JP2012059575A - Spotlight - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spotlight using a light source of a wide-angle light distribution, in which wide-angle diffused light is condensed to enhance light utilization efficiency.SOLUTION: The spotlight 1 includes a light source 3 of a wide-angle light distribution, a condenser lens 4 for making light from the light source 3 a parallel light, a first convex lens 5 for condensing the parallel light to its focal point F1, and a second convex lens 6 located at a region separated further from the light source 3 than the focal point F1 of the first convex lens 5. The condenser lens 4 has a cavity 41 for composing an light incident surface of a concave shape facing the light source 3 and condenses the light from the light source 3 by covering the light source 3 with the cavity 41 to make the parallel light. This parallel light becomes a virtual light source of a point light source condensed at the focal point F1 of the first convex lens 5. This virtual light source is arranged at the focal point F2 of the second convex lens 6 and the light from the virtual light source is made incident to the second convex lens 6 and becomes spotlight for emission. With this, a wide-angle diffused light from the light source 3 is condensed without any leakage and spot-irradiated, and light utilization efficiency can be enhanced.

Description

  The present invention relates to a spotlight that can perform spot illumination by changing a beam angle according to the size of an irradiated object in a stage, a studio, an exhibition hall, or the like.

  An example of this type of spotlight is shown in FIG. The spotlight 100 uses a light source 103 such as a high-intensity discharge lamp or a halogen lamp, which is provided in a housing 102 and has directional characteristics of irradiation in all directions. Spot irradiation is performed by 105. The beam angle that determines the diameter of the spot light from the convex lens 105 is varied by moving the light source 103 and the reflecting mirror 104 together by the slide mechanism 106.

  Further, as shown in FIGS. 7A and 7B, a spotlight using a plurality of LEDs as a light source is known (see, for example, Patent Document 1). The spotlight 101 condenses light from a plurality of LEDs 107 having a narrow-angle light distribution into parallel light by a plano-convex array lens 108, condenses it to a virtual focal point F by a plano-convex lens 109, and further controls an irradiation angle. Spot irradiation is performed by the lens 110. The spotlight 101 moves the irradiation angle control lens 110 by a lens sliding mechanism, thereby adjusting the distance between the irradiation angle control lens 110 and the virtual focal point F, and irradiating the spotlight 101 while changing the beam angle of the spot light.

JP 2007-52957 A

  However, in this type of spotlight, the light from the light source 103 is narrowed from all directions to the front, but still has a wide-angle directivity characteristic of about 180 °, so as shown in part A of FIG. , A part of the light is not collected by the convex lens 105, and the light use efficiency is lowered. In recent years, a white LED having a wide-angle light distribution of about 180 °, which is a combination of a blue LED and a B / Y phosphor that converts the wavelength of blue light to yellow light, has been used as an illumination light source. However, the spotlight 100 does not include an optical system suitable for condensing light having a wide-angle light distribution as described above when using such a white LED as a light source. It is difficult to increase.

  In the spotlight 101 as shown in FIG. 7, when a light source with a wide-angle light distribution such as a white LED is used as the LED 107, the wide-angle component incident on the array lens 108 at a critical angle or more is totally reflected. For this reason, light loss due to reflection occurs, and the wide-angle diffused light from the light source cannot be collected at the virtual focal point F, and the light utilization efficiency is reduced.

  The present invention has been made to solve the above problems, and provides a spotlight capable of condensing wide-angle diffused light and improving light utilization efficiency in a spotlight using a light source with a wide-angle light distribution. With the goal.

  In order to achieve the above object, the spotlight of the present invention has a light source with a wide-angle light distribution and a concave light incident surface facing the light source, and collimates light from the light source incident on the light incident surface. A light collecting lens, a first convex lens for condensing light emitted from the light collecting lens, and a region farther from the light source than the focal point of the first convex lens, along the optical axis of the light source And a second convex lens that is slidably supported.

  In this spotlight, it is preferable that the condenser lens and the first convex lens are integrated.

  According to the spotlight of the present invention, almost all of the wide-angle diffused light from the light source is incident on the concave-shaped light incident surface of the condensing lens and becomes parallel light, and is collected at the focal point of the first convex lens without leakage. Since it irradiates from 2 convex lenses, light utilization efficiency can be improved.

The block diagram of the spotlight which concerns on the 1st Embodiment of this invention. The perspective view of each lens arrange | positioned on the optical axis of a spotlight same as the above. The block diagram of the light source of a spotlight same as the above. The figure which shows the adjustment position of the virtual light source at the time of wide angle light distribution of a spotlight same as the above. (A) is a block diagram of the spotlight which concerns on the 2nd Embodiment of this invention, (b) is a figure which shows the adjustment position of the virtual light source at the time of wide-angle light distribution of the spotlight. The block diagram of the conventional spotlight. (A) is a block diagram of the other conventional spotlight, (b) is a perspective view of a light source and an array lens in the spotlight.

  A spotlight according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the spotlight 1 includes a housing 2, a light source 3 with a wide-angle light distribution, a condenser lens 4, a first convex lens 5, a second convex lens 6, an internal A housing 7 and a position adjusting mechanism 8 are provided. The condenser lens 4 has a cavity 41 serving as a concave light incident surface facing the light source 3, and emits light from the light source 3 incident on the cavity 41 as parallel light. The 1st convex lens 5 condenses the parallel light radiate | emitted from the condensing lens 4 to the focus F1. The second convex lens 6 is in a region farther from the light source 3 than the focal point F 1 of the first convex lens 5, and is slidably supported along the optical axis 10 of the light source 3.

  The housing 2 houses the second convex lens 6, the internal housing 7, and the position adjustment mechanism 8, and the internal housing 7 houses the light source 3, the condenser lens 4, and the first convex lens 5. . The light source 3, the condenser lens 4, and the first and second convex lenses 5 and 6 are sequentially arranged along the irradiation direction on the common optical axis 10, and the inner housing 7 is attached to the position adjustment mechanism 8 and is light. It is movable along the axis 10. In this spotlight 1, the light from the light source 2 is converted into parallel light by the condenser lens 4, the parallel light is condensed at the focal point F 1 of the first convex lens 5, and the internal housing 7 is moved by the position adjusting mechanism 8. The distance between the focal point F1 and the second convex lens 6 is adjusted to change the spot diameter and irradiate the irradiated object.

  The casing 2 forms a rectangular or circular outer case for mounting internal components such as the second convex lens 6, the inner casing 7, and the position adjusting mechanism 8, and the members thereof are used for stage lighting and the like. Since heat resistance is required, metals such as aluminum, steel, and magnesium are desirable. The housing 2 has an opening on the side surface on the irradiation direction side facing the light source 3, and a second convex lens 6 is attached to the opening.

  As will be described later, the light source 3 is a white LED composed of a blue LED and a B / Y phosphor that converts the wavelength of blue light (B) from the blue LED into yellow light (Y). Wide angle diffused light is emitted toward the front.

  As the condensing lens 4, a glass lens using an optical material BK7 (referred to as borosilicate crown glass) or a resin lens using acrylic, polycarbonate, or the like is used, and particularly when illumination with high illuminance is required. A glass lens with high heat resistance is used. The condensing lens 4 has a barrel-shaped lens body 40 that forms a rotating body with the optical axis 10 as a central axis. The lens body 40 includes a concave cavity 41 formed on a surface facing the light source 3, a reflection surface 42 that reflects light that has entered the lens body 40 through the cavity 41 in the direction of the optical axis 10, and a reflection surface And a flat emission surface 43 for emitting the light reflected by 42 to the outside. The condenser lens 4 is disposed so that almost all of the light emission side of the light source 3 is covered with the cavity 41, and almost all of the wide-angle diffused light from the light source 3 is incident on the cavity 41. The shape of the lens body 40 is not limited to a barrel shape.

  The cavity 41 forms a rotating body having the optical axis 10 as a central axis. This cavity 41 has an opening 44 for covering the light source 3, a mortar-shaped incident surface 45 on which mainly light of a wide-angle component of the wide-angle diffused light of the light source 3 is incident, a narrow surface close to the optical axis 10 that forms its top surface. And an incident surface 46 on which angular component light is incident. The incident surface 46 is formed in a convex shape.

  In the condenser lens 4, of the wide-angle diffused light incident on the cavity 41 from the light source 3, the light incident on the incident surface 45 is converted into parallel light along the optical axis 10 by the reflecting surface 42 and incident on the incident surface 46. The converted light is converted into parallel light along the optical axis 10 by a convex lens action. That is, the condensing lens 4 condenses not only light in the vicinity of the optical axis from the light source 3 but also light diffused to a wide angle other than that as parallel light, and all the light from the light source 3 is directed to the first convex lens 5. And emitted as parallel light.

  The first convex lens 5 is a plano-convex lens that uses a lens member similar to the condensing lens 4 and has a planar incident surface 51 that faces the exit surface 43 of the condensing lens 4 and an exit surface 52 that forms a convex surface. The incident surface 51 has the same shape as the exit surface 43 of the condenser lens 4. The first convex lens 5 condenses the parallel light from the condenser lens 4 at the focal point F 1, and the light condensed at one point of the focal point F 1 is equivalent to the second convex lens 6. It becomes a virtual light source of a point light source.

  The second convex lens 6 is a plano-convex lens in which the same lens member as the first convex lens 5 is used, the incident surface facing the first convex lens 5 forms a plane, and the exit surface in the irradiation direction forms a convex shape. Become. The second convex lens 6 is arranged at a position of the focal point F2 at the position of the focal point F1 (virtual light source) of the first convex lens 5 and in a region farther from the light source 3 than the virtual light source of the focal point F1. Here, since the internal housing 7 is movable along the optical axis 10 in the housing 2, the housing 2 is movable relative to the internal housing 7. The second convex lens 6 fixed to is equivalently supported so as to be slidable along the optical axis 10.

  The internal casing 7 is a rectangular or circular cylinder made of the same member as the casing 2, has an opening for mounting the first convex lens 5 in the irradiation direction, and is a cylinder facing the opening. The light source 3 is provided on the bottom surface, and also serves as a lens holder that holds the condenser lens 4 and the first convex lens 5 in the cylinder.

  The position adjustment mechanism 8 is a mechanism for changing the distance between the virtual light source at the focal point F1 and the second convex lens 6, and moves on the rail 21 laid on the bottom surface in the housing 2 along the optical axis 10. Installed as possible. The position adjusting mechanism 8 includes, for example, a movable base that supports the internal housing 7, can be slid on the rail 21, and can be fixed at an arbitrary position on the rail 21 with a fixing tool such as a screw. And The position adjusting mechanism 8 may be configured to move the inner casing 7 along the optical axis 10 and fix it at a desired position. Instead of moving the inner casing 7, the positions of the inner casing 7 and the virtual light source are fixed to the casing 2, and the second convex lens is moved along the optical axis 10 and fixed at a desired position. May be. For example, the second convex lens is fixed to a lens holder slidable in the optical axis direction, a gear provided on the lens holder and a rack fixed in the housing 2 are engaged, and the rotation of the gear is manually or automatically performed. It is possible to use a known lens sliding mechanism such as sliding the lens holder back and forth along the optical axis direction.

  As shown in FIG. 3, the light source 3 includes an LED 31 that emits blue light, an insulating substrate 32 in which the LED 31 is embedded and mounted, and a B / Y of a wavelength conversion element that covers the LED 31 embedded in the insulating substrate 32. And a phosphor 33. The light source 3 is formed as a white LED that generates white light by blue light from the LED 31 and yellow light emitted from the B / Y phosphor 33 that has received the blue light. As shown in the figure, the white LED has a Lambertian distribution of emitted light, and forms a wide-angle light distribution D that irradiates the front in a range of about 180 °.

  In the spotlight 1 configured as described above, the light from the light source 3 is converted into parallel light by the condenser lens 4 and condensed at the focal point F1 of the condenser lens 4 to become a virtual light source. The distance from the second convex lens 6 is changed by operating the position adjustment mechanism 8. By this operation, the beam angle which spreads with respect to the optical axis 10 in the spot light emitted from the second convex lens 6 is changed. In the state shown in FIG. 1, since the position of the virtual light source at the focal point F1 is adjusted to the position of the focal point F2 of the second convex lens 6, the light emitted from the second convex lens 6 becomes parallel light. It is irradiated as a narrow-angle light spot light with a narrow beam angle.

  FIG. 4 shows a state where the beam angle of the light emitted from the second convex lens 6 is enlarged and the spot light forms a wide-angle light distribution. In this state, the first convex lens 5 is brought closer to the second convex lens 6 by the adjustment of the position adjusting mechanism 8, and the position of the virtual light source at the focal point F 1 is second than the focal point F 2 of the second convex lens 6. It arrange | positions so that it may approach to the entrance plane side of the convex lens 6 of this. At this time, the spot light emitted from the second convex lens 6 has a wide-angle light distribution in which the beam angle is expanded and the optical axis 10 is expanded.

  When adjusting the beam angle of the spot light, the first convex lens 5 substantially contacts the second convex lens 6 from the state shown in FIG. 1 where the focal point F1 and the focal point F2 of the second convex lens 6 coincide. It is possible to move within the range up to. In this adjustment range, almost all of the light from the virtual light source at the focal point F1 is incident on the second convex lens 6, so that the light utilization efficiency is hardly lowered even if the beam angle changes. If the virtual light source at the position of the focal point F1 is located closer to the light source 3 than the position of the focal point F2 of the second convex lens 6, light distribution with a wide beam angle can be achieved, but the second light source from the virtual light source can be obtained. The diameter of the incident light on the convex lens 6 is larger than the lens diameter of the second convex lens 6. For this reason, all of the light from the virtual light source is not incident on the second convex lens 6, and the casing 2 is elongated in the direction of the optical axis 10, thereby increasing the size of the entire apparatus. In order to prevent such a situation, in this embodiment, the virtual light source is prevented from moving to the light source 3 side with respect to the position of the focal point F2 of the second convex lens 6, and the light from the virtual light source is always the second convex lens. 6 and the beam angle can be adjusted widely.

  As described above, according to the present embodiment, almost all of the wide-angle diffused light from the light source 3 is collected in the cavity 41 of the condenser lens 4 to become parallel light, and the parallel light is converted into the first convex lens 5. It becomes a virtual light source focused to the focal point F1, and almost all is incident on the second convex lens 6. Thereby, when the light source 3 having a wide-angle light distribution is used, the light from the light source 3 can be spot-irradiated without omission and high light utilization efficiency can be obtained.

  Further, since the light source 3 is composed of one white LED, it can be reduced in size as compared with the case of using a high-intensity discharge lamp, a halogen lamp, or a plurality of LEDs. Further, as compared with the case where a plurality of LEDs are used, color unevenness does not occur on the irradiated surface due to color variations between the LEDs.

  Next, a spotlight according to the second embodiment of the present invention will be described with reference to FIGS. In this embodiment, the condenser lens 4 and the first convex lens 5 are integrated in the above-described embodiment. In the condensing lens 4a of the present embodiment, the exit surface 43 of the condensing lens 4 and the incident surface 51 of the first convex lens 5 are integrated. In the condenser lens 4 a, the incident surface side is the cavity 41 of the lens body 40 as in the above embodiment, and the emission surface side is the emission surface 43 a corresponding to the emission surface 52 of the first convex lens 5. The condensing lens 4a converts the light from the light source 3 incident in the cavity 41 into parallel light along the optical axis 10 at the reflecting surface 42, and the parallel light at the focal point F1 by the convex emission surface 43a. Condensed to form a virtual light source.

  According to the present embodiment, the condensing lens 4a is free from surface reflection that is likely to occur at the interface between the exit surface 43 of the condensing lens 4 and the incident surface 51 of the first convex lens 5 in the above-described embodiment, thereby eliminating light loss. Therefore, the light use efficiency can be increased.

  In addition, this invention is not restricted to the structure of said embodiment, A various deformation | transformation is possible in the range which does not change the summary of invention. For example, although the light source 3 is a single LED, a plurality of LEDs may be used. Further, the white LED is not limited to the B / Y phosphor as a wavelength conversion element combined with the blue LED, and other wavelength conversion elements such as red and green phosphors combined to generate white light may be used. Good.

DESCRIPTION OF SYMBOLS 1 Spotlight 3 Light source 4, 4a Condensing lens 41 Cavity (it comprises a concave-shaped light incident surface)
45, 46 Incident surface (light incident surface)
5 First convex lens 6 Second convex lens

Claims (2)

A light source with a wide-angle light distribution;
A condensing lens having a concave-shaped light incident surface facing the light source, and collimating light from the light source incident on the light incident surface;
A first convex lens for condensing light emitted from the condenser lens;
A spotlight comprising: a second convex lens which is located in a region farther from the light source than the focal point of the first convex lens and is slidably supported along the optical axis of the light source.   The spotlight according to claim 1, wherein the condenser lens and the first convex lens are integrated.

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