EP2868966B1

EP2868966B1 - A bulb with LEDs

Info

Publication number: EP2868966B1
Application number: EP14460044.2A
Authority: EP
Inventors: Piotr Skrobotowicz
Original assignee: Auto Power Electronic
Current assignee: Auto Power Electronic
Priority date: 2013-08-05
Filing date: 2014-07-23
Publication date: 2017-04-26
Anticipated expiration: 2034-07-23
Also published as: EP2868966A1; PL224281B1; PL404996A1

Description

The subject of the invention is a bulb with LED diodes, designed to illuminate (in particular) industrial halls, laboratory work stands, sports facilities as well as to illuminate architectonic objects and streets.
Known from the patent description - US 2009080205 - "Led lamp having heat dissipation structure", the LED bulb consists of the bulb base, a radiator connected with the base, printed circuit boards with LED diodes, thermally coupled in a way enabling heat exchange into the external part of the radiator and a fan mounted inside the bulb base. The bulb base consists of threaded neck connected with two-element cover. The bulb's neck has an external screw thread and it is of standard size enabling screwing the thread into a bulb socket of standard size. The bottom part of the cover has a ring protruding from the neck and a lower part of the flange expanding upwards above the ring. The upper part of the cover has a ring in its upper part and the second part of the flange directed downwards, composing a lower edge to connect elements with the use of the flange the diameter of which is smaller than the ring in the lower part of the cover and a thread at the internal area to connect the radiator. The upper part of the flange with the diameter which gradually increasing from its upper to its lower part, has holes enabling assembly of contacts to connect LED diodes with an electric controller, located at the bulb base. The bottom part of the flange has a constant diameter and it is of shape similar to a pipe, it also has symmetrically spaced holes designed to enable circulation of air pressed from the outside into the internal space between the lower and upper part of the cover for air circulation around LED diodes. Radiator is made of a material characterized by high thermal conduction, such as aluminium or copper. The radiator has an element in the form of a cylinder with a set of ribs directed into the inside. The ribs are symmetrical in relation to the central cylinder's axis, and the thickness of each of them gets smaller into the axis direction. The radiator has arms directed into the outside in relation to the axis of the cylinder with a hole through its centre. The number of arms corresponds to the number of printed circuit boards with LED diodes. The ribs at the external arms of the radiator are erected into two opposite perpendicular directions in relation to the axis of the arm. Every pair of ribs is directed spaced into opposite directions and perpendicular in relation to the arms of the radiator and every arm is symmetrical in relation to the other ones. The internal surface of external ribs is flat and designed to thermally contact the relevant circuit printed board with LED diodes. Every circuit printed board with LED diodes has dimensions slightly smaller than the size of extreme ribs in radiators. LED diodes are installed in a line on a circuit printed board at its entire length. A fan, including the piezoelectric one, is installed in the upper part of a cover. A direction sensor located at the hole coming through the radiator's cylinder or inside the bulb base makes that the fan generate the flow of the air upwards, acc. to natural ventilation of the LED bulb. In an alternative solution, the fan is installed at the top of the radiator and it is designed to press the air into the radiator's interior or to suck the air via the cylinder into the radiator. External ribs of the LED lamp's radiator absorb thermal energy from circuit printed boards with LED diodes, which dissipates equally in the entire radiator. The LED bulb is cooled down by atmospheric air entering through the holes in the bottom part of the cover and leaving it via the upper part of the radiator's cylinder. Alternative solution is when the air is entering through the upper part of the radiator's cylinder and leaves it via holes in the cover.
Known from patent description - WO 2010/096498 - LED light bulbs for space lighting, the LED bulb is equipped with circuit printed boards with LED diodes located around the central axis. Glass or plastic bulb or transparent housing comprises (inside) circuit printed boards with LED diodes and other elements which compose a complete LED bulb, similar to a traditional bulb in terms of appearance. Circuit printed boards with LED diodes are mounted on multi-dimensional frame. Dependably on the needs arising from thermal load and weight, the frame is made of aluminium or other heat conducting material, bent into a shape assuring multi-dimensional 3D structure. The frame has upper and lower planes, holes spaced from the frame's area to the heat exchanging pipe. The heat exchanging pipe, as a structure or a material able to transfer heat by delivering it from the part characterized by high temperature to the element characterized by lower temperature, is located alongside the central bulb axis and has two ends: nearer and further. The frame is fixed on the nearer end of the heat exchanging pipe. The frame has upper and lower spaces, holes spaced from the frame's area to the heat exchanging pipe. Areas on the frame may be directed flat and vertically or be bent forwards or backwards dependably on the required profile of light beam of the lamp and a way the LED diodes emit their light. LED diodes are connected in the form of a series circuit by connecting ends (plus and minus) of every LED diode, with the use of wires. Diodes can be also connected in the form of series and parallel series dependably on the used elements and needs in the applied solenoid controller. A pair of conducting wires supply LED diodes by means of an electronic controller. The electronic controller is located inside a standard Edison bulb base in a lamp, which consumes AC current via conducting contacts. The farther end of the heat conducting pipe reaches the radiator with ribs. Ribs are spaced from the base, which delivers heat from the farther end of the heat exchanging pipe, to the ribs located outside. In the same structure the fan is located below the radiator and directs the air flow alongside the ribs in the radiator. The entire bulb may be tightly closed and then, flow of the cooling air is directed alongside the ribs and around the external part of the bulb. Other possibility is to use a hole at the ribs and then, the air flows alongside the ribs and it is directed into the bulb's interior.
Known from patent description US 2003/038291 , "Semiconductor light source", the semiconductor light source is composed of a bulb made of transparent glass with the radiator with LED diodes inside. The radiator has a shape of a multifaceted solid, inside which there is an air chamber with a cooling air inlet and outlet. Fig. 6 presents a cross-section of the radiator of the semiconductor light source. The semiconductor systems or heavy-duty LED diodes are surface-mounted in the radiator cavity by means of a heat-conducting binder or by soldering, or mechanical connection. The radiator is usually made of aluminium or copper with a thickness adequate for transferring heat from chips and for keeping chips cool. The internal radiator walls can be lined with a thermoelectric material in order to reduce the radiator temperature. The layer of the thermoelectric material can be parallel to the air chamber. The fan can be located in the air chamber or in its vicinity, in order to force the air flow from the inlet, through the air chamber with the thermoelectric material, down to the outlet, while evacuating heat. The lower end of the radiator is connected with a threaded bulb's base with an electrode at its end.
Known from patent description US2010181888 "Light emitting diode lamp", the lamp has a mask, a base, a fan and an additional heat dissipating plate. The mask houses the tube with LEDs mounted on the base. The tube with LEDs is constructed as a hollow structure. A portion of the tube is located in the mask. The mask is connected with the heat dissipating plate, which can be formed as a heat dissipating fin, can have a plurality of grooves being formed on its surface or can be made of aluminium. The mask and the tube are configured with a plurality of openings. The fan can be mounted at the end of the tube with LEDs or arranged inside it. The heat dissipating plate is located outside of the mask and mounted on the base for enabling the heat generated from the LEDs to be transmitted rapidly from to the heat dissipating plate through the conduction of the tube and the base.
The essence of the LED bulb, acc. to the invention consists in that the arterial internal part of the radiator comprises four areas of the same radius of curvature connected with one another alongside in corners with two arms with ends bent into the outside, and between corners alongside the arterial internal part there are located ribs of alternating grooves alongside their lengths, but the height of the ribs is identical that is between their flat ends and bent flat ends of arms of the corners there are located movable sliding boards, accordingly: side printed circuit boards with LED diodes and boards directing the cooling air into the inlet channels and boards with inserts directing the cooling air from the cooling air outlet channels. Advantageous situation takes place when a part of the cover in the form of a roll characterized by smaller diameter of the base, connected with the bulb base, converts into a part in the form of a reversed pyramid with square base connected with a perpendicular part converting into a roll part characterized by larger diameter of the base, however, corners of the part in the form of the reversed pyramid with square base and corner of the perpendicular part are rounded at the entire length, and part in the form of the reversed pyramid with square base has cooling air inlet holes, while between the perpendicular part and the roll part with a larger diameter of the base there is located a part with cooling air outlet holes. Advantageous situation takes place when relation of the part of the radiator located over the collar to the length of part of the radiator located in a cover with base shaft is 2.4: 1.
The bulb with LED diodes acc. to the invention enables oriented forced cooling air flow in air-tight inlet and outlet channels, which assures equal temperature of printed boards with LED diodes and the radiator, efficiently cooling down the LED diodes and elements of electronic systems. The thermal contact of printed boards with LED diodes and radiator's ribs assure maximal heat transmission. The structure of ribs of the radiator with extended side areas assures efficient transfer of the heat generated by LED diodes and the control system into the flowing cooling air in the air-tight inlet channels, arterial chamber and outlet channels. Thanks to separated air-tight inlet channels, arterial chamber, cooling air outlet channels and the collar there is eliminated access of pollution into hermetically closed space of the bulb with LED diodes between this bulb and the radiator with printed boards with LED diodes located on it. Movable connection of circuit printed boards with LED diodes with radiator enables simple assembly but most of all - thermal contact with the radiator and tightness of inlet channels, the arterial chamber and cooling air outlet channels. In the bulb with LED diodes, acc. to the invention it is possible to apply LED diodes of total summed up power higher compared with previously known solutions. The structure of the cover makes it possible to mount a part of the radiator inside easily and place the bulb with LED diodes acc. to the invention in the socket. Keeping the ratio 2.4:1 between the location of the part of the radiator located over the collar to the length of the part of the radiator located in the cover optimizes the cooling of the radiator directly and of the LED diodes indirectly.
The subject of the invention is explained in the fig. 1 which presents the design of the bulb with LED diodes in an exploded view, fig. 2 presents the design of the bulb with LED diodes as a partial section, fig. 3 presents the cross section A-A of a part of the radiator with circuit printed boards with LED diodes, and fig. 4 presents general view of the cover.
The bulb with LED diodes, acc. to the invention, is equipped with a radiator 6 which arterial internal part 20 comprises four areas 21 of the same radius of curvature, connected with one another alongside in corners with two arms 22, with ends bent into the outside. Between corners alongside the arterial internal part 20 there are located ribs 23 of alternating grooves 24 alongside their length. Height of ribs 23 is identical that is such, that between their flat ends and bent flat ends of arms 22 of corners, there are located movable sliding boards, accordingly: side printed circuit boards 4 with LED diodes 5 and boards 7 directing the cooling air into the inlet channels 18 and boards with inserts 9 directing the cooling air from outlet channels 19 into the cooling air outlet holes 13. Radiator 6 is made of material characterized by serious thermal conduction, such as aluminium or copper. Two ribs neighbouring each other 23 or a rib 23 and one of arms 22 of radiator's corner 6 together with external area of the channel 20 of the radiator 6 and side printed boards 4 with LED diodes 5 compose air-tight inlet channels 18 and air tight cooling air outlet channels 19. Air-tight inlet channels 18 and air tight cooling air outlet channels 19 are connected with one another through air tight arterial chamber 17 of the cooling air located between upper radiator's end 6 with blind internal part with a channel 20, upper printed board 3 with LED diodes 5, parts of side printed boards 4 with LED diodes 5 protruding above the upper end of the radiator 6 connected air-tightly with elongating elements 2 of the radiator's corner 6. Channels located between the radiator's internal part 6 and boards 9 directing the cooling air are covered with a lid 10. Outlet holes 13 of the cooling air are located directly under the collar 8 comprising four identical elements and separating the part of the radiator 6 with printed boards 4 with LED diodes 5 from the part of the radiator 6 with boards 9 directing the cooling air from outlet channels 19 into the outlet holes 13. Lengths of elements elongating 2 the corners of the radiator 6 are equal to parts of circuit printed boards 4 with LED diodes 5 protruding over the upper end of the radiator 6. Part of the radiator 6 with printed boards 4 with LED diodes 5 is located inside 16 the transparent glass 1 and remaining part of the radiator 6 with boards 7 directing the cooling air into the outlet channels 18 and with boards 9 directing the cooling air from outlet channels 19 together with a fan 11, is located in the cover 12 with threaded base 15 E9 - E40 or GU. The base 15 is inseparably connected with the cover 12, with a part in the form of a roll of smaller base diameter 28, which converts into a part in the form of the reversed pyramid with square base 27, which is connected with the perpendicular part 26 converting into a roll-shaped part, characterized by a greater diameter of the base 25. Corners of the part in the form of the reversed pyramid with square base 27 and perpendicular part 26 are rounded at their entire length. Part in the form of the reversed pyramid with square base 27 has inlet holes 14 for the cooling air, and between the perpendicular part 26 and the roll part of higher diameter of the base 25 there is located a part with cooling air outlet holes 13. The cover 12 is air-tightly connected with a glass 1 of the bulb with LED diodes acc. to the invention. LED control system 5 is located in the internal part 20 of the radiator 6.
The fan 11 sucks cooling air via inlet holes 14 located in the cover 12 directly over the base 15, which is pressed into the cooling air inlet channels 18 located between internal part 20 of the radiator 6, ribs 23 and boards 7 directing the cooling air into these inlet channels 18, connected by a collar 8 with printed boards 4 with LED diodes 5. Cooling air from the inlet channels 18 goes into arterial chamber 17, and from there into outlet channels 19 and via the cooling air outlet holes 13 in the cover 12 it goes out of the bulb with LED diodes acc. to the invention.

Claims

The bulb with LED diodes with transparent glass (1), with air tight cooling air inlet (18) and outlet channels (19), connected by an air tight arterial chamber (17) located between an upper end of a radiator (6) with blind internal part (20), an upper printed circuit board (3) and parts of side printed circuit boards (4) with LED diodes (5) protruding above the upper radiator's end (6), the radiator (6) has an arterial internal part (20) with ribs outside alongside entire length, with a fan (11) located in a cover (12) with a base (15) and a collar (8) separating a part of the radiator (6) with side printed circuit boards (4) with LED diodes (5) from a part of the radiator (6) with boards (7) directing the cooling air into inlet channels (18), with boards with inserts (9) directing the cooling air from outlet channels (19) into outlet holes (13), characterized in that the arterial internal part (20) of the radiator (6) comprises four areas (21) of the same radius of curvature connected with one another alongside in corners with two arms (22) with ends bent into the outside, and between corners alongside the arterial internal part (20) there are located ribs (23) with alternating grooves (24) alongside their length, but the height of the ribs (23) is identical that is such, that between their flat ends and bent flat ends of arms (22) of the corners there are located movable sliding boards, accordingly: side printed circuit boards (4) with LED diodes (5) and boards (7) directing the cooling air into the inlet channels (18) and boards with inserts (9) directing the cooling air from the cooling air outlet channels (19).
Bulb acc. to claim 1, characterized in that part of the cover (12) in the form of a roll with smaller diameter of the base (28) connected with the base (shaft) (15), converts into a part in the form of reversed pyramid with square base (27), which is connected with a perpendicular part (26) converting into part in the form of a roll with a larger diameter of the base (25), however, corners of the part in the form of the reversed pyramid with the square base (27) and corners of the perpendicular part (26) are rounded at the entire length, and part in the form of the reversed pyramid with square base (27) has cooling air inlet holes (14), while between the perpendicular part (26) and the roll part with a larger diameter of the base (25) there is located a part with cooling air outlet holes (13).
Bulb acc. to claim 1, characterized in that the relation of the length of the part of the radiator (6) located under the collar (8) to the length of part of the radiator (6) located in the cover (12) with the base (15) is 2.4:1.