WO2005066688A1 - Illumination system - Google Patents

Abstract

An illumination system comprises a lens array (2) where a plurality of spherical surfaces (2b) of identical shape are formed continuously and directly above a line, a wiring board (3) disposed substantially in parallel with the lens array (2) at a predetermined interval, and light emitting diodes (4) respectively disposed between each spherical face (2b) of the lens array (2) and the wiring board (3) in such a manner that the optical axis k becomes substantially normal to the surface of the wiring board (3). The light emitting diodes (4) are arranged on the wiring board (3) at pitches y and z different from the pitch x for forming the spherical surfaces (2b).

Description

 Specification

 Lighting equipment

 Technical field

 The present invention relates to a lighting device for illuminating an object to be illuminated, and is suitable, for example, as a lighting device used for a head-up display for a vehicle.

 Background art

 [0002] Conventionally, a display device as shown in Fig. 7 has been known, and a liquid crystal display element 10 in which a polarizing member is adhered to the front and rear surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates, and a hard liquid crystal display. A light source 12 connected to the wiring board 11 and illuminating the liquid crystal display element 10 is provided. The display image emitted by the liquid crystal display element 10 illuminated by the light source 12 is reflected by a reflecting mirror 13 so that a windshield of a vehicle or a semi-transparent plate is provided. There is a projector such as a (reflecting plate) that projects onto the display unit 14 (for example, see Patent Document 1). Such a display device is called a head-up display.

 [0003] Such a display device has a structure in which the light is projected onto the display unit 14, so that a part of the light is transmitted at the time of this projection or an unnecessary part of the display device is illuminated. However, there is a problem that the light amount is lost. In addition, since it is necessary to project a display image with good contrast even in the daytime, it is necessary to illuminate the liquid crystal display element 10 with the light source 12 having high luminance. Therefore, there has been a demand for efficient illumination using a plurality of light sources having high directivity such as light emitting diodes.

 [0004] On the other hand, the display image projected on the display unit 14 is desired to be displayed larger and the display device is desired to be reduced in size, and a concave reflecting mirror (concave reflecting plate) is required. By using 13, the display image of the liquid crystal display element 10 was enlarged and displayed.

 Patent Document 1: JP-A-10-48565

 Disclosure of the invention

 Problems to be solved by the invention

[0005] By using a light source having a high directivity such as a powerful display device, the illumination efficiency is increased, but the illumination light with the light source intensity is concentrated and emitted in the front direction. . Therefore, when displaying a wide angle of view to project a large display image, Since the outer luminance of the display image projected on the display portion is lower than the inner luminance, there is a problem that the appearance deteriorates.

 [0006] Therefore, an object of the present invention has been made in view of the above-described problem, and it is an object of the present invention to provide an illumination device using a plurality of light sources, which can perform illumination without uneven brightness. is there.

 Means for solving the problem

[0007] As described in claim 1, the lighting device of the present invention includes a lens member having a plurality of spherical surfaces of the same shape continuously formed on a straight line or a flat surface, and a predetermined distance from the lens member. A lighting device comprising: a wiring board provided substantially in parallel; and a light source provided between each spherical surface of the lens member and the wiring board so that an optical axis is substantially perpendicular to the wiring board. The light source provided at least outside of the light sources is provided on the wiring board so that the optical axis passes inside the apex of the spherical surface.

 [0008] Further, as described in claim 2, in the lighting device according to claim 1, the spherical surfaces of the lens members are provided at evenly spaced intervals, and the light source is arranged in a uniform manner. It is characterized by being provided at an interval smaller than the interval of the spherical surface.

 [0009] Further, as described in claim 3, in the lighting device according to claim 1, the illuminated member transmitted and illuminated by the illumination light emitted through the lens member, And a magnifying member for refracting or reflecting transmitted light transmitted through the lighting member to perform enlarged display.

 [0010] Further, as described in claim 4, the lighting device of the present invention includes a lens member having a plurality of spheres of the same shape continuously formed in a straight line or a plane, and a predetermined distance from the lens member. A lighting device comprising: a wiring board provided substantially in parallel with each other at V; and a light source provided between each spherical surface of the lens member and the wiring board so that an optical axis is substantially perpendicular to the wiring board. In the apparatus, the light source is provided on the wiring substrate at a pitch different from a pitch at which the spherical surface is formed.

[0011] Furthermore, as described in claim 5, the lighting device of the present invention has a lens member having a plurality of curved surfaces continuously formed in a straight line or a plane, and a predetermined distance from the lens member and substantially flat. A lighting device comprising: a wiring board provided in a row; and a light source provided between each curved surface of the lens member and the wiring board so that an optical axis is substantially perpendicular to the wiring board. The light source is provided on the wiring substrate at a pitch different from a pitch at which the curved surface is formed.

 [0012] Also, as described in claim 6, in the lighting device according to claim 5, the lens member also has a convex shape force formed by combining at least a first curved surface and a second curved surface. It is characterized by the fact that

 The invention's effect

 The present invention can provide an illumination device that illuminates an object to be illuminated with a plurality of light sources and that can perform illumination without uneven brightness.

 Brief Description of Drawings

 FIG. 1 is a diagram showing a configuration of a head-up display mounted on a vehicle according to an embodiment of the present invention.

 FIG. 2 is a diagram showing a main configuration of a display device according to the embodiment.

 FIG. 3 is a diagram showing an illumination structure of the display device according to the embodiment.

 FIG. 4 is a diagram showing an illumination structure of the display device according to the embodiment.

 FIG. 5 is a diagram showing another example of the lighting structure.

 FIG. 6 is a diagram showing another example of a lighting structure.

 FIG. 7 is a diagram showing a conventional example.

 Explanation of symbols

[0015] 2 lens member (lens array)

 2b spherical surface

 2c vertex

 3 Wiring board

 4 Light emitting diode (light source)

 5 Liquid crystal display element (illuminated member)

 7 Concave mirror (enlarged member)

k optical axis BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, taking an example in which the present invention is applied to a display device of a vehicle head-up display for displaying a vehicle speed, an engine speed, and the like.

 FIG. 1 shows a vehicle head-up display mounted on a vehicle. This head-up display for a vehicle has a structure in which a display image projected by a display device C provided above a dashboard B of a vehicle A is reflected in a direction of an observer E by a surface of a windshield (display unit) D. Te ru. The observer E can observe the displayed image as a virtual image V, superimposed on the landscape.

 Further, the display device C according to the embodiment of the present invention is provided so as to be embedded in the upper part of the dashboard B, and will be described with reference to FIG. The display device C includes a lens array (lens member) 2, a wiring board 3, a light emitting diode (light source) 4, a liquid crystal display element (illuminated member) 5, and a cylindrical reflection member provided in a housing 1. It is mainly composed of a member 6 and a concave mirror (enlarged member) 7.

 The housing 1 is also made of a synthetic resin material having a light-shielding property, and is provided with an opening la that opens an upper portion (front glass side) of a position where the concave mirror 7 is provided. Further, in the housing 1, a light shielding wall lb is formed integrally with the housing 1 for preventing sunlight from entering a liquid crystal display element to be described later and causing a virtual image V to be seen (pushed out). The housing 1 is provided with a light-transmitting cover lc made of a light-transmitting synthetic resin material (for example, acrylic), and is provided so as to cover the opening la.

 The lens array 2 is made of a light-transmitting synthetic resin material (for example, acrylic), and is provided in the housing 1. The lens array 2 is formed by forming a plurality of similarly convex spherical surfaces, and the vertices of the spherical surfaces are provided at uniform intervals on a straight line. The lens array 2 refracts the illumination light from the light emitting diode 4 by the spherical surface, and can irradiate a uniform illumination light to a liquid crystal display element (to be described later) as a member to be illuminated.

The wiring board 3 is preferably an aluminum board having high thermal conductivity, and is provided in the housing 1 so as to be parallel to the lens array 2 at a predetermined interval. The wiring board 3 mounts at least electronic components such as the light emitting diode 4, and supplies power to the electronic components. Wiring for supplying power is provided. Note that the predetermined interval differs depending on the directivity of the light emitting diode 4 and the spherical shape of the lens array 2, and is selected such that there is less uneven brightness.

 The light emitting diode 4 can be a chip LED, and is mounted on the surface of the wiring substrate 3 on the lens array 2 side so that the optical axis is substantially perpendicular to the surface of the wiring substrate 3. The light-emitting diodes 4 have a narrow directivity (20 degrees to 30 degrees in the present embodiment), and are provided at positions corresponding to the spherical surfaces of the lens array 2.

 The liquid crystal display element 5 has a polarizing member attached to the front and rear surfaces of a liquid crystal cell in which liquid crystal is sealed in a pair of translucent substrates. The liquid crystal display element 5 is provided in the housing 1, and is provided at a position where illumination light from the light emitting diode 4 reaches via the lens array 2. The illumination light transmitted through the liquid crystal display element 5 is projected on the concave mirror 7 as a display image. The liquid crystal display element 5 includes an arithmetic circuit (not shown) that measures a vehicle speed and an engine speed based on output signals from a vehicle speed sensor and an engine rotation sensor provided in the vehicle A, and drives the liquid crystal based on the arithmetic result. The measured value of the speed of the vehicle A and the engine speed can be expressed as numerical values by a liquid crystal drive circuit (not shown).

 The cylindrical reflecting member 6 is formed of a white synthetic resin material in a cylindrical shape having both ends opened, and is provided so that one opening is closed by the liquid crystal display element 5. The cylindrical reflecting member 6 is provided so that illumination light from the light emitting diode 4 can be incident through the lens array 2 on the other opening side. Therefore, the cylindrical reflecting member 6 prevents the illumination light from the light-emitting diode 4 from being reflected by the inner wall of the cylindrical reflecting member 6 and leaking to and irradiating the liquid crystal display element 5 except for the liquid crystal display element 5. It is provided so as to condense light, and efficient illumination can be obtained.

 [0025] The concave mirror 7 is provided below the opening la in the housing 1, and reflects a display image projected through a liquid crystal display element 5, which will be described later, to the windshield D side. The concave mirror 7 is provided so that the angle can be adjusted so that the observer E can easily view the displayed image. The concave mirror 7 is formed by a reflective surface 7a having a predetermined curvature in order to display the display image on the windshield D in an enlarged manner.

Next, an illumination structure as a main part of the present invention will be described with reference to FIGS. [0027] The lens array 2 has a smooth incident surface 2a through which the illumination light from the light emitting diode 4 is incident, and a plurality of spherical surfaces 2b provided on the opposite side of the incident surface through the illumination light. The illumination light is configured to be given a desired refraction and irradiated (emitted) to the liquid crystal display element 5 side. The lens array 2 is formed by forming a plurality of similarly convex spherical surfaces 2b, and the vertices 2c of the spherical surfaces 2b are provided at uniform intervals X on a straight line. The spherical surface 2b is set according to the material (refractive index) of the lens array 2 and the distance between the light-emitting diodes 4 and the incident surface force of the lens array 2, so that the illumination light from the light-emitting diodes 4 is not uniform. The liquid crystal display element 5 is formed so as to have a curvature and a size so as to irradiate the liquid crystal display element 5 so as not to be present.

 The light emitting diode 4 is provided such that its optical axis k is substantially perpendicular to the surface of the wiring substrate 3 and the surface of the lens array 2 located parallel to the wiring substrate 3. The light emitting diodes 4 are provided corresponding to the respective spherical surfaces 2b, and are provided so that the optical axis k intersects the respective spherical surfaces 2b. As shown in FIG. 3, the light emitting diode 4 positioned outside of the plurality of light emitting diodes is provided so that the optical axis k intersects the spherical surface 2b on the center side (inside) of the vertex 2c of the spherical surface 2b. The light emitting diodes 4 are arranged at intervals smaller than the interval X of the spherical surface 2b, and in this case, the distance y, z between the optical axis k and the vertex 2c increases as the distance from the optical axis k to the outer side increases. It is provided so as to be large.

 [0029] Therefore, the illumination light of the light emitting diode 4 located on the outside has a large amount of components refracted outward (toward the end) by the corresponding spherical surface 2b. As shown in FIG. 4, a display image of uniform brightness is provided not only on the front side (inside of the reflection surface 7a) but also on the outside of the liquid crystal display element 5 with respect to the reflection surface 7a of the concave mirror 7, as shown in FIG. Can be projected.

[0030] As described in claim 1, the illumination structure of the display device includes a lens array 2 in which a plurality of spherical surfaces 2b of the same shape are continuously formed on a straight line, and a predetermined distance from the lens array 2. A light-emitting diode 4 provided between each spherical surface 2b of the lens array 2 and the wiring board 3 such that the optical axis k is substantially perpendicular to the surface of the wiring board 3; The light emitting diode 4 provided at least outside of each light emitting diode 4 is provided on the surface of the wiring board 3 so that the optical axis k passes inside the vertex 2c of the spherical surface 2b. Provide an illuminating device capable of performing illumination without uneven brightness. can do.

 Further, the spherical surfaces 2b of the lens array 2 are provided at evenly spaced intervals, and the light emitting diodes 4 are provided at smaller intervals than the intervals of the spherical surfaces 2b. With the configuration, illumination without uneven luminance can be performed.

 In addition, the above-described illumination structure includes a liquid crystal display element 5 that is transmitted and illuminated by illumination light emitted from the light emitting diode 4 via the lens array 2, and reflects transmitted light transmitted through the liquid crystal display element 5. A concave mirror 7 for enlarged display. Therefore, even when the display image is enlarged, it is possible to prevent the outer luminance of the display image from being lower than the inner luminance. It can be carried out.

 Although the lens array 2 shown in the embodiment of the present invention has been described with an example in which the incident surface 2a is smooth, the present invention is not limited to this. It may have a concave or convex surface corresponding to the position of the spherical surface. In addition, as shown in FIG. 5, the illuminating light from the light-emitting diode 40 does not irradiate to the adjacent spherical surface 20b instead of the corresponding spherical surface 20b, and has a reflecting surface that emits to the liquid crystal display element side. The lens array 20 provided with the groove 20d may be applied.

 [0034] Further, for example, by providing a lens array having a honeycomb-shaped spherical surface and arranging and arranging the light emitting diodes at positions corresponding to the lens array, the light emitting diodes can be densely provided. It can be performed. Even in this case, by applying the present invention, effects similar to those of the above-described embodiment can be obtained.

 As shown in FIG. 5, the light source 40 is provided on the wiring board 30 at a pitch larger than the pitch at which the spherical surface 20b is formed, and the illumination target (for example, a liquid crystal display element) and the lens array 20 are connected to each other. A light-transmitting light diffusion plate is provided between them. Therefore, the member to be illuminated (the liquid crystal display element) can be illuminated with more light sources, and the illumination structure has high luminance and no luminance unevenness.

Next, another embodiment will be described with reference to FIG. FIG. 6 shows a part of a lens array 21 having a lens 21a having a different shape on the emission surface side with respect to the above-described lens arrays 2 and 20, and the other configurations are the same. Detailed explanation is omitted. [0037] The lens array 21 includes convex-shaped lenses 21a having a combination of a first curved surface 21b and a second curved surface 21c. Note that the curved surface in the present embodiment is formed in a shape having a spherical or aspherical force. The lens 21a has a first curved surface 21b for obtaining the emitted light L1 condensed at a predetermined width with respect to the optical axis kl of the light emitting diode 41, and a light (illuminating the surrounding portion of the light emitted from the light emitting diode 41). A second curved surface 21c for refracting light other than the light transmitted through the first curved surface 21b to obtain the emitted light L2.

 When a lighting device using the powerful lens array 21 is used for the display device C of the head-up display for a vehicle, the display image reflected on the windshield D by the first curved surface 21b can be viewed by the observer E in frontal force. The brightness of the display image at the time of visual recognition can be increased, and the second curved surface 21c allows the observer E to position the virtual image V slightly different from the visual recognition position (the position where the virtual image V can be visually recognized well). Even if there is, the display image can be visually recognized, and a wide viewing angle can be secured.

 The display device C according to the embodiment of the present invention described above has an example in which the display image to be projected is reflected by the front glass D in the direction of the observer E. However, the display unit of the present invention may be a dashboard B that is not a windshield D, a hard reflector that is fixed to the housing 1 and provided exclusively, or a translucent reflector that is attached to the inner surface of the windshield 4. The structure may be such that the display image is reflected in the direction of the observer by a (computer).

 Further, in addition to the configuration of the present invention, a case where a concave lens is provided between the concave mirror and the liquid crystal display element or between the liquid crystal display element and the light source to enlarge the display at a larger ratio. It is also possible to prevent uneven brightness.

 In the present invention, the magnified display may be performed by refraction by the force lens, which is the one that is magnified and displayed by the concave mirror 7.

 Further, in the embodiment of the present invention, the above-described display device C has been described as an example. However, the present invention is not limited to this. Just fine. For example, the light source may be a point light source such as a bulb or a linear light source such as a cold-cathode tube as long as a plurality of light sources are provided, but the effect is great if the directivity is high.

Claims

The scope of the claims  [1] A lens member in which a plurality of spherical surfaces of the same shape are continuously formed in a straight line or a plane, a wiring substrate provided substantially in parallel with the lens member at a predetermined interval, and an optical axis in the wiring substrate A light source provided between each spherical surface of the lens member and the wiring board so as to be substantially perpendicular to the lighting device,  The illumination device, wherein the light source provided at least outside of the light sources is provided on the wiring board such that the optical axis passes inside the apex of the spherical surface.  [2] The spherical surface of the lens member is provided at intervals uniformly arranged, and the light source is provided at a smaller interval than the interval of the spherical surface. The lighting device according to the above.  [3] An illuminated member that is transmitted and illuminated by illumination light radiated through the lens member through the lens member, and an enlarged member that refracts or reflects transmitted light transmitted through the illuminated member to display the enlarged light. The lighting device according to claim 1, further comprising:  [4] A lens member in which a plurality of spherical surfaces of the same shape are continuously formed in a straight line or a plane, a wiring board provided substantially in parallel with the lens member at a predetermined interval, and an optical axis in the wiring board. A light source provided between each spherical surface of the lens member and the wiring board so as to be substantially perpendicular to the lighting device,  The lighting device, wherein the light source is provided on the wiring board at a pitch different from a pitch at which the spherical surface is formed. [5] A lens member having a plurality of curved surfaces formed continuously in a straight line or a plane, a wiring substrate provided substantially in parallel with the lens member at a predetermined interval, and an optical axis substantially perpendicular to the wiring substrate. A light source provided between each curved surface of the lens member and the wiring board so that  The lighting device according to claim 1, wherein the light source is provided on the wiring substrate at a pitch different from a pitch at which the curved surface is formed. 6. The lighting device according to claim 5, wherein the lens member has a convex shape formed by combining at least a first curved surface and a second curved surface.