JP2004325829A - Illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminator which provides bright and well balanced illumination. <P>SOLUTION: The illuminator is provided with a meter display panel (a display panel)4, point shaped light sources 8 and dimming plates 6 which are used to adjust the light beams from the light sources 8 to the panel 4 side. A plurality of prism sections P are provided on a back surface section 61 of the dimming plate 6. The prism section P has a top section T and a pair of side sections S1 and S2 which are crossed at the section T and the sections P are continuously provided in a concentric circular manner using the light source 8 as a reference. In the prism section P, a fictitious line XL is defined as a line which goes through the top section T and is extended to the plate thickness direction of the dimming plate 6. A tilt angle with respect to the reference line XL of the side section S2 located at a further side from the light source 8 among the pair of side sections S1 and S2 is set to be larger as it moves further from the point light source 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a lighting device such as an instrument device mounted on, for example, an automobile, a motorcycle, an agricultural machine, a construction machine, a ship, and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this type of lighting device, those described in Patent Documents 1 and 2 below are known. The illuminating device described in Patent Literature 1 illuminates an instrument display panel with backlight by a point light source disposed directly below the instrument display panel, and a translucent dimming is provided between the instrument display panel and the light source. A member is arranged, and dimming printing is performed on a dimming member area close to the light source to adjust light reaching the instrument display panel, thereby suppressing illumination unevenness. On the other hand, the lighting device described in Patent Literature 2 arranges a light guide plate behind an instrument display panel, arranges a light source at a side end of the light guide plate, and illuminates the instrument display panel with side lights. V-grooves having different formation densities according to the distance from the light source are formed in the light guide plate, and illumination unevenness is suppressed by increasing the luminance of an area far from the light source.
[0003]
[Patent Document 1]
JP-A-2002-137654
[Patent Document 2]
JP 2000-180632 A
[Problems to be solved by the invention]
However, the backlight illumination type illumination device described in Patent Document 1 attempts to make the illumination uniform by dimming printing on the light source, but sets dimming printing to match the transmitted light amount in a region far from the light source. In addition, since the overall transmitted light amount is leveled, there is a problem that the overall transmitted light amount is apt to be reduced even though the illumination uniformity can be increased. In addition, the sidelight type illumination device described in Patent Document 2 has a configuration in which light from the light source is taken in from the side end portion of the light guide plate, so that only a part of the irradiation light emitted from the light source can be effectively used, and in particular, is far from the light source. There is a problem that it is difficult to secure the amount of light in the area, and there is a limit to how to deal with the V-groove or the like.
[0006]
In view of the above, the present invention provides a lighting device capable of performing bright and well-balanced lighting in order to address the above-described problem.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a display panel, a point light source disposed behind the display panel, and a light source disposed behind the display panel so as to cover a front side of the light source. A light-adjusting plate for adjusting light from the light source to the display panel side, the light-adjusting plate introducing light from the light source, and a light introduced from the rear surface to the display plate side. A plurality of prism portions having a front portion, a back portion, a top portion, and a pair of sides intersecting at the top portion, the plurality of prism portions being provided concentrically with respect to the light source. When an imaginary line extending through the light control plate in the thickness direction of the light control plate is used as a reference, an inclination angle of a side portion of the pair of side portions located closer to the light source with respect to the reference line moves away from the light source. According to Characterized in that it is set to be hear.
[0008]
Further, the invention is characterized in that the prism portion is continuously formed on a plate material made of a synthetic resin.
Further, the present invention is characterized in that a reflector is provided behind the light control plate to reflect light from the light source toward the light control plate.
[0010]
Further, the invention is characterized in that a plurality of the light sources are arranged, and a plurality of the prism units are provided based on each of the light sources.
[0011]
Also, the present invention is an instrument display panel panel having an index portion corresponding to a pointer on which the display panel rotates, wherein the plurality of light sources are arranged in an arc shape with reference to the rotation center of the pointer. I do.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an instrument device serving as a lighting device according to the present invention will be described with reference to the drawings. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a front view of an instrument device, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is applied to the instrument device of FIG. It is principal part sectional drawing (hatching is abbreviate | omitted) of a light control plate.
[0013]
As shown in FIGS. 1 and 2, the instrument device according to the present embodiment includes a circuit board 1, a driving device 2, a frame 3, an instrument display panel (display panel) 4, a pointer 5, and light control. A plate 6.
[0014]
The circuit board 1 is a rigid circuit board, and is provided with point light sources 7 and 8 made of, for example, light-emitting diodes for illuminating the instrument display panel 4 and the pointer 5 from behind at the front.
[0015]
The drive device 2 is mounted behind the circuit board 1, and the drive shaft 21 extends forward through the circuit board 1.
[0016]
The frame 3 is made of, for example, a white synthetic resin having a high light reflectance, is disposed on the front side of the circuit board 1, and supports the instrument display panel 4 from behind.
[0017]
The frame 3 is formed in a cylindrical shape surrounding the light source 7, a light guide portion 31 for guiding the light from the light source 7 to the hands 5, and a conical surface surrounding the light source 8. And a reflection portion 32 for guiding the light to the instrument display panel 4 side.
[0018]
In addition, the frame 3 supports the light control plate 6, and at this time, the light control plate 6 is arranged so as to close the open end side of the reflection portion 32.
[0019]
The instrument display panel 4 prints, on a substrate 40 made of a light-transmitting synthetic resin, a scale 41 to be indicated by the pointer 5, an index portion 41 made up of numerals, and a ground portion 42 constituting the background of the index portion 41. Formed.
[0020]
In the case of the present embodiment, the index portion 41 is formed by printing using a translucent ink (for example, white), and the ground portion is formed by using a light-shielding ink (for example, black). The light indicator 41 emits light.
[0021]
The pointer 5 includes a pointing part 51 made of a translucent resin and a light-shielding cover 52 covering a required part of the pointing part, and a driving device whose rotation center part extends through the light guiding part 31 of the frame 3. 2 drive shaft 21.
[0022]
The instruction unit 51 receives light from the light source 7 from the center of rotation and emits light linearly.
[0023]
The light control plate 6 is made of a substantially colorless and transparent light-transmitting synthetic resin, and is arranged so as to cover the front of the light source 8 and the open end side of the reflection portion 32.
[0024]
The dimming plate 6 is formed as a donut-shaped flat plate having a rear portion 61 for introducing light from the light source 8 and a front portion 62 for emitting light introduced from the rear portion 61 to the display plate 4 side. This adjusts the light traveling from 8 to the instrument display panel 4 side.
[0025]
The front portion 61 is formed as a substantially smooth surface, but a plurality of prism portions P having a triangular cross section having a top portion T and a pair of sides S1 and S2 intersecting at the top portion T are formed on the back portion 62. Have been.
[0026]
These prism portions P are continuously formed so as to concentrically spread with respect to each light source 8 so as to match the light emission characteristics of the point light source 8 which spreads conically around the light emission center axis (light emission point). As shown in FIG. 3, the prism portions P are formed at a predetermined pitch such that the height of the projection from the back surface portion 62 and the depth of the valley connecting the adjacent prism portions P are equal to each other. With reference to a virtual line XL extending in the thickness direction of the light control plate 6 (direction perpendicular to the plane direction of the light control plate 6) through T, each side S1, S2 with respect to this virtual line XL Are set as follows.
[0027]
That is, the prism part P located around the light source 8 has a tilt angle θa of the side S1 located closer to the light source 8 with respect to the reference line XL, and the reference line XL of the side S2 located farther from the light source 8. Are set to be different from each other, and the tilt angle θb of the side portion S2 is set to be different for each prism portion P according to the distance between the light source 8 and the prism portion P. The inclination angle θb of the side portion S2 is set to gradually increase as the distance from the light source 8 increases.
[0028]
For example, in FIG. 3, the prism part P included in the group G1 close to the light source 8 has the inclination angle θb of the side S2 set to about 30 degrees, and is included in the group G2 farther from the light source than the group G1. In the prism part P, the inclination angle θb of the side part S2 is set to about 35 degrees, and in the prism part P included in the group G3 farthest from the light source 8, the inclination angle θb of the side part S2 is set to about 40 degrees. ing. As a result, in the present embodiment, the inclination angle θb of the side portion S2 gradually changes over a range from 30 degrees to 40 degrees. Note that the inclination angle θa of the side portion S1 is set to a substantially constant value of about 10 degrees in all the groups G1 to G3.
[0029]
As described above, in each prism P around the light source 8, the inclination angle θb of the side portion S2 is set to gradually increase as the distance from the light source 8 increases, so that the light enters through the side portion S1 and is reflected through the side portion S2. The light to be emitted can be made closer to the direction perpendicular to the plane direction of the light control plate 6, that is, the direction of the imaginary line XL (for example, see light ray L in FIG. 3), and the amount of light reaching the instrument display panel 4 (Intensity) is increased so as to be substantially constant in the plane direction, so that bright and well-balanced light is supplied to the instrument display panel 4, and the instrument display panel 4 is efficiently and efficiently arranged in the plane direction. Illumination can be performed in a well-balanced manner.
[0030]
Further, since the reflecting portion 32 is located behind the light control plate 6, the light reflected through the light controlling plate 6 can be taken into the light controlling plate 6 again through the reflecting portion 32. The use efficiency has been improved, and efficient lighting has been realized.
[0031]
As described above, according to the present embodiment, the instrument display panel (display panel) 4, the point light source 8 disposed behind the instrument display panel 4, and the front side of the light source 8 are covered. And a light control plate 6 for adjusting light from the light source 8 to the instrument display panel 4 side, and the light control plate 6 introduces light from the light source 8. And a front part 62 for emitting light introduced from the back part 61 to the instrument display plate 4 side. The back part 61 has a pair of sides S1 and S2 intersecting the top part T and the top part T. And a plurality of prism portions P concentrically continuous with each other with respect to the light source 8. The prism portions P are based on an imaginary line XL extending through the top portion T in the thickness direction of the light control plate 6. When the distance between the pair of sides S1 and S2 is far from the light source 8 Inclination angle relative to the reference line XL of the side portion S2 which is located is by being set to be larger as the distance from the light source 8, brighter instrument display panel 4, moreover can be well-balanced illumination.
[0032]
According to the present embodiment, the prism portion P is continuously formed on the light control plate 6 which is a plate material formed by injection molding of a synthetic resin. However, the plate material serving as a base material and the plate material having the prism portion P are combined. The light control plate 6 may be configured. However, the use of a single member as in this embodiment is advantageous in terms of cost. Further, the prism portion P may be continuously formed on the back surface of the substrate 40 constituting the instrument display panel 4, or a plate material having the prism portion P may be provided. When the prism portions P are continuously formed on the back surface of the substrate 40, the printed layer on the surface functions as a display panel, and the substrate 40 functions as a light control plate.
[0033]
In addition, according to the present embodiment, by providing the reflector 32 that reflects the light from the light source 8 to the light control plate 6 side behind the light control plate 6, the illumination efficiency can be increased.
[0034]
Further, according to the present embodiment, a plurality of light sources 8 are arranged, and a plurality of prism portions P are provided based on the individual light sources 8, so that an object such as an instrument display panel having a relatively large illumination area can be used. It is advantageous for lighting.
[0035]
FIG. 4 shows a second embodiment of the present invention. In this embodiment, a rough surface 63 is provided on a front surface portion 62 of a light control plate 6 for the purpose of suppressing light near immediately above a light source 8. It is. The rough surface may be one in which a predetermined shape is regularly arranged or an irregular shape as long as the intensity in the vicinity immediately above the light source 8 can be suppressed by irregular reflection.
[0036]
With such a configuration, the intensity of light near immediately above the light source 8 can be suppressed, so that the uniformity of brightness in this portion can be increased.
[0037]
FIG. 5 shows a third embodiment of the present invention. In this embodiment, a plurality of dimming prism portions 64 are provided on the back surface portion 61 of the light control plate 6 which is opposed to a position immediately above the light source 8. The sides 64a and 64b of the dimming prism portion 64 have the same inclination angle of approximately 45 degrees with respect to the imaginary line XL, and diffuses light near immediately above the light source 8 to diffuse the light. This suppresses the portion from becoming too bright.
[0038]
With this configuration, the same advantages as in the second embodiment can be obtained.
[0039]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a lighting device that can achieve an initial object and can perform bright and well-balanced lighting.
[Brief description of the drawings]
FIG. 1 is a front view of a lighting device (instrument device) according to a first embodiment of the present invention.
FIG. 2 is a sectional view taken along line AA of FIG.
FIG. 3 is a sectional view of a main part of a light control plate applied to the embodiment.
FIG. 4 is an essential part cross-sectional view showing a second embodiment of the present invention.
FIG. 5 is an essential part cross-sectional view showing a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit board 2 Drive device 3 Frame 4 Instrument display panel (display panel)
5 Hands 6 Light control plates 7 and 8 Light source 21 Drive shaft 31 Light guide 32 Reflector 40 Substrate 41 Indicator 42 Ground 51 Indicator 52 Light-shielding cover 61 Back 62 Front 63 Rough surface 64 Light-reducing prism 64 a , 64b Each side G1 Group G2 Group G3 Group L Ray P Prism S1, S2 Side T Top XL Virtual line θa Tilt angle θb Tilt angle

Claims (5)

A display panel;
A point light source disposed behind the display panel,
A light control plate arranged behind the display panel so as to cover the front side of the light source and adjusting light reaching the display panel side from the light source;
The dimming plate has a back surface for introducing light from the light source, and a front surface for emitting light introduced from the back surface to the display plate side,
On the back surface portion, a plurality of prism portions having a top portion and a pair of side portions intersecting at the top portion and provided concentrically with respect to the light source are provided,
These prism portions are based on an imaginary line extending in the thickness direction of the light control plate through the top portion, with respect to the reference line of a side portion of the pair of side portions located on a side far from the light source. A lighting device, wherein an inclination angle is set to increase as the distance from the light source increases. The lighting device according to claim 1, wherein the prism portion is formed continuously with a plate material made of a synthetic resin. The lighting device according to claim 1, wherein a reflector is provided behind the light control plate to reflect light from the light source toward the light control plate. The lighting device according to claim 1, wherein a plurality of the light sources are arranged, and a plurality of the prism units are provided based on each of the light sources. 5. The display panel according to claim 4, wherein the display panel is an instrument display panel panel having an index portion corresponding to a rotating pointer, and the plurality of light sources are arranged in an arc based on a rotation center of the pointer. Lighting equipment.

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