JP2007088377A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of obtaining a desired light distribution property by making a projection image caused by a lens crisp while lessening a loss of light coming into the lens in a shadowless lamp for a medical care. <P>SOLUTION: A reduction in heat generation and occurrence of disconnection are prevented by constituting: plural LED lamps having luminescent colors such as white or three primary colors; and the lighting system in which a light obtained by introducing and permeating lights from the LED lamps in light guides which are provided at each of these LED lamps and are formed to a profile having at least one or more functions of a directivity controlling, a color mixing, an equalization of a brightness and a setting of an irradiation profile, is gathered at a desired position by an objective lens and a light distribution of a desired profile is formed by an image formation to a desired position by total lights from these light guides and the objective lens. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention irradiates light emitted from a virtually wide range to a predetermined range with uniform brightness, and is suitable for viewing in a state where no shadow is generated on an object, for example, when performing precision work, etc. The present invention relates to a configuration of an illumination device suitable for the illumination.

  As a configuration of a conventional lighting device 90 of this type, as shown in FIGS. 7 and 8, a plurality of LED elements 91 are mounted on a substrate 92 in a vertical and horizontal matrix, for example. A convex lens 93 (which may be a Fresnel lens) is provided in correspondence with the LED element 91 so that the light from each LED element 91 is projected as a parallel light beam or a light beam having an appropriate spread.

  Accordingly, all the convex lenses 93 are also arranged on a single lens substrate 93a. When all the LED elements 91 are turned on, the entire surface of the lens substrate 93a also emits light. By doing in this way, the light from each LED element 91 irradiates a parallel light beam having the light emitting area of the lens substrate 93a, and within this light emitting area, substantially shadowless illumination is performed. It becomes.

The LED element 91 used in the above may be whitened by molding the LED element 91 that emits blue light with an epoxy resin added with a phosphor that emits yellow light upon receiving light from the LED element 91. Alternatively, the LED element 91 that emits light closer to ultraviolet rays may be molded with a resin in which phosphors of three colors R (red), G (green), and B (blue) are added. Furthermore, for example, a combination of LED elements 91 that emit R, G, and B, such as a cathode ray tube and a liquid crystal display, may be used to obtain white color by mixing colors.
JP 2004-281352 A

  However, in the case of the illumination device 90 having the conventional configuration described above, the illuminance is low as in the case where the light from the LED element 91 as the light source is combined with a filament of an incandescent bulb and a reflecting mirror having a paraboloid of revolution. It is difficult to obtain a spot that is uniform and has a shape close to the desired one, and the resulting light distribution tends to be a so-called sharpness. For example, when used as a surgical light for dentists, the light distribution is Not only the part of the oral cavity but also reaches the patient's field of vision, which causes dazzling and uncomfortable feeling of light distribution.

  In addition, the LED element 91 is structurally difficult to combine with a reflecting mirror, and the capture rate of the light amount when combined with a lens or the like is low, and all of the light amount emitted from the LED element 91 itself is effectively used. Therefore, in order to obtain the illumination device 90 having the same brightness, there is a problem that the configuration becomes complicated, for example, the number of the LED elements 91 is increased.

  According to the present invention, as means for solving the above-described conventional problems, a plurality of LED lamps having white or three primary colors are provided, and light from the LED lamps is provided in each of these LED lamps. The light introduced into and transmitted through a light guide formed into a shape having at least one function of control of color, color mixing, uniformity of brightness, and setting of irradiation shape is collected at a desired position by an objective lens. The present invention solves the problems by providing an illumination device characterized by forming a light distribution of a desired shape by forming an image at a desired position by combining the light from the light guide and the objective lens. Is.

  According to the present invention, a light guide having a desired light distribution characteristic in cross section is attached to the upper surface (light emitting surface) of the LED lamp, and the light guide is attached between the LED lamp and the lens. By gradually changing to an area suitable for projection with a lens, loss of light incident on the lens is reduced, and the projected image by the lens is sharp, and desired light distribution characteristics are obtained. There are advantages.

  Below, this invention is demonstrated in detail based on embodiment shown in a figure. First, FIGS. 1 to 2 illustrate a configuration in which one light guide 13 and one objective lens 14 are used for one LED lamp 12 in the illumination device 1. In the present invention, as will be described below, the LED lamp 12 and the incident surface 13a of the light guide 13 are similar to each other and have substantially the same area. A plurality of LED chips are sealed, and a total light emitting area of about 2 mm × 5 mm is employed.

  1 and 2 indicate a light emitting unit of the lighting device 1 according to the present invention. The light emitting unit 10 is an LED mounted on a substrate 11 such as a glass epoxy circuit board. The lamp 12, the light guide 13 in which the surface of the LED lamp 12 and the entrance surface 13a are opposed to each other, and the exit surface 13b is provided on the opposite side, and the objective lens 14 that projects the exit surface 13b of the light guide at an appropriate magnification It consists of and.

  In FIG. 1, only the optical configuration is shown to clarify the configuration. However, in actual implementation, as shown in FIG. 2, the objective lens 14, the light guide 13, the LED lamp 12, etc. A light source holder 16 for holding the LED lamp 12 and the light guide 13, a base 17 for mounting the light source holder 16 at a predetermined position, and the base 17 and the objective lens 14 are connected to each other. Further, a support column 18 and the like for keeping the emission surface 13b and the objective lens 14 at a predetermined interval are also provided.

  In the present invention, the LED lamp 12 is considered to be a high-efficiency white LED as a light source in principle. However, this may be a color mixture of light from R, G, and B primary color LED lamps, or a white LED and For example, it may be a color mixture with a red LED lamp, and in short, any light color may be used as long as the shape, color, etc. of the object to be viewed are clearly seen.

  Here, the inventor provides the light guide 13 so that the light from the LED lamp 12 is directed in one direction and efficiently enters the objective lens 14, and the shape of the exit surface 13b of the light guide 13 is set to a desired arrangement. By resembling the shape of the light characteristics and projecting this shape on the irradiation surface, it is considered that a so-called cut is good, and a lighting device having a light distribution shape in which only a necessary part is irradiated can be obtained, and the conditions are obtained. Therefore, the light guide 13 was examined.

  Assuming a dental surgical light, the light distribution pattern H is a rectangle having an irradiation area of 220 mm × 80 mm. At this time, about 700 mm is required as a space from the illumination device 1 to the irradiation surface (oral cavity of the patient) as a work space for a doctor or the like. Therefore, the projection magnification by the objective lens 14 can be set from the ratio of the size of the irradiation area and the area of the exit surface 13 b of the light guide 13.

  Here, when the LED lamp 12 that emits white light using a phosphor is employed, according to the result of the study by the inventors, the light contains a large amount of diffusing components at the time when the light is emitted. By increasing the length L of the light guide 13 shown in FIG. 4, the uniformity of light is improved by internal reflection, and even if light unevenness, color unevenness, etc. occur on the incident surface 13a, the light emitted from the exit surface 13b It is possible to prevent light unevenness and color unevenness from occurring.

  However, since the above-mentioned inner surface reflection is performed between two parallel sides, the directionality of light does not change, it is diffused over a wide range, and part of the light does not enter the objective lens 14. , Produce something that slips through. That is, the light beam capture rate of the objective lens 14 is reduced, the light distribution becomes dark, and the light distribution shape is not cut well.

Therefore, the inventor provided the light guide 13 with a shape such that (area of the incident surface 13a) <(area of the exit surface 13b). Actually, the size (area) of the entrance surface 13a is 2.5 mm × 5.9 mm (14.7 mm ² ), whereas the size (area) of the exit surface 13b is 4.9 mm × 12. 6 mm (61.7 mm ² ) and about 4.2 times.

  By doing in this way, when the light reflected on the inner surface in the light guide 13 is subjected to inner surface reflection on the surface spreading in the light traveling direction, the traveling direction in the center direction is half the angle that the inner surface spreads. Change, that is, converge. However, since the degree of convergence differs depending on the number of internal reflections, it is necessary to determine a length L that produces internal reflections for the number of times that a preferable degree of convergence is obtained.

  At this time, as apparent from the above description, the number of internal reflections is not determined only by the length L of the light guide 13, but also by the inclination (expansion) from the incident surface 13a to the exit surface 13b. Since it will be affected, it is only necessary to obtain the slope and the length L that can obtain the optimum condition by adjusting both.

  As a result of the inventor's trial manufacture and examination, good results are easily obtained when the inclination angle of the side surface of the light guide 13 is set to a range of 20 ° or less, and the length L is the diameter of the exit surface 13b. Alternatively, when the cross section is rectangular, it is highly likely that a good result will be obtained when the combination is set in a range that is 0.5 times or more the length M of the long side.

  Of course, the incident surface 13a of the light guide 13 and the shape of the light emitting portion of the LED lamp 12 that causes light to enter the incident surface 13a are, for example, as long as the shape of the incident surface 13a is rectangular. When the shape of the lamp 12 is also rectangular, the light from the LED lamp 12 can be efficiently taken into the light guide 13 and the light utilization efficiency is improved.

  FIG. 4 is an example of the overall configuration of the illumination device 1 configured as described above. Here, eight light emitting units 10 are used, and the illumination device 1 is used as a dentist operating light. It is shown as an example of time. In practice, a case 2 for holding the light emitting unit 10 or a joint for freely adjusting the irradiation direction of the lighting device 1 is provided.

  And in the illuminating device 1 in this embodiment, all the light from each light emission unit 10 distributes the light to the whole surface of the predetermined light distribution pattern H. May emit a substantially parallel light beam and form a light distribution pattern H as a whole.

The measurement result of the illumination device 1 configured as described above is shown. When the LED lamp 12 (light emission area 10 mm ² ) luminous flux is about 120 lm (4.5 W) and the irradiation area is about 220 mm × 80 mm, there are six pieces. It became clear that the combination of the light emitting units 10 (power consumption 27 W) provided an illuminance equivalent to that of a surgical lamp using a 55 W halogen lamp as a light source, and about 50% power saving was possible. (FIG. 4 shows an example using eight light emitting units 10).

  Therefore, according to the present invention, the illuminating device 1 having a desired brightness can be configured with the required number of efficient light-emitting units 10, so that overall reduction in size and weight is possible, and a large amount directly like a filament. Since a light source that emits infrared rays is not used, a device for reducing the amount of infrared rays reaching the patient, such as an infrared transmission reflector, is unnecessary, and the configuration is simplified.

  Furthermore, in the present invention, since the shape formed on the exit surface 13b of the light guide 13 is projected by the objective lens 14 to form a light distribution shape, the shape of the exit surface 13b is changed. Thus, for example, a circular or elliptical system can be freely used, so that the lighting device 1 can have a high degree of freedom with respect to the light distribution shape.

  FIG. 5 shows another embodiment of the illumination device 1 according to the present invention. In the previous embodiment, the objective lens 14 was provided corresponding to each light guide 13. In the second embodiment, one objective lens is combined with the plurality of light guides 13.

  In the second embodiment, as shown in FIGS. 5 and 6, the light guide 13 </ b> A has a shape in which a plurality of the cylindrical objective lenses 15 along the cylindrical central axis Z are aligned in a line. With this configuration, the light distribution characteristic when the cylindrical central axis Z is installed horizontally can be set by expanding the left and right directions on the light guide 13A side. The illumination device 1 can be formed in which the shape viewed from the front is made thinner and smaller than the previous embodiment.

  FIG. 6 is a plan view, and in the previous embodiment, it is necessary to finely adjust each light emitting unit 10 in the left-right direction and the vertical direction so that the light from each light-emitting unit 10 overlaps the light distribution pattern H. However, in this other embodiment, it is only necessary to direct the light guide 13A toward the center. For example, when the light guide 13A is attached, each of the light guides 13A is automatically designed to be directed in a necessary direction. It is possible to reduce the manufacturing cost.

  In addition, in the illuminating device in this 2nd embodiment, the illumination intensity equivalent to the operating light which used the 55W halogen lamp as a light source is obtained by using eight light emission units 10, and the power consumption at this time is 36W In addition, the power consumption is still lower than that of the halogen lamp, the fever is less, and the discomfort to the patient can be reduced.

  In the second embodiment, as shown in FIG. 6, the long side of the exit surface 13b of the light guide 13A is formed in an arc shape, so that the irradiation width in the left-right direction is narrowed, and the difference between light and dark, The so-called light distribution interruption can also be improved. Further, since the direction orthogonal to the cylindrical central axis Z is controlled on the cylindrical objective lens 15 side as described above, the same plate thickness may be used and the formation is simple.

  Although the above description has been mainly described with respect to an example of a dentistless surgical lamp, any lamp can be applied as long as it is used as a lamp that uses a LED as a light source to form a predetermined light distribution characteristic. At this time, the light from the lamp can be visible light or invisible light such as infrared rays.

It is explanatory drawing which shows embodiment of the illuminating device which concerns on this invention by the principal part. Example 1 It is sectional drawing which follows the AA line of FIG. It is explanatory drawing which shows the example of the shape of a light guide. It is explanatory drawing which shows the operation state of 1st embodiment. It is explanatory drawing which shows another embodiment of the illuminating device which concerns on this invention by the principal part. (Example 2) It is a top view of another embodiment. It is a front view which shows a prior art example. It is sectional drawing which follows the BB line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Illuminating device 2 ... Case 10 ... Light-emitting unit 11 ... Board | substrate 12 ... LED lamp 13, 13A ... Light guide 13a ... Incident surface 13b ... Outgoing surface 14 ... Objective lens 15 ... Cylindrical objective lens 16 ... Light source holder 17 ... Base 18 ... Prop

Claims (7)

  A plurality of LED lamps having white or three primary colors, and light from the LED lamps are provided in each of these LED lamps, directivity control, color mixing, brightness uniformity, irradiation shape setting, The light introduced into and transmitted through the light guide formed into a shape having at least one of the above functions is collected at a desired position by the objective lens, and the total of the light from the light guide and the objective lens is desired. An illumination device characterized in that a light distribution having a desired shape is formed by image formation at a position.   The illumination device according to claim 1, wherein the objective lens is a cylindrical lens.   In order to control the directivity of the LED lamp, the shape of the light guide is (area of the incident portion) <(area of the exit portion), and the cross-sectional tendency in the light transmission direction is substantially similar. The lighting device according to claim 1 or 2, wherein   2. The light guide according to claim 1, wherein the light guide has a length equal to or more than 0.5 times the long side of the light guide when the entire length is the diameter of the exit surface or the cross section is rectangular. 2. The lighting device according to 2.   The illumination device according to claim 1 or 2, wherein a shape of an incident surface of the light guide is substantially the same as a shape of a light emitting portion of an LED lamp that causes light to enter the incident surface.   The condition when the light guide is in the state of (incident surface area) <(exit surface area) is that the inclination angle of the side surface from the incident surface to the output surface is 20 ° or less. The illuminating device in any one of Claims 1-5.   The lighting device according to claim 1, wherein the LED lamp is a white light emitting LED lamp.

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