JP2006123794A - Vehicle lighting device and illumination module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system for a vehicle capable of casting beams uniformly to the whole area to be illuminated even in case a comparatively wide area approximately with a diameter of 300 mm is to be illuminated in spot form. <P>SOLUTION: The lighting system 10 has an LED light source 20 and a photo-conductive member 30 to diffuse the beams cast from the LED 20, and illuminates the specified irradiation surface inside the vehicle in the spot form. The photo-conductive member 30 is formed from a material having such a structure that particulates for diffusion of light are dispersed in a resin base material approximately transparent which admits permeation of the light from the LED light source 20, and in part thereof a light condensation part 35 is formed to condense the light from the LED light source 20 onto the irradiation surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle illumination device that illuminates, for example, the interior of a vehicle in a spot shape, and an illumination module for a vehicle including the vehicle illumination device.

  In many cases, a lighting device for in-vehicle lighting is disposed on the interior ceiling of an automobile, and the types of lighting devices are classified into an indirect lighting type and a direct lighting type. Alternatively, a module obtained by combining them is also known, and this is sometimes called an “illumination module”.

  Here, the indirect illumination is for illuminating a relatively wide area in the vehicle, and is used, for example, when a passenger gets on and off. On the other hand, direct illumination illuminates a relatively narrow range in a spot shape, and is used, for example, when an occupant views a map in a vehicle. Such a direct illumination type illumination device is sometimes called a “map lamp” because of its function.

As a direct illumination type illumination device, a configuration having a light source and a light guide member for scattering (diffusing) light from the light source is generally used. The light source may be, for example, an LED (light emitting diode), and the LED has advantages that it can be driven with power saving compared to a light bulb, has a small amount of heat generation, and is advantageous for downsizing. The light guide member may be, for example, a resin molded product having a textured surface, and an illumination device including such a light guide member is also disclosed in Patent Document 1, for example.
Japanese Patent No. 3271445

  By the way, in the direct illumination type illumination device, the illumination range on the irradiation surface set so as to be located in the vicinity of a passenger (for example, a driver) is often set to have a diameter of about 300 mm. This is because it is assumed that the occupant can see, for example, an A4 size map well throughout. Further, in this type of lighting device, it is desirable that “irradiance unevenness (luminance unevenness)” and “color unevenness” in the illumination range are small and uniform illumination can be performed so that a passenger can visually recognize fine characters and figures.

  However, when trying to illuminate a relatively wide range with a diameter of about 300 mm, it is difficult to illuminate the entire range uniformly so that the area near the center is bright, but becomes darker toward the periphery of the illumination range. there were. In practical use of the lighting device, regarding “color unevenness”, the value in the XYZ color system (also referred to as “CIE1964 auxiliary standard color system”) falls within the range of ± 0.015 with respect to the illumination range of 300 mm in diameter. In terms of “irradiance unevenness”, it is desirable that the difference in illuminance is within a range of about ± 20 lux with respect to the illumination range having a diameter of 300 mm.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a vehicle lighting device and an illumination module capable of uniformly irradiating the entire illumination range even when a relatively wide illumination range having a diameter of about 300 mm is illuminated in a spot shape. There is to do.

  In order to achieve the above object, an illumination device for a vehicle of the present invention includes an LED light source and a light guide member that scatters light emitted from the LED light source, and an irradiation surface set at a predetermined position inside the vehicle. The light guide member is made of a material in which light scattering microparticles are dispersed in a substantially transparent resin base material that transmits light from the LED light source, A condensing part for condensing the light from the LED light source toward the irradiation surface is formed in a part thereof. Note that the “predetermined position” inside the vehicle where the irradiation surface is set is a position near the occupant's hand in the case of an automobile, for example.

  According to the vehicle illumination device of the present invention configured as described above, the light from the LED light source is scattered by the fine particles when passing through the light guide member, and thus is emitted from the light guide member in a uniform state. To do. On the other hand, the light from the LED light source is condensed by the condensing part, and the present invention performs the light condensing action by the condensing part and the light scattering action by the fine particles. It is a combination. According to the vehicle lighting device having such a configuration, for example, by changing the proportion of fine particles dispersed in the resin base material and the shape of the light collecting portion according to the characteristics of the LED light source to be used, the entire illumination range can be obtained. Can be uniformly irradiated.

  The vehicle illumination device of the present invention may include a plurality of LED light sources, and the light guide member may include a plurality of light collecting portions corresponding to each of the LED light sources. In this case, it is preferable that the plurality of LED light sources are arranged so that the optical axes of the respective LED light sources do not intersect with each other on the irradiation surface (so as not to overlap each other).

  More specifically, the condensing part is formed in a convex lens shape, and the lens thickness is preferably 4.0 to 8.0 mm, and the focal length is preferably 630 to 720 mm. Moreover, it is preferable that the distance between a LED light source and a light guide member is 0.5-3.0 mm. As the LED light source, a white LED having a chromaticity range of x = 0.264 to 0.296 and y = 0.248 to 0.305 in the XYZ color system can be used. .

  In addition, the present invention is applicable to an illumination module that is used by being attached to the ceiling of an automobile.

  As described above, according to the vehicle lighting device and the illumination module of the present invention, the light from the LED light source is scattered and collected by passing through the condensing part of the light guide member in which fine particles are dispersed. Since it comprised, even when it is a case where the comparatively wide illumination range about 300 mm in diameter is illuminated in the spot form, the whole illumination range can be irradiated uniformly.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal cross-sectional view showing an illumination module for an automobile ceiling part in which the illumination device of the present invention is partially provided. FIG. 2 is a plan view of the illumination module of FIG. 1 viewed from the lower surface side. FIG. 3 is an exploded perspective view for explaining the configuration of the illumination module of FIG.

  As shown in FIG. 1, the illumination module 50 is attached to the ceiling 41 of the automobile to illuminate the interior of the automobile, and is formed in a long contour shape extending in the front-rear direction of the automobile (lateral direction in FIG. 1). Has been. A central portion 55 is formed at approximately the center in the longitudinal direction of the illumination module 50. In the present embodiment, the illumination module 50 is disposed so that the central portion 55 is located substantially above the occupant 60. Note that an occupant 60 shown in FIG. 1 represents an occupant (for example, a driver) who sits in the front seat of the vehicle.

  The illumination module 50 includes a front illumination device 10 and a rear illumination device 11 with a central portion 55 interposed therebetween, and both of these illumination devices 10 and 11 are direct illumination type (spot type) illuminations. The structure is almost the same. As shown in FIG. 2, the front side illumination device 10 is provided with two types, one for illuminating the driver's seat side and the other for illuminating the passenger's seat side. The rear illumination device 11 irradiates the rear seat side, and two are provided in the same manner as the front illumination device 10. In addition, although the main characteristic part of this invention is the structure of the illuminating devices 10 and 11, the detailed structure shall be later mentioned with reference to other drawings. Moreover, since the illuminating devices 10 and 11 have substantially the same configuration, in the following description, only one of the front illuminating devices 10 will be described as a representative example as necessary.

  As shown in FIG. 3, the illumination module 50 includes a housing upper 51 for attaching the entire illumination module 50 to the ceiling 41 of the automobile, a light guide member 30 that functions as a light guide plate for the lighting devices 10 and 11, and a light guide. And a housing lower 52 for holding the member 30.

  Although not illustrated in detail, the housing upper 51 has a shape that allows a predetermined space to be formed between the housing upper 51 and the light guide member 30, and the LED light source 20 used in the lighting devices 10 and 11 in this space. Etc. are arranged. The housing lower 52 is formed in a contour shape corresponding to the housing upper 51, and is configured to be attached to the housing upper 51 via an engaging claw. A long opening 52a is opened at the center of the housing lower 52, and the light guide member 30 is exposed from the opening 52a when assembled (see FIG. 2). The light guide member 30 is held so as to be sandwiched between the housing upper 51 and the housing lower 52, and the contour shape of the opening 52 a is such that the light guide member 30 does not fall off. It is smaller than the contour shape.

  The light guide member 30 has a circular portion 33 formed at a position corresponding to the central portion 55 of the illumination module 50, and plate-like portions 32 a and 32 b extend from both sides of the circular portion 33. The plate-like portion 32a is a portion extending toward the front side of the automobile, and the lighting device 10 is provided at the front end side thereof, while the plate-like portion 32b is a portion extending toward the rear side, A lighting device 11 is provided on the distal end side.

  The light guide member 30 may be a resin molded product in which the plate-like portions 32a and 32b and the circular portion 33 are integrally formed, but the plate-like portions 32a and 32b and the circular portion 33 are separate members. It may be configured. Moreover, as a shaping | molding method, injection molding and cast molding can be utilized, It is preferable that the plate | board thickness part (32a, 32b) plate | board thickness (average plate | board thickness) is 4.0-8.0 mm. The light scattering ability improves as the plate thickness increases. However, if the plate thickness is too thick, the light transmittance may decrease and the illuminance may be insufficient. It is desirable to set appropriately according to the illuminance.

  Next, the illumination device 10 will be described in more detail with reference to FIGS. 4 and 5. 4 is an enlarged perspective view of a part of the light guide member as viewed from the upper surface side, and FIG. 5 is a cross-sectional view taken along the line AA of FIG. As described above, there are two lighting devices 10 for the driver's seat side and for the passenger seat side, and only one of them will be described.

  As shown in FIG. 4, the illuminating device 10 is comprised by the light guide member 30 mentioned above and the three LED light sources 20 arrange | positioned in a line along the AA line as a light source.

  Each LED light source 20 is disposed on a substrate 22, and each substrate 22 is held by a holding member (not shown) made of, for example, a resin molded product. This holding member is attached to the housing upper 51, whereby the LED light source 20 and the substrate 22 are fixed to the housing upper 51 via the holding member. In addition, in the illuminating device 10, each LED light source 20 is hold | maintained with each independent board | substrate 22, However, You may arrange | position three LED light sources 20 on one board | substrate.

  In detail, the LED light source 20 is divided into LED light sources 20a, 20b, and 20c as shown in FIG. 5A, and these three LED light sources have their main optical axes 2a, 2b, and 2c (hereinafter, referred to as “light source”). They are arranged at a predetermined arrangement pitch so that they are simply called “main optical axis 2”. In FIG. 1, the three main optical axes 2 are illustrated as intersecting at one point on the irradiation surface 3, but do not actually intersect. If the optical axes intersect each other, the light from each LED light source 20 is concentrated too much at one point, and as a result, for example, uneven illuminance often increases. Therefore, in practice, it is preferable that the main optical axes 2 a to 2 c of the LED light sources 20 do not intersect each other on the irradiation surface 3. In addition, the configuration of the present embodiment in which the main optical axes 2a to 2c are substantially parallel as described above, and the configuration in which the main optical axes intersect at one point on the irradiation surface (the main optical axes are relatively large angles). The configuration of the present embodiment can obtain uniform illumination characteristics over a wider range in the direction along the main optical axis. The reason for this is that, in the case of the present embodiment, the main optical axes 2a to 2c are substantially parallel to each other, and therefore the position where the map or the like is actually viewed (actual irradiation surface) is slightly deviated from the preset irradiation surface 3. This is because the lighting characteristics do not change greatly. Thus, it is preferable that the illuminating device 10 can illuminate uniformly over a relatively wide range in the main optical axis direction because the occupant 60 does not need to perform special alignment or the like when viewing a map or the like. .

  In the configuration of FIG. 5, the main optical axes 2a to 2c intersect with a vertical axis (not shown) at an inclination angle of about 30 °. The LED light source 20 may be a white LED, for example, and its color characteristics are in the range of x = 0.290 to 0.300 and y = 0.290 to 0.305 in the XYZ color system. It is preferable that the light intensity is in the range of 7000 to 15000 mcd.

  A light condensing part 35a for condensing the light emitted from each LED toward the irradiation surface 3 corresponding to each of the LED light sources 20a, 20b, 20c on the plate-like part 32a of the light guide member 30. , 35b, 35c (hereinafter, also simply referred to as “light collecting portion 35”) are partially formed. Thus, since the condensing part 35 of this embodiment is formed integrally with the light guide member 30, the material of the light guide member 30 itself becomes the material of the light condensing part 35. Thus, providing the condensing part 35 integrally in a part of the light guide member 30 is, for example, compared with a method of attaching the condensing part provided as a separate member to the light guide member in a subsequent process. Although it is preferable in that the number of steps can be reduced, the present invention is not limited to this. In short, it is important that the light condensing part 35 for condensing the light from the LED light source 20 is provided, and various modifications can be made to the peripheral structure of the light converging part 35, such as the mounting structure of the light condensing part 35. It is.

  The material of the condensing part 35, in other words, the material of the light guide member 30 is made of fine particles for scattering light on a base material made of a substantially transparent acrylic resin or polycarbonate resin that transmits light from the LED light source 20. It is dispersed. These fine particles are, for example, spherical silicone resins having a diameter of about 2 to 100 μm, and are dispersed at a ratio of 0.02 to 0.06% by weight with respect to the base material. When light having a visible wavelength of about 400 to 800 nm is incident on the base material in which the fine particles are dispersed in this way, the light is reflected by the fine particles in the base material and causes light scattering (Mie scattering phenomenon). Therefore, the light from the LED light source 20 having a relatively strong light directivity can be effectively scattered.

  The shape of the condensing part 35 is the light emission characteristic of the LED light source 20, the condensing characteristic required for the condensing part 35, the positional relationship between the condensing part 35 and the light source 20, and the distance to the hand of the occupant 60 (that is, The distance to the irradiation surface 3) is set. In this embodiment, the condensing part 35 has a convex lens shape having an entrance surface 36 and an exit surface 37, and both the entrance surface 36 and the exit surface 37 are convex and curved surfaces that are mirror-finished. Yes.

More specifically, the curvature of the entrance surface 36 and the exit surface 37 is suitable to have a focal length of 650 to 700 ± 20 mm in consideration of the distance to the hand of the occupant 60. The thickness of the light collecting portion 35 of the main optical axis in two directions (lens thickness) t ₃₅ is preferably 4.0～8.0Mm. It is preferable that the diameter of the condensing part 35, that is, the diameter of the condensing part 35 when projected on a plane orthogonal to the main optical axis 2 is 5.0 to 10.0 mm. The distance L ₁ between the LED light source 20 and the condensing unit 35 is preferably 0.5 to 3.0 mm.

  When the light condensing part 35 is not formed on the light guide member 30, that is, when light from the LED light source 20 is incident on a simple plate-shaped light guide member, the position of the LED light source 20 is too close to the light guide member. (Especially about 2 mm or less), only the portion where the LED light source 20 is arranged is locally brightened when viewed from the occupant 60 side, and there is a possibility that the appearance is degraded. On the other hand, it is possible to cope with this by moving the position of the LED light source 20 away from the light guide member, but this causes the illumination module 50 to be enlarged. Therefore, using the light collecting unit 35 as in the present embodiment is advantageous in that the illumination module 50 can be reduced in size.

  In addition, it is preferable to arrange | position the light-shielding material (not shown) which consists of sheet | seat materials, such as aluminum foil, for example, and the site | part of the condensing part 35 was hollowed on the upper surface of the light guide member 30 by this. Light is prevented from leaking from a region other than the light condensing part 35 in the member 30.

  Next, operation | movement of this illuminating device 10 comprised as mentioned above is demonstrated. First, when the occupant 60 presses a switch (not shown), the LED light source 20 of the lighting device 10 is turned on. The light emitted from the LED light source 20 enters the light collecting portion 35 of the light guide member 30. The light incident on the condensing unit 35 is scattered by being reflected by the fine particles dispersed in the condensing unit 35, and together with this, the irradiation surface 3 (see FIG. 1) is illuminated in a spot shape.

Hereinafter, the present invention will be specifically described with reference to examples.
(Example)
In this example, the lighting device 10 was manufactured under the following conditions.
(1) Light guide member base resin: Acrylic resin (Mitsubishi Rayon Co., Ltd.)
Microparticles: Silicone resin particles (manufactured by GE Toshiba Silicone), average particle size = 4.5 μm, dispersion concentration = 0.04 wt%.
Condensing part shape: outer diameter = φ6.5 mm, thickness t ₃₅ = 6.9 mm, focal length = 710 mm
(2) Light source LED
Type: White LED (manufactured by Nichia Corporation, model name “NSPW500BS”)
[Chromaticity range (x = 0.264 to 0.296, y = 0.248 to 0.305), luminous intensity = 11000 mcd, emission spectrum = 400 to 800 nm]
Peripheral structure: arrangement pitch = 15 mm, distance L ₁ between the light source and the condensing part = 1.0 mm, converging diameter of the optical axis of the three light source LED = within 10 mm, distance from the condensing part to the irradiation surface = 710 mm
In addition, "the convergence diameter of the optical axis of 3 light source LED" here means the diameter of the range in which each main optical axis 2a-2c of an LED light source is settled in an irradiation surface.
(Comparative example)
As a comparative example, a lighting device was manufactured using a light guide member in which fine particles for light scattering were not dispersed.
(1) Light guide member base resin: Acrylic resin (Mitsubishi Rayon Co., Ltd.)
Fine particles: None Condensing part shape: Same as in the above example (outer diameter = φ6.5 mm, thickness t ₃₅ = 6.9 mm, focal length = 710 mm)
(2) Light source LED
The type and peripheral structure are the same as in the above embodiment.

(Measuring method)
The lighting devices of Examples and Comparative Examples produced as described above were arranged on the ceiling 41 of the automobile, and the automobile (5-seat sedan type passenger car) was placed in a dark room. With the illumination device turned on, chromaticity measurement (XYZ system) and illuminance measurement were performed within the 300 mm diameter range at the position of the irradiated surface. For measurement of chromaticity (XYZ system) and measurement of illuminance, a measuring device manufactured by Konica Minolta, Inc., a color illuminometer CL-200 was used.

(Measurement results and evaluation)
FIG. 6 shows an evaluation graph of color unevenness in Examples and Comparative Examples. As can be seen from FIG.
(1) Value variation in Example x coordinate system: 0.290 to 0.300 (maximum difference Δ = 0.010)
Value variation in the y coordinate system: 0.290 to 0.305 (maximum difference Δ = 0.015)
(2) Value variation in comparative example x coordinate system: 0.288 to 0.303 (maximum difference Δ = 0.015)
Value variation in y coordinate system: 0.283 to 0.307 (maximum difference Δ = 0.020)
Thus, the illumination device of this example had a smaller chromaticity difference (color unevenness) than that of the comparative example. Further, although not shown in numerical values, in the comparative example, discontinuous color irregularities, linear patterns, and the like were confirmed.

Next, FIG. 7 shows an illuminance unevenness evaluation graph of the example and the comparative example. As can be seen from FIG.
(1) Illuminance of Examples: 10.1 to 31.2 lux (maximum difference Δ = 21.1)
(2) Illuminance of comparative example: 7.3 to 51.2 lux (maximum difference Δ = 43.9)
And the illumination device of an Example had the illuminance nonuniformity in the measurement range of an irradiation surface small compared with the thing of a comparative example. On the other hand, in the comparative example, the illuminance near the center, which is in the vicinity of the optical axis, is partially increased, while the illuminance is greatly decreased toward the periphery, and the illuminance unevenness is increased. Moreover, it was confirmed that such a result was similarly obtained when the distance from the condensing part 35 to the irradiation surface 3 was within the range of 630-720 mm. This means that the map is well illuminated even if the position of the map seen by the occupant 60 deviates somewhat from the preset irradiation surface 3.

  According to the illuminating device of the present embodiment as described above, the irradiation color is within a measurement range having a diameter of 300 mm centered on the optical axis 2 within the irradiation surface that is 630 to 720 mm away from the light collecting unit 35. XYZ color system with x = 0.290 to 0.300, y = 0.290 to 0.305, variation within ± 0.015, good irradiation characteristics with small “color unevenness” Could get. Also, the illuminance in the same measurement range is in the range of 10.0 to 40.0 lux, and the variation is within about ± 20 lux, and good irradiation characteristics with small “irradiance unevenness” can be obtained. .

  As described above, the present invention has been described by taking the illumination module 50 and the illumination devices 10 and 11 provided therein as examples. However, the present invention is not limited thereto and can be variously modified. For example, the illumination module may not have two illumination devices 10 and 11 respectively, and may have only one illumination device 10 that illuminates the driver's seat side, for example. Moreover, the shape of the condensing part 35 can also be changed as needed, for example, one surface may be convex and the other surface may be planar or concave. And the shape of the three condensing parts 35a-35c may be the same, and may differ according to the position arrange | positioned. Moreover, in the illuminating device 10, if necessary, you may comprise so that only one or two of the three LED light sources 20 can be selectively lighted.

It is a longitudinal cross-sectional view which shows the illumination module of the motor vehicle ceiling part in which the illuminating device of this invention was provided partially. It is the top view which looked at the illumination module of FIG. 1 from the lower surface side. It is a disassembled perspective view for demonstrating the structure of the illumination module of FIG. It is the expansion perspective view which looked at a part of light guide member from the upper surface side. It is sectional drawing in the AA cut line of FIG. It is a figure which shows the evaluation graph of the color nonuniformity of an Example and a comparative example. It is a figure which shows the evaluation graph of the illumination intensity nonuniformity of an Example and a comparative example.

Explanation of symbols

2, 2a, 2b, 2c Main optical axis 3 Irradiation surface 10, 11 Illumination device 20, 20a, 20b, 20c LED light source 22 Substrate 30 Light guide member 32a, 32b Plate portion 33 Circular portion 35, 35a, 35b, 35c Light part 36 Incident surface 37 Output surface 50 Illumination module 51 Housing upper 52 Housing lower 52a Opening 55 Central part 60 Crew

Claims (7)

A vehicle illumination device that has an LED light source and a light guide member that scatters light emitted from the LED light source, and illuminates an irradiation surface set at a predetermined position inside the vehicle in a spot shape,
The light guide member is made of a material in which fine particles for light scattering are dispersed in a substantially transparent resin base material that transmits light from the LED light source, and a part of the light guide member is irradiated with the light from the LED light source. An illumination device for a vehicle in which a condensing part for condensing light toward a surface is formed.   2. The vehicle illumination device according to claim 1, wherein a plurality of the LED light sources are provided, and the light guide member includes a plurality of the light collecting portions corresponding to the LED light sources.   The vehicle illumination device according to claim 2, wherein the plurality of LED light sources are arranged so that optical axes of the respective LED light sources do not intersect each other on the irradiation surface.   4. The vehicle illumination according to claim 1, wherein the condensing part is formed in a convex lens shape, the lens thickness is 4.0 to 8.0 mm, and the focal length is 630 to 720 mm. apparatus.   The vehicle illumination device according to any one of claims 1 to 4, wherein a distance between the LED light source and the light guide member is 0.5 to 3.0 mm.   The LED light source is a white LED and has a chromaticity range of x = 0.264 to 0.296 and y = 0.248 to 0.305 in an XYZ color system. The vehicle lighting device according to claim 1. An illumination module that has one or more vehicle lighting devices according to any one of claims 1 to 6 and is used by being attached to a ceiling portion of an automobile.

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