JP2013171748A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp type LED lighting device capable of shining a whole surface of a cylindrical pipe member.SOLUTION: An LED lighting device (100) of a first viewpoint includes: a drive circuit (70) capable of being connected with an AC power source and obtaining pulsating voltage by rectifying AC voltage of the AC power source; m pieces of LEDs (40) directly connected with the drive circuit; a long-size LED substrate (50) for arranging m pieces of LEDs in a first direction; a cylindrical light-transmitting member (10) storing the LED substrate and extended in the first direction; and a support member (60) extended in a second direction crossing the first direction so as to support the LED substrate in a cylinder of the light-transmitting member.

Description

  The present invention relates to a fluorescent lamp type LED lighting apparatus using a laser light emitting diode (hereinafter referred to as LED).

  As an example of an illuminating device using an LED, for example, there is an LED illuminating device having a cylindrical shape that is compatible with an existing fluorescent lamp standard and a heat radiating part that radiates heat generated from the LED to the outside. . As for the power source for the LED lighting device, it is generally desirable to use an alternating current as a power source such as a household power source. On the other hand, the LED is a DC drive element and emits light only with a forward current. Moreover, the forward voltage Vf of LED currently used extensively as a lighting use is about 3V to 5V. The LED does not emit light unless Vf is reached. For this reason, the LED lighting device performs full-wave rectification of alternating current using a bridge circuit, smoothes it using a smoothing capacitor, and then drives the LED using a drive circuit such as a constant current circuit or a switching power supply circuit. Since a lot of heat is generated from the LED and the drive circuit, the LED lighting device has a heat radiating plate made of a metal material or the like.

  For example, the LED illumination device of Patent Document 1 has a recess for attaching a support substrate for supporting the LED substrate in a pipe member made of a translucent synthetic resin or the like. The support substrate is inserted into the recess and attached in the pipe member. An aluminum extrusion mold is used for the support substrate. A heat sink (fin) is disposed on the support substrate. A drive circuit including a plurality of LEDs, a capacitor, an inductance, and the like is mounted on the LED substrate. Then, the support substrate dissipates heat from the LED mounted on the LED substrate and the drive circuit to a space on the opposite side of the LED from the LED mounting surface of the support substrate (a space equal to or less than half of the pipe member cylindrical circle). doing. And the space | gap of the other side is interrupted | blocked by the light of LED with the support substrate and the heat sink.

JP 2009-266432 A

  In the existing fluorescent lamp, since the entire surface of the cylinder shines, a lighting plate to which the fluorescent lamp is attached is provided with a reflector on the side opposite to the illumination direction. However, the LED illumination device of Patent Document 1 has a cylindrical shape that is compatible with existing fluorescent lamp standards, but the LED light does not reach the opposite side of the cylindrical LED mounting surface. For this reason, if a user attaches and uses the fluorescent lamp type LED lighting apparatus disclosed in Patent Document 1 on the ceiling of a room or the like, the direction directly below the LED lighting apparatus is bright, but the ceiling surface and its surroundings become dark. I felt that the whole room was dark. Further, when an aluminum extrusion mold is used, the manufacturing cost is increased and the weight of the LED lighting device is increased.

Therefore, the present invention provides an LED lighting device in which the entire surface of a cylindrical pipe member shines.
An LED lighting apparatus according to a first aspect includes a drive circuit that can be connected to an AC power source and obtains a pulsating voltage obtained by rectifying the AC voltage of the AC power source, m LEDs directly connected to the drive circuit, and m The LED is disposed in the first direction and has a long LED substrate having a first width in the second direction intersecting the first direction, and a second member that extends in the first direction that accommodates the LED substrate. A cylindrical light-transmitting member having a second width that is twice or more the first width in the direction, and a support member extending in the second direction so as to support the LED substrate in the cylinder of the light-transmitting member; Is provided.

In the LED lighting device according to the second aspect, m LEDs are determined as follows.
Vac * 0.8 / Vf <m <Vmax * 0.8 / Vf
Here, Vac is the supplied AC effective voltage, Vmax is the supplied AC maximum voltage, and Vf is the forward voltage of the LED.
In the LED lighting device of the third aspect, the inner peripheral surface of the light transmissive member has a plurality of narrow grooves extending in the first direction evenly, and one end of the support member enters the groove.

In the LED lighting device according to the fourth aspect, the inner peripheral surface of the light transmissive member has a pair of holding grooves extending in the first direction, and one end of the support member enters the holding groove.
In the LED lighting device according to the fifth aspect, the support member is formed of a transparent or translucent member, and is arranged so that the light emitting point of the LED is located at the center of the cross section of the light transmissive member.
In the LED lighting device according to the sixth aspect, the drive circuit includes a rectifier circuit that rectifies the AC voltage and a constant current circuit that sets the pulsating voltage to a constant current.
In the LED lighting device of the seventh aspect, the drive circuit further includes a capacitor that smoothes the pulsating voltage.

  In the fluorescent lamp type LED lighting device, the entire surface of the cylindrical pipe member shines.

(A) is a top view (XZ surface) which cuts and shows a part of fluorescent lamp type LED lamp. (B) is a top view (YZ surface) which cuts and shows a part of fluorescent lamp type LED lamp. It is an AA cross-sectional enlarged view of the LED lighting 100. It is the drive circuit 70 of the LED lighting 100. It is a voltage waveform by the drive circuit 70. It is a voltage waveform by the drive circuit 70 smoothed by the smoothing capacitor. It is a cross-sectional enlarged view of the LED illumination lamp 110.

<First Embodiment>
(Whole structure of lighting device)
Fig.1 (a) has shown typically the example of 1 structure of the LED illumination light 100 which is a fluorescent lamp type illuminating device. Since both sides of the LED illumination lamp 100 in the long axis direction have the same structure and the same members, only the structure and members on one side will be described in the first embodiment.

  As shown in FIG. 1, the appearance configuration of the LED illumination lamp 100 includes a cylindrical pipe member 10 and cap-shaped first and second caps that close both ends of the pipe member 10 in the long axis direction. 20 and cylindrical first and second joint members 30 for connecting and fixing the pipe member 10 and the base 20. Inside the pipe member 10, an LED substrate 50 on which LEDs 40 as a plurality of light emitting elements are mounted is housed in an airtight manner.

(Configuration of pipe member)
The pipe member 10 of the LED illuminating lamp 100 shown in FIG. 1 is composed of a light-transmitting cylindrical member made of a synthetic resin such as an acrylic resin or a polycarbonate resin. The pipe member 10 is formed to extend in the major axis direction (Z-axis direction) by extrusion molding, and has almost the same size, dimension, and outer shape as an existing straight tube fluorescent lamp. On the inner peripheral side of the pipe member 10, a plurality of fine narrow grooves 12 are formed for light diffusion (see FIG. 2).

  The narrow groove 12 on the inner peripheral side of the pipe member 10 is a groove formed by extrusion molding. As shown in FIG. 2, the shape of the groove may be a wave shape, may be a sharp V-shaped groove, or may be a U-shaped groove with a rounded tip. Further, a plurality of protruding walls from the inner wall toward the center of the pipe member 10 may be used. The size of the narrow groove 12 is appropriately determined so as to be suitable for the inner diameter of the pipe member 10 and light diffusion.

  The material of the pipe member 10 is preferably a material having an appropriate reflectance and light diffusivity without impairing light transmittance. As an example of the pipe member 10, for example, a synthetic resin in which light diffusing agent fine particles such as calcium carbonate and titanium oxide are dispersed to impart light diffusibility, or a coating layer in which the light diffusing agent fine particles are applied to the surface of the synthetic resin is used. Examples thereof include those provided with light diffusibility such as those provided.

(Composition of base)
The base 20 of the LED illumination lamp 100 has a cylindrical cross section. The base 20 is made of a material such as bakelite, aluminum, or aluminum alloy. The base 20 supports a pair of terminal pins 21 in an insulating manner. One end of the terminal pin 21 opposite to the protruding end is electrically connected to the plurality of LEDs 40 via a rectifier circuit connected to the terminal pin 21. As will be described later, since the LED illumination lamp 100 generates less heat, the base 20 can be eliminated, and the joint member 30 described below can also serve as the base 20.

(Composition of joint member)
The joint member 30 joined to the base 20 has a cylindrical cross section. The material of the joint member 30 is made of, for example, polybutylene terephthalate resin or polycarbonate. The joint member 30 is bonded to the outer peripheral surface of the end portion of the pipe member 10 by an adhesive, and is bonded to the outer peripheral surface of the base 20 to the adhesive. Although not shown, the pipe member 10 and the base 20 may be directly connected and the joint member 30 may be omitted.

(Configuration of LED board)
As shown in FIGS. 1 and 2, the LED substrate 50 extending in the long axis direction of the pipe member 10 is supported in the pipe member 10 by a support member 60. FIG. 2 is an AA cross-sectional enlarged view of FIGS. 1 (a) and 1 (b). The material of this LED board 50 consists of material of a glass epoxy board | substrate and a polyester-type composite base material, for example. The LED 40 is disposed on the + X side of the LED substrate 50.

  A wiring pattern (not shown) for mounting an LED module in which a plurality of LEDs 40 are connected in series is formed on the LED substrate 50. A drive circuit 70 made of, for example, a fuse, a resistor, a rectifying diode, or the like is mounted on the end of the LED substrate 50 on the base side. A plurality of LEDs 40 mounted in series on the LED substrate 50 are electrically connected via these drive circuits 70.

  The width W1 of the LED substrate 50 in the Y-axis direction is preferably not more than half of the inner diameter φD of the pipe member 10, particularly preferably not more than 1/3. Light emitted from the LED 40 to the + X axis side is reflected by the narrow groove 12 on the inner peripheral side of the pipe member 10 toward the + X axis side and reaches the narrow groove 12 of the pipe member 10 on the −X side of the LED substrate 50. It is. When the width W1 of the LED substrate 50 is larger than half of the inner diameter φD of the pipe member 10, the light emitted from the LED 40 to the + X axis side does not reach the −X side of the LED substrate 50 so much. For this reason, it is preferable that the width W2 of the LED 40 in the Y-axis direction is as small as possible, and the width W1 of the LED substrate 50 is made equal to or slightly larger than the width W2 of the LED 40.

  The number of LEDs 40 mounted on the LED substrate 50 is set in consideration of the voltage of the AC power supply and the forward voltage Vf of the LEDs 40. If the AC effective voltage is 100 V and the forward voltage Vf is 3.2 V, 32 to 39 LEDs are arranged, and preferably the number of LEDs 40 mounted on the LED substrate 50 is 37 to 39. As illustrated in FIG. 1A or 1B, the LEDs 40 may be arranged not only in a single line in the Y-axis direction and in a straight line in the Z-axis direction, but also in two lines in the Y2 line. . Even when the LEDs 40 are arranged in two rows, the width W1 of the LED substrate 50 in the Y-axis direction is made equal to or less than half of the inner diameter φD of the pipe member 10. Further, the configuration in which the LEDs 40 are linearly mounted on the LED substrate 50 with a predetermined interval is illustrated, but the LEDs 40 may be mounted so that the intervals are different.

  As the LED 40, for example, a flat top PLCC (Plastic leaded chip carrier) package LED is used. Further, the LED 40 is composed of, for example, a white single color LED. The LED 40 may be composed of LEDs having three different colors of red LED, green LED and blue LED, or two colors of LEDs having a complementary color relationship. . Even with these combinations, the light emitted from the LED illumination lamp 100 is white. The forward voltage of the LED 40 varies depending on the color, but is 1.5V to 2.5V for a red or green LED, and 3.0V to 3.7V for a white or blue LED. Hereinafter, in this embodiment, a case where a white monochromatic LED is used will be described.

(Configuration of support member)
The support member 60 supports the LED substrate 50 so that the light emitting point of the LED 40 mounted on the LED substrate 50 is positioned substantially at the center of the cross section of the pipe member 10. Both ends of the support member 60 enter the narrow groove 12 on the inner peripheral side of the pipe member 10, and the LED substrate 50 is fixed near the center of the support member 60. The material of the support member 60 is made of a transparent material such as acrylic resin or polycarbonate, or a translucent material. Particularly in the case of semi-transparency, the width in the Z-axis direction is made as thin as possible within a range in which the LED substrate 50 can be supported so as not to block the light LE. Light emitted from the LED 40 to the + X axis side is reflected by the narrow groove 12 on the inner peripheral side of the pipe member 10 toward the + X axis side and reaches the narrow groove 12 of the pipe member 10 on the −X side of the LED substrate 50. It is.

  The material of the support member 60 may be a metal member. If it is a strong metal member, the support member 60 may be a wire having a diameter of, for example, φ1 mm or less. This is because the support member 60 is extremely thin and does not block the light of the LED 40 reflected by the narrow groove 12 on the inner peripheral side of the pipe member 10 on the + X axis side. When the support member 60 is a wire, a land for soldering the wire to the LED substrate 50 is formed in advance. Then, solder the wire to the land.

  Although not particularly illustrated, the support member 60 may be a transparent or translucent thin flat plate such as an acrylic resin or polycarbonate. In this case, a thin flat plate may be bonded to the LED substrate 50 with an adhesive.

(Light irradiation of LED lighting 100)
In FIG. 2, the light emitted from the LED 40 is indicated by an arrow LE. An arrow LE indicates light inside the pipe member 10 by a dotted line, and light emitted from the pipe member 10 to the outside by a solid line.

  In general, the directivity characteristic of LED 40 (the half-value angle * 2 at which the luminous intensity seen from the direction inclined from the X axis is 50%) is about 120 °. The light LE emitted from the LED 40 toward the + X-axis side first spreads in the 120 ° direction and reaches the narrow groove 12 on the inner peripheral side of the pipe member 10. A part of the light LE is transmitted outside the + X axis of the pipe member 10, and the remaining light LE is diffusely reflected by the narrow groove 12 on the inner peripheral side of the pipe member 10. The reflected light LE reaches the narrow groove 12 on the inner peripheral side of the −X-axis side pipe member 10. Here, a part of the light LE is transmitted to the outside of the −X axis of the pipe member 10, and the remaining light LE is diffusely reflected by the narrow groove 12 on the inner peripheral side of the pipe member 10. The light LE is repeatedly transmitted and reflected, so that the light LE is irradiated in all directions outside the pipe member 10.

(Heat dissipation of LED lighting 100)
The LED illumination lamp 100 uses a household AC 100V power source. On the other hand, the LED 40 is a DC drive element and emits light only with a forward current. Further, the forward voltage Vf of the LED 40 is 3.0V to 3.7V. The LED 40 does not emit light unless it reaches Vf, and on the contrary, if Vf exceeds Vf, an excessive current flows. AC 100V is an effective value, and the maximum voltage after full-wave rectification is 141V. When the LED 40 is connected to this power source and driven by a constant current circuit, if only 20 LEDs of Vf = 3.2V are connected and driven by the constant current circuit, the LED is turned on in a range where the power source voltage exceeds 64V. It becomes. However, since most of the electric power is heat, measures to dissipate heat are necessary. Further, the extra heat has a problem that the life of the LED 40 itself or the pipe member 10 is reduced.

  The LED illuminating lamp 100 of the first embodiment is not attached with a heat sink or the like formed of an aluminum alloy or the like on the LED substrate 50. Further, no heat sink or the like is attached to the pipe member 10. The LED illumination lamp 100 irradiates the light LE from all directions outside the pipe member 10. That is, the LED lighting 100 does not particularly include a member for measures against heat dissipation.

(Drive circuit for LED lighting 100)
FIG. 3 shows a drive circuit 70 for the LED lighting 100. The drive circuit 70 includes a bridge circuit 72 composed of a diode bridge for full-wave rectification, and a constant current circuit 73 composed of a transistor and a resistor. The drive circuit 70 drives the plurality of LEDs 40 with the constant current circuit 73 without performing smoothing with the smoothing capacitor after full-wave rectification of the AC power source with the bridge circuit 72. The constant current circuit 73 includes, for example, a resistor 74, a current detection npn transistor 75, a current control npn transistor 76, and a current detection resistor 77. Further, a diode 78 for preventing reverse current and a resistor 79 for current control are arranged in series with the plurality of LEDs 40. The resistor 79 prevents an excessive current from flowing through the LED 40 and changes the resistance value according to the number of the LEDs 40.

  Since this drive circuit 70 is composed of a semiconductor element, it has a common operating temperature range with the LED 40 and is suitable for miniaturization. Further, since the drive circuit 70 does not have a constant voltage circuit, it can be miniaturized. Therefore, as shown in FIG. 1A, the back side (−X axis side) of the narrow width LED substrate 50. But it can be implemented.

  The gate electrode of the current control npn transistor 76 is connected to a voltage drop detection point A when the emitter current passes through the current detection resistor 77. The npn transistor 76 causes a collector current corresponding to the potential at the point A to flow, and decreases the base current of the npn transistor 75 for current detection. As a result, the emitter current Ie1 of the npn transistor 75 for current detection decreases and the collector current Ic1 decreases. Therefore, the collector current Ic1 of the current control npn transistor 76 is controlled to be substantially constant.

  FIG. 4 shows voltage waveforms generated by the drive circuit 70. Since smoothing is not performed, the voltage value changes periodically. On the other hand, the LEDs are connected to each other in series as shown in FIG. For this reason, it is lit only when the applied voltage exceeds the total value of the forward voltage Vf of the LED 40. On the other hand, a voltage exceeding the total value of the forward voltage Vf becomes a power loss and needs to be radiated.

Therefore, an appropriate number m of LEDs 40 connected in series is defined by the following Equation 1. The relationship among the number m of LEDs 40, the supplied AC effective voltage Vac, the supplied AC maximum voltage Vmax, and the forward voltage Vf of the LED is as follows.
Vac * / Vf <m <Vmax * 0.9 / Vf Equation 1

  For example, assuming that the effective voltage Vac = 100V, the maximum voltage Vmax = 141V, and the forward voltage Vf = 3.2V, the number m of LEDs 40 is 32 to 39. If the number m of LEDs 40 is 37 to 39, there is almost no power loss and the amount of heat generation is small, so that a heat sink or the like is not necessary. In FIG. 4, the shaded time voltage region indicates a region where the LEDs 40 are lit when the number m of LEDs 40 is 32.

<Modification>
In FIG. 3, the pulsating voltage from the bridge circuit 72 is not smoothed, but the pulsating voltage may be smoothed. When smoothing the pulsating voltage, a smoothing capacitor CP indicated by a dotted line in FIG. 3 may be arranged in parallel with the bridge circuit 72.

  FIG. 5 shows a voltage waveform by the drive circuit 70 smoothed by the smoothing capacitor CP. In FIG. 5, the shaded time voltage region indicates a region where the LED 40 is lit when the number m of LEDs 40 is 32. By smoothing, the voltage does not drop greatly, and the LED 40 can be always lit.

Second Embodiment
FIG. 6 schematically shows a configuration example of the LED illumination lamp 110 of the second embodiment. The appearance configuration of the LED illumination lamp 110 is the same as that of the LED illumination lamp 110 of the first embodiment. However, the cylindrical pipe member 10 ′ and the support member 60 ′ of the LED illumination lamp 110 are different. The LED illuminating lamp 110 also does not particularly include a member for heat dissipation.

(Configuration of pipe member)
A fine groove is not formed on the inner peripheral side of the pipe member 10 '. The material of the pipe member 10 ′ is a synthetic resin having an appropriate reflectance and light diffusivity without impairing light transmittance. The pipe member 10 ′ has light diffusibility by dispersing light diffusing agent fine particles such as calcium carbonate and titanium oxide in a synthetic resin, for example.

  A pair of holding grooves 15 are formed in the long axis direction (Z-axis direction) on the inner peripheral side of the pipe member 10 ′. The holding groove 15 is formed at a position facing the center of the pipe member 10 '.

  The support member 60 ′ supports the LED substrate 50 so that the light emitting point of the LED 40 mounted on the LED substrate 50 is positioned substantially at the center of the cross section of the pipe member 10 ′. One end of the support member 60 ′ enters the holding groove 15. The other end of the support member 60 ′ is divided into two forks, and the forks sandwich the LED substrate 50. The material of the support member 60 ′ is made of a transparent or translucent material such as acrylic resin or polycarbonate.

  Also in FIG. 6, the light emitted from the LED 40 is indicated by an arrow LE. The arrow LE indicates the light inside the pipe member 10 ′ by a dotted line and the light emitted from the pipe member 10 ′ by a solid line.

  The light LE emitted from the LED 40 toward the + X-axis side first spreads in the 120 ° direction and reaches the inner peripheral surface 14 of the pipe member 10 ′. A part of the light LE is transmitted outside the + X axis of the pipe member 10 ′, and the remaining light LE is reflected by the inner peripheral surface 14 of the pipe member 10 ′. The reflected light LE reaches the inner peripheral surface 14 of the −X-axis side pipe member 10 ′. In this case, a part of the light LE is transmitted outside the −X axis of the pipe member 10 ′, and the remaining light LE is reflected by the inner peripheral surface 14 of the pipe member 10 ′. The light LE is repeatedly transmitted and reflected, so that the light LE is irradiated in all directions outside the pipe member 10 '.

According to the LED illumination lamp 100 according to the first embodiment and the LED illumination lamp 110 according to the second embodiment, the following effects are obtained.
(1) Even if it does not have a heat sink or the like, the amount of heat due to self-heating of the LED 40 is small, and deformation of the pipe member 10 or 10 ′ due to heat can be prevented.
(2) A heat radiating plate such as aluminum is not required, and the weight can be reduced and the cost can be reduced. In addition, the drive circuit 70 includes a bridge circuit 72 and a constant current circuit 73, and does not require a constant voltage circuit. Therefore, the drive circuit 70 can be reduced in size and cost can be reduced. When the drive circuit 70 includes the smoothing capacitor CP, the LED can be turned on constantly without blinking.
(3) Since the width of the LED substrate 50 can be reduced and a space is formed between the LED substrate 50 and the pipe member 10 or 10 ′, light is irradiated from the side opposite to the light emitting point of the LED 40. The

DESCRIPTION OF SYMBOLS 10,10 '... Pipe member 12 ... Narrow groove, 14 ... Inner peripheral surface, 15 ... Holding groove 20 ... Base 30 ... Joint member 40 ... LED
DESCRIPTION OF SYMBOLS 50 ... LED board 60, 60 '... Support member 70 ... Drive circuit, 72 ... Bridge circuit, 73 ... Constant current circuit CP ... Smoothing capacitor

Claims (7)

A drive circuit that can be connected to an AC power source and obtains a pulsating voltage obtained by rectifying the AC voltage of the AC power source;
M LEDs directly connected to the drive circuit;
An elongate LED substrate having the m LEDs arranged in a first direction and having a first width in a second direction intersecting the first direction;
A cylindrical light-transmitting member made of a light-transmitting member, extending in the first direction to accommodate the LED substrate, and having a second width that is twice or more the first width in the second direction;
A support member extending in the second direction so as to support the LED substrate in a cylinder of the light transmissive member;
LED lighting device comprising: The LED lighting device according to claim 1, wherein the m LEDs are determined as follows.
Vac * 0.8 / Vf <m <Vmax * 0.8 / Vf
Note that Vac is the supplied AC effective voltage, Vmax is the supplied AC maximum voltage, and Vf is the forward voltage of the LED. The inner peripheral surface of the light transmissive member has a plurality of narrow grooves extending in the first direction equally,
The LED lighting device according to claim 1, wherein one end of the support member enters the groove. The inner peripheral surface of the light transmissive member has a pair of holding grooves extending in the first direction,
The LED lighting device according to claim 1, wherein one end of the support member enters the holding groove.   The said support member is formed with a transparent or semi-transparent member, and arrange | positions so that the light emission point of the said LED may be located in the cross-sectional center of the said light transmissive member. LED lighting device.   6. The LED lighting device according to claim 1, wherein the drive circuit includes a rectifier circuit that rectifies the AC voltage and a constant current circuit that makes the pulsating voltage constant. The LED lighting device according to claim 6, wherein the drive circuit further includes a capacitor that smoothes the pulsating voltage in parallel with the rectifier circuit.