JP2014143161A - Light projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED-type light projector of a large amount of light that is desired.SOLUTION: A light projector has a plurality of light emitting diode elements 1 being a light source, a copper substrate 2 disposed of the plurality of light emitting diode elements 1 thereon, and a cylindrical mounting plate 3 for use in mounting LEDs 1 in which an inner cylinder formed of thermally-conductive materials forms a stair shape recessed toward the center. A substrate 2 is provided on a stage surface of each stage in the inner cylinder of the mounting plate 3. A contour of the substrate 2 provided on the stage surface of the mounting plate 3 is a hollow shape similar to the shape of an irradiated surface. A contour of a substrate 2A provided at the center of the irradiated surface is quadrangular or circular. The mounting plate 3 is a reflector. The light projector comprises a plurality of fins 4 for heat dissipation fixed to the mounting plate 3 so as to come into contact with the stage surface in the inner cylinder of the mounting plate 3 in the direction perpendicular to the irradiation direction Dx.

Description

  The present invention relates to a projector using a light emitting diode element as a light source. In particular, the present invention relates to a projector suitable for illumination in a relatively large facility outdoors.

  In recent years, with the progress of technology for obtaining white light with a light-emitting diode element, the conversion from an illumination lamp such as an incandescent lamp, a fluorescent lamp, and a mercury lamp to a light-emitting diode-type illumination lamp is rapidly progressing. And a light emitting diode element has come to be used also as a light source of a projector with a large amount of light. Hereinafter, in the present invention, a semiconductor chip of a light emitting diode including electrodes is referred to as a light emitting diode element (LED).

  The projector is an illuminating device for irradiating the irradiation target at a certain distance from the light source with light having a predetermined brightness within a predetermined irradiation range. Therefore, the light source of a relatively large projector used for night lighting, garden lighting, or signage lighting of a playground or stadium such as a tennis court corresponds to the required irradiation distance, irradiation range and illuminance. A large amount of light is required. For example, a mercury lamp-based metal halloid lamp projector can be provided with a light source with a large amount of light, and therefore can provide light with sufficient brightness in a wide irradiation range to an irradiation object far away.

  If the irradiation distance which is the same as the mercury lamp projector is obtained for the LED projector, the amount of heat generated by the LED exceeds the allowable amount. On the other hand, in the LED projector, since the light of the LED as a light source has directivity, it is easy to irradiate the spot light within a predetermined irradiation range as compared with the mercury lamp projector. Therefore, for example, as representatively shown in Patent Document 1, a flat plate-shaped heat dissipation with a large wing area is achieved while condensing by a reflector and suppressing the amount of heat generated by the LED by improving the irradiation efficiency within a predetermined irradiation range. A heat sink with fins is provided.

  However, when a larger amount of light is obtained from the light source, the temperature of the LED of the light source becomes so high that it cannot be touched. For this reason, it is difficult to prevent damage to the LED and reduce energy loss due to heat generation only by naturally radiating heat with air. Although it is possible to increase the heat dissipation effect by enlarging the heat sink body and increasing the number of fins and the blade area, the mass of the heat sink increases and the total weight of the projector increases. Further, in the metal integral molding process, it is difficult to add a sufficient number of thin plate-shaped fins having a larger blade area.

  For example, in an LED-type illuminating lamp installed in a closed space such as an automobile headlamp disclosed in Patent Document 2 or Patent Document 3, high-temperature air is efficiently convected between the fins. In order to enhance the heat dissipation effect, a plurality of fins may be provided in the radial direction orthogonal to the irradiation direction. However, since a certain amount of time is required until heat is transmitted from the LED, which is a heat generation source, to the fins, the heat dissipation effect is not sufficient as a heat sink of a projector having a larger light quantity.

  Providing a forced cooling device such as a blower fan or a water cooling device not only increases power consumption, but also increases the number of parts and makes the structure of the projector more delicate. As a result, productivity is greatly reduced. In particular, in an outdoor lighting facility that is exposed to direct sunlight and wind, snow and rain, a projector equipped with a cooling device is more easily damaged. As a result, compared to a projector using a so-called light bulb as a light source such as a mercury lamp projector that does not require a cooling device, the burden of work and costs required for installation and maintenance by installation, inspection, repair, or replacement is increased.

JP 2011-113814 A JP 2006-143114 A JP 2006-351351 A

  When the light is collected by the reflector and the irradiation efficiency is made as high as possible, the light has to be concentrated on a limited irradiation range. For this reason, when it is necessary to illuminate a wider irradiation area with substantially uniform brightness, a plurality of projectors are arranged side by side to provide illumination so that the boundaries of the irradiation ranges of the nuclear projectors overlap. As a result, since a larger number of projectors are required compared to mercury lamp projectors, the burden of work and costs required for facilities and maintenance is still large, which hinders the spread of LED projectors.

  In view of the above problems, an object of the present invention is to provide an LED projector that can irradiate light having a required illuminance on a wider irradiation region. Another object of the present invention is to provide a projector that has a relatively simple structure and is not easily damaged. Another object of the present invention is to provide a projector that can maintain the ambient temperature of an LED at a safe temperature only by naturally radiating heat with air. Specific advantages that can be obtained by the present invention will be described in detail in the description of the embodiments of the present invention.

  In order to achieve the above object, the projector of the present invention includes a plurality of light emitting diode elements (1) that are light sources, a plurality of substrates (2) on which a plurality of light emitting diode elements (1) are disposed, and heat conduction. A cylindrical mounting plate (3) formed of a material having a plurality of steps with the inner cylinder recessed toward the center, and a substrate (2) provided on each step surface. To be.

  In the projector of the present invention, specifically, the mounting plate (3) is a reflector. In addition, it includes a plurality of fins (4) for heat radiation fixed to the mounting plate (3) so as to contact the step surface in a direction perpendicular to the irradiation direction (Dx). In particular, the outer shape of the substrate (2) provided on each step surface of the mounting plate (3) is a hollow shape similar to the shape of the opening (10) of the mounting plate (3), and is formed at the center of the irradiation surface. The external shape of the board | substrate (2) provided is made square or circular. Reference numerals are given for convenience of explanation, and the present invention is not specifically limited to the embodiments shown in the drawings.

  The LED projector of the present invention has a cylindrical mounting plate with an inner cylinder having a staircase shape, and a substrate is provided on each step surface, so that the irradiation surface of the projector facing the irradiation direction is approximately LEDs can be provided over the entire surface. Therefore, the light quantity in a single projector can be increased and the irradiation range can be expanded. As a result, light having a required illuminance can be given to a wider irradiation area, and the number of projectors can be reduced, thereby bringing about an effect of reducing work and cost burden on facilities and maintenance.

  In addition, since the inner cylinder has a configuration in which the substrate is provided on each step surface of the cylindrical mounting plate having a staircase shape, the LEDs as the heat generation sources are arranged approximately evenly on the entire surface of the mounting plate. At this time, the mounting plate is formed of a heat conductive material. Therefore, the mounting plate acts as a heat sink that absorbs heat from the substrate, and has a large area for absorbing and radiating heat. Therefore, the heat generated from the LED of the light source is absorbed in a state of being uniformly distributed over almost the entire surface of the mounting plate, and is radiated in a shorter time. As a result, a larger amount of light can be obtained. Further, the temperature can be kept low only by heat radiation, and it is difficult to damage with a relatively simple configuration.

It is the front view and upper side sectional drawing of the light projector of this invention. It is a set figure of the light projector of the present invention.

  FIG. 1 shows an embodiment of a projector according to the present invention. In the present invention, as shown in FIG. 1, the direction in which the projector is installed is defined as an irradiation direction Dx. And the surface which goes to the irradiation direction Dx is made into the front surface or front surface of a projector, and the opposite surface of a front surface is made into a back surface or a back surface. Further, the right side is the right side, the left side is the left side, the upper side is the upper side, and the lower side is the lower side with respect to the irradiation direction Dx. The direction from the rear surface to the front surface along the irradiation direction Dx is the front-rear direction, the direction from the upper surface to the lower surface is the vertical direction or the vertical direction, and the directions of the left and right side surfaces are the horizontal direction or the horizontal direction. A plane from which light is emitted on the front surface is referred to as an irradiation surface.

  The projector according to the embodiment includes a plurality of light-emitting diode elements (LEDs) 1 that are light sources, a plurality of substrates 2 on which the plurality of LEDs 1 are arranged, and a thermally conductive material, and the inner cylinder is recessed toward the center. A plurality of step-shaped cylindrical mounting plates 3. In particular, the projector according to the embodiment includes a plurality of heat-radiating elements fixed to the mounting plate 3 so as to be in contact with the step surfaces of the inner cylinders of the mounting plate 3 in a direction perpendicular to the irradiation direction Dx. The fin 4 is included. The mounting plate 3 for mounting the substrate 2 is specifically a reflector. Hereinafter, the reflector will be described as the mounting plate 3.

  The plurality of LEDs 1 are supplied with electric power from a DC power source (not shown) provided at a position far away from the projector. For example, an input terminal is provided on the side surface of the projector, and the input terminal and a DC power source are connected by a cable. Since the distance between the projector and the DC power source is limited, depending on the scale of the facility where the lighting equipment for installing the projector is provided, the plurality of projectors can be supplied from the plurality of DC power sources, respectively. .

  The LEDs 1 are electrically connected in series in units of several to a dozen. A series unit composed of a plurality of LEDs 1 connected in series is connected in parallel. Arranged on the substrate 2 in a number sufficient for the required amount of light so that the maximum amount of light that can be obtained when the maximum rated current value is supplied from the DC power supply exceeds the required amount of light. Has been. Therefore, even when a certain LED 1 is damaged and a specific series unit is electrically disconnected, it is possible to continue irradiating with a required amount of light.

  The substrate 2 is made of copper. The LEDs 1 are arranged on the substrate 2 in units of series units. The substrate 2 is connected to a printed wiring board provided nearby, and current is supplied from the printed wiring board. Although the board | substrate 2 can be used as a printed wiring board, the heat dissipation effect is inferior compared with a copper board | substrate. The plurality of substrates 2 are provided on each step surface of the reflector 3. The outer shape of the substrate 2 is basically formed in a hollow plate shape similar to the shape of the irradiation surface of the projector, in other words, the shape of the opening 10 of the reflector 3. However, the outer shape of the substrate 2A provided at a position corresponding to the center of the irradiation surface does not need to be annular, and is rectangular or circular.

  In the projector according to the embodiment shown in FIG. 1, since the shape of the opening 10 is circular, the substrate 2 is formed in an annular shape. However, the outer shape of the substrate 2 may not be a ring shape that is completely closed. Moreover, the external shape of the board | substrate 2 should just be a shape which can arrange | position LED1 as uniformly as possible over the whole irradiation surface. For example, the shape of the substrate 2 can be a sector. When the shape of the board | substrate 2 is a fan shape, it can be made into the some same-shaped fan shape. When the shape of the substrate 2 is a fan shape, a plurality of identical fan-shaped substrates 2 can be combined to form a single annular substrate as a whole.

  The LEDs 1 are arranged on each substrate 2 and the central substrate 2A so that the LEDs 1 are approximately uniformly distributed on the irradiation surface of the projector. For example, in the projector of the embodiment, the LEDs 1 are arranged on the substrate 2 in a row at the same interval so as to surround the center O of the irradiation surface of the projector. At this time, the number of LEDs 1 arranged on each substrate 2 is basically a multiple of the number of series units of LEDs 1.

  The copper substrate 2 can quickly conduct the heat generated from the LED 1 to the reflector 3 to dissipate heat. Therefore, the heat dissipation effect is high and no cooling device is required. When the substrate 2 is a printed wiring board made of resin such as glass epoxy, the substrate is prepared by mixing fine powder of a heat conductive metal such as aluminum into the molten resin so that the printed wiring is electrically insulated. The substrate 2 may be given thermal conductivity by molding. Further, by sufficiently reducing the thickness of the substrate 2, heat can be easily transferred to the reflector 3, and heat can be efficiently radiated.

  In particular, when the substrate 2 is a printed wiring board having substantially no thermal conductivity, a hollow plate shape having substantially the same shape as the step surface is formed on each step surface of the inner cylinder of the reflector 3. A thin copper plate can be provided in an overlapping manner. At this time, since the copper plate absorbs heat generated from the LED 1 in a shorter time, the temperature rise of the LED 1 can be sufficiently suppressed.

  As described above, in the projector according to the embodiment, the LEDs 1 are uniformly arranged on the step surface of each step in the cylindrical reflector 3 having a step-shaped inner cylinder. Therefore, for example, in the case of the projector according to the embodiment shown in FIG. 1, the LED 1 can be arranged over almost the entire irradiation surface viewed from the front of the projector facing the irradiation direction Dx, and the light quantity in a single projector To increase the irradiation area.

  At this time, in the projector according to the embodiment, the reflector 3 formed of a thermally conductive material has a heat sink function. Since the copper substrate 2 in which the LEDs 1 are evenly distributed is provided on the step surface of each step of the inner cylinder of the reflector 3, the entire inner cylinder of the reflector 3 may be biased toward a specific LED 1. The heat generated from each LED 1 is evenly absorbed and dissipated.

  In the projector according to the embodiment, the performance of each LED 1 can be maximized by reducing the load caused by the heat generated on the LED 1 without any variation among the plurality of LEDs 1, thereby reducing energy loss and increasing the amount of light. Can do. Further, the projector according to the embodiment is advantageous in that even if the number of LEDs 1 is increased, the ambient temperature does not rise so much, and the amount of heat generated by the light source as a whole can be suppressed.

  In the projector according to the embodiment, since the mounting plate formed of a heat conductive material is the reflector 3, performance as a reflecting plate is required. Therefore, the mounting plate is formed of aluminum sheet metal. The reflective surface is coated with a highly reflective reflective material that is generally flat so as not to scatter the reflected light. Metal fine particles capable of forming a reflecting surface such as aluminum, silver, and titanium oxide are uniformly vacuum-deposited on the entire inner cylinder of the reflector 3 or at least the inner surface of the side wall member 3A on which the substrate 2 is not provided.

  The thickness of the inner cylinder of the reflector 3 is made as thin as possible in consideration of the strength and the heat dissipation effect. Therefore, the projector can be made lighter than the amount of light to be output. As shown in FIG. 2, in the reflector 3 of the projector according to the embodiment, the side wall material 3A and the stepped surface material 3B are integrally formed by a pressure press. When it is difficult to manufacture the inner cylinder of the reflector 3 by a pressure press depending on the material of the reflector 3, the side wall material 3 </ b> A and the stepped material 3 </ b> B are welded, or a thermally conductive adhesive is used. Assembled and assembled.

  In the projector according to the embodiment, since the shape of the opening 10 is circular, the cylindrical reflector 3 is provided. The number of steps of the inner cylinder of the reflector 3 may be two or more steps as long as the effect of the present invention can be obtained. As the mounting plate, the steps of the inner cylinder of the reflector 3 may basically have the same size. Further, the size (height) of each step may be the same as the width of the step surface. However, the size of the step is not essentially limited, and a design change is possible. For example, in the projector according to the embodiment, since the mounting plate is the reflector 3, the number of steps and the size of the steps are determined to be suitable sizes in consideration of the irradiation distance, the irradiation range, and the irradiation efficiency.

  When the mounting plate is the reflector 3, the angle at which light is diffused with respect to the irradiation direction Dx can be reduced as the step size of each step is larger than the width of the step surface. As shown in FIG. 1, in the reflector 3 in the embodiment, the step is slightly larger than the width of the step surface. Therefore, in the projector according to the embodiment, the illuminance within the predetermined irradiation range is increased by reflecting the light of the LED 1 of the light source, for example, as indicated by a dotted line to suppress the diffusion of the light. .

  The step of each step of the inner cylinder of the reflector 3 can be changed in size for each step. However, the step closer to the opening 10 of the reflector 3 is made larger. When the size of each step is changed, the cross-sectional shape of the reflector 3 as viewed from the side of the projector approximates a bowl shape as a whole, so that the irradiation range is relatively narrow, but the light emitted from the LED 1 of the light source is reduced. Diffusion can be suppressed more efficiently.

  When the number of steps of the inner cylinder is small, in order to suppress light diffusion, a detachable reflector is separately attached so as to surround the opening 10 to collect light emitted from the LED 1 in the irradiation direction Dx. It is possible to make it light. In order to protect the LED 1 from wind and rain, a transparent lamp shade or lens having a high light transmittance can be provided on the front surface of the projector so as to cover the opening 10.

  In the projector according to the embodiment, a plurality of fins 4 for heat dissipation are provided in a radial direction that is a direction perpendicular to the irradiation direction Dx. The fin 4 is a hollow plate having a hole at the center formed of a material having a relatively high thermal conductivity and a small specific gravity, such as aluminum or pitch-based carbon fiber, which is used as a heat dissipation material. As shown in FIG. 2, the fin 4 of the projector according to the embodiment is an aluminum hollow circular plate (annular plate).

  The fin 4 is fixed to the reflector 3 so as to come into contact with each step surface of the reflector 3 as a mounting plate. Specifically, the fin 4 is attached so that the entire surface is in close contact with a back surface of the stepped surface material 3B of the inner cylinder of the reflector 3 with a fastening material such as a screw. The fins 4 can be provided so as to contact the reflector 3 indirectly. For example, a heat conductive silicon paste is interposed between the inner cylinder of the reflector 3 and the fins 4 so that the adhesion between the bonding surface of the fins 4 and the bonding surface of the stepped material 3B can be further increased. .

  The projector according to the embodiment can be provided with a heat sink 5 indicated by dotted lines and diagonal lines in FIG. The heat sink 5 is formed of an aluminum cast cylinder as shown by a dotted line in FIG. The heat sink 5 is provided so as to be in close contact with the side wall member 3 </ b> A of the reflector 3. The heat sink 5 contacts the fins 4. The heat sink 5 absorbs heat from the side surface of the reflector 3 and transmits it to the fins 4. Therefore, the strength and heat dissipation effect can be increased by the heat sink 5. However, since the heat sink 5 increases the total weight of the projector, it should be provided only when strength and a heat dissipation effect are required.

  When the heat sink 5 is provided, the fins 4 </ b> A can be added between the fins 4 as shown in FIG. 1. The fin 4A is attached by fitting a fan-shaped flat plate 4B obtained by equally dividing the circular fin 4 into two or more as shown in FIG. Therefore, the fin 4A has the same shape as the fin 4 in appearance, and has an equivalent heat dissipation effect. Therefore, heat dissipation can be further improved by providing the fins 4A.

  The terminal 6 is provided on the rear surface of the projector, and distributes power supplied from a DC power source outside the projector to each LED 1. The inner cylinder of the reflector 3 is attached and fixed to the front surface of the terminal 6. In the projector according to the embodiment, the terminal 6 is formed by combining a plurality of block-shaped aluminum castings. Therefore, the terminal 6 also serves as a heat sink. When the terminal 6 is used as a heat sink, a plurality of heat radiating plates 7 are provided on the back surface of the terminal. The terminal 6 absorbs heat transmitted through the reflector 3 and radiates heat from the heat radiating plate 7. Therefore, the heat dissipation effect can be further increased.

  The cover 8 is made of a rust-proof metal or reinforced resin. The cover 8 of the projector according to the embodiment is made of stainless steel. The cover 8 has a plurality of ventilation holes (not shown). Warm and hot air that convects around the fins 4 through the air holes circulates. The outer shape of the cover 8 is arbitrary, but the space covered by the cover 8 is made as large as possible. The cover 8 is provided with a fixture (not shown). The projector is attached to an illumination tower or an illumination stand of an illumination column so that the projector can be rotated in the front-rear direction and the left-right direction by a fixture.

  Several examples of the projector according to the embodiment described above are specifically mentioned, but modifications and applications are possible without departing from the technical idea of the present invention. For example, in the projector of the embodiment, the step of the cylindrical mounting plate having a staircase inner cylinder is parallel to the irradiation direction, but an angle can be given to the step.

  The projector of the present invention can be applied to lighting used in various industries, such as lighting of night lighting equipment in outdoor facilities, garden lighting, signboard lighting, and lighting at construction sites. The present invention contributes to the popularization of LED projectors that reduce power consumption, do not contain designated harmful substances, and have the advantages of relatively safe LEDs.

1 Light-emitting diode element (LED)
2 Substrate 3 Mounting plate (reflector)
4 Fin 5 Heat sink 6 Terminal 7 Heat sink 8 Cover

Claims (4)

  A plurality of light-emitting diode elements that are light sources, a plurality of substrates on which the plurality of light-emitting diode elements are disposed, and a multi-step staircase shape that is formed of a thermally conductive material and has an inner cylinder that is recessed toward the center. A projector having a cylindrical mounting plate on which the substrate is provided on each step surface.   The projector according to claim 1, wherein the mounting plate is a reflector.   The projector according to claim 1, comprising a plurality of fins for heat dissipation fixed to the mounting plate so as to contact the step surface in a direction perpendicular to an irradiation direction.   The outer shape of the substrate provided on the step surface of each step of the mounting plate is a hollow plate shape similar to the shape of the opening of the reflector, and the outer shape of the substrate provided in the center of the irradiation surface is square or circular. The projector according to claim 1.

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