Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V14/00—Controlling the distribution of the light emitted by adjustment of elements
  • F21V14/06—Controlling the distribution of the light emitted by adjustment of elements by movement of refractors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V13/00—Producing particular characteristics or distribution of the light emitted by means of a combination of elements specified in two or more of main groups F21V1/00 - F21V11/00
  • F21V13/02—Combinations of only two kinds of elements
  • F21V13/04—Combinations of only two kinds of elements the elements being reflectors and refractors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2115/00—Light-generating elements of semiconductor light sources
  • F21Y2115/10—Light-emitting diodes [LED]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
  • H01L33/58—Optical field-shaping elements
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
  • H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
  • H01L33/58—Optical field-shaping elements
  • H01L33/60—Reflective elements

Definitions

• the present invention relates to a lighting fixture for projecting a light beam at a variable projection angle, and to the relative operating method.
• the present invention relates to a fixture used for lighting and comprising one or more spot light sources, each defined by one or more light- emitting diodes (LED) , and to which the following description refers purely by way of example.
• LED light- emitting diodes
• lighting fixtures include lamps comprising a spot light source for emitting a number of light rays, defining a light beam, in an emission direction substantially crosswise to a predetermined projection axis/ and a concave reflecting surface designed to receive the light beam emitted by the light source and reflect it outwards of the lighting fixture in a projection direction at a given projection angle with respect to the projection axis.
• the light source is normally defined by a side-emitting LED located centrally inside the hollow of the concave reflecting surface; and the concave reflecting surface is defined by a parabolic reflecting member partly surrounding the LED to reflect the LED-emitted light beam in the predetermined projection direction.
• Lighting fixtures of the type described above have the major drawback of failing to allow for adjustment of the projection angle between the direction of the light beam projected by the fixture and the projection axis, thus limiting the operating and application scope of the fixture.
• lighting fixtures of the type described above normally have a substantially zero projection angle, i.e. generate a light beam in a projection direction substantially parallel to the projection axis, and so produce a collimated light beam of predetermined dimensions normally comparable with the dimensions characterizing the concave reflecting surface.
• Such lighting fixtures fail to provide for controlled focusing of the projected light beam, as required, for example, in any application (stage, entertainment, exhibitions) in which the size of the projected light beam spot must be adjusted to the size of an object or area for illumination, which in some cases may be extremely small.
• a lighting fixture as claimed in Claim 1 and, preferably, in any one of the following Claims depending directly or indirectly on Claim 1.
• Figure 1 shows, schematically, a lighting fixture in accordance with the teachings of the present invention, and with an optical refracting member in a first operating position;
• Figure 2 shows, schematically, the Figure 1 lighting fixture with an optical refracting member in a second operating position
• Figures 3, 4, 5, 6 show sections of respective variations of an optical member forming part of the Figure 1 lighting fixture
• Figure 7 shows a variation of the Figure 1 lighting fixture .
• the present invention is substantially based on the principle of interposing an optical refracting member of transparent material between a concave reflecting surface, and a spot light source located inside the hollow of the concave reflecting surface, so as to refract the light beam emitted by the spot light source/ and at the same time producing relative movement, along a predetermined projection axis, ' between the optical refracting member and the spot light source, ' so as to produce a controlled deviation of the direction of the light beam with respect to its emission direction.
• the angle of incidence of the light beam on the concave reflecting surface can be adjusted to accordingly adjust the projection angle between the direction of the light beam reflected by the concave surface and the projection axis.
• the present invention is substantially based on the principle of moving the optical refracting member along the projection axis to "modulate" refraction of the emitted light beam, and so produce a corresponding "virtual" movement of the light source, along the projection axis, with respect to its fixed position, to achieve controlled adjustment of the incidence angle and a corresponding adjustment of the projection angle of the projected light beam.
• number 1 indicates as a whole a lighting fixture for projecting a light beam in a. projection direction C offset by a projection angle ⁇ with respect to a reference projection axis A, and which provides for adjusting projection angle ⁇ on command to control focusing of the projected light beam.
• Lighting fixture 1 substantially comprises: at least one preferably spot light source 2 for emitting a number of light rays, defining a light beam, in an emission direction B substantially crosswise to projection axis A; and a concave reflecting surface 3, the hollow of which houses light source 2, and which is designed to reflect the light beam outwards of lighting fixture 1 in a projection direction C at projection angle ⁇ with respect to projection axis A.
• lighting fixture 1 also comprises a supporting base 4, preferably lying in a plane perpendicular to projection axis A, and for supporting light source 2 and concave surface 3.
• concave surface 3 is defined by a preferably parabolic reflector fixed rigidly to supporting base 4 so as to be substantially coaxial with projection axis A and surround light source 2; and light source 2 comprises at least one LED 2a, e.g. a side-emitting LED, housed centrally in the hollow of the parabolic reflector and fixed stably to supporting base 4, preferably at the intersection of supporting base 4 and projection axis A.
• LED 2a e.g. a side-emitting LED
• lighting fixture 1 also comprises an optical refracting member 5 made of preferably transparent material and shaped to fit between light source 2 and concave reflecting surface 3, so that the light beam travels through it in the emission direction and is refracted; and an actuating device 6 for producing, on command, relative movement, along projection axis A, between optical refracting member 5 and light source 2. Which relative movement produces a controlled deviation of the direction of the emitted light beam with respect to its emission direction, and so adjusts projection angle ⁇ of the projected light beam.
• actuating device 6 moves optical refracting member 5 along projection axis A to adjust the direction of the light beam emitted by light source 2 and accordingly adjust the angle of incidence ⁇ of the light beam on concave reflecting surface 3.
• the angle of incidence ⁇ of the light beam corresponds to the angle between the direction of the incident light beam and an axis D through the point of incidence of the light beam on concave surface 3 and perpendicular to concave surface 3.
• actuating device 6 moves optical refracting member 5, along projection axis A, between a first operating position ( Figure 1) , in which optical refracting member 5 does not intercept, and therefore produces no refraction of, the light beam emitted by spot light source 2, so that a substantially collimated light beam is projected; and a second operating position ( Figure 2) , in which optical refracting member 5 is interposed, between spot light source 2 and concave reflecting surface 3 to adjust projection angle ⁇ and accordingly focus the projected light beam.
• the concave surface reflects the light beam in the predetermined projection direction C - which, in the example shown, has a substantially zero projection angle ⁇ with respect to projection axis A - so that a collimated light beam is projected.
• optical member 5 when optical member 5 is in the second operating position, the light beam emitted by light source 2 travels through optical refracting member 5, is refracted twice, and is deviated with respect to emission direction B.
• the rays in the light beam impinge on concave surface 3 at respective angles of incidence ⁇ differing from incidence angles ⁇ in the first operating position, and are reflected by concave surface 3 at projection, angles ⁇ differing from corresponding projection angles ⁇ in the first operating position.
• the angle of incidence ⁇ and projection angle ⁇ in the second operating position are greater than the angle of incidence ⁇ and projection angle ⁇ in the first operating position respectively/ and the increase in projection angle ⁇ therefore focuses the projected light beam.
• actuating device 6 may adjust the axial position of optical refracting member 5, on command, to adjust the angle of incidence ⁇ and projection angle ⁇ of the light beam and so "modulate", i.e. accurately control, the degree of focus of the light beam.
• optical refracting member 5 is defined by a body made of rigid transparent material, e.g. glass, or plastic material, such as polycarbonate, polymethyl methacrylate, polystyrene, or any other similar transparent plastic material, and in which a seat 7 is formed to house spot light .source 2, i.e. LED 2a, when optical refracting member 5 is in the second operating position.
• rigid transparent material e.g. glass
• plastic material such as polycarbonate, polymethyl methacrylate, polystyrene, or any other similar transparent plastic material
• seat 7 is shaped to comprise a preferably cylindrical inner surface 8 coaxial with axis A and sized to house light source 2.
• inner surface 8 of seat 7 is positioned facing light source 2 to receive the rays of the light beam emitted by light source 2.
• inner surface 8 defines a separating surface between optical refracting member 5 and air, and so produces a first refraction of the emitted light beam.
• the body of optical refracting member 5 comprises an outer surface 9, which faces concave surface 3 when optical refracting member 5 is in the second operating position.
• outer surface 9 defines a separating surface between optical refracting member 5 and air, and produces a second refraction of the light beam before it impinges on concave surface 3.
• outer surface 9 is substantially ogival or spherical in shape with a continuous regular outline.
• annular recesses 9a are formed on outer surface 9 of optical refracting member 5, and are connected to one another so that outer surface 9 as a whole is substantially ogival or spherical in shape with a substantially discontinuous, irregular
• outer surface 9 of optical refracting member 5 may be truncated-cone-shaped with a continuous regular outline.
• annular recesses 9a are formed on outer surface 9, and are connected to one another so that outer surface
• Actuating device 6 may be defined by an electromechanical actuating member appropriately connected to lighting fixture 1 to support optical refracting member 5 coaxially with axis A, and which, as stated, moves optical refracting member 5, on command, along axis A, between the first and second operating position.
• actuating device 6 comprises an electrically operated linear actuator (shown by a dash line) , which in turn comprises a fixed component 6a fixed stably to a fixed portion of lighting fixture 1 (e.g. to supporting base 4); and a movable member defined, for example, by a movable rod connected to optical member 5 and movable linearly, along projection axis A and with respect to fixed component 6a, to move optical refracting member 5 between the first and second operating position.
• an electrically operated linear actuator shown by a dash line
• a fixed component 6a fixed stably to a fixed portion of lighting fixture 1 e.g. to supporting base 4
• a movable member defined, for example, by a movable rod connected to optical member 5 and movable linearly, along projection axis A and with respect to fixed component 6a, to move optical refracting member 5 between the first and second operating position.
• the electromechanical actuating member may be connected electrically to an electronic control module 10, e.g. an electronic control board preferably, though not necessarily, integrated in supporting base 4, and which, on the basis of control signals generated, for example, by an external control device (not shown) , controls the electromechanical member to move optical refracting member 5 along projection axis .A and so control focusing of the light beam.
• an electronic control module e.g. an electronic control board preferably, though not necessarily, integrated in supporting base 4
• control signals generated, for example, by an external control device not shown
• actuating device 6 comprises a manually operated mechanical member, which in turn comprises a fixed tubular portion 11 coaxial with axis A, connected preferably to supporting base 4, and sized to house concave surface 3; and a cover member 12 supporting optical refracting member 5 and connected to fixed tubular portion 11 to translate along projection axis A and so move optical refracting member 5 axially with respect to light source 2.
• cover member 12 comprises a movable tubular portion 13 coaxial with projection axis A; and a flat top 14, which extends in a plane perpendicular to projection axis A, is connected stably to optical refracting member 5, and is preferably made of the same transparent material as optical refracting member 5, so that the light beam reflected by concave surface 3 can travel through it.
• movable tubular portion 13 of cover member 12 is screwed to fixed tubular portion 11, so that manual rotation of cover member ' 12 about projection axis A produces a corresponding translation of cover member 12 along projection axis A.
• movable tubular portion 13 is connected telescopically to fixed tubular portion 11, so that movement of cover member 12 along projection axis A produces a corresponding translation of optical refracting member 5 along projection axis A.
• actuating device 6 moves optical refracting member 5 into the first operating position ( Figure 1) .
• the emitted light beam impinges directly on concave ' surface 3 with no change in its emission direction B, and concave surface 3 reflects the incident light beam in a direction C substantially parallel to axis A to project a substantially collimated light beam.
• Light focusing i.e. adjustment of projection angle ⁇
• actuating device 6 moving optical refracting member 5 from the first to the second operating position, so that optical refracting member 5 intercepts and gradually deviates the rays in the emitted light beam to gradually focus the light, which reaches maximum focus when optical member 5 reaches the second operating position.
• lighting fixture 1 has the big advantage of adjusting the focus of the projected light, while at the same time ensuring a high degree of efficiency.
• changes may be made to lighting fixture 1 as described and illustrated herein without, however, departing from the scope of the present invention as defined in the accompanying Claims.
• lighting fixture 1 comprises a number of light sources 2 aligned with one another a predetermined distance apart on the surface of supporting base 4.
• optical refracting member 5 may be shaped to comprise a number of inner seats I 1 each for housing a respective light source 2, i.e. LED 2a, when optical refracting member 5 is in the second operating position; or may be shaped to comprise one inner seat 7 sized to house all the light sources.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Securing Globes, Refractors, Reflectors Or The Like (AREA)
• Non-Portable Lighting Devices Or Systems Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=35520873

Family Applications (1)

Country Status (2)

Family Cites Families (5)

• 2005
  • 2005-05-20 EP EP05761404A patent/EP1886358A1/de not_active Withdrawn
  • 2005-05-20 WO PCT/IT2005/000292 patent/WO2006123376A1/en not_active Application Discontinuation

Non-Patent Citations (1)

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