Lighting fixture

Abstract

To provide a lighting device having a simple structure using LEDs as light sources.SOLUTION: A lighting device 1 includes: an LED module 10 including several kinds of LED elements 11; a lens 46 disposed on an optical path of light emitted from the LED module 10; a diffuser panel 32 disposed between the LED module 10 and the lens 46 on the optical path; a light limit member 34 having an opening 36 disposed between the LED module 10 and the lens 46 on the optical path and having a predetermined shape; and a moving mechanism 50 configured to change a distance between the LED module 10, the diffuser panel 32, and the light limit member 34 and the lens 46.SELECTED DRAWING: Figure 1A

Description

Technical Field

[0001] The present invention relates to a lighting fixture.

Background Art

[0002] As a kind of lighting fixture for production spaces such as stages, TV studios, wedding venues, etc., a lighting fixture having a simple configuration combining a light source and a single lens, as disclosed in Patent Document 1 for example, is known. In recent years, as a light source of lighting fixtures, light emitting diodes (LEDs) are increasingly being used instead of conventional halogen bulbs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a lighting fixture having a simple configuration using an LED as a light source.

Means for Solving the Problems

[0005] According to one aspect of the present invention, a lighting fixture includes an LED module including a plurality of types of LED elements, a lens disposed on an optical path of light emitted from the LED module, a diffusion plate disposed between the LED module and the lens on the optical path, a light limiting member having an opening of a predetermined shape disposed between the LED module and the lens on the optical path, and a moving mechanism configured to change distances between the LED module, the diffusion plate, the light limiting member, and the lens.

Effects of the Invention

[0006] According to the present invention, it is possible to provide a lighting fixture having a simple configuration using an LED as a light source.

Brief Description of the Drawings

[0007]

Figure 1A

Figure 1B

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0008] An embodiment will be described with reference to the drawings. This embodiment relates to a lighting fixture for a production space such as a stage spotlight. The lighting fixture of this embodiment is a lighting fixture having a simple configuration in which a light source of a light emitting diode (LED) and a single lens are combined.

[0009] [Configuration of Lighting Fixture] FIG. 1A is a right side view schematically showing a configuration example of the lighting fixture 1 according to the present embodiment, and is a view showing a state in which a right side portion of the housing 60 is removed so that the inside can be seen. FIG. 1B is a front view schematically showing a configuration example of the lighting fixture 1 according to the present embodiment. FIG. 2 is a perspective view schematically showing a configuration example of the lighting fixture 1 according to the present embodiment, and is a view showing a state in which a right side portion of the housing 60 is removed so that the inside can be seen.

[0010] The lighting fixture 1 includes a housing 60 having an elongated cylindrical shape along the optical axis 90. An opening 61 is provided on the optical axis 90 at one end side (front side) of the housing 60, and the other end side (rear side) is closed. The opening 61 is a light emission port of the lighting fixture 1. A lens 46 is provided in the opening 61. The lens 46 is a condenser lens such as a convex lens or a Fresnel lens, for example. The side of the housing 60 where the lens 46 is provided is referred to as the front side, and the opposite side is referred to as the rear side.

[0011] On the optical axis 90 inside the housing 60, an LED module 10 which is a light source is provided. The LED module 10 is attached to an attachment surface 21 of a heat sink 20 provided perpendicular to the optical axis 90. The LED module 10 mainly emits illumination light along the optical axis 90 in the direction of the lens 46.

[0012] FIG. 3 is a front view schematically showing a configuration example of the LED module 10. The LED module 10 has a plurality of LED elements 11 each of which emits light. The LED module 10 of the present embodiment has a plurality of types of LED elements 11 that emit different types of light. In the example of the present embodiment, the LED module 10 has three types of LED elements 11 that emit light of different colors (wavelengths). The LED module 10 has a red LED element 14 that emits red light, a green LED element 15 that emits green light, and a blue LED element 16 that emits blue light. In this example, in the LED module 10, a red element row 17 in which the red LED elements 14 are arranged in a row, a green element row 18 in which the green LED elements 15 are arranged in a row, and a blue element row 19 in which the blue LED elements 16 are arranged in a row are each provided in a plurality of rows.

[0013] Returning to FIGS. 1A to 2, the description will be continued. On the optical path between the LED module 10 and the lens 46, a diffusion plate 32 and a light limiting member 34 are provided. The light limiting member 34 includes an aperture plate 35 provided perpendicular to the optical axis 90, that is, parallel to the main surface of the LED module 10, and having an aperture 36 of a predetermined shape. In the present embodiment, the aperture 36 is circular. The light limiting member 34 has, for example, plate-like legs 37, and the aperture plate 35 is fixed to, for example, the heat sink 20 via the legs 37.

[0014] The diffusion plate 32 is provided so as to cover the aperture 36 of the light limiting member 34. The diffusion plate 32 has, for example, fine irregularities. The diffusion plate 32 diffuses the light emitted from the LED module 10 and incident on the diffusion plate 32, and makes the luminance distribution of the light emitted from each LED element 11 of the LED module 10 gentle. The diffused circular light emitted from the aperture 36 of the light limiting member 34 is emitted from the lighting fixture 1 via the lens 46 to illuminate the irradiated object.

[0015] The lighting fixture 1 includes a light source unit 42 formed as described above by the LED module 10, the heat sink 20, the diffusion plate 32, and the light limiting member 34.

[0016] The lighting fixture 1 includes a moving mechanism 50 configured to change the distance between the light source unit 42 and the lens 46. The moving mechanism 50 has a moving table 51. The heat sink 20 is fixed to the moving table 51. That is, the light source unit 42 integrating the LED module 10, the heat sink 20, the diffusion plate 32, and the light limiting member 34 is placed on the moving table 51.

[0017] The moving mechanism 50 has a screw shaft 53 and a guide rod 55 that extend parallel to the optical axis 90. The guide rod 55 is provided inside the housing 60. The moving table 51 is configured to move in the direction of the optical axis 90 along the guide rod 55. The screw shaft 53 extends from inside the housing 60 through the rear side of the housing 60 to the outside of the housing 60. The screw shaft 53 is rotatably supported about its axis. An operation handle 54 is fixed to the rear end of the screw shaft 53 that extends outside the housing 60. A helical groove is provided on the outer periphery of the screw shaft 53 inside the housing 60. The helical groove of the screw shaft 53 engages with a pin 52 fixed to the moving table 51.

[0018] When the operation handle 54 is operated to be rotated, the helical groove rotates together with the screw shaft 53, and the moving table 51 moves back and forth by the pin 52 that engages with this groove. That is, the distance between the lens 46 and the light source unit 42 on the moving table 51 changes.

[0019] By changing the distance between the lens 46 and the light source unit 42, the spread of the circular light emitted from the lighting fixture 1 can be changed, and the range illuminated by the lighting fixture 1 can be changed. That is, the lighting fixture 1 is configured such that the irradiation angle of the illumination light can be changed. Not limited to this, for example, the lighting fixture 1 may be configured to be able to change the irradiation angle (field angle) in the range of about 8° to 75°.

[0020] [Function of Lighting Fixture] The function of the lighting fixture 1 of the present embodiment will be described with reference to the drawings. FIG. 4 shows a case where the diffuser plate 32 that can move back and forth along the optical axis 90 is located at the focal point F' of the lens 46, and the red LED element 14 and the blue LED element 16 among the LED elements 11 of the LED module 10 are emitting light. In FIG. 4, the red light emitted from the red LED element 14 is indicated by a broken line, and the blue light emitted from the blue LED element 16 is indicated by a dotted line.

[0021] The light emitted from the red LED element 14 and the blue LED element 16 of the LED module 10 is incident on the diffusion plate 32, diffused by the diffusion plate 32, and mixed in color. As a result, magenta light is emitted from the diffusion plate 32. Here, since the opening 36 of the light limiting member 34 to which the diffusion plate 32 is attached is circular, the diffusion plate 32 in the opening 36 portion functions as a magenta light source having a circular light emitting surface.

[0022] The light radiated from the pseudo light source of the diffusion plate 32 in the opening 36 portion exits from the lighting fixture 1 through the lens 46 and illuminates the object to be irradiated. Since the pseudo light source composed of the diffusion plate 32 in the opening 36 portion is a circular light source that emits light of a uniform color, even when the diffusion plate 32 is located at the focal point F' of the lens 46 as shown in FIG. 4, the image of the pseudo light source projected on the irradiation surface 94 is a circular image of a uniform color without color unevenness, and the irradiation light 96 is round.

[0023] FIG. 5 is a diagram showing a state in which the diffusion plate 32 is brought closer to the lens 46 than the focal point F'. By bringing the light source unit 42 closer to the lens 46, the irradiation range of the illumination light emitted from the lighting fixture 1 can be increased. Also in this case, on the irradiation surface 94, the irradiation light 96 is circular light of a uniform color without color unevenness.

[0024] In FIG. 4, the case where the red LED element 14 and the blue LED element 16 emit light has been described as an example, but the light emitting state of the LED module 10 can be appropriately changed. Regardless of the light emitting state of the LED module 10, the lighting fixture 1 functions in the same manner. For example, if the red LED element 14, the green LED element 15, and the blue LED element 16 emit light with the same brightness, the lights of each color are mixed by the diffusion plate 32, white light is emitted from the diffusion plate 32, and white light is emitted from the lighting fixture 1 through the lens 46. In addition, light of a color corresponding to the ratio of the outputs of the LED elements 11 of each color is emitted from the diffusion plate 32 in the opening 36 portion toward the lens 46 and is emitted from the lighting fixture 1.

[0025] FIG. 6 schematically shows a case of a lighting fixture according to a comparative example having the same configuration except that the diffusion plate 32 and the light limiting member 34 are not provided. In this example, the LED module 10 as a light source is located at the focal point F' of the lens 46, and the red LED element 14 and the green LED element 15 are lit. In FIG. 6, the red light emitted from the red LED element 14 is indicated by a broken line, and the green light emitted from the green LED element 15 is indicated by a dotted line.

[0026] Although there is a deviation due to spherical aberration, the light drawn by a solid line incident on the lens 46 from the LED element 11 located on the focal point F' of the LED module 10 is emitted from the lighting fixture 1 parallel to the optical axis 90. On the other hand, the light incident on the lens 46 parallel to the optical axis 90 from the LED element 11 located at a position away from the focal point F' of the LED module 10 passes through the front focal point F of the lens 46 and reaches the irradiation surface 94. As a result, when a plurality of LED elements 11 are arranged in a square shape in the LED module 10, an image of the LED module 10 is projected onto the irradiation surface 94, and the square-shaped blurred irradiation light 96 is irradiated. Further, when the red LED element 14 and the green LED element 15 form a red element row 17 and a green element row 18, an uneven irradiation light 96 is irradiated in which a row of red light and a row of green light corresponding to the red element row 17 and the green element row 18 are recognized, and a row of yellow light is recognized at a position where they are mixed. In particular, conspicuous color unevenness is recognized at the upper and lower ends of the irradiation light 96.

[0027] When the LED module 10 is brought closer to the lens 46 than the focal point F' of the lens 46, the irradiation range can be expanded. In this case, since no image is formed, the image of the LED module 10 becomes less conspicuous on the irradiation surface 94, but in this case as well, the color unevenness derived from the red element row 17 and the green element row 18 is likely to be conspicuous in the irradiation light 96.

[0028] Unlike the case of the comparative example as described above, according to the lighting fixture 1 according to the present embodiment, the circular opening 36 of the light limiting member 34 and the diffusion plate 32 irradiate the irradiation surface 94 with a clean circular irradiation light 96 without color unevenness regardless of the position of the light source unit 42. In the present embodiment, such clean illumination can be realized by a simple configuration of the diffusion plate 32 and the light limiting member 34. Further, according to the present embodiment, clean irradiation light 96 can be obtained regardless of the arrangement of the LED elements 11 of the LED module 10. Therefore, the degree of freedom in the design of the LED module 10 is high, which also leads to cost reduction of the LED module 10 by simplifying wiring and the like.

[0029] According to the present embodiment, with a very simple structure including the light source unit 42 having the above-described simple configuration, one lens 46, and a moving mechanism 50 that changes the distance between the light source unit 42 and the lens 46, it is possible to irradiate a round irradiation light 96 without color unevenness, and an excellent lighting fixture 1 that can change the irradiation diameter with one operation of the operation handle 54 can be provided.

[0030] In the lighting fixture 1 of the present embodiment, since three-color LED elements are used as the light source, the lighting fixture 1 can irradiate illumination light of various colors by controlling the light emission amount for each color.

[0031] [Modification Example] The configuration of the LED module 10 may be any. The types of LED elements 11 included in the LED module 10 may be any combination, such as a combination of three types (three colors) of LED elements as in the above-described embodiment, a combination of two types or four or more types of LED elements, or even one type of LED element. The LED module 10 may be, for example, one in which two white LEDs having different color temperatures (for example, incandescent color and daylight color) are arranged. The arrangement of the LED elements 11 does not have to be square, and may be arranged in a circular shape or a polygonal shape. Different types of LED elements 11 do not have to be arranged in a row as in the above-described embodiment, and may be arranged in any arrangement.

[0032] Although the shape of the aperture 36 of the light-limiting member 34 is generally circular, the shape of the irradiated light 96 can be appropriately changed by changing the shape. Accordingly, the shape of the aperture 61 of the housing 60 may be appropriately changed.

[0033] The diffusion plate 32 may not be attached to the light-limiting member 34, and any configuration may be used as long as the light emitted from the LED module 10 is diffused by the diffusion plate 32 and shaped by the light-limiting member 34.

[0034] The configuration of the light-limiting member 34 may take other forms. For example, the light-limiting member 34 may have a cylindrical shape with the optical axis 90 as the axis. In this case, the end face of the cylinder can function as the aperture 36. Also, in this case, openings may be appropriately provided on the side surface so that heat does not accumulate.

[0035] Other members such as other optical elements may be added to the lighting fixture 1 as needed.

[0036] As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the present invention.

Explanation of Reference Numerals

[0037] 1 Lighting fixture 10 LED module 11 LED element 14 Red LED element 15 Green LED element 16 Blue LED element 17 Red element row 18 Green element row 19 Blue element row 20 Heat sink 21 Mounting surface 32 Diffusion plate 34 Light-limiting member 35 Aperture plate 36 Aperture 37 Leg 42 Light source unit 46 lenses 50 moving mechanism 51 moving table 52 pin 53 screw shaft 54 operation handle 55 guide rod 60 housing 61 opening 90 optical axis 94 irradiation surface 96 irradiation light

Claims

1. An LED module including a plurality of types of LED elements and attached to a heat sink, a lens disposed on the optical path of the light emitted from the LED module, an aperture plate having an aperture of a predetermined shape disposed between the LED module and the lens on the optical path, and a light limiting member having a pair of plate-like legs extending from the aperture plate and fixed to the heat sink so as to straddle the LED module and facing each other, a diffusion plate attached to the aperture plate disposed between the LED module and the lens on the optical path so as to cover the aperture, a light source unit in which the LED module, the diffusion plate, and the light limiting member attached to the heat sink are integrated, and a moving mechanism configured to change the distance between the light source unit and the lens and comprising, in the LED module, the plurality of LED elements are arranged in a planar manner, and each LED element is configured to emit light along the optical axis along which the LED module, the aperture, the diffusion plate, and the lens are arranged, and no optical element is disposed between the LED element and the diffusion plate, a lighting fixture.

2. The lighting fixture according to claim 1, wherein the lens is composed of a single condensing lens.

3. The lighting fixture according to claim 1 or 2, wherein the LED module includes a plurality of types of LED elements that emit lights having different colors from each other.

4. The lighting fixture according to any one of claims 1 to 3, wherein the LED module includes a plurality of types of LED elements that emit lights having different color temperatures from each other.

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