JP2013197007A - Optical module for led lighting and local lighting fixture using optical module for lighting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical module for LED lighting in which light is irradiated correctly into a necessary irradiation region and luminance of sharp and non-blurring distribution light is enhanced without making large a size of a projection lens, and to provide a local lighting fixture using the optical module for lighting.SOLUTION: An optical module includes an LED light source (2), a guide mask member (3) having an oblong-shaped slit, and a projection lens (4) having a focal point adjacent to the slit. The projection lens (4) comprises an incident face (20) facing the LED light source and a central emission face (21a) of a cylindrical shape as well as spherical-shaped emission faces (21b, 21c) on both sides. With this arrangement, a lighting fixture having no blurring and high luminance can be obtained.

Description

  The present invention relates to an illumination unit using an LED (light emitting diode), and more particularly to an LED illumination optical module for a local illumination device that performs local illumination without giving a shadow to an object, and a local illumination lamp using the illumination optical module.

  In recent years, lighting devices using LED light sources have been put into practical use from the viewpoint of energy saving. As a light source for LED illumination, an LED light source having an emission spectrum in the visible range is generally used, and an LED element having an emission spectrum that does not include infrared rays and ultraviolet rays is used. Therefore, since the irradiation light does not contain infrared rays, the use of an incandescent light source is changed to an illumination device using an LED light source in applications where it is not desired to give thermal energy to an object.

  In addition, a dental LED lighting fixture having a shadowless effect has been proposed as a medical lighting device. The present inventor has proposed Patent Document 1 as such a dental LED lighting device.

  The lighting lamp described in Patent Document 1 is configured using a plurality of optical modules including an LED light source, a guide mask member provided with a slit, and a projection lens.

JP 2010-170805 A

  The illumination optical module and the illumination lamp disclosed in Patent Document 1 were able to obtain a light distribution with a necessary sharpness and a sharp light distribution with the required illuminance correctly irradiated with light in a predetermined irradiation area. However, the maximum illuminance was slightly low.

  In order to increase the required illuminance value on the irradiated surface, an LED light source with high emission luminance may be used as the light source. However, a high-luminance LED light source causes an increase in cost. Moreover, when the electric power sent to LED is increased in order to make it high brightness, the heat_generation | fever in LED becomes large and is not preferable. In order to increase the illuminance value without changing the output of the light source, the maximum illuminance can be increased by increasing the focal length of the projection lens.

  However, even if the focal length of the projection lens is simply increased, the outer diameter of the projection lens also increases in proportion to the focal length. Therefore, when performing local illumination like a dental LED lighting device, the light emission area increases, which is not preferable. In addition, the projection lens volume is significantly increased, leading to an increase in weight and size of the entire lighting device.

  Accordingly, an object of the present invention is to provide an LED illumination optical module that can obtain higher illuminance without increasing the entire outer diameter of the projection lens, and a local illumination lamp using the illumination optical module.

In order to solve the above problems, an optical module for LED illumination is
An LED light source, a guide mask member provided with a horizontally long slit through which light emitted from the LED light source passes, and a projection lens whose focal point is located near the slit,
The LED light source has an LED element, a reflection wall provided around the LED element, and a mold layer that covers the LED element, and has a horizontally long rectangular shape with a flat emission surface of the LED light source,
The projection lens includes an incident surface facing the LED light source, and a concatenated exit surface composed of a cylindrical center exit surface and spherical exit surfaces on both sides of the center exit surface,
The longitudinal direction of the LED light source, the longitudinal direction of the slit, and the central axis direction of the central exit surface are parallel to each other.

  Furthermore, the width in the longitudinal direction of the emission surface of the LED light source and the width of the central emission surface are the same.

According to another aspect of the present invention, a plurality of the illumination optical modules are attached to the housing at an angle so that the optical axis is directed toward the center of an arc having a radius of a predetermined distance. A local lighting fixture is provided.

According to the present invention, the maximum illuminance can be increased by slightly increasing the projection lens size according to the light source.

FIG. 1 is a perspective view showing a configuration of an optical module for LED illumination according to the present invention. FIG. 2 is a front view showing a slit state of the guide mask member. FIG. 3 is a perspective view showing the LED device. 4A and 4B show a relationship between the lens and the LED device. FIG. 4A is a schematic side view showing a case where the lens 10 of the present embodiment is used, and FIG. 4B is described in Patent Document 1 for comparison. It is a schematic side view which shows the case where the lens which has a focus in the slit vicinity and to which the diffusion cut was given was used. FIG. 5 is a schematic cross-sectional view for explaining a light distribution pattern when the lens of the present embodiment shown in FIG. 4A is used. FIG. 6 is a perspective view showing a light distribution pattern by the LED illumination optical module. FIG. 7 is a perspective view showing a dental surgical light.

  Hereinafter, an LED illumination optical module and a local illumination lamp using the LED illumination optical module according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a configuration of an optical module for LED illumination according to the present invention, FIG. 2 is a front view showing a slit state of a guide mask member, and FIG. 3 is a perspective view showing an LED device.

  As shown in FIG. 1, an illumination optical module 1 according to the present invention includes an LED light source 2, a guide mask member 3, and a projection lens 4.

  The LED light source 2 has an LED device 6 mounted on a base plate 5. The LED device 6 covers the periphery of a plurality of LED chips 7 with a mold resin 8 containing a phosphor, and emits light having a different wavelength from the phosphor contained in the mold resin by light emitted from the LED chip 7. For example, this emits white light. In this embodiment, as shown in FIG. 3, the plurality of LED chips 7 and the resin mold 8 are provided in a recess 8a surrounded by an outer frame 8b. The LED light source 2 has a horizontally long rectangular shape with a short side surface 2a, and the LED chip 7 has a plurality of chips arranged in the longitudinal direction. The outer frame 8b is a reflection wall that reflects the light emitted from the LED chip 7 and the light emitted from the phosphor included in the resin mold 8, and extends toward the light exit surface 2b of the LED light source 2 in the optical axis direction. We are open. The LED light source 2 is filled with the resin mold 8 so as to be the same height as the end of the outer frame 8b on the side of the emission surface 2b so that the emission surface 2b is flat.

  In this embodiment, the LED device 6 emits white light by covering the periphery of the LED chip 7 with a mold resin 8 containing a phosphor. However, the present invention is not limited to this, and the three primary colors of R, G, and B are used. Any LED chip and phosphor can be suitably implemented as long as the desired emission color can be obtained by using the LED chips 7, 7, and 7. Further, the phosphor is not limited to a fluorescent pigment, a fluorescent dye, or the like.

  The guide mask member 3 is a plate-like member having a slit 9 formed at the center, and is disposed between the LED light source 2 and the projection lens 4. The guide mask member 3 is formed of a metal material such as an aluminum material, a ceramic material, or the like, and its surface is colored by painting, baking painting, aluminum vapor deposition, or the like.

  The slit 9 is an opening formed in a rectangular shape that matches a desired light distribution pattern shape, and is positioned in front of the resin mold 8 of the LED light source 2 as shown in FIG. Thereby, a part of the light emitted from the LED device 6 is blocked by the guide mask member 3, and a clear light-emitting light source area having the shape of the slit 9 matching the desired light distribution pattern shape is formed.

  Note that the slit 9 is desirably smaller than the size that forms the desired light distribution pattern shape, so that the desired irradiation area is not exceeded even if the mounting angle accuracy of the illumination optical module 1 is not high.

  Further, the surface of the guide mask member 3 is coated with blue, amber, white, camouflage, etc., or a metal film such as Al or Ag is vapor-deposited, or is subjected to surface treatment by sputtering or plating. In conventional illumination optical modules, components such as the internal light source are visible through the lens when it is turned off. For example, when black is used in many components, it may be difficult for external light to enter the lens. Since it looks like a black lens, the optical module for the surgical light deteriorates. However, the surface of the guide mask member 3 can be painted, metal film deposited, sputtered, plated, etc. to improve the appearance when not lit as a clear and bright image, thereby increasing the commercial value.

  The projection lens 4 includes a lens 10 formed of a transparent resin material such as acrylic and polycarbonate, a glass material, and a lens holder 11 that holds the lens 10. The lens 10 is a convex lens divided into a plurality of sections.

The relationship between the projection lens 4 and the LED light source 2 will be described with reference to FIGS.
4A and 4B show the relationship between the lens 10 and the LED device 6. FIG. 4A is a schematic side view showing the case where the lens 10 of the present embodiment is used, and FIG. 2 is a schematic side view showing a case where a lens 100 having a focal point in the vicinity of the slit and subjected to diffusion cut is used, and the same components as those in FIG. FIG. 5 is a schematic cross-sectional view for explaining a light distribution pattern when the lens 10 of the present embodiment shown in FIG. 4A is used.

  The lens 10 is roughly divided into a central portion 10a including the optical axis Ax, a left side portion 10b located on the left side of the central portion, a right side portion 10c located on the right side of the central portion, and a flange portion 10d around the lens. Is formed. The flange portion 10 d serves as an attachment fixing portion for being sandwiched by the lens holder 11. An incident surface 20 facing the emission surface 2b of the LED light source 2 is formed on the LED light source 2 side in all regions of the central portion 10a and the side portions 10b and 10c. It has an exit surface 21 consisting of a central exit surface 21a of the part 10a, a left exit surface 21b of the lens left side portion 10b, and a right exit surface 21c of the lens right side portion 10c. In FIG. 5, the central portion 10a is shown enlarged in the horizontal direction of the drawing as compared with the side portions 10b and 10c for easy understanding.

  The lens central portion 10 a is a semi-cylindrical cylindrical lens having a flat incident surface 20 and a cylindrical emission surface 21 a, and the central axis direction of the column is parallel to the longitudinal direction of the LED light source 2. The focal point of the lens central portion 10 a is located in the vicinity of the slit 9. The lens central portion 10a passes through the slit 9 to converge and diffuse light formed in a desired light distribution pattern shape in a direction orthogonal to the central axis of the cylinder, and directly passes in a direction parallel to the central axis of the cylinder. Let As a result, the light that has passed through the slit 9 is controlled to have a desired horizontal distribution size of the light distribution pattern. In addition, the width | variety of the lens center part is taken as the magnitude | size which substantially corresponds with the width L of the longitudinal direction of the LED light source 2, as shown in FIG. Further, the width of the central portion of the lens may be equal to the width L1 of the recess 8a. This is because by setting the width of the lens central portion between L1 and L, it is possible to increase the illuminance by increasing the overlap in the central portion of the light distribution pattern described later.

  The lens left side portion 10b and the lens right side portion 10c are formed symmetrically about the optical axis Ax. The lens left side portion 10b will be described, and the lens right side portion 10 is omitted because of symmetry. The lens left side portion 10b has a hemispherical shape having a flat incident surface 20 and a hemispherical left side exit surface 21b (a ¼ spherical shape that forms a hemisphere when the lens left side portion 10b and the lens right side portion 10c are combined. The entrance surface and the exit surface are connected without a step so as to be a surface continuous with the lens central portion 10a. Therefore, the exit surface 21 is a connected exit surface in which the left side exit surface 21b, the center exit surface 21a, and the right side exit surface 21c are smoothly continuous. The radius of the hemispherical shape is generally set to [(projection lens width-L (lens center width)) / 2]. The focal point of the lens left side portion 10 b is located in the vicinity of the slit 9. The left side portion 10b controls the light passing through the slit 9 and having a desired light distribution pattern shape to diffuse in the horizontal direction, which is the same as the longitudinal direction of the slit 9. As a result, the light that has passed through the slit 9 is controlled to have a desired horizontal distribution size of the light distribution pattern. The exit surface may be divided into a plurality of sections to form a diffusion surface.

  Next, the light distribution pattern will be described. First, the light distribution pattern of Patent Document 1 will be described. In the illumination optical module of Patent Document 1, the light emitted from the LED light source 2 travels as indicated by an arrow in FIG. FIG. 6 illustrates a light distribution pattern of Patent Document 1. In Patent Document 1, in the control of the size of the light distribution pattern in the left-right direction, as shown in FIG. 6, the width W in the left-right direction is distributed to the region A only by the light source area formed by the slit 9 when combined with a normal convex lens. Although not, the light distribution is controlled up to the region B by the function of horizontal diffusion when combined with the lens 10. In the vertical direction, the projection light is projected forward with parallel rays by a pure objective lens effect, and the light is distributed at the same height T as that of a normal convex lens. As a result, the light distribution has a desired shape and size, and has a good sharpness distribution without a blurring of the outline that causes a gentle illuminance distribution slope to the left and right.

  Next, the light distribution pattern in the case of the present embodiment will be described. Also in the case of the present embodiment, the light emitted from the LED light source 2 in FIGS. 4A and 5 proceeds as indicated by the arrow. Since the shape of the lens left side portion 10b and the right side portion 10c is not different from that of Patent Document 1, the shape and size are the same as in FIG. 6, and there is no outline blurring that causes a gentle illuminance distribution slope to the left and right. The light distribution is good. Since the lens central portion 10a is provided, the lens shifts to the left or right.

  In the present embodiment, there is a lens central portion 10a. For this reason, the light emitted from the width corresponding to L1 proceeds without converging in the longitudinal direction of the LED light source 2. The arrows in FIG. 5 schematically indicate direct light from the LED chip. A light distribution pattern passing through the lens center portion 10a and the lens left side portion 10b is denoted by P1, and a light distribution pattern in which light from the LED chip similarly passes through the lens center portion 10a and the lens right side portion 10c is denoted as P2. The light distribution patterns P1 and P2 are formed to overlap each other. At this time, in the overlapped region P3, light from all the regions of the lens central portion 10a, the lens left side portion 10b, and the lens right side portion 10c overlap, and the maximum illuminance at the center portion is increased. Can be high. In FIG. 5, the overlapping of the light distribution patterns P1 and P2 is illustrated as being shifted up and down for easy understanding, but in actuality, it is a combined light distribution pattern in which a part overlaps without shifting up and down. .

  Further, in the illumination optical module 1 according to the present invention, when the light is controlled by using the reflector, the deviation of the incident angle is further doubled by the addition of the emission angle, so that the position of the LED light source 2 and the slit 9 is displaced. Even if it occurs, the deviation of the irradiated position is controlled to 1 / refractive index because it is controlled by the lens refraction phenomenon, and light is correctly irradiated into a desired irradiation region without high assembly accuracy.

  Next, the illumination optical module 1 configured as described above will be described. FIG. 6 is a perspective view showing a light distribution pattern by the LED illumination optical module, and FIG. 7 is a perspective view showing a dental surgical light.

  As shown in FIG. 7, a plurality of the surgical lamps 12 are attached to the outer peripheral portion of the casing 13. The housing 13 includes a plurality of planes 14 aiming at a predetermined angle. The illumination optical module 1 has a housing 13 with its optical axis directed toward the center of an arc having a radius of the predetermined distance so that light is distributed in a desired irradiation area on a screen at a predetermined distance. Is attached to the flat surface 14 of the outer periphery of the. As a result, a plurality of light distributions by the plurality of illumination optical modules 1 are irradiated in a desired irradiation region S as shown in FIG. 6 to obtain a desired illuminance. The predetermined distance is the distance to the patient's mouth in the case of a surgical light for dentistry.

  Next, the operation of the surgical light 12 will be described in detail. In the present embodiment, a surgical light for dentistry using an LED light source as the surgical light 12 will be described as an example. In this embodiment, a surgical light for dentistry is described as an example. However, the illumination optical module of the present invention can be used for illumination used for various precision operations and the like, and is particularly limited thereto. Not.

  As shown in FIG. 1, the surgical light 12 includes an illumination optical module 1 including an LED light source 2, a guide mask member 3, and a projection lens 4. A part of the light emitted from the LED light source 2 is blocked by the slit 9 formed in the guide mask member 3, and is formed into a desired light distribution pattern shape. The light that has passed through the slit 9 is diffused in the horizontal direction by the lens 10 of the projection lens 4 and controlled to have a desired light distribution pattern size in the left-right direction.

  In the LED light source 2, an LED device 6 is attached on a base plate 5, and the LED device 6 is covered with a mold resin 8 a containing a phosphor 8 around the LED chip 7. The LED chip 7 and the resin mold 8a are provided in a circular recess provided in the outer frame 8b. In the present embodiment, the light emission size, that is, the size in the longitudinal direction of the recess is 3 mm to 4 mm, and the size in the short direction. 2 mm to 3 mm is used.

  Subsequently, a plurality of illumination optical modules 1 including the LED light source 2, the guide mask member 3, and the projection lens 4 are attached to the outer periphery of the housing 13 shown in FIG. To do. In the case of a surgical light for dentistry, the illumination optical module 1 is attached at an angle so that the optical axis is directed to the center of an arc having a radius of 700 mm.

  At this time, for example, when the light emission size is a circle of φ4, if the shape of the slit 9 of the guide mask member 3 is a rectangle with a vertical height of 1.8 mm and a horizontal width of 4 mm, the vertical height of the light distributed by the lens 10 is the focal point. If the slit 9 has a rectangular shape with a vertical height of 1.6 mm and a horizontal width of 4 mm, the vertical height of the distributed light is 70 mm.

  When the light is emitted as φ4 without using the slit 9, the vertical height of the distributed light is 180 mm, and the light enters the patient's eyes. By controlling, the vertical height of the light distribution pattern is controlled. In the case of a rectangular light source of 4 mm (horizontal direction) × 3 mm (vertical direction), the vertical height is 135 mm, which is smaller than 180 mm. In order to solve the problem of vertical height without using the guide mask member 3, it is necessary to increase the focal length by at least twice, which increases the depth of the surgical light and increases the size of the front view. The size of the shadow lamp increases, and the advantage of using the LED light source 2 as a compact shadowless lamp decreases.

  Since the slit 9 is formed so that the light distribution pattern by the illumination optical module 1 is smaller than the desired light distribution pattern, the slit 9 exceeds the desired irradiation area even if the mounting angle accuracy of the plane 14 is not high. There is no.

  The focal length F of the lens 10 is 10 mm, the thickness is 10 mm, and the width of the central portion of the lens is 2 mm. At this time, a horizontally long light distribution pattern with a height of 70 mm was obtained on a screen 700 mm ahead, and the maximum illuminance when the lens central portion was not provided was 2100 Lx. On the other hand, when the central portion of the lens is provided, even when the same light source is used, it becomes 2800 Lx, which can be improved by 30%. In addition, the lens incident area is increased by 8% even when the lens central portion is provided. Thus, higher illuminance can be obtained from a limited light emitting area.

  Moreover, since the illumination optical module 1 is controlled by the lens refraction phenomenon even when the position of the LED light source 2 or the slit 9 is displaced, the displacement of the irradiation position is suppressed as compared with the case where the light is controlled using the reflection of the reflector. Even if there is no high assembly accuracy, light is correctly irradiated into a desired irradiation region. As a result, light does not enter the patient's eyes, and the patient does not feel uncomfortable.

  For example, when the light emitting area of the LED device 6 is 6.4 mm 2 and the luminous flux is 80 lm (1.1 W), the number of the lighting optical modules 1 attached is 10 illumination optical modules 1 (total power consumption 11 W), Illuminance equivalent to a surgical light using a 55 W halogen bulb as a light source was obtained. As a result, the surgical light 12 of the present invention has a power consumption of 55 W to 11 W, which is 80% power saving.

  As described above, according to the illumination optical module 1 according to the present invention, the guide mask member that matches the desired light distribution pattern shape and the projection lens that diffuses in the horizontal direction can be used correctly without high assembly accuracy and mounting accuracy. It is possible to provide an LED illumination optical module and an LED illumination lamp that emit light within a desired irradiation area, and has a necessary illuminance and has a sharp outline without blurring.

  The above embodiment is merely an example in all respects. The present invention is not construed as being limited to these descriptions. For example, the guide mask may be formed integrally with the base plate. The present invention can be implemented in various other forms without departing from the spirit or main features thereof.

  The present invention can be applied not only to a dental surgical light but also to a surgical light for other purposes, and also to a local lighting device such as a spotlight, a product sample illumination lamp, or a garden light.

DESCRIPTION OF SYMBOLS 1 Optical module for surgical lamps 2 LED light source 3 Guide mask member 4 Projection lens 5 Base plate 6 LED device 7 LED chip 8 Resin mold 9 Slit 10 Lens 11 Lens holder 12 Surgical lamp 13 Case 14 Plane 20 Incident surface 21 Emission surface

Claims (4)

An LED light source, a guide mask member provided with a horizontally long slit through which light emitted from the LED light source passes, and a projection lens whose focal point is located near the slit,
The LED light source has an LED element, a reflection wall provided around the LED element, and a mold layer that covers the LED element, and has a horizontally long rectangular shape with a flat emission surface of the LED light source,
The projection lens includes an incident surface facing the LED light source, and a concatenated exit surface composed of a cylindrical center exit surface and spherical exit surfaces on both sides of the center exit surface,
The optical module for LED illumination, wherein the longitudinal direction of the LED light source, the longitudinal direction of the slit, and the central axis direction of the central exit surface are parallel.   2. The optical module for LED illumination according to claim 1, wherein a width in a longitudinal direction of an emission surface of the LED light source and a width of the central portion emission surface are the same.   3. The local portion of the illumination optical module according to claim 1 or 2, wherein a plurality of the illumination optical modules are attached to the housing at an angle so that the optical axis is directed to a center of an arc having a radius of a predetermined distance. Lighting fixture.   The local illumination lamp according to claim 3, wherein a light distribution size at the distance is smaller than a desired light distribution size.

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