JPH11203928A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system inhibiting convective fluctuation of illumination light and illuminating brightly. SOLUTION: This lighting system 1 has a xenon lamp 10 integrated with a condensing reflector, and an illuminating means 20 for uniformizing an illumination distribution. Here, the illuminating means 20 is composed of at least a collimator lens 21 and a pair of fly eye lenses 22, 23, and a spherical aberration of the collimator lens 21 is set to be more than 0.01f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device suitable for use in, for example, a liquid crystal projector.

[0002]

2. Description of the Related Art For example, a 150 to 250 W class metal halide lamp has a luminous efficiency of 60 to 75 lm / W and is widely used in liquid crystal projectors and the like. In this metal halide lamp, a metal halide emits light in light of the principle of light emission, and therefore, high-efficiency light emission is possible. However, the size of the light emitting portion (light source) is a problem in forming an optical system. . For example, a 250 W class metal halide lamp requires a distance of about 3 mm between electrodes in consideration of life, but the size of the light emitting portion is not optically negligible along with the size of light emission of the metal halide.

[0003] A xenon lamp is known as a light source whose light emitting portion is close to a point light source. In the case of bulb-type xenon lamps, the distance between electrodes was limited and the danger of explosion was great.However, recently, with the development of a reflector-integrated xenon lamp consisting of a ceramic body, the distance between electrodes was reduced. The xenon lamp has been developed to have a long life even with a distance between the electrodes of, for example, about 1 mm.

Further, the xenon lamp integrated with a reflector has a luminous efficiency of 20 to 30 lm / W, which is less than half that of a metal halide lamp. However, in practice, even a 500 W class xenon lamp with a built-in reflector is based on xenon gas emission principle, so that the light emitting portion is very small and good light collecting characteristics can be obtained. Therefore, it was found that a brightness higher than that of a metal halide lamp was obtained as a screen light flux for a projector.

[0005]

The conventional xenon lamp integrated with a reflector has a very simple optical system because of the short distance between electrodes and light emission close to a point light source. However, xenon gas is contained in the reflector. Due to the filling, large convection of gas was generated at the time of lighting. For this reason, there is a defect that fluctuation of illumination light is largely generated on the screen.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a lighting device which can suppress convection fluctuation of illumination light and can perform bright illumination. .

[0007]

According to a first aspect of the present invention, there is provided an illuminating apparatus having a condensing type reflector-integrated xenon lamp and illuminating means for uniformizing the illuminance distribution, wherein the illuminating means is at least a collimator. The collimator lens includes a lens and a pair of fly-eye lenses, and the spherical aberration of the collimator lens is set to 0.01f or more.

According to a second aspect of the present invention, there is provided an illuminating apparatus having a condensing-type reflector-integrated xenon lamp and illuminating means for uniformizing an illuminance distribution, wherein the illuminating means has an aspect ratio of 3 to 4. Square tube with opening diagonal length of 5-10m
m, and the light pipe is arranged near the second focal point of the xenon lamp with integrated reflector.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing a lighting device according to an embodiment of the present invention. This illumination device 1 includes a condensing-type reflector-integrated xenon lamp 10 and illumination means 20 for making the illuminance distribution uniform.

As shown in FIG. 1, a reflector-integrated xenon lamp 10 includes a ceramic reflector 11 having an elliptical reflecting mirror 11a therein, and a reflector 11 made of a ceramic.
Transparent plate 12 for closing the elliptical reflecting mirror 11a
A xenon gas (xenon gas) 13 filled in a closed space between the reflector 11 and the metal conductive portion 16, and protrudes into the reflector 11 from a central opening of the ellipsoidal reflecting mirror 11 a. A metal anode 14 serving as a light emitting part, and a metal conductive part 16 serving as a light emitting part protruding into the reflector 11 from near the center of the transparent plate 12 so as to be separated from the tip of the anode 14 by a predetermined gap (for example, about 1 mm). And a metal cathode 15 connected thereto. When a current flows from the anode 14 to the cathode 15 of the xenon lamp 10 with the integrated reflector, the xenon gas 13 emits light due to the excitation of the electrodes 14 and 15, and the white light is emitted from the light emitting portion (the electrodes 14 and 15) having the first focus. (In the vicinity of 15), and once converged at the second focal point (f2) of the elliptical reflecting mirror 11a, converted into parallel light by the collimator lens 21 and irradiated to the first fly-eye lens 22 side. It has become.

As shown in FIG. 1, the illumination means 20 includes a collimator lens 21 and a pair of fly-eye lenses 22 and 2.
3 at least. The collimator lens 21 converts white light from the reflector-integrated xenon lamp 10 into parallel light, and its spherical aberration is set to 0.01f or more. Each of the fly-eye lenses 22 and 23 has a plurality of micro lenses arranged therein, and averages a luminance distribution (makes a uniform illuminance distribution).

In FIGS. 1 and 2, bright portions are indicated by oblique lines. FIG. 2A shows a collimator lens 21.
First fly-eye lens 22 when spherical aberration of lens is small
The upper illuminance portion is shown, and FIG.
6 shows an illuminance portion on the first fly-eye lens 22 when the spherical aberration of No. 1 is 0.01f or more. FIG. 3 shows the relationship between the spherical aberration of the collimator lens 21 and flicker.

According to the illuminating device 1 of the embodiment described above, considering the light-collecting characteristics of the illuminating means 20, the spherical aberration of the collimator lens 21 constituting a part of the illuminating means 20 is desired to be as small as possible. When the spherical aberration is reduced, as shown in FIG. 2A, the illuminance portion on the first fly-eye lens 22 is divided into a dark portion at the center and a bright portion around. That is, the center of the optical axis becomes dark illumination light, and the convection fluctuation of the illumination light largely occurs. Therefore, if the spherical aberration of the collimator lens 21 is increased (at least 0.01 f) within a range that does not impair the light-collecting characteristics of the illumination means 20, as shown in FIG. The dark part in the upper center becomes brighter,
The convection fluctuation of the illumination light is reduced. Thereby, the illuminance of the entire lighting device 1 can be improved, and the convection fluctuation of the illumination light of the lighting device 1 observed on the screen can be suppressed to a level without any problem.

As shown in FIG. 3, flicker can be reduced by setting the spherical aberration of the collimator lens 21 of the illuminating means 20 to 0.01f or more. Further, since the distance between the anode 14 and the cathode 15 of the xenon lamp 10 with the integrated reflector can be set to about 1 mm, the condensing spot can be made extremely small, and highly efficient illumination can be achieved.

FIG. 4 is a block diagram showing a lighting device according to another embodiment of the present invention. This illumination device 1 'includes a condensing-type reflector-integrated xenon lamp 10 and illumination means 20' for uniforming the illuminance distribution. Since the reflector-integrated xenon lamp 10 is the same as that of the illumination device 1 of the above embodiment, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIGS. 4 and 5, the illumination means 20 '
Comprises at least a light pipe 24 and a pair of convex lenses 25 and 26. This light pipe 24
Is a square tube having an aspect ratio of 3 to 4 and an opening diagonal length L of 5
The front opening is set near the second focal point f2 of the reflector-integrated xenon lamp 10.

According to the illuminating device 1 'of the embodiment described above, the lighting means 20' uses the light pipe 24 having a rectangular tube having an aspect ratio of 3: 4 and an opening diagonal length L of 5 to 10 mm. By arranging the light pipe 24 near the second focal point f2 of the xenon lamp 10 with the integrated reflector, the white light from the xenon lamp 10 with the integrated reflector can be converted into a light pipe due to the light-collecting characteristics that cannot be achieved with a conventional metal halide lamp. 24 can be effectively collected,
High-efficiency lighting becomes possible. Thereby, the convection fluctuation of the illumination light of the illumination device 1 ′ with respect to the screen can be suppressed to a level without any problem.

Also, as shown in FIG.
There is a difference in utilization efficiency due to the light-collecting characteristics between the metal halide lamp A of W and the xenon lamp B with a reflector integrated with 300 W. When a light pipe of, for example, 6 mm having an opening diagonal length L in a range of 5 to 10 mm is used, It can be seen that the usage efficiency is about six times different from the metal halide lamp. Further, when multiplied by the luminous efficiency, it can be seen that the use of the reflector-integrated xenon lamp is about two to three times brighter than the metal halide lamp.

[0020]

As described above, according to the illumination device of the first aspect of the present invention, the illumination means comprises at least a collimator lens and a pair of fly-eye lenses, and the spherical aberration of the collimator lens is reduced by 0.01 f. With the above setting, it is possible to suppress the convection fluctuation of the illumination light, reduce the lifter, and improve the illuminance.

According to the illumination device of the second aspect of the present invention, a light pipe having an aspect ratio of 3 to 4 and having a diagonal length of 5 to 10 mm is used as the illumination means. Since it is arranged near the second focal point of the integrated xenon lamp, it is possible to suppress the convection fluctuation of the illumination light, reduce the lifter, and improve the illuminance.

[Brief description of the drawings]

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

FIG. 2A is an explanatory diagram showing an illuminance portion on a first fly-eye lens when the spherical aberration of a collimator lens of the illumination device is small, and FIG. 2B is a diagram showing a spherical aberration of the collimator lens of 0.01 f or more. FIG. 4 is an explanatory diagram showing an illuminance portion on a first fly-eye lens in the case of FIG.

FIG. 3 is an explanatory diagram showing a relationship between a spherical aberration of a collimator lens and flicker in the illumination device.

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

FIG. 5 is a perspective view of a light pipe used in a lighting device according to another embodiment.

FIG. 6 is an explanatory diagram showing a relationship between a diagonal length of an opening of a light pipe and a use efficiency based on a difference in light-collecting characteristics in the illumination device according to the other embodiment.

[Explanation of symbols]

 Reference Signs List 1, 1 'lighting device 10 reflector-integrated xenon lamp 20, 20' lighting means 21 collimator lens 22, 23 pair of fly-eye lenses 24 light pipe f2 second focus L diagonal aperture of light pipe

Claims (2)

[Claims] 1. An illumination device having a condensing type reflector-integrated xenon lamp and illumination means for uniformizing the illuminance distribution, wherein the illumination means comprises at least a collimator lens and a pair of fly-eye lenses. An illumination device, wherein the spherical aberration of the collimator lens is set to 0.01f or more. 2. An illuminating device having a condensing type reflector-integrated xenon lamp and an illuminating means for uniformizing the illuminance distribution, wherein the illuminating means has a rectangular cylindrical shape having an aspect ratio of 3: 4. A light pipe having an opening diagonal length of 5 to 10 mm is used, and this light pipe is used as the second light source of the xenon lamp integrated with the reflector.
An illuminating device arranged near a focal point.