JP4622877B2 - lighting equipment - Google Patents

Description

  The present invention relates to a hanging type lighting fixture supported by being suspended from a ceiling.

  2. Description of the Related Art A hanging type lighting fixture that is supported by being suspended from a ceiling and emits light downward has been provided (see, for example, Patent Document 1). In a hanging-type lighting fixture, a lighting unit that supplies power to a light source to turn it on is generally arranged above the light source so that the light from the light source is not blocked and the lighting fixture can be miniaturized.

As this type of lighting fixture, there is one having a shade made of a light-transmitting material and covering a light source. If such a lighting fixture is used, the visual effect that a shade emits light can be obtained, and the light of the light source can pass through the shade to illuminate the ceiling surface, thereby obtaining the effect of indirect illumination. .
JP-T-11-501148

  However, the conventional lighting fixture has a problem that the shade is heated by the radiant heat of the light source, and this heat is transmitted to the lighting means, so that the temperature of the lighting means tends to rise.

  The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a lighting fixture in which the temperature of the lighting means is hardly increased while obtaining a visual effect such that a shade emits light.

の条件を満たすことを特徴とする。 The invention of claim 1 includes a fixture main body having a socket for holding the light source and supported by being suspended from the ceiling surface, and is housed in the fixture main body and positioned above the light source and electrically connected to the light source to turn on the light source. A lighting means to be connected, a reflector that is mechanically coupled to the fixture body and interposed between the lighting means and the light source, and distributes light of the light source downward, and is made of a light-transmitting material and reflected when viewed from below A cylindrical shape that surrounds the entire circumference of the plate, and a part of the shade that projects downward from the reflector, and the incident light is incident directly from the light source on the inner surface of the portion of the shade that projects downward from the reflector. Each of the surface and the lower end surface of the shade has a straight section in a cross section including the light source and parallel to the vertical direction, and an angle formed by the incident surface and the lower end surface of the shade in the cross section is A. Incident angle of light shade to incident surface The maximum value B, and the relative refractive index to air of the material of the shade n, the critical angle at which light is emitted from the shade into the air when the alpha, formula

It satisfies the following conditions .

According to the present invention, it is possible to obtain a visual effect such that a shade emits light when light from a light source is incident on a shade having translucency. Further, since the radiant heat of the light source is blocked by the reflector and the position where the light of the light source is incident on the shade is the lower end portion of the shade, the lighting means located above the light source is hardly affected by heat. . Therefore, it is difficult for the temperature of the lighting means to rise. Furthermore, the light from the light source incident from the incident surface of the shade enters the lower end surface of the shade at an incident angle greater than the critical angle and is totally reflected by the lower end surface of the shade, which is higher than when the above conditions are not satisfied. The light emitted to can be increased.

  According to a second aspect of the present invention, in the first aspect of the invention, at least a portion surrounding the reflector on the outer side surface of the shade is inclined over the entire circumference so as to reduce the cross-sectional area in the horizontal section upward. The part surrounding the instrument main body is characterized in that it does not protrude to the outside of the part surrounding the reflector as viewed from below.

  According to this invention, compared with the case where an inclination is not provided in the outer peripheral surface of a shade, the external shape of a shade can be made small and compact.

The invention of claim 3 is characterized in that, in the invention of claim 1 or claim 2 , a scattering means for scattering the light of the light source is provided on the outer surface of the shade.

  According to the present invention, the light of the light source is diffused on the outer side surface of the shade, whereby a soft impression light can be obtained. In addition, since the light emitted in the horizontal direction and downward increases, the shade can be made to shine brighter.

ADVANTAGE OF THE INVENTION According to this invention, the visual effect that a shade light-emits can be acquired because the light of a light source injects into the shade which has translucency. Further, since the radiant heat of the light source is blocked by the reflector and the position where the light of the light source is incident on the shade is the lower end portion of the shade, the lighting means located above the light source is hardly affected by heat. . Therefore, it is difficult for the temperature of the lighting means to rise. Furthermore, the light from the light source incident from the incident surface of the shade enters the lower end surface of the shade at an incident angle greater than the critical angle and is totally reflected by the lower end surface of the shade, which is higher than when the above conditions are not satisfied. The light emitted to can be increased.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  In the present embodiment, as shown in FIG. 1, an instrument main body 1 that is suspended and supported from a ceiling surface (not shown), and made of aluminum, for example, is attached to the lower side of the instrument main body 1 so that light from a light source is directed downward. A reflecting plate 2 that distributes light and a shade 3 that is made of glass and surrounds the entire periphery of the instrument body 1 and the reflecting plate 2 when viewed from below.

  The appliance main body 1 has, for example, a hollow cylindrical shape, and a socket 11 to which a base of a light bulb shaped lamp La as a light source is mechanically and electrically connected is provided at a lower end portion. Specifically, for example, a halogen lamp, an incandescent lamp, or a fluorescent lamp can be used as the lamp La. In addition, a lighting circuit (not shown) for supplying power to the lamp La and lighting it is housed above the socket 11 in the appliance body 1. The power for the lighting circuit is supplied from a commercial power source via an electric wire C drawn from the ceiling. Since the lighting circuit can be realized by a known technique, illustration and detailed description thereof are omitted. In order to suspend and support the instrument body 1 from the ceiling surface, for example, a known means such as a string or a pipe can be used.

  The reflector 2 has a circular bottom plate 21 whose thickness direction is directed in the vertical direction, a cylindrical side wall 22 projecting downward from the outer periphery of the bottom plate 21, and a laterally projecting outward from the lower end of the side wall 22. It has a dome shape having a flange piece 23 provided and having an open lower surface as a whole. An insertion hole 21 a through which the socket 11 is inserted is vertically penetrated at the center of the bottom plate 21, and the light emitting portion of the lamp La is located below the bottom plate 21. The dimensional shape of the insertion hole 21a is selected so that there is almost no gap between the socket 11 and the inner surface of the insertion hole 21a. That is, the light emitting part of the lamp La and the lighting circuit are partitioned by the reflecting plate 2, and radiant heat from the light emitting part of the lamp La to the lighting circuit is blocked by the reflecting plate 2. The side wall 22 is inclined so as to increase the inner diameter and the outer diameter downward. This inclination gradually decreases downward, and the inner surface and the outer surface of the side wall 22 are each spherical. Furthermore, the lower end of the side wall 22 protrudes downward from the lamp La, and the reflecting plate 2 completely covers a portion of the inner surface of the shade 3 below the lamp La. The reflector 2 is screwed to the instrument main body 1 with a screw S that is inserted into a screw insertion hole (not shown) provided in the bottom plate 21 and screwed into the instrument main body 1, for example.

  The shade 3 has a cylindrical shape opened up and down as a whole. The outer surface of the shade 3 is inclined upward in the direction of decreasing the outer diameter, and this inclination is smaller than the lower part at the upper end portion surrounding the upper end portion of the instrument body 1. That is, the part surrounding the reflector 2 on the outer surface of the shade 3 is inclined over the entire circumference so as to reduce the cross-sectional area in the horizontal section upward, and the part surrounding the instrument body 1 in the shade 3 is It does not protrude to the outside of the part surrounding the reflector 2 when viewed from below. Thereby, compared with the case where the inclination of the outer surface of the shade 3 is made constant over the entire vertical width, the outer shape of the shade 3 is made compact. Further, the inner surface of the shade 3 is provided with a step 31 for making the upper inner diameter smaller than the lower inner diameter, and the step 3 is placed on the flange 23 of the reflector 2 so that the shade 3 is The instrument body 1 is supported via a reflector 2. In addition, a portion of the shade 3 below the step 31 protrudes downward from the reflector 2. Accordingly, the light of the lamp La is incident on the inner surface of the shade 3 below the step 31 (hereinafter referred to as “incident surface”) 32. The light incident on the shade 3 is reflected on the surface of the shade 3, the outer surface of the reflector 2, and the outer surface of the instrument body 1 as indicated by an arrow in the right half of FIG. As a result, a visual effect as if the shade 3 is emitting light is obtained.

  Here, the respective shapes of the reflector 2 and the shade 3 are rotationally symmetric with respect to a common vertical axis of symmetry, and the lamp La is located on this axis of symmetry. Further, the lower end surface 33 of the shade 3 has a truncated cone shape that is inclined upward as the distance from the symmetry axis increases. Furthermore, the incident surface 32 of the shade 3 has an inverted frustoconical shape inclined so as to increase its inner diameter downward. That is, in the shade 3, the lower end surface 33 and the incident surface 32 each have a straight cross-sectional shape in a cross section including the symmetry axis. Here, the incident surface 32 and the lower end surface 33 are smoothly connected through a downwardly convex curved surface, but this curved surface is not included in the incident surface 32 or the lower end surface 33.

In this embodiment, light incident from the lamp La in the shades 3 through the incident surface 32 so as not to exit from the lower end surface 33 of the shade 3 is totally reflected at the lower end surface 33 of the shade 3, the incident surface 32 of the shade 3 and the lower The angle formed by the end face 33 (the angle formed by the straight line in the above cross section; hereinafter referred to as “lower end angle”) is selected. A specific method for calculating the lower end angle will be described below with reference to FIG. 2 schematically showing the present embodiment.

  Let the lower end angle be A (°). In addition, as shown in FIG. 2, the incident light is incident on the light incident at an angle (hereinafter referred to as “maximum incident angle”) B (°) having the maximum incident angle to the incident surface 32 among the light of the lamp La. An exit angle from the surface 32 into the shade 3 is B ′ (°), and an incident angle through the shade 3 after entering from the entrance surface 32 to the lower end surface 33 is C (°). The relative refractive index of the material of the shade 3 with respect to air (hereinafter simply referred to as “refractive index”) is set to n. Since the absolute refractive index of air is approximately 1, the above-described refractive index n is approximately equal to the absolute refractive index of the material of shade 3. Further, a critical angle (hereinafter simply referred to as “critical angle”) when light is emitted from the shade 3 into the air is set to arcsin (1 / n) = α (°). That is, A may be selected so that C> α.

  Here, since A + (90−B ′) + (90−C) = 180 from the sum of the inner angles of the triangles at the lower end of FIG. 2, C = A−B ′ is obtained, and the condition to be obtained is A− B ′> α, that is, A> B ′ + α. Furthermore, since SnB = nsinB ′ according to Snell's law, since B ′ = arcsin (sinB / n), the final condition is as follows.

  In the present embodiment, the shade 3 is made of glass, the refractive index n is 1.5, and the critical angle α is 42 °. Further, the maximum incident angle B of the light of the lamp La with respect to the incident surface 32 is 43.5 °. Therefore, the right side of the above equation is about 69.3 °. Therefore, in the present embodiment, the lower end angle A is set to 70 °. As a result, the light of the lamp La incident on the shade 3 from the incident surface 32 is totally reflected on the lower end surface 33 of the shade 3, and the amount of light emitted upward is increased compared to the case where the above formula is not satisfied. be able to.

  According to the above configuration, the light of the lamp La incident on the shade 3 reflects the inside of the shade 3 and is emitted upward, so that the visual effect that the shade 3 emits light and the indirect illumination that illuminates the ceiling surface. An effect is obtained. Further, since the reflector 2 is interposed between the lighting circuit and the light emitting part of the lamp La, the radiant heat from the lamp La to the lighting circuit is blocked by the reflector 2. Furthermore, the position where the light of the lamp La enters the shade 3 is the lower end of the shade 3, and the light of the lamp La does not enter the shade 3 around the lighting circuit. Therefore, since the lighting circuit is not easily affected by the temperature increase of the shade 3, the temperature of the lighting circuit is hardly increased.

  The material of the shade 3 is not limited to glass as long as it is a light-transmitting material, and may be, for example, an acrylic resin. Moreover, the material of the reflecting plate 2 is not limited to aluminum, and for example, a white synthetic resin may be used.

  Further, for example, the pigment is applied to the outer surface of the shade 3 so that the density of the pigment particles does not excessively impair the translucency of the shade 3, and the light of the lamp La on the outer surface of the shade 3 It may be scattered by particles. In this case, the pigment becomes the scattering means in the claims. If this configuration is adopted, the light passing through the inside of the shade 3 is diffused on the outer surface of the shade 3 as shown by broken arrows in FIG. By increasing the amount of light emitted to the shade, the shade 3 appears to shine brighter. The scattering means is not limited to the pigment. For example, the light of the lamp La may be scattered on the outer surface of the shade 3 by roughening the outer surface of the shade 3. The surface portion becomes the scattering means.

It is a figure which shows this embodiment, The left half of (a) is sectional drawing, The right half of (a) is explanatory drawing which shows the path | route of the light radiate | emitted from a light source and injects into a shade, (b) is a bottom view. is there. It is explanatory drawing which shows the method of calculating the conditions of a lower end angle in the same as the above. It is explanatory drawing which shows another form same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Instrument body 2 Reflector 3 Sede 11 Socket La lamp

Claims (3)

An instrument main body having a socket for holding the light source and supported by being suspended from the ceiling surface, a lighting means that is housed in the instrument main body and is located above the light source and is electrically connected to the light source to light the light source, and the instrument main body And a reflector plate that is interposed between the lighting means and the light source and distributes light from the light source downward, and a cylinder that is made of a light-transmitting material and surrounds the reflector plate as viewed from below. A shade that is shaped and partly projects below the reflector ,
Of the inner surface of the portion of the shade that protrudes below the reflector, the incident surface on which direct light is incident from the light source and the lower end surface of the shade each have a straight section in a cross section that includes the light source and is parallel to the vertical direction. And
In the cross section, the angle formed by the incident surface of the shade and the lower end surface is A, the maximum incident angle of the direct light from the light source on the incident surface of the shade is B, the relative refractive index of the material of the shade to the air is n, the light When the critical angle at the time of emission from the shade into the air is α, the equation

A lighting apparatus characterized by satisfying the following conditions .   The part surrounding at least the reflector on the outer surface of the shade is inclined over the entire circumference so that the cross-sectional area in the horizontal cross section becomes smaller upward, and the part surrounding the instrument body in the shade is seen from below the reflector. The lighting fixture according to claim 1, wherein the lighting fixture does not protrude to the outside of a portion surrounding the luminaire. The lighting apparatus according to claim 1 or 2, wherein scattering means for scattering light from the light source is provided on an outer surface of the shade .

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