JPH11176229A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance efficiency of light. SOLUTION: A lighting system is composed of a lamp 1 which emits parallel beams of light having a small light quantity in the central part compared with the peripheral zone of the region to be illuminated and a light deflecting member 2 equipped with a refracting surface to which parallel beams from the lamp 1 are fed, which deflects the light from the peripheral zone to the central part of the optical axis, and emits as parallel beams in the specified position. The arrangement further includes an optical means equipped with a plurality of slopes which can deflect the beams incident from the lamp 1 to the specified direction and whose angles of inclination are set to respective values, wherein the arrangement of the optical means is such that the beams of light from the lamp deflected by the slopes are synthesized in the specified space so as to form a virtual light emission surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device.

[0002]

2. Description of the Related Art FIG. 6 is a schematic diagram showing an example of the configuration of an optical system of a single-panel type color filterless liquid crystal projector. The lamp 40 is, for example, a parabolic reflector 4.
0a, and reflects the light emitted from the light emitting unit 40b forward. Although not shown, it is also known to use a lamp having an elliptical reflector, for example, and to arrange light collecting means such as a condenser lens in front of the lamp to collect light. The light beam (RGB) emitted from the lamp 40 is converted into parallel light by the light condensing system 41, and is separated into RGB colors by the color separation unit 43. The light deflection system 41 will be described later in detail with reference to FIG.

The color separation section 43 is composed of a dichroic mirror 43R that reflects only red light, a dichroic mirror 43G that reflects only green light, and a dichroic mirror 43B that reflects only blue light. About 4 horizontally
They are arranged with an angle of about 5 °. Each dichroic mirror 43 (R, G, B) is arranged with a predetermined tilt angle δ so as to diverge and emit in the same direction as a horizontal line of an image formed by a liquid crystal panel described later. Each color light reflected here is emitted at an angle of divergence of 2δ to perform color separation.

[0004] Each color light (R, R,
G, B) are, for example, about 4
The light is reflected by a total reflection mirror 44 arranged at an angle of 5 ° and is incident on a liquid crystal panel section 48 including, for example, a polarizing plate 45, a liquid crystal panel 46, a polarizing plate 47, and the like. The liquid crystal panel 46 drives a liquid crystal forming a pixel by a driving signal supplied from a path (not shown), and
The light modulation is performed by controlling the transmission of each color light incident through the reference numeral 5. Then, the light beams of the respective colors RGB modulated by the liquid crystal panel unit 48 are magnified by the projection lens 49 via the polarizing plate 47 and projected on a screen 50 hung on a wall or the like, for example. The total reflection mirror 44 is not necessarily required in the illustrated configuration because it is arranged in consideration of miniaturization of the optical system. Therefore, the color separation unit 43
It is also possible to configure so that each color light separated by the above is directly incident on the liquid crystal panel unit 48.

Here, the configuration of the liquid crystal panel 46 and the optical paths of the RGB color lights will be described with reference to the schematic diagram of FIG. On the incident surface of the liquid crystal panel 46, for example, a TFT (Thin Film Trangist) for driving a liquid crystal to correspond to a high definition panel is provided.
er) A microlens array 62 in which microlenses 62a, 62a, 62a,... is formed in a counter substrate of the substrate, that is, in a stage preceding the liquid crystal unit 61. The RGB light beams condensed by the microlens 62a are light-modulated by the liquid crystal unit 61, and are subjected to black matrixes 63 and 6.
The light is emitted from the pixels P which are the gaps of 3, 63... To form an image. Note that, in this figure, as an example, each color light of RGB that is incident on one micro lens 62a is shown. The distance F indicates the focal length (principal point to focal point) of the micro lens 62a, and the distance d indicates the distance from the principal point of the micro lens 62a to the emission portion of the pixel.

The R light (broken line) separated by the color separation unit 43,
G light (solid line) and B light (dashed line) are 2δ
The light enters the microlens 62a at an angle of?, And is condensed and emitted to the pixel P corresponding to the microlens 62a. That is, although not shown, each micro lens 62a, 62a, 62a.
When the light, the G light, and the B light enter, the R, G, and B color lights are condensed and combined for one pixel P, respectively. Therefore, a color image can be formed without having to provide a color filter on the liquid crystal panel 46.

As described above, by providing the microlens array 62 in front of the liquid crystal unit 61, the light collection efficiency can be increased, and the effective aperture ratio can be improved by reducing the absorptivity when no color filter is used. Is achieved.

[0008]

By the way, the lamp 40
The light emitting unit 40a itself has an electrode (tube axis) direction,
That is, it has a characteristic of emitting light having a directivity substantially in the shape of a figure 8 in the lateral direction of the electrode without emitting light in the emission direction of light from the lamp 40. Further, since the holding member of the light emitting unit 40a is fixed by making a hole in the central part of the reflector 40b, when it is desired to extract the emitted light within a specified angle, when the lamp 40 is viewed from the front, the light There is a problem that the center portion is in a hollow state (a donut shape). Therefore, the light deflection system 41 shown in FIG. 8 is provided to solve these problems. FIG. 8 shows only the lamp 40, the light deflection system 41, and the liquid crystal panel unit 48.

The lamp 40 emits light with the incident end face of the glass rod 51 as a converging point. The light condensed on this incident end face and incident on the glass rod 51 is
The light is made uniform by the internal reflection inside the glass rod 51 and is emitted from the emission end face. Thereby, the emission end face of the glass rod 51 can be set as a virtual light emitting point. The light having the emission end face as a virtual light emission point serving as a diffusion surface light source is enlarged and projected by a collimating lens 52 including, for example, a plurality of lenses. Then, on the image plane of the collimating lens 52, (image plane−
By arranging the Fresnel lens sheet 53 having a focal length of (the exit pupil position), the luminous flux in which the principal ray is parallel and in the angular range represented by the exit pupil diameter ÷ (image plane-exit pupil position) = tan θ ⁻¹ Can be formed.

However, the light deflection system 41 can effectively use the light of the lamp 40, but has a large number of parts and
There is a problem that the mechanism is complicated and costly. Also,
Since the light of the lamp 40 is condensed on the glass rod 51, the incident end face of the glass rod 51 is heated, and there is a problem that the heating causes cloudiness and the coating is burned.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a light-emitting lamp capable of emitting parallel light having a smaller amount of light in a central portion than in a peripheral portion in an illumination area. An optical system having a refraction surface capable of receiving parallel light from the light-emitting lamp, deflecting light from the peripheral portion toward a central portion of an optical axis, and emitting the parallel light at a predetermined position. The lighting device is constituted by the means.

Also, a light-emitting lamp capable of emitting parallel light having a smaller amount of light at a central portion thereof than at a peripheral portion in an illumination area, and light incident from the light-emitting lamp can be deflected in a predetermined direction. An optical unit having a plurality of inclined surfaces each having an inclined angle set therein, wherein the optical unit combines light of the light-emitting lamp deflected by the plurality of inclined surfaces in a predetermined space to generate a virtual light; The lighting device is configured so that a light emitting surface can be formed.

According to the present invention, the number of components can be realized, and the light in the peripheral portion of the lamp can be moved to the central portion having a small amount of light and emitted as parallel light. Also,
Since the virtual light emitting surface can be formed in the space, the heating of the optical element can be suppressed.

[0014]

Embodiments of the present invention will be described below. FIG. 1 illustrates a configuration example of a lighting device according to the first embodiment. Note that the lighting device shown in this drawing will be described as being applied to the display device described with reference to FIG. Therefore, the liquid crystal panel unit 3 is provided with the liquid crystal panel unit 48 described with reference to FIG.
It corresponds to. The lamp 1 includes a reflector 1a, a light emitting unit 1
b so that parallel light can be emitted from the opening. A light deflecting member 2 is provided in front of the lamp 1.
Is arranged. The light deflecting member 2 is formed in a substantially V-shape by a transparent member such as glass, for example, and is arranged such that a mountain side faces the lamp 1 and a vertex on the mountain side corresponds to an arrangement position of the light emitting unit 1b. . And lamp 1
Is deflected inward due to refraction at the time of incidence on the light deflecting member 2, and further converted into parallel light again by refraction at the time of emission, and then emitted.

That is, the light deflecting member 2 corresponds to the light deflecting system 41 shown in FIG. 8, and by arranging the light deflecting member 2, light near the center of the lamp 1 is emitted by the light emitting section 1.
The light can be emitted as parallel light having an optical path corresponding to the arrangement position of b (the central portion of the lamp 1). This allows
The central part can be illuminated using the light of the peripheral part. As described above, in the lighting device of the present embodiment, by arranging the light deflecting member 2, the light of the lamp 1 can be effectively used with a smaller number of components than in the related art.

Next, a modification of the first embodiment will be described with reference to FIGS. FIG. 2 is a diagram illustrating a configuration example of an illumination device configured to include a light collecting member 10 and a light deflecting member 11 as a modification. The condensing member 10 has an outer periphery having the same diameter as the opening of the reflector 1a, and has, for example, concentric slope portions 10a and 10b inclined outward on the incident side.
10c and 10d are formed, and the emission side is constituted by a plane. A plane portion 10e is formed in the central portion on the incident side,
This part is arranged so as to face the central part of the lamp 1.

The light deflecting member 11 has, for example, concentric inclined surfaces 11a, 11b, 11 inclined inward on the incident side.
c and 11d are formed, and the emission side is flat. On the incident side, the vertices of the valleys formed by the slopes 11 b and 11 c are arranged so as to face the center of the lamp 1. Further, since the emission area of the light deflecting member 11 is formed to have a size corresponding to the illuminated area of the liquid crystal panel section 3, for example, when the area of the illuminated area of the liquid crystal panel section 3 is smaller than the opening of the lamp 1. However, efficient illumination can be performed.

Next, an optical path in the light collecting member 10 and the light deflecting member 11 will be described with reference to FIG. The parallel light from the lamp 1 is first transmitted to the slope 10 (a, b, c,
The light is incident on d), deflected inward and emitted. Light collecting member 1
The light emitted after being deflected by 0 is the slope 1 of the light deflecting member 11.
1 (a, b, c, d), is converted into parallel light again, and emitted. In this case, for example, light incident on the incident portion 10ar indicated by hatching is the slope portion 11b.
Light incident on the wall of the lamp 1 and incident on the incident portion 10br is emitted from the wall of the inclined portion 11b and cannot be used. However, light at the peripheral portion of the lamp 1 is collected at the central portion of the illumination area. Therefore, it is possible to emit efficient light from the light deflecting member 11 according to the illumination area.

As described above, in the modified example, the number of parts is larger than that of the example shown in FIG.
The light deflecting member 11 can be configured to be thinner, and the same light collecting effect can be obtained. Also, by reducing the thickness, the recycling time (cooling time) in the manufacturing process can be shortened.
It is possible to improve productivity.

Next, a second embodiment of the present invention will be described. FIG. 4 is a diagram illustrating a configuration of a lighting device according to the second embodiment. The collimating lens 2 shown in FIG.
5. The Fresnel lens sheet 26 corresponds to the collimator lens 52 and the Fresnel lens sheet 53 shown in FIG.

A light-collecting member 20 (fly-eye shape) having a plurality of inclined surfaces 21a, 21b,. By condensing the light and combining the light in a space, a virtual light emitting surface 23 with less unevenness in light amount is formed. In addition,
The central portion 22 of the light condensing member 20, that is, the position corresponding to the light-emitting portion 1 and the incident surface of the collimator lens 25 in the lamp 1 has a planar shape without any inclination.

FIG. 5 shows the light exit surface of the light collector 20 when viewed from the front. The outer periphery of the light collecting member 20 is, for example, circular, corresponding to the opening of the lamp 1. Each slope 21 has a similar shape to the aspect ratio of the liquid crystal panel, and is arranged, for example, in a square on the emission surface. Further, the emission surface of each slope portion 21 is configured to have such an inclination that the light of the lamp 1 can be collected at a position corresponding to the virtual light emitting surface 23 as described in FIG. . Therefore, the condensing member 20 is configured such that a plurality of prisms are gathered except for the central portion 22 thereof.

The virtual light emitting surface 23 formed by the light condensing member 20 is formed so as to have a width corresponding to the emission surface of the slope 21. Therefore, the slope 21 is formed in a shape capable of forming a desired virtual light emitting surface 23. Although the virtual light emitting surface 23 corresponds to the end face on the emission side of the glass rod 51 shown in FIG. 8, since it is an aerial image, there is no generation of bias in heat generation for a specific optical element.

The aerial image as the virtual light emitting surface 23 is enlarged and projected by the collimator lens 25 shown in FIG. 4, and the image plane of the collimator lens 25 has (image plane-exit pupil position).
By arranging the Fresnel lens sheet 26 having a focal length of と, a principal ray is formed in parallel, and a luminous flux in an angle range represented by an exit pupil diameter 面 (image plane-exit pupil position) = tan θ ⁻¹ is formed. Will be able to

By arranging such a condensing member 20 in front of the lamp 1, the light of the lamp 1 can be refracted at a predetermined angle by the slope 21 corresponding to the incident portion and emitted. It is possible to form the virtual light emitting surface 23 with less light quantity unevenness in the space.

In the lighting device according to the second embodiment,
In the illumination area of the lamp, the central portion having a small light amount is also illuminated, so that efficient illumination can be performed. Further, since the virtual light emitting surface 23 is formed in the space, the virtual light emitting surface 23 is effective for an optical system using a glass rod, and can reduce heating of the optical element.
This makes it possible to suppress clouding of the optical element and burning of the coating caused by heating. According to the first and second embodiments, a light beam with excellent parallelism can be obtained. Therefore, even when applied to a color filterless liquid crystal projector, the light use efficiency can be improved. become able to.

[0027]

As described above, according to the present invention, the number of parts is realized in the conventional glass rod type optical system, and the light in the peripheral portion of the lamp is moved to the central portion where the light amount is small. It can be emitted as parallel light.
Therefore, it is possible to obtain a light beam with little unevenness in light amount and excellent in parallelism, and it is possible to improve light use efficiency.
In addition, since the virtual light emitting surface can be formed in the space, the heating of the optical element can be suppressed, and problems such as clouding and burning of the coating can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a lighting device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration example of a lighting device as a modification of the first embodiment.

FIG. 3 is a diagram illustrating an optical path of a light condensing member and a light deflecting member of the illumination device shown in FIG.

FIG. 4 is a diagram illustrating a configuration example of a lighting device according to a second embodiment of the present invention.

FIG. 5 is a front view of a light collecting member of the illumination device according to the second embodiment.

FIG. 6 is a diagram illustrating a configuration example of a display device including a conventional lighting device.

7 is a diagram illustrating a configuration of the liquid crystal panel illustrated in FIG. 6 and an optical path of RGB light.

FIG. 8 is a diagram illustrating a configuration of a light deflection system shown in FIG.

[Explanation of symbols]

1 lamp, 1a reflector, 1b light emitting part, 2, 1
1 light deflecting member, 3 liquid crystal panel portion, 10, 20 light collecting member, 10a, 10b, 10c, 10d, 11a, 11
b, 11c, 11d, 21a, 21b, 21c, 21
d, 21e, 21f, 21g, 21h, 21i, 21j
Bevel, 23 virtual light emitting surface, 25 collimating lens, 26 Fresnel lens sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03B 21/14 G03B 21/14 A

Claims (2)

[Claims] 1. A light-emitting lamp capable of emitting parallel light having a smaller amount of light at a central portion thereof than at a peripheral portion in an illumination area, and light from the peripheral portion receiving parallel light from the light-emitting lamp. The illumination device is formed by optical means having a refraction surface capable of deflecting light toward a central portion of an optical axis and emitting parallel light at a predetermined position. 2. A light-emitting lamp capable of emitting parallel light having a smaller amount of light at a central portion than at a peripheral portion in an illumination area, and light incident from the light-emitting lamp can be deflected in a predetermined direction. An optical unit having a plurality of inclined surfaces each having an inclined angle set, wherein the optical unit combines light of the light-emitting lamp deflected by the plurality of inclined surfaces in a predetermined space. A lighting device characterized in that the lighting device is configured to be able to form a virtual light emitting surface.