore, there are some problems in mass production.

Reference 5 discloses a circuit substrate and a lighting system using the same. Here, there are the following problems: when the LED is positioned lower than the circuit substrate, a part of the light emitted from the LED is blocked by the circuit substrate itself. This is because the LED is mounted inside the tab that has been bent perpendicularly to the circuit substrate.

When the LEDs are mounted outside the tabs, the overall lighting system becomes too high. This is because both the LED and the light diffusing member must protrude towards the outside of the tab.

In reference 5, an LED is mounted at a position offset from a circuit substrate. When the LEDs are arranged on the center line, the circuit substrate must be offset from the center line. Therefore, there is a problem that the circuit substrate must be subjected to stress when used in a bent state.

Further, in order to supply current to the LED mounted on the tab, a conductive trace is formed on the circuit substrate. In reference 5, since all the conductive traces for the positive and negative sides are formed on a common circuit substrate, the width of the circuit substrate cannot be narrower than a fixed dimension. Therefore, the size reduction of the circuit substrate is very limited.

In view of the above, in reference 6 (japanese patent application laid-open as No. 2013-118169), the applicant proposed a band-shaped LED lamp including:

an LED mounting circuit substrate;

a light emitting unit; and

a transparent or translucent flexible insulating material covering the light emitting unit,

an LED mounting circuit board includes:

a long belt-shaped flexible substrate;

LED mounting portions on which LEDs are mounted in an array in a width direction of a long strip-shaped flexible substrate; and

first and second substrates including at least two feeding patterns for feeding current to the LEDs, the first and second substrates being positioned at both sides in a width direction of the LED mounting portion, wherein:

the light emitting unit is formed by:

mounting an LED and an electronic component on an LED-mounted circuit substrate; and

at least one of the first substrate and the second substrate is folded with respect to the LED mounting portion.

List of cited references

Reference 1: japanese unexamined patent application publication (translation of PCT application) No.2004-526185

Reference 2: registered japanese utility model No.3098840

Reference 3: registered Japanese patent No.3897260

Reference 4: japanese patent application laid-open No.9-297549

Reference 5: USP No.7377787

Reference 6: japanese patent application published as No.2013-118169

Reference 6 may propose a band-shaped LED lamp that can be bent in a direction perpendicular to a light emitting direction, is long, compact, and waterproof. In addition, the circuit board is hardly under stress. However, the ribbon light source cannot radiate uniform, continuous and smooth light. Since it is configured only by placing the power supply of the LED in a linear state.

In the embodiment of reference 6, a solid semicircular light diffusion case is mounted around the cover of the light emitting unit to diffuse light emitted from the LED in the longitudinal direction of the LED mounting circuit substrate, thereby forming a linear light source. According to this structure, there are the following problems.

The thickness of the light diffusion portion in the light diffusion case becomes too large. The light emitted from the LED light source in the LED light emitting portion is attenuated too much. The light radiated from the light diffusion portion becomes dark yellow or the like in chromaticity, thereby significantly reducing the visual lighting effect. The luminous intensity also varies depending on the observation angle.

In order to solve these problems, a method of disposing a light diffusion portion on an upper surface of an insulating case into which a light emitting unit is inserted may be considered.

According to this method, the thickness of the light diffusion portion must not be less than 5 mm to achieve the confinement of smooth and continuous light. In short, the thickness of the light diffusion portion becomes too large.

The light emitted from the LED is so attenuated that light of the necessary intensity cannot be obtained. In addition, the color of the radiated light must deteriorate the initial color of the light emitted from the LED.

In view of the above, an object of the present invention is to provide a band-shaped LED lamp that can maintain the color and intensity of initial light radiated from an LED and can radiate smooth and uniform light.

Disclosure of Invention

In order to solve the subject, there is provided a band-shaped LED lamp according to the present invention, comprising: an LED unit including a plurality of LEDs linearly arranged at predetermined intervals, the plurality of LEDs emitting light in a light emitting direction; a band-shaped insulating case including a space into which the LED unit is inserted and a partition plate made of a light-transmitting material through which at least a part of light is transmitted; and a light diffusion portion continuously installed outside the band-shaped insulating case, the light diffusion portion including an open space and a bent portion surrounding the open space, the bent portion being made of a light diffusion material and diffusing light transmitted through the partition plate and the open space.

In the present invention, at least a part of light emitted from the LEDs in the LED unit housed in the band-shaped insulating case is transmitted through the partition plate, radiated to an open space between the partition plate and the light diffusion portion, and then radiated to the light diffusion portion including the bent portion. At the light diffusion portion, light is diffused in the width direction and the longitudinal direction of the light diffusion portion by the light diffusion material. The predetermined interval for arranging the LEDs is appropriately selected so that light radiated from the outside of the light diffusion portion is continuous, not as a point light source, but as a linear light source.

The LEDs in the LED unit may be connected with wires for emitting light. The LED unit may be formed to be foldable transversely to the light emitting direction. The tape-shaped insulating case and the light diffusion portion may be made of a flexible material. This enables the structure of the ribbon LED lamp itself to be flexible.

The flexible tape-shaped insulating case includes a partition plate and a light diffusion portion, which may be integrally formed by two-color molding. Although the partition plate and the light diffusion portion may be formed using different kinds of materials with respect to whether or not the light diffusion material is contained therein, the two-color molding can integrally form the partition plate and the light diffusion portion.

An air gap existing between the space of the band-shaped insulating case and the LED unit may be filled with at least one of synthetic resin and synthetic rubber for sealing. The entirety of the air gap along the entire length of the tape-shaped insulating case may be filled. Alternatively, only a part of the air gap near the openings at both ends of the tape-shaped insulating case may be filled. When the air gap between the space of the band-shaped insulating case and the LED unit is filled with at least one of synthetic resin and synthetic rubber, the band-shaped LED lamp is provided with a moisture-proof and waterproof construction, and may also be suitable for outdoor use.

The present invention provides a ribbon-shaped LED lamp from which beautiful, smooth and uniform light close to the original light emitted by the LED can be emitted with less attenuation.

Drawings

Fig. 1 is an exploded perspective view in embodiment 1 according to the present invention;

fig. 2 is a sectional view of an example in which an insulating case and a light diffusion portion in embodiment 1 according to the present invention are integrally formed;

fig. 3 is a sectional view of another example in which an insulating case and a light diffusion portion in embodiment 1 according to the present invention are integrally formed;

fig. 4 is a graph showing a directional characteristic of an LED in the present invention;

fig. 5A is a sectional view of a light diffusion portion and a circuit substrate constituting a linear light source, and fig. 5B is a graph showing luminance characteristics according to the present invention;

fig. 6(a) to 6(c) are graphs for measuring chromaticity in embodiment 1 according to the present invention and a comparative example;

fig. 7 is a graph showing chromaticity values of light from the light diffusion portion in embodiment 1 according to the present invention and a comparative example;

fig. 8(a) to 8(c) are graphs for measuring chromaticity in embodiment 1 according to the present invention and a comparative example;

fig. 9 is a graph showing chromaticity values of light from the light diffusion portion in embodiment 1 according to the present invention and a comparative example;

fig. 10A is a plan view of the entire unit of an LED-mounted circuit substrate in embodiment 1 according to the present invention, and fig. 10B is an expanded plan view of one of the circuits;

fig. 11 is a diagram showing a state where an LED and an electronic component are wired to be mounted on a circuit substrate in embodiment 1 according to the present invention;

fig. 12 is a view showing a step of mounting LEDs and electronic components on a circuit substrate and other steps of assembling the circuit substrate into a light emitting unit of a T-shaped cross section in embodiment 1 according to the present invention, fig. 12(a) is a plan view, and fig. 12(b) to 12(e) are front views;

fig. 13A is a side view, fig. 13B is a front view, and fig. 13C is a plan view of a light emitting unit U in embodiment 1 according to the present invention; and

fig. 14 is an exploded perspective view in embodiment 2 according to the present invention.

Detailed Description

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Fig. 1 shows a band-shaped LED lamp in embodiment 1 according to the present invention.

The band-shaped LED lamp includes: an LED unit 20; a tape-shaped insulating case 30; and a light diffusing portion 34.

In the LED unit 20, a plurality of LEDs 11 are linearly arranged at predetermined intervals. Each of the LEDs 11 is connected to power cables 15 and 16 to emit light. The LED unit 20 is formed to be able to bend in a lateral direction with respect to a light emitting direction of the LED 11.

The band-shaped insulating case 30 includes a space 31 in the inside thereof, and the LED unit 20 is inserted into the space 31. The tape-shaped insulating case further includes a partition plate 32 facing the light emitting direction. At least a portion of the light may be transmitted through the separation plate 32.

The light diffusion part 34 is continuously installed outside the partition plates 32 of the band-shaped insulating case 30. The light diffusion portion 34 is made of a light diffusion material to diffuse light transmitted through the partition plates 32 of the tape-shaped insulating case 30 via the open space 33.

At least a part of the light emitted by the LED11 is transmitted through the partition plate 32, radiated in the open space 33 within about 180 degrees, and emitted into the light diffusion portion 34.

After that, the light reaches the inside of the light diffusion portion 34 having a curved semicircular cross section, and is diffused thereby.

As a result, smooth and uniform light is radiated outward from the entire surface of the light diffusion portion 34.

In this embodiment, the light diffusion portion 34 has a curved semicircular sectional shape. Alternatively, both sides of the upper portion from the bottom portion near the partition plate 32 of the light diffusion portion 34 may be linearly formed and then may be smoothly connected to the semicircular portion.

In the LED unit 20, each of the LEDs 11 may be directly connected to the power cables 15 and 16. Alternatively, each of the LEDs 11 may be mounted on a flexible printed circuit substrate (FPC), and its conductive member is sealed with synthetic resin and/or synthetic rubber to constitute a unit. A unit having a structure capable of being bent in a lateral direction with respect to a light emitting direction described in reference 6 can be used as the LED unit 20.

In the case where the LED unit 20 has a bendable structure, silicone rubber is preferably used as the synthetic rubber for sealing the conductive member of the LED unit 20. When the band-shaped insulating case 30 into which the LED unit 20 is inserted is also made of a flexible material, the entire band-shaped flexible LED lamp itself may be flexible.

Among the components surrounding the tape-shaped insulating case 30, the partition plate 32 is at least light-transmissive (transparent or translucent). The light diffusion portion 34 is made of a light diffusion material formed by mixing a light diffusing agent to at least one of a transmissive synthetic resin and a transmissive synthetic rubber.

In some cases, all or a part of the face of the tape-shaped insulating case 30 other than the partition plate 32 may be made of a light diffusion material. For example, in the case of fig. 2, the entirety of the tape-shaped insulating case 30 except for the partition plate 32 is made of a light diffusion material.

In the case of fig. 3, the partition plate 32 and the lower portion 35 are made of at least one of a transmissive synthetic resin and a transmissive synthetic rubber, and the remaining portion thereof is made of a light diffusing material.

In order to save the cost of the forming process, a commonly used two-color mold is used to form the tape-shaped insulating case 30.

The belt-shaped insulating case 30 equipped with the light diffusion portion 34 can be integrally formed by pouring two materials, which are at least one of a transmissive synthetic resin and a transmissive synthetic rubber and a light diffusion material having a light diffusing agent, into a metal mold built in a two-color molding machine.

Although inorganic and inexpensive particles of indefinite shape such as calcium silico-carbonate and barium sulfate may be used as the light diffusing agent, it is more preferable to use silicone resin and/or acrylic resin particles of minute size that suppress reflection of incident light.

The transmissive synthetic resin and the transmissive synthetic rubber may be selected from the group consisting of commercially available materials. For example, a polyether resin is preferable as the transmissive synthetic resin, and a silicone rubber is also preferable as the transmissive synthetic rubber.

Fig. 4 is a graph showing relative light intensities of LEDs in embodiment 1 according to the present invention. The relative light intensity characteristic in the width direction of the LED11 is shown using an almost circular contour line in contact with the light emitting surface of the LED 11. The bottom point of the contour contacts the surface of the LED 11.

When the curvature and the position of the semicircle of the light diffusion portion 34 are set such that the lower surface of the light diffusion portion 34 is inscribed in one of the contour lines, the luminance of the light coming out of the light diffusion portion 34 becomes uniform in the width direction.

Fig. 5 illustrates a linear light source configured using a plurality of LEDs and a light diffusing portion according to the present invention. As shown in fig. 5A, SMD type LEDs 11 of about 0.3 watt are arranged on a circuit substrate 10 at intervals of about 10 mm. The LED11 emits 50-120 milliwatts of light. The partition plate 32 exists between the LED11 and the open space 33, and the light diffusion portion 34 is located adjacent to the open space 33 at a distance d away from the partition plate 32 in the vertical direction.

The thickness of the light diffusion portion 34 is preferably 1 mm to 5 mm, and more preferably 2 mm to 3 mm. In this case, the light emitted by the LED11 directly enters the light diffusion portion 34, and is thereafter diffused thereby. The light radiated from the light diffusion portion 34 is recognized as soft diffused light by the human eye.

When the thickness is less than 1 mm, the light diffusion effect of the light diffusion portion is reduced. However, when the thickness is not less than 5 mm, the light transmitted through the light diffusion portion 34 is chromatically converted into dark yellow or the like, and the attenuation of the light increases.

Generally, the brightness distribution of light emitted by a simple LED11 is like a gaussian distribution around the optical axis of the LED 11. In the luminance distribution of the light coming out of the light diffusion portion 34, the legs of the gaussian distribution of the LEDs 11 are overlapped in the horizontal direction, so that the overlapped legs are added to each other to be raised as shown with the symbol "C-2" in fig. 5B, whereby the luminance distribution of the light becomes almost flat as a whole.

Since the luminance distribution is changed according to the distance d of the open space 33 between the light diffusion part 34 and the partition plate 32, it is necessary to appropriately set the distance d to make the luminance distribution smooth.

When the distance d is too small, the light emitted by the LED strongly comes out of the light diffusion portion 34 in a spot state, and the luminance value thereof is kept high. However, the luminance distribution significantly changes in the horizontal direction as shown in fig. 5B using the symbol "C-1", and the commercial value as an LED lamp significantly decreases.

In contrast, when the distance d is excessively large, the luminance distribution in the horizontal direction becomes uniform as shown with the symbol "C-3" in fig. 5B.

However, the luminance value from the light diffusion portion 34 cannot reach 3000[ cd/m ] as required for the illumination system²]The luminance value of (a).

The distance d should preferably be set to 5-15 mm, more preferably 5-9 mm. Thereafter, the luminance value from the light diffusion portion 34 can be made to 3000[ cd/m ] as required²]Or a larger luminance value.

Meanwhile, the luminance distribution in the horizontal direction slightly varies as shown with the symbol "C-2" in fig. 5B, and the unevenness thereof can be controlled to be small so that the human eye does not notice it.

The lower surface of the partition plate 32 and the upper surface of the LED11 are positioned so that these surfaces are in contact with each other. The distance from the LED11 to the lower surface of the light diffusion member may be fixed to a fixed value without variation for each product. Therefore, variation in the luminance distribution for each product can be suppressed.

The open space 33 is formed between the partition plate 32 and the light diffusion portion 34 according to the following reason.

If the open space 33 of the light diffusion portion 34 is omitted and the light diffusion material is filled to form a solid member instead of the open space 33, the thickness of the light diffusion portion 34 becomes too large, so that the degree of diffused light that has been emitted from the LED11 but not radiated from the upper surface of the light diffusion portion 34 cannot be increased too much.

As a result, the luminance is reduced to make the lamp look dim, the light coming out of the light diffusion portion 34 becomes dark yellow or the like in chromaticity, and the visual lighting effect is significantly reduced.

The results of the actual measurements will now be discussed. Fig. 6 is a view showing how elements are arranged when measuring the change in the attenuation amount and color temperature of light in the case where an open space is provided and a light diffusion portion is arranged therein, and in another case where an open space is not provided and a light diffusion material is filled solid instead of the open space.

Six SMD type LEDs are linearly arranged at intervals of 10 mm to form a light source, and the LEDs are turned on at 70 milliwatts each. A colorimeter No.52001(Yokogawameters & Instruments Corporation) having a light-shielding cylinder was used as the colorimeter 50. As shown in fig. 6(a), the distance between the LED 40 and the colorimeter 50 is set to 21 mm.

In the case where an open space is provided between the LED 40 and the light diffusion portion 42, as shown in fig. 6(b), the light coming out of the light diffusion portion 42 becomes smooth and uniform under the condition that the air gap is 5.5 mm and the thickness of the light diffusion portion 42 is 2 mm.

In another case where an open space is not provided and the light diffusion material is filled instead of the open space, as shown in fig. 6(c), the light coming out of the light diffusion portion 43 becomes smooth and uniform under the condition that the thickness of the light diffusion portion 43 is 6 mm.

Table 1 shows the measurement results of luminance and chromaticity in these cases. Fig. 7 is a chromaticity diagram on which chromaticity data is plotted in these cases.

As is clear from fig. 7, in the case of "# 13" in which no open space is provided and the light diffusion portion 43 is solid, the color temperature shifts to the yellow side significantly and the light becomes dark yellow as compared with the case of "# 12" in which open space is provided. In addition, it is apparent that the luminance is significantly reduced in the case of "# 13". Here, a symbol of "# 11" in fig. 7 represents chromaticity data in the case where there is no light diffusion portion.

Considering the above results, in order to:

a state in which the position of the LED light source is prevented from appearing in the dotted pattern to obtain smooth and uniform light; and

the color shift and attenuation of the light is reduced,

increasing the thickness of the light diffusing material is not effective.

In contrast, the light diffusion layer should be formed thin, having a thickness of about 2 mm; and the light diffusing layer should be disposed a distance of about 5 millimeters away from the LED.

TABLE 1

LD (light diffusion)	(a) Without LD part	(b) Space + LD part	(c) LD part only
				x (chroma)	0.3615	0.3793	0.4042
y (chroma)	0.3482	0.3556	0.3835
				L (luminance [ cd/m)2])	23,440	7,361	3,203

As shown in fig. 5A, in another case where an open space is not provided between the partition plate 32 and the light diffusion portion 34 and at least one of the transparent synthetic resin and the transparent rubber is filled in place of the open space to form the transparent member, ultraviolet rays easily damage the transparent member, resulting in the following failure: the luminescent color of the light changes to dark yellow or the like, and the attenuation of the light increases.

Hereinafter, a result of measuring chromaticity of light coming out from the light diffusion portion when the color of the transparent member is changed to yellow will now be described.

Fig. 8 shows an experimental approach. One of the SMD type LEDs 40 is turned on at 45 milliwatts as a light source.

Fig. 8(a) shows a case where the light emission of the LED is directly measured. Fig. 8(b) shows a case where a 4 mm transparent vinyl chloride material 44 is used as a filler and a 2 mm light diffusion portion 42 is disposed on the upper side thereof. Fig. 8(c) shows a case where a substrate made of a vinyl chloride material 45 having a thickness of 4 mm is used instead of the transparent vinyl chloride material 44 in fig. 8 (b). The vinyl chloride material 45 has been retained for 5 years and turns yellow.

Table 2 shows the results measured by the colorimeter 50. Since the color of the solid transparent member has changed to yellow, the luminance has been from 3,239[ cd/m ]²]Reduced to 2,448[ cd/m ]²]I.e. a 25% decrease.

Fig. 9 shows the measured chromaticity values on a chromaticity diagram. A symbol "# 21" shows chromaticity in a case where light emission of the LED is directly measured, a symbol "# 22" shows chromaticity in a case where the transparent vinyl chloride material 44 and the light diffusion portion 42 are overlapped, and a symbol "# 23" shows chromaticity in a case where the deteriorated vinyl chloride material 45 whose color has become yellow and the light diffusion portion 42 are overlapped.

As shown in fig. 9 using the symbols "# 22" and "# 23", the chromaticity is shifted to the orange side, and the light becomes a dark color.

TABLE 2

	(a) Direct measurement	(b) Transparent vinyl chloride	(c) Deteriorated vinyl chloride
				x (chroma)	0.4415	0.4559	0.4751
y (chroma)	0.3832	0.3896	0.4009
				L (luminance [ cd/m)2])	11,510	3,239	2,448

To solve this problem, the open space 33 is provided between the partition plate 32 and the light diffusion portion 34.

When the separation plate 32 is made of a light diffusion material containing a light diffusing agent, the separation plate 32 diffuses light to reduce the brightness reaching the front surface of the light diffusion portion 34, whereby the separation plate 32 looks darker.

This is because the partition substrate 32 of the tape-shaped insulating case 30 is formed to be light-transmissive.

Even if the partition substrate is made of at least one of transparent synthetic resin and transparent synthetic rubber, light cannot be transmitted through it at a rate of 100%.

When the thickness of the partition plate 32 becomes larger, the luminance slightly decreases and the chromaticity of light also slightly changes from white to yellow. Therefore, it is preferable to set the thickness of the partition plate 32 within 1-2 mm.

In another case where an open space is not provided between the partition plate and the light diffusion portion, and the transparent synthetic resin and the light diffusion material are filled in place of the open space, the entire weight becomes 20 to 30% heavy.

Since the tape-like product is used to illuminate ceilings and walls of buildings, the product should be as light as possible.

In case of lighting a ceiling, a shelf including a groove having a width suitable for a product is first installed on the ceiling, and thereafter, the product is inserted into the groove to be fixed.

The heavy overall weight may cause a malfunction in which the product is detached from the groove and sags. The worst is that the product falls. In view of the above, the part between the partition plate and the light diffusion material should preferably be hollow.

As described above, fig. 2 and 3 are sectional views showing examples of forming the insulating case and the light diffusion portion included in embodiment 1 according to the present invention.

In the example of fig. 2, only the partition plate 32 has light transmissivity, and the tape-shaped insulating case 30 and the light diffusion portion 34 are made of a light diffusion material.

In this example, light emitted from the LED11 comes out from the light diffusion portion 34. In addition, a portion of the diffused light also exits the side portion 36. That is, the diffused light comes out from almost all of the strip-shaped insulating case 30.

In the example of fig. 3, the partition plate 32 and the lower portion 35 of the tape-shaped insulating case 30 have light transmissivity, and the upper portion of the tape-shaped insulating case 30 and the light diffusion portion 34 are made of a light diffusion material.

In the example of fig. 3, since light from the LED11 does not naturally reach the lower portion 35 of the tape-shaped insulating case 30, the lower portion does not need to have light transmissivity.

Where should be made of the light diffusion material may vary depending on the location where the ribbon LED lamp is used. Situations other than fig. 2 and 3 may be considered. Two-shot molding can also form the desired component in these cases.

Next, fig. 10 to 13 show an embodiment of a circuit substrate for mounting an LED thereon to constitute the LED unit 20. The LED unit 20 is inserted into the space 31 of the band-shaped insulating case 30 shown in fig. 2 and 3. The circuit substrate in this embodiment is the same as that described in reference 6.

Fig. 10A is a plan view of the entirety of one cell, and fig. 10B is an expanded plan view of one circuit. As shown in fig. 10A and 10B, the LED-mounted circuit substrate in the present embodiment may be hereinafter simply referred to as "circuit substrate".

The circuit substrate 10 is configured as follows. The LED mounting portion 1 is formed at a central portion in the width direction of a long, flexible, and belt-shaped substrate. And, a plurality of LEDs are mounted on the LED mounting part 1 in an array state.

In both sides in the width direction of the LED mounting portion 1, a first substrate 2 and a second substrate 3 are provided. On the first substrate 2 and the second substrate 3, power patterns for supplying current to the plurality of LEDs are formed.

The LED mounting portion 1, the first substrate 2, and the second substrate 3 are formed foldable to each other.

In this embodiment, the LED mounting portion 1 and the first substrate 2 are connected with the connection piece 4 having the cutout portions 4a and 4b at both ends thereof. The LED mounting portion 1 and the second substrate 3 are connected by a connecting piece 5 having cutout portions 5a and 5b at both ends thereof.

Since it is difficult to narrow the width of a part of the connecting sheet 5 to pass one or more pairs of power supply patterns, forming the cutout portions 5a and 5b may be omitted in some cases.

Both end portions in the width direction of the flexible substrate are connected to the first substrate 2 and the second substrate 3 using connecting pieces. Independent island-shaped LED mounting portions are formed at intervals on a flexible substrate to constitute the LED mounting portion 1.

When the first substrate 2 and the second substrate 3 are folded with respect to the LED mounting portion 1 and the rear surfaces of the first substrate 2 and the second substrate 3 are overlapped (see fig. 12(e)), the island-shaped LED mounting portions are independently positioned, thereby forming a space between a plurality of island-shaped LED mounting portions to be separated.

Thereby, in the step of bending the first substrate 2 and the second substrate 3 perpendicularly to the surface of the LED mounting portion 1, and in the other step of bending the upper portions of the first substrate 2 and the second substrate 3 perpendicularly to the remaining portions thereof, the LED mounting portion is subjected to only slight stress, and the bending step can be easily performed.

An LED zone P1 of the power supply pattern is formed on the LED mounting part 1. The surface mounting type LED is to be mounted on the LED land P1. A power pattern P2 for transmitting a positive voltage from a DC power source is formed on the first substrate 2. Also, a ground pattern P3 to be connected to a ground line of a DC power supply is formed on the second substrate 3.

At the power pattern P2 and the ground pattern P3, vias H1 and H2 are opened. On the opposite surfaces of the patterns P2 and P3, external electric wires are connected to the through holes H1 and H2 by soldering.

In addition to the ground pattern P3, a resistance zone P4 and a diode zone P5 are also formed on the second substrate 3. In one unit of the circuit substrate 10, four circuits C1-C4 each having the same configuration are formed. As shown in fig. 11, the configuration is configured to include LEDs-1 to 24, resistors R1 to R8, and reverse flow blocking diodes D1 to D4.

In embodiment 1, one unit of the circuit substrate 10 has a length L of 240 mm, a width of 24 mm, a substrate thickness of 100 μm, and a copper foil (conductive pattern) having a thickness of 35 to 50 μm. The scope of the present invention is not limited to these values.

Fig. 10(a) shows a case where four circuits form one unit. However, in order to realize a linear light source having a length of one meter or more, the power pattern P2 and the ground pattern P3 of many units are preferably connected in parallel with an external electric wire, thereby forming a lighting system having a desired length.

Fig. 12 shows:

a step of mounting the surface-mount type LED11 and the electronic component 12(a resistor and a diode in this example) on the circuit substrate 10;

a step of soldering the electric wires 13 and 14 on the power pattern P2 and the ground pattern P3; and

and a step of forming the soldered circuit substrate into a light emitting unit U having a T-shaped cross section.

Fig. 12(a) is a plan view, and fig. 12(b) to 12(e) are a front view and a sectional view.

Fig. 12(b) shows a state in which the circuit substrate 10 is not yet bent. From this state, as shown in fig. 12(c), the cutout portions 4b and 5b are bent downward by 90 degrees using the cutout portions 4b and 5b as bent portions.

As shown in fig. 12(d), the cutout portions 4a and 5a are further bent while keeping the first substrate 2 and the second substrate parallel downward.

Finally, as shown in fig. 12(e), the rear surfaces of the connection pieces 4 and 5 are in contact with the rear surface of the LED mounting portion 1, and the rear surfaces of the first substrate 2 and the second substrate 3 are also in contact with each other. The contacted rear surfaces are bonded with an adhesive to form a light emitting unit U having a T-shaped cross section.

The light emitting unit U may be freely bent as a whole in a direction perpendicular to the surfaces of the first and second substrates 2 and 3. This is because the rear surfaces of the first and second substrates 2 and 3 are combined into one flexible board, and the upper LED mounting portion 1 forming the T-shaped cross section is separated from the adjacent LED mounting portions 1.

Fig. 13A is a side view, fig. 13B is a front view, and fig. 13C is a plan view of the light-emitting unit U.

As shown, a plurality of light emitting units U are connected in parallel with power supply wires 13 and 14. The power cables 15 and 16 are connected to ends of the wires 13 and 14 of the first light emitting unit U by soldering. As the electric wires 13 and 14, for example, a copper plate, a single wire, a twisted wire, and a mesh wire, which can transmit electric current, larger than the power supply pattern of the conductive foil on the first substrate 2 and the second substrate 3, are used.

The outer sides of the plurality of light emitting units U linearly connected to each other may be sealed by light-transmitting silicone rubber to manufacture the LED unit 20 of a T-shaped cross section. The manufactured LED unit 20 may be inserted into the space 31 of the almost T-shaped cross-section from the opening of the band-shaped insulating case 30 shown in fig. 2 and 3 to form a band-shaped LED lamp.

Alternatively, a plurality of light emitting units U connected linearly may be inserted into the space 31 of the almost T-shaped cross section from the opening of the band-shaped insulating case 30 shown in fig. 2 and 3 without sealing with light-transmissive silicone rubber. Here, the space 31 is formed to insert the unit U in the following manner: the upper surface of the LED11 slides along the lower surface of the partition plate 32.

Since the lower surface of the partition plate 32 and the upper surface of the LED11 are positioned to contact each other, the distance from the LED11 to the lower surface of the light diffusion portion 34 is fixed to have a fixed value without variation for each product. As a result, variation in the luminance distribution for each product can be suppressed.

Thereafter, the air gap between the space 31 and the LED unit U is filled with silicon rubber from the opening at the end of the band-shaped insulating case 30 to a position where the sealing feature can be fixed, whereby the air gap is substantially sealed.

Since a portion of the length of the tape-shaped insulating case 30 may not be sealed to reduce the consumption volume of the silicon rubber. Furthermore, the sealing characteristics of the ribbon LED lamp may also be maintained.

In the above, silicone rubber was used for sealing. A synthetic resin for sealing, such as a commercially available epoxy resin or the like, may be used instead. Also, light transmissive materials have been used. Alternatively, no light transmissive material may be used.

The LED mounting substrates shown in fig. 10 to 13 are merely examples. The LED unit 20 applied to the band-shaped LED lamp according to the present invention is not limited thereto.

Fig. 14 shows an LED unit 21 in embodiment 2 according to the present invention.

As described above, the LED unit 20 in embodiment 1 relates to an example in which a sealed transparent silicone rubber surrounds the light emitting unit U in fig. 13.

In embodiment 2, the LED unit 21 includes a plurality of light emitting units U linearly connected to each other.

Referring now to fig. 12 and the like, the rear surfaces of the first substrate 2 and the second substrate 3 are adhered to each other. However, the rear surfaces of the LED mounting portion 1 and the connection pieces 4 and 5 may not be adhered.

In embodiment 2, the LED unit 21 is inserted into the space 31 of the tape-shaped insulating case 30, and then the space 31 is filled with transparent silicone rubber, thereby forming a flexible tape-shaped LED lamp. Since the structures and effects other than the above are the same as those of embodiment 1, the description thereof is omitted.

Each of embodiment 1 and embodiment 2 according to the present invention can provide a band-shaped LED lamp in which attenuation of light is less and smooth and uniform light of almost white color can be radiated.

The LED units 20 and 21 may be bent in a lateral direction with respect to a light emitting direction of the LED11, and the band-shaped insulating case 30 is made of a flexible material. Therefore, the band-shaped LED lamp itself has a flexible structure.

The partition plate 32 and the light diffusion portion 34 are formed by two-color molding. The materials having mutually different optical properties may be integrally formed.

The air gap between the LED units 20 and 21 and the space of the band-shaped insulating case 30 are filled with synthetic resin or synthetic rubber for sealing. Therefore, the band-shaped LED lamp itself has a moisture-proof and waterproof construction, and is also suitable for outdoor use.

The ribbon-shaped LED lamp according to the present invention can radiate smooth and uniform light, which is close to white light originally emitted by the LED light source and whose attenuation is small. Therefore, the band-shaped LED lamp is suitable for use as, for example, various indoor lighting systems, outdoor decorative lighting systems, and the like.

Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.

Description of the symbols

1: LED mounting part

2: first substrate

3: second substrate

4: connecting sheet

4a and 4 b: cut-out part

5: connecting sheet

5a and 5 b: cut-out part

10: LED mounting base plate (Circuit board)

11：LED

12: electronic parts (resistor, diode)

13 and 14: electric wire

15 and 16: power cable

20 and 21: LED unit

30: strip-shaped insulating shell

31: space(s)

32: partition board

33: open space

34: light diffusing part

40：LED

42 and 43: light diffusing part

44: vinyl chloride material

45: deteriorated vinyl chloride material

50: chromaticity measuring instrument

Claims (4)

1. A ribbon LED lamp comprising:

an LED unit including a plurality of LEDs linearly arranged at predetermined intervals, the plurality of LEDs emitting light in a light emitting direction;

a band-shaped insulating case including a space into which the LED unit is inserted and a partition plate made of a light-transmitting material through which at least a part of light is transmitted; and

a light diffusion portion continuously installed outside the band-shaped insulating case, the light diffusion portion including an open space and a bent portion surrounding the open space, the bent portion being made of a light diffusion material and diffusing light transmitted through the partition plate and the open space.

2. The ribbon LED lamp of claim 1, wherein:

the plurality of LEDs are connected with a plurality of wires;

the LED unit is formed to be bendable in a lateral direction with respect to the light emitting direction; and

the tape-shaped insulating case and the light diffusion portion are made of a flexible material.

3. The band-shaped LED lamp according to claim 1, wherein the band-shaped insulating case and the light diffusion portion are integrally formed by two-color molding.

4. The ribbon LED lamp of claim 1, wherein:

an air gap exists between a space of the strip-shaped insulating case and the LED unit inserted into the space; and

the air gap is filled with at least one of synthetic resin and synthetic rubber.