JPH09106705A - Light source device and projection display device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device which can be arranged in place distant from a projection display device main body and realizes a projection display device with its high brightness and color uniformity. SOLUTION: A light source 1 is provided with a lamp 11, a reflecting mirror 12, a light refraction means 19, lenses (14a, 14b, and 14c), and a light guide 16. The emission light flux of the light refraction means 19 is incident to the light guide 16, the emitted dispersion light flux from the light guide 16 is converged by means of the lenses, and a light bulb 6 is illuminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for a projection display device for projecting an image using a light valve and a projection display device using the same.

[0002]

2. Description of the Related Art There is a projection type display device such as a video projector as a device for displaying a color image on a large screen. However, a liquid crystal projector which is advantageous in miniaturization and weight saving has been noticed in place of a CRT projector which has a large capacity and weight. Are gathering. Even in a multi-projection display device in which a plurality of screens are combined to form a large screen, it is possible to provide a compact device as a whole if the liquid crystal projector system is capable of reducing the capacity of each unit. The inventions of Japanese Patent Laid-Open No. 63-123019 and Japanese Patent Laid-Open No. 6-138386 are multi-projection devices using a liquid crystal panel, both of which are disclosed to increase the screen size and resolution by combining a plurality of projection units. Has been done.

By the way, the optical characteristics of the projection type display device using the light valve largely depend on the characteristics of the illumination optical system for illuminating the light valve, especially the characteristics of the light source. For example, a halogen lamp, a metal halide lamp, a xenon lamp, etc. are used as the light source of a liquid crystal projector, but a non-point light source is focused by a parabolic mirror, an ellipsoidal mirror, or a spherical mirror having a nearly ideal shape. Therefore, display unevenness actually occurs on the projection screen due to various illumination optical systems. Further, individual differences in efficiency, color temperature, life characteristics, etc. do not become so small that they can be ignored due to variations caused by manufacturing reasons for the lamp. In reality, uneven brightness and uneven colors deteriorate the quality of the projected image on the screen.

As a measure to solve such a problem, a liquid crystal projector using an optical fiber is disclosed in Japanese Patent Laid-Open No. 4-204.
It is disclosed in Japanese Patent No. 883. FIG. 6 is a block diagram of a conventional light source device. In the figure, 11 is a metal halide lamp, 110 is a lamp luminous body, 12 is a reflector, and 1 is a reflector.
Reference numeral 4a is a lens, 165 and 166 are connectors, 16 is an optical fiber bundle, 14b is a lens, 14c is a condenser lens, 60 and 61 are polarizing plates, 6 is a liquid crystal panel, and 8 is a projection lens.

Next, the operation will be described. The light emitted from the illumination system including the metal halide lamp 11 and the reflector 12 is condensed by the lens 14a and is incident on the optical fiber bundle 16 to which the connectors 165 and 166 are attached. The optical fiber bundle 16 is composed of a large number of elemental optical fibers, and the arrangement of the elemental optical fibers on the incident end face and the other emitting end face are rearranged without correlation. Therefore, even if the light incident on the incident end face has any brightness distribution, light having a uniform brightness distribution is emitted from the exit end face. The emitted light having a uniform luminance distribution is spread by the lens 14b and is condensed by the condenser lens 14c.
Also, the liquid crystal panel 6 having the two polarizing plates 60, 61 can be irradiated, and an image without unevenness in illuminance can be projected on the screen by using the projection lens 8.

[0006]

By the way, when a parabolic mirror or an ellipsoidal mirror is used, as shown in FIG.
It is common to set the optical axis in the longitudinal direction of 10 (in the case of a discharge lamp, the direction of the discharge arc), but when the focal point is located at the light emitter 110 of the lamp, the lamp insertion portion of these reflectors. Since the light is not reflected at the hole portion and the light is blocked by the metal halide lamp 11 itself, there occurs a phenomenon called "invisible" in which the light amount near the center of the illumination light distribution is relatively small. In this case, it means that the light of the angle component close to the optical axis of the illumination light is relatively small.

However, in an optical guide such as an optical fiber that utilizes total reflection of light due to a difference in refractive index, light is transmitted while preserving the angular distribution, so that there is a deviation in the angular distribution of the incident light, and there is a deviation in the optical axis. When the close angle component is relatively small, as shown in FIG.
Appears. FIG. 7 is a configuration diagram showing the operation of the light guide.
In the figure, 16 is a light guide, 81 is incident parallel light, and 82 is
Is emitted light, and 83 is an illumination luminous flux. When parallel light 81 inclined by a with respect to the optical axis is incident on the light guide 16, total reflection is repeated inside, and then the light is emitted at the same angle a as the incident angle. As a result, the illumination light flux 83 becomes a circular light flux whose central portion is relatively dark. This phenomenon is the same when a small-diameter optical fiber is used, which is an unavoidable problem in an optical guide that utilizes total internal reflection of light.
The technique disclosed in Japanese Unexamined Patent Publication No. 4-204883 is capable of eliminating uneven illuminance and uneven color. However, even when the element optical fibers are arranged at both ends in an uncorrelated manner, each element fiber has an angular distribution of incident light. To save the property,
In the state where the angular distribution of the incident light is uneven, as a result, there is a problem that the "middle void" cannot be avoided.

Further, in the case of a liquid crystal projector in which a plurality of screens are combined to form a multi-screen, not only the unevenness of brightness in each unit screen due to the above-mentioned "middle-out" phenomenon but also each unit is installed. The unevenness of color due to the difference in the characteristics of the light source appears remarkably, and the quality of the image is significantly deteriorated. The technique disclosed in Japanese Unexamined Patent Publication No. 6-138386 does not consider such a variation in the quality of a plurality of images due to the characteristic difference of a plurality of light sources, and one of the light source lamps is lit due to the life or the like. When it disappeared, there was a problem that part of the multi-screen was missing.

The present invention has been made to solve the above problems, and a first object is to eliminate unevenness in brightness and color due to an illumination system including a lamp, a reflector and the like. Then, a light source device that emits an illumination light flux with excellent uniformity of angle distribution characteristics is obtained. A second object is to obtain a light source device that averages variations in optical characteristics such as brightness and colors of a plurality of light sources and emits a plurality of illumination light fluxes with excellent uniformity of angle distribution characteristics. In addition, the third
The purpose of is to obtain a light source device which can be arranged at a position apart from the main body of the projection display device and facilitates temperature management and lamp replacement work.

A fourth object is to obtain a projection display device of high quality in which uneven brightness and uneven color on the projection screen are remarkably reduced. Further, a fifth object is a high-quality multi-projection display device in which variations in optical characteristics such as brightness and colors of a plurality of light sources are averaged and brightness and color unevenness and variations on a projection screen are significantly reduced. Is what you get. Further, a sixth object is to prevent a part of the screen from being lost even if the light source is turned off due to a failure of the light source or the like, and the device can be continuously used by the remaining light source. A light source device for a screen projection display device is obtained.

[0011]

In the light source device according to the present invention, the light source means, the reflection mirror means for condensing the light emitted from the light source means, and the luminous flux condensed by the reflection mirror means. A light refraction means for correcting the azimuth angle,
At least 1 for converging the light transmitted through the light refraction means
One first lens means, a light guide means, and at least one second lens means for irradiating the light valve with the light emitted from the light guide means.

Further, one or more light source means, the same number of reflection mirror means as the light source means for collecting the light emitted from each light source means, and the light source means for converging the light collected by each reflection mirror means. The same number of first lens means as
The light guide means having the same number of incident ends as the light source means and one or a plurality of emission ends, and the second number of the same number as the emission ends for substantially collimating the light emitted from the respective emission ends of the light guide means.
The lens means, the reflecting mirror means and the first lens means, and the same number of light refracting means as the light source means for correcting the azimuth angle of the incident light.

The reflecting mirror means is a spheroidal mirror, and the light source means is arranged near the first focal point position of the spheroidal mirror.

The light source means is a high pressure discharge lamp,
The light emitting portion of this high-pressure discharge lamp is arranged on the rotation axis which is separated from the first focus of the spheroidal mirror to the side of the second focus by 2 to 3 mm.

When the focal length of the parabolic surface is f and the Cartesian coordinate system is (X, Y), the reflecting mirror means:

[0016]

(Equation 2)

A curve satisfying the following conditional expression is constituted by a paraboloid of rotation orthogonal obtained by rotating around a Y axis.

The light refracting means has a cone shape and is arranged near the second focal point of the ellipsoidal mirror.

Further, the light refracting means has a cone shape and is arranged in the vicinity of the converging point position of the rotation orthogonal parabolic mirror.

The light guide means is a gel-like transparent medium,
An optical fiber filled with a liquid transparent medium, a transparent glass medium, or a transparent polymer medium in a clad material having a lower refractive index than these media, a plurality of element optical fibers bundled, and element light at an incident end and an exit end The optical fiber is composed of a bundle optical fiber in which fibers are arranged uncorrelated, an optical fiber made of a single molded plastic or molded rubber, a light-reflecting hollow light guide, or a combination thereof.

Further, the light guide means is arranged so that the exit end face position thereof does not coincide with the front focus position of the second lens means.

Further, in the projection type display device using the light source device according to the present invention, the light valve means for forming an image, the light source means for generating the illumination light of the light valve means, and the output from the light valve means. It is composed of projection lens means for transmitting projected light and enlarging and projecting an image formed on the light valve means.

Further, a plurality of light valve means for forming an image and the illumination light of the light valve means 1 are generated.
It is composed of one or a plurality of light source means and a plurality of projection lens means for transmitting the light emitted from the light valve means and enlarging and projecting the image formed on the light valve means.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION In a light source device according to an embodiment of the present invention, a light refraction means changes the azimuth angle of a light beam having a non-uniform angular distribution condensed by a reflection mirror means, and relatively. The angle component near the optical axis where the intensity is weak is reduced.

Further, by the light refracting means and the light guiding means having one or more entrance / exit ends, the light fluxes emitted from the plurality of light sources are combined to cancel the variations in the optical characteristics, and then one or more arbitrary ones are again provided. It can be separated into illumination light beams.

Further, by using a spheroidal mirror as the reflecting mirror means, the luminous flux emitted from the light source means can be condensed with high efficiency.

Further, a high pressure discharge lamp is used as the light source means, and the light emitting part of the high pressure discharge lamp is arranged at a position separated from the first focus of the spheroidal mirror to the second focus side by 2 to 3 mm, and the luminous flux emitted from the light source means is arranged. Can be condensed with high efficiency.

Further, by using a rotating orthogonal parabolic mirror as the reflecting mirror means, the light flux emitted from the light source means having a linear light emitting portion can be converged into a small focused spot.

Further, it is possible to transmit light by using optical fibers of various configurations or hollow light guides as the light guide means, or to combine and separate light fluxes emitted from an arbitrary number of light source means.

Further, by arranging the light refracting means in the shape of a cone in the vicinity of the second focus position of the reflecting mirror composed of the spheroidal mirror, among the lights having the non-uniform angle distribution condensed by the reflecting mirror, It is possible to reduce low-angle components having relatively weak intensity.

Further, by disposing the light refracting means in the shape of a cone and arranging it in the vicinity of the converging point position of the reflecting mirror composed of the rotating orthogonal parabolic mirror, the light refracting means has a non-uniform angular distribution. It is possible to reduce low-angle components of light, which have relatively weak intensity.

Further, by arranging the exit end face of the light guide means so as not to coincide with the front focal position of the second lens means, the light flux emitted from the second lens means can be made into a divergent light flux.

Further, in the projection type display device using the light source device according to the embodiment of the present invention, the light source device can be arranged at an arbitrary position apart from the projection type display device body by the light guide means. Further, the light refraction means changes the azimuth angle of the light flux having the non-uniform angle distribution collected by the reflection mirror means, and reduces the angle component near the optical axis where the intensity is relatively weak.

Further, the light guide device can be used to dispose the light source device at an arbitrary position apart from the main body of the projection type display device.
Further, the light refraction means changes the azimuth angle of the light flux having the non-uniform angle distribution collected by the reflection mirror means, and reduces the angle component near the optical axis where the intensity is relatively weak.

The present invention will be specifically described below with reference to the drawings showing the embodiments thereof. Embodiment 1 FIG. 1 is a configuration diagram of a light source device according to a first embodiment of the present invention. In the figure, 11 is a lamp, which is a white lamp such as a metal halide lamp, a xenon lamp, and a halogen lamp. Reference numeral 12 denotes a concave reflecting mirror, which is a known spheroidal mirror or a rotary orthogonal parabolic mirror (OPR) described later. Reference numeral 19 denotes a light refracting element such as a cone-shaped prism, which is arranged near the converging position of the reflecting mirror 12. Reference numerals 14a to 14c are lenses that substantially collimate or converge the light flux. Reference numeral 16 is an optical fiber bundle, and the incident end face is arranged at a position where the convergent light beam diameter from the lens 14b is minimized. The light source 1 includes a concave reflecting mirror 12, a lamp 11, a photorefractive element 19, a light guide 16 and a lens 14. The configuration after the lens 14c is the same as that of FIG. 6 showing the conventional example.

Next, the operation will be described. The light flux emitted from the lamp 11 is reflected by the reflection mirror 12 to become a convergent light flux, and is incident on the photorefractive element 19 arranged near the converging point. The divergent light flux emitted from the photorefractive element 19 is a lens 14a.
Are collimated by the lens 14b and become a convergent light beam again by the lens 14b and enter the incident end face of the light guide 16. The divergent light flux emitted from the emission end face of the light guide 16 is converted into a parallel illumination light flux again by the lens 14c, and the light valve 6 arranged behind can be efficiently illuminated.

As the above-mentioned photorefractive element 19, either a transparent glass medium or a transparent polymer medium is formed into a conical shape, and as shown at 19 in FIG. It is preferable that the conical body is arranged and used so as to be aligned with the optical axis of the cone toward the incident side. Reflection mirror 12
In the illumination optical system that condenses the light flux of the lamp using, the non-reflection portion by the circular hole for holding the lamp provided at the rear portion of the reflection mirror 12 and the angle close to the optical axis because the light flux is blocked by the lamp 11 itself. A region having a low light intensity (hatched portion in the drawing) occurs in the component, and uneven illumination of the light valve 6 occurs. By selecting the apex angle of the conical body and the refractive index of the material as in the present embodiment, the divergence angle of the light beam can be changed by utilizing the refraction effect at the interface between the photorefractive element 19 and air. . In the light source device of the present invention, it was confirmed that a region having a low light intensity with a half angle of about 10 degrees with the optical axis was removed, and a highly uniform light beam was obtained after the photorefractive element 19.

As the light guide 16, it is preferable to use a bundled optical fiber in which a large number of known small-diameter optical fibers are bundled. Since the angular distribution of the light flux incident on the light guide 16 is made uniform by the above-described photorefractive element 19, the arrangement of the element fibers at the incident end of the bundle optical fiber and the irradiated surface is rearranged uncorrelated, The intensity distribution of light on the illuminated surface can be made uniform. If the illuminance unevenness and the color unevenness are within the allowable range in the projected image on the screen (not shown), the degree of randomization of this rearrangement does not have to be perfect, and in this case, since the stress applied to the element fiber is small, Internal loss such as total reflection loss is suppressed, and highly efficient optical transmission can be performed. Further, the element fibers may have various diameters.

If the light intensity distribution can be made uniform, the light guide 16 may be formed by combining a plurality of media. Bundled optical fiber with random array, gel-like transparent medium, liquid-like transparent medium,
Light guide with a structure in which either a transparent glass medium or a transparent polymer medium is filled in a cylindrical clad material whose refractive index is lower than these media, or a light guide made of a single molded plastic or molded rubber, light reflection It is also possible to use a hybrid structure in which a light guide having a transparent hollow structure is connected to improve the transmittance as a whole.

The maximum light receiving angle of the light guide 16 is defined by the refractive index of the medium forming the light guide 16. When the convergence angle of the light beam emitted from the lens 14b is larger than the maximum light receiving angle, a negative lens (not shown) is added after the lens 14b so that the light beam can be efficiently incident on the light guide 16. It is also possible to improve the incident efficiency by applying a non-reflective coating to the incident end face and the output end face of the light guide 16.

The maximum divergence angle of the light beam emitted from the light guide 16 is also defined for the same reason as the maximum light receiving angle. The lens 14c is an N.V. lens capable of sufficiently capturing the light flux emitted from the light guide 16. A. The rough specifications are determined by the (numerical aperture) and the focal length determined by the diameter of the collimated light beam. It is known that the light valve 6 can be illuminated most efficiently by using the above-mentioned bundle optical fiber for the light guide 16 and arranging it so that the position of the emitting end face coincides with the front focal position of the lens 14c. However, in this case, it was revealed from the experiment that the array structure of the emission end face appears on the screen (not shown), and the image quality is significantly deteriorated.

The light guide 1 is placed at the front focus position of the lens 14c.
A lens 1 having a diameter such that the diameter of the illuminating light flux becomes smaller than the diagonal length of the light valve 6 when the emission end faces of 6 are arranged.
It has been clarified experimentally that the above-mentioned array structure can be removed by using 4c and arranging the emitting end face of the bundle optical fiber 16 closer to or farther from the lens 14c than the front focal position of the lens 14c. In the experiment, a metal halide lamp with an arc length of 3 mm combined with an elliptical mirror, a conical prism with a diameter of 20 mm, an element fiber diameter of 50 μm, a bundle diameter of 6 mm, and a length of 500 m.
m bundle optical fiber bundle, focal length 38.5 mm,
A condenser lens 14c having a diameter of 50 mm and a front focal length of 24.3 mm is sequentially arranged to form an illumination optical system, and has a rectangular screen area of 19.8 mm in length and 26.4 mm in width arranged at a position of 135 mm from the vertex of the condenser lens. By illuminating a simulated light valve and projecting it approximately 23 times using a projection lens, the relationship between the array structure on the projection screen and the distance between the exit end face of the optical fiber and the condenser lens was investigated.

In the case of the above construction, the optical fiber exit end face
When the distance between the condenser lenses was about 29 mm, an emission end face image having a diameter of about 470 mm was formed on the projection screen, and the array structure was confirmed. From this position, set the exit end face of the optical fiber to 1
When the condenser lens is moved closer to or farther from the condenser lens by about 0 to 20 mm, the illumination light flux from the condenser lens can sufficiently cover the rectangular screen area, and the array structure on the projection screen becomes invisible. It has also been clarified that efficient illumination can be performed by the above method when the illumination light flux diameter on the projection screen in the state where the optical fiber array structure is clearly imaged is about 70% or more of the diagonal length of the rectangular screen area. .

It is known that a spheroidal mirror is used as the reflecting mirror 12 and a lamp emission point is arranged in the vicinity of the first focus so that the emitted light of the lamp can be condensed in the vicinity of the second focus with high efficiency. In this case, it is desirable to dispose the light emitting point with a slight shift from the first focus, so that the light can be condensed more efficiently. In this light source device, the reflector 12 has an opening diameter of 66 m.
m, an elliptical mirror having a distance from the first focus to the second focus of 60 mm, and a metal halide lamp having a discharge arc length of 3 mm was used as the lamp 11, but the arc center was 2 to 3 mm from the first focus position to the second focus side. It was optimal when they were staggered.

As a modification of the reflecting mirror 12, an orthogonal parabolic mirror (Orthogonal Parabolic Mirror) is used.
A reflector (OPR) may be used. A normal parabolic mirror uses a curved surface obtained by rotating a curve whose (x, y) cross section is given by the equation (1) around the x axis when the focal length is f, as a reflecting surface. y ² = 4fx (1) On the other hand, the OPR shown in FIG. 4 uses a curved surface obtained by rotating the curves given by the equations (2) and (3) around the Y axis as a reflecting surface.

[0046]

(Equation 3)

Here, (X, Y) is (x, Y in the equation (1).
This is a Cartesian coordinate system that is translated so that the point (f, 0) of the y) coordinate is the origin. FIG. 4 is a configuration diagram of an orthogonal parabolic mirror (OPR). In the figure, 11a is a linear light source, 12 is a reflecting mirror made of OPR, and F is a focal position of OPR12. In the OPR12, the linear light source 1 is placed on the Y axis (rotation axis).
1a (for example, a discharge arc of a metal halide lamp) is arranged to have an effect of efficiently condensing a light beam emitted in a direction perpendicular to the extending direction of the linear light source 11a at one point of the focus position F. Also in the present invention, the linear arc of the discharge lamp is O.
It is desirable to arrange it on the rotation axis of PR12.

In the first embodiment described above, the case where the diameter of the light beam emitted from the light refracting element 19 is larger than the effective diameter of the light guide 16 has been described. The lenses 14a and 14b may be omitted and the light emitted from the photorefractive element 19 may be directly incident on the light guide 16 if the light receiving angle and the effective diameter thereof are necessary and sufficient.

Embodiment 2 In the first embodiment described above, the case of illuminating one light valve has been described. However, when illuminating a plurality of (n) light valves, 1: n branched light corresponding to the number of light valves is provided. It is also possible to use a guide. FIG. 2 is a configuration diagram of a light source device according to a second embodiment of the present invention, and specifically shows a configuration of the light source device when four light valves are illuminated. In the figure, 16a is a 1: 4 branched light guide,
16ab is a branching portion of the branching light guide 16a, and 14d, 14
e, 14f, 14g are lens means, 61, 62, 63,
64 is a light valve. The operation of the components having the same reference numerals as those in FIG. 1 is the same as that in FIG.

Next, the operation will be described. Light refraction means 1
The light flux emitted from 9 enters the branched light guide 16a and is split into four at the branching portion 16ab. It is desirable to separate the light guides in the branch portion 16ab into four equal parts if the light valves in the subsequent stages are the same, but it is not necessary to separate the parts into equal parts depending on the application. When an optical fiber bundle in which small-diameter optical fibers are bundled is used for the branching light guide, the above-mentioned randomization is preferably performed near the branching portion and the emitting end, but may be performed at other portions. Furthermore, it is desirable to change the degree of randomization according to the application. The light flux that has been separated and randomized in this way is branched into the light guide 16a.
The light enters the lens means 14d, 14e, 14f and 14g arranged so as to correspond to the four emission ends of.
The illumination light flux emitted from the lens means 14d, 14e, 14f, 14g illuminates the light valves 61, 62, 63, 64. The optical system after each lens means 14d, 14e, 14f, 14g is the same as that of FIG. 6 showing the conventional example.

As the medium forming the branched light guide 16a, not only the bundled optical fiber having the random arrangement described above but also a gel-like transparent medium, a liquid-like transparent medium,
A transparent glass medium or a transparent polymer medium can be used. The branched light guide 16a can be formed by using a light guide having a structure in which any one of these media is filled in a cylindrical clad material having a lower refractive index. It is of course possible to connect the plurality of light guides to form the branched light guide 16a, but in this case, it is desirable to use an optical adhesive on the connection surface in order to reduce light loss. Further, it is possible to arbitrarily change the diameter and the length of the branched light guide according to the purpose. Also, as a light guide, connect a light guide made of a single molded plastic or molded rubber, a light guide with a light-reflecting hollow structure,
It is also possible to use a hybrid structure having an improved transmittance as a whole.

Embodiment 3. 3 is a configuration diagram of a light source device according to a third embodiment of the present invention. In the figure, 11,
Reference numeral 31 denotes a lamp, which is a white lamp such as a metal halide lamp, a xenon lamp, and a halogen lamp. Also, 1
Reference numerals 2 and 22 denote concave reflecting mirrors, which are known spheroidal mirrors or rotary orthogonal parabolic mirrors (OPR). 19,
Reference numeral 29 denotes a light refracting element such as a cone-shaped prism, which is arranged near the converging position of the reflecting mirrors 12 and 22. 14
Reference numerals a, 14b, 14c, and 24a, 24b, 24c are lenses that substantially collimate or converge the light flux. 16
Is a light guide, and 161, 162 are its incident end faces, 1
Reference numerals 63 and 164 denote emission end faces thereof. The incident end faces 161 and 162 are arranged at positions where the convergent light flux diameters from the lenses 14b and 24b are minimized. Concave reflecting mirrors 12, 22, lamps 11, 31, light refracting elements 19, 2
The light source 1 is composed of 9, a light guide 16, lenses 14a, 14b, 14c, and 24a, 24b, 24c. Although the light valves 61 and 62 are illuminated by the light source 1, the configuration after the lenses 14c and 24c is similar to that of FIG. 6 showing the conventional example.

Next, the operation will be described. Lamp 11,
The light flux emitted from 31 is reflected by the reflection mirrors 12 and 22 to be a convergent light flux, and is incident on the photorefractive elements 19 and 29 arranged in the vicinity of the focal point. The divergent light beams emitted from the light refracting elements 19 and 29 are collimated by the lenses 14a and 24a, respectively.
The lenses 14b and 24b again form a convergent light beam, and the light guide 1
The light is incident on the incident end faces 161 and 162 of No. 6. Light guide 16
The divergent light fluxes emitted from the emission end faces 163 and 164 are converted into parallel illumination light fluxes by the lenses 14c and 24c, and the light valves 61 and 62 arranged in the rear can be efficiently illuminated.

In the third embodiment, the light guide 16 is a multi-branched light having a plurality of incidence surfaces corresponding to the number of lamps, a central portion where the light guides are bundled, and a plurality of emission end surfaces corresponding to the number of light valves. I am using a guide. As the material of the light guide 16, it is preferable to use a bundled optical fiber in which a large number of known small-diameter optical fibers are bundled. A sufficient distance is provided between the incident side equal division, the combination, and the emission side equal division at the central portion (coupling portion 16ab) so that the element fibers forming one emission end are gathered equally from each incident side. If the randomization of the array described in the first embodiment is performed at the exit end, the photorefractive element 19,
In addition to the effect of 29, it is possible to eliminate the color unevenness caused by the characteristic difference between the plurality of light sources.

The light guide 16 may be formed by combining a plurality of media. It is preferable to use a bundle optical fiber for equal division on the incident side, combining, and equal division on the output side in the coupling section, but even if the element optical fibers with circular cross sections are closely packed, there is no loss due to the formation of gaps. Inevitable. Therefore, only the coupling part has a multi-branching structure using a bundle optical fiber, and each branch is made of a gel transparent medium, a liquid transparent medium, a transparent glass medium, or a transparent polymer medium having a high transmittance. , A light guide with a structure filled in a cylindrical clad material with a lower refractive index than the medium, or a light guide made of a single molded plastic or molded rubber, or a light guide with a light-reflecting hollow structure, and connected as a whole. It is also possible to use a hybrid structure with an improved transmittance.

The behavior of the light beam emitted from the light guide 16 is the same as that described in the first embodiment, and detailed description thereof will be omitted. According to the configurations described in the first to third embodiments, the light source device 1 can be installed in a place apart from the projection display apparatus main body 100. FIG. 5 is a configuration diagram of a projection type display device according to a third embodiment of the present invention. In the figure, 1 is a light source device, 16 is a light guide, and 80a, 80b, 80c, 80.
Reference numeral d denotes a projection unit, which contains an optical system from the light guide 16 to the projection lens. 10 is a screen. A portion 100 surrounded by a dotted line portion is the main body of the projection display device.

As shown in FIG. 5, by making the light source device 1 independent of the projection type display device main body 100 via the light guide 16, the temperature control of the lamp (not shown) built in the light source device 1 becomes easy. Instead, when combining and re-branching with the light guide 16 using a plurality of lamps, the brightness of the entire screen is reduced even if one of the lamps does not light and needs to be replaced. However, the device can cope with a lamp failure while continuously used.

In the present embodiment, the case where the number of light sources and the number of light valves are the same has been described, but even if they are different, the number of incident ends and the number of outgoing ends of the multi-branched light guide 16 are made to correspond. It goes without saying that the same effect can be obtained. That is, one or a plurality of incident ends on the light guide 16 side and one or a plurality of emitting ends may be combined.

As described above, not only the configurations described in the first to third embodiments but also the projection type display device using a plurality of light valves can be applied by color-separating light using an optical element such as a dichroic mirror. Is. The light valve includes both a transmissive type and a reflective type, but can be applied to any of these types of illumination.

[0060]

Since the present invention is configured as described above, it has the following effects.

Since it is possible to remarkably reduce the illuminance unevenness, the color unevenness, and the non-uniformity of the angular distribution characteristic of the illumination light flux due to the light source means, the reflection mirror, etc., the light valve can be highly efficient.
And it can illuminate with high quality. Further, the light source means can be arranged at an arbitrary position without being limited to the arrangement of the light valve.

Even if there is only one light source means, it is possible to simultaneously obtain a plurality of illumination light fluxes in which variations in brightness and color are averaged, so that a plurality of light valves are illuminated with high efficiency and high quality. be able to. Further, even if there are variations in the brightness, color and angle distribution characteristics of the plurality of light source means, one or a plurality of illumination light fluxes that are uniformized can be obtained simultaneously, so that one or a plurality of light valves. Can be illuminated with high efficiency and high quality. Furthermore, even if one of the plurality of light source means is turned off, the remaining light source means can be turned on to continuously illuminate the light valve.

Further, since the spheroidal mirror can regulate the light collection efficiency by the eccentricity, it is possible to use a relatively small one, and it is possible to collect the light flux emitted from the light source means with high efficiency. .

Even if the light source means is a linear light source such as a high pressure discharge lamp, it is possible to collect light with high efficiency by using a spheroidal mirror.

Further, since the rotating orthogonal parabolic mirror can converge the emitted light flux of the lamp having the linear light emitting portion into a small condensing spot, it becomes possible to reduce the core diameter of the light guide means, and it is highly efficient. A light source device that is lightweight and inexpensive can be provided.

Further, the light refracting means can reduce the low-angle component, which is relatively weak in intensity, of the light having the non-uniform angle distribution condensed by the spheroidal mirror.
It is possible to obtain an illumination light flux having a uniform angle distribution characteristic with less unevenness in brightness and color.

Further, the light refracting means can reduce the low-angle component, which has a relatively weak intensity, of the light having the non-uniform angle distribution condensed by the rotating orthogonal parabolic mirror, so that the brightness is reduced. Therefore, it is possible to obtain an illumination light flux having a uniform angle distribution characteristic with less color unevenness.

Further, since members made of various materials can be used in combination for the light guiding means, a highly efficient light guiding means can be constructed according to the application.

Further, since the light flux emitted from the second lens means can be made into a divergent light flux, illumination unevenness due to the structural pattern of the emission end face of the light guide means can be reduced, and a high-quality illumination light flux. Can be obtained.

Further, since it is possible to remarkably reduce the unevenness of the illuminance of the luminous flux, the unevenness of color, and the nonuniformity of the angular distribution characteristic due to the light source means, the reflection mirror, etc., it is possible to obtain a projection image of high quality. A display device can be provided. Furthermore, since the light source device can be arranged separately from the projection type display device main body, the degree of freedom in the structure of the device main body increases, and not only the device can be made compact, but also the light source device Can be arranged at any place other than the container accommodating the optical system after the light guide, so that the temperature control of the light source means and the replacement of the light source means can be easily performed.

Further, it is possible to remarkably reduce the unevenness of illuminance, the unevenness of color and the unevenness of the angular distribution characteristic of the illumination light flux due to the light source means, the reflection mirror and the like, so that a plurality of high quality projected images can be obtained. A multi-screen projection display device can be provided. Furthermore, since the light source device can be arranged separately from the projection type display device main body, the degree of freedom in the structure of the device main body increases, and not only the device can be made compact, but also the light source device Can be arranged at any place other than the container accommodating the optical system after the light guide, so that the temperature control of the light source means and the replacement of the light source means can be easily performed. Further, it is possible to provide a multi-screen projection display device which can be continuously used by turning on the remaining light source means even if one of the plurality of light source means is turned off.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a light source device that is Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of a light source device that is Embodiment 2 of the present invention.

FIG. 3 is a configuration diagram of a light source device that is Embodiment 3 of the present invention.

FIG. 4 is a configuration diagram of an orthogonal parabolic mirror (OPR).

FIG. 5 is a configuration diagram of a projection display device according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a conventional light source device.

FIG. 7 is a configuration diagram showing an operation of a light guide.

[Explanation of symbols]

1 light source, 11 lamps, 12 reflection mirrors, 19 light refracting means, 14a, 14b, 14c lenses, 15 illumination luminous flux, 6 light valves.

Front page continued (72) Inventor Akira Oueto 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (11)

[Claims] 1. Light source means, reflection mirror means for collecting light emitted from the light source means, at least one first lens means for converging light collected by the reflection mirror means, and The light reflection means has a light guide means for entering and transmitting the light converged by the first lens means and at least one second lens means for substantially collimating the light emitted from the light guide means. A light source device characterized in that a light refracting means is inserted between the mirror means and the first lens means. 2. One or more light source means, as many reflection mirror means as the light source means for collecting the light emitted from each light source means, and a light source means for converging the light collected by each reflection mirror means. The same number of first lens means, a plurality of incident ends as the number of light source means, a central portion bundled into one, a light guide means having a plurality of emission ends, and from each emission end of this light guide means It has a configuration including the same number of second lens means as the emission end for making the emitted light substantially parallel, and inserts the same number of light refraction means as the light source means between the reflection mirror means and the first lens means. A light source device characterized by: 3. The light source device according to claim 1, wherein the reflection mirror means is a spheroidal mirror, and the light source is arranged near the first focal point position of the spheroidal mirror. 4. The light source means is a high pressure discharge lamp,
4. The light source device according to claim 3, wherein the light emitting portion of the high-pressure discharge lamp is arranged on the rotation axis that is separated from the first focal position of the spheroidal mirror by 2 to 3 mm toward the second focal point. 5. The reflection mirror means, where a rectangular coordinate system is (X, Y) with a focal length of a paraboloid being f, The light source device according to claim 1 or 2, wherein the light source device is a paraboloid of rotation orthogonal obtained by rotating a curve satisfying the following conditional expression about the Y axis. 6. The light refracting means has a cone shape, the reflecting mirror means is a spheroidal mirror, and the light refracting means is disposed near the second focal point position of the spheroidal mirror. The light source device according to claim 1 or 2. 7. The light refracting means has a cone shape, the reflecting mirror means is a rotation orthogonal parabolic mirror, and the light refracting means is arranged in the vicinity of the focal point of the rotation orthogonal parabolic mirror. The light source device according to claim 1 or 2, wherein 8. The light guide means comprises a gel-like transparent medium, a liquid-like transparent medium, a transparent glass medium, or a transparent polymer medium filled in a clad material having a refractive index lower than that of the medium. Any of a fiber, a bundle optical fiber in which a large number of element optical fibers are bundled and the element optical fibers at the entrance end and the exit end are arranged in a non-correlated manner, an optical fiber made of a single molded plastic or molded rubber, and a light-reflecting hollow light guide. The light source device according to claim 1 or 2, wherein the light source device is configured by one or a combination thereof. 9. The light source device according to claim 1, wherein the light guide unit is arranged so that the exit end face position thereof does not coincide with the front focus position of the second lens unit. 10. Light valve means for forming an image,
The light source means for generating the illumination light of the light valve means, and the projection lens means for transmitting the light emitted from the light valve means and enlarging and projecting the image formed on the light valve means are provided. Item 2. A projection display device, which is the light source device according to item 1. 11. A plurality of light valve means for forming an image, one or a plurality of light source means for generating illumination light of the light valve means, and a light valve means for transmitting light emitted from the light valve means. A projection display device comprising a plurality of projection lens means for enlarging and projecting the formed image, wherein the light source means is the light source device according to claim 2.