JP2001013586A - Light source device, illuminator and projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device by which an area to be irradiated is efficiently illuminated with light radiated by a lamp by a small converging angle. SOLUTION: This device is provided with the lamp 21, a concave mirror 22 by which the light radiated by the lamp 21 is reflected and is converged at a small area, and a correction lens 23 arranged on the emission side of the concave mirror 22. The correction lens 23 is provided with a first lens 34 in which at least a peripheral part has positive power and a second lens 35 in which at least the peripheral part has negative power. When the radius of an emitter picture is set as H and the maximum inclination of a light beam passing through the center of the emitter picture is set as U, the light source device whose H sinU is reduced by the correction lens 23 is provided.

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 converting the directivity of light emitted from a lamp to emit convergent light,
The present invention relates to an illumination device that uniformly illuminates a predetermined irradiation area using the light source device, and a projection display device using the illumination device.

[0002]

2. Description of the Related Art In order to obtain a large-screen image, a method of forming an optical image corresponding to an image signal on a light valve, irradiating the optical image with light, and enlarging and projecting the image on a screen by a projection lens is better than the conventional method. Are known. Recently, a projection type display device using a liquid crystal panel as a light valve has attracted attention (for example, Japanese Patent Application Laid-Open No. 62-133424). As a liquid crystal panel, in order to obtain a high-quality projected image, an active matrix type in which a twisted nematic (TN) liquid crystal is used as a liquid crystal material and a TFT is provided in each pixel as a switching element is used, and red, green, and blue are used. A system using three liquid crystal panels for use is becoming mainstream.

As a light source device, an arc discharge lamp such as a metal halide lamp, an ultra-high pressure mercury lamp, and a xenon lamp is used. In order to efficiently guide the light emitted from the lamp to the light valve, a concave mirror such as an elliptical mirror or a parabolic mirror is used. In order to improve the uniformity of the illuminance of a projected image, an integrator combining two lens array plates or a rod integrator formed of a transparent quadratic prism is also combined with a light source device.

In a TFT liquid crystal panel, since a black matrix is provided to shield TFTs and wiring from light, the pixel aperture ratio (the ratio of the area of all the openings of the black matrix to the total area of the display area) is reduced. However, there is a problem that the light output of the projection display device is reduced accordingly. This problem becomes more serious as the number of pixels of the liquid crystal panel increases and the pixel density increases. In order to solve this problem, there has been proposed a method of improving the light output by disposing a lens array having one positive lens corresponding to each pixel on the incident side of the liquid crystal panel in close proximity (for example, Japanese Patent Application Laid-Open No. HEI 1-1990). No. 189,885,
JP-A-2-262185).

In a liquid crystal panel using a TN liquid crystal, it is necessary to dispose polarizing plates on the incident side and the output side. The incident side polarizing plate is used to extract linearly polarized light having a plane of polarization oriented in a predetermined direction from natural light. Since the incident side polarizing plate absorbs unnecessary polarized light components, there is a problem that the efficiency of the projection display device is low. To solve this problem, natural light emitted from the light source device is split into two linearly polarized lights by a polarization beam splitter, and the polarization direction of one of the linearly polarized lights is reduced to 1 /.
A polarization conversion optical system in which both linearly polarized lights are transmitted through the incident side polarizing plate by being rotated by 90 ° by a two-wavelength plate has been used (for example, Japanese Patent Application Laid-Open No. 8-234205).
JP-A-6-202094).

Next, as an illumination device useful for illuminating the other side of a narrow gap, there is an optical fiber illumination device using a bendable optical fiber bundle. In this configuration, the lamp is arranged so that the center of the luminous body is located at the first focal point of the ellipsoidal mirror, and the end face (incident surface) of the optical fiber bundle is located at the second focal point. Recently, metal halide lamps have been used as lamps to increase light output.

[0007]

When the above-mentioned microlens array or polarization conversion optical system is used, in order to obtain a sufficient effect of improving the efficiency, it is necessary to direct the illumination light incident on the microlens array or polarization conversion optical system. It is necessary to narrow the sex. For that purpose, it is necessary to shorten the length of the luminous body,
If the luminous body length is forcibly shortened, there is a problem that the lamp life is shortened. Further, in order to make the projection display device compact, the screen size of the liquid crystal panel is also reduced, but there is a problem that the light output is reduced.

[0008] The optical fiber lighting device is required to have a higher light output depending on the application. To further increase the output light from the optical fiber bundle, it is preferable to increase the effective diameter of the optical fiber bundle. However, this causes a problem that the minimum radius of curvature at which the optical fiber bundle can be bent becomes large.

The present invention provides a light source device that can efficiently illuminate an irradiation area with a smaller convergence angle when the irradiation area has the same size. Providing a lighting device that illuminates well,
It is another object of the present invention to provide an efficient projection display device having a large light output. It is another object of the present invention to provide an optical fiber lighting device having a large light output.

[0010]

In order to achieve the above object, the present invention has the following arrangement.

A first light source device according to the present invention includes a lamp, a concave mirror, and a correction lens, and an optical system combining the concave mirror and the correction lens is rotationally symmetric about an optical axis. Two reference points on the optical axis having a property such that all light rays emitted from one reference point, reflected by the concave mirror, and transmitted through the correction lens pass at or near the second reference point. The lamp is disposed such that a central axis of the light emitter substantially coincides with the optical axis, and a center of the light emitter substantially coincides with the first reference point. The radius of the luminous body image formed at the reference point 2 is H, the maximum inclination angle of the light beam passing through the center of the luminous body image is U, and the luminous body is formed corresponding to the luminous body in a configuration in which the correction lens is removed. The position where the radius of the illuminant image is minimum is the image point. Te, said image point H ₀ of the radius of the luminous body images formed, when the angle of the open end and connecting it straight and said image point and the optical axis of the concave mirror and U _0, and the concave mirror The correction lens is configured to satisfy the following expression.

[0012]

(Equation 4)

In the first light source device, a lamp having a longer luminous body length than the luminous body diameter can be used as the lamp.

In the first light source device, it is preferable that the concave mirror is an ellipsoidal mirror, and the first reference point is located at a first focus of the ellipsoidal mirror or in the vicinity thereof.

Alternatively, in the first light source device,
The reflecting surface of the concave mirror may be a rotating body deformed on the basis of a spheroid, and the first reference point may be located at a first focus of the spheroid or in the vicinity thereof.

In the first light source device, at least one lens surface of at least one of the lenses constituting the correction lens may be aspheric.

A second light source device according to the present invention includes a lamp, a concave mirror, and a correction lens, and an optical system in which the concave mirror and the correction lens are combined is rotationally symmetric about an optical axis. Two reference points on the optical axis having a property such that all light rays emitted from one reference point, reflected by the concave mirror, and transmitted through the correction lens pass at or near the second reference point. The lamp is disposed such that a central axis of the light emitter substantially coincides with the optical axis, and a center of the light emitter substantially coincides with the first reference point. The correction lens is formed at a second reference point and the first lens and the second lens are sequentially arranged from the concave mirror side.
Wherein the first lens has a positive power at least at a peripheral portion thereof, and the second lens has a negative power at least at a peripheral portion thereof.

In the second light source device, a lamp having a longer luminous body length than the luminous body diameter can be used as the lamp.

In the second light source device, it is preferable that the concave mirror is an elliptical mirror and the first reference point is located at the first focal point of the elliptical mirror or in the vicinity thereof.

Alternatively, the reflecting surface of the concave mirror may be a rotating body deformed on the basis of a spheroid, and the first reference point may be located at the first focal point of the spheroid or in the vicinity thereof.

In these cases, the focal length of the first lens is f _I and the focal length of the second lens is f _{I I.}

[0022]

(Equation 5)

(Equation 6)

It is desirable to satisfy the following.

In the second light source device, it is preferable that the first lens has a convex surface at least at the peripheral portion of the exit side surface, and the second lens has a concave surface at least at the peripheral portion of the entrance side surface. Further, the exit side surface of the second lens may be formed as an aspheric surface such that the central portion is convex and the peripheral portion is concave.

Further, a third lens having a positive power can be arranged on the exit side of the second lens.

A third light source device according to the present invention includes a lamp, a concave mirror, and a correction lens, and an optical system combining the concave mirror and the correction lens is rotationally symmetric about an optical axis. Two reference points on the optical axis having a property such that all light rays emitted from one reference point, reflected by the concave mirror, and transmitted through the correction lens pass at or near the second reference point. The lamp is arranged such that a central axis of the light emitter substantially coincides with the optical axis, and a center of the light emitter substantially coincides with the first reference point; The range of the ray height of the ray emitted from both ends at the second reference point is the ray at the position where the radius of the illuminant image formed corresponding to the illuminant in the configuration in which the correction lens is removed is the minimum. All smaller than the high range And it features.

In the third light source device, a lamp having a long luminous body length with respect to the luminous body diameter can be used as the lamp.

In the third light source device, it is preferable that the concave mirror is an elliptical mirror and the first reference point is located at the first focal point of the elliptical mirror or in the vicinity thereof.

Alternatively, in the third light source device,
The reflecting surface of the concave mirror may be a rotating body deformed on the basis of a spheroid, and the first reference point may be located at a first focus of the spheroid or in the vicinity thereof.

The illumination device according to the present invention comprises a light source device for emitting convergent light, a transparent column having a circular or polygonal cross section, and a relay lens, and the first to third light source devices as the light source device. The transparent column is disposed such that the incident surface thereof substantially coincides with the second reference point of the light source device, and light emitted from the light source device passes through the inside of the transparent column along the longitudinal direction thereof. The light is emitted from the emission surface while being reflected inside, and a real image corresponding to the emission surface of the transparent column is formed at a position separated by the relay lens.

In the above illuminating device, a positive lens may be arranged close to the entrance surface of the transparent column, or the entrance surface of the transparent column may be reduced so that the spread angle of the light emitted from the transparent column is reduced. Is preferably a convex surface. In addition, a positive lens is arranged in proximity to the exit surface of the transparent column so that the divergence angle of light incident on the relay lens is reduced, or
The exit surface of the transparent column may be made convex.

[0032] The projection display device of the present invention comprises: an illumination device;
A light valve device that receives light emitted from the illumination device and forms an optical image according to a video signal, and a projection lens that receives light emitted from the light valve device and magnifies and projects the optical image on a screen. And the above-mentioned lighting device is used as the lighting device.

In the above-mentioned projection type display device, a positive lens is provided on the incident side of the light valve device so that any principal ray incident on the image display surface of the light valve device is substantially perpendicular to the image display surface. It is good to arrange.

In the above projection display device, the light valve device has two-dimensionally arranged pixels, and a lens array in which minute positive lenses corresponding to the respective pixels are two-dimensionally arranged on the incident side of the light valve device. Can be provided.

In the projection display device, the sectional shape of the transparent column of the illumination device is substantially similar to the effective display region of the light valve device, and the irradiation area of the light radiating the light valve device is effective of the light valve device. It is preferable to include the display area.

A first optical fiber illumination device according to the present invention includes a light source device for emitting convergent light and an optical fiber bundle, wherein the light source device is the first to third light source devices, The bundle is arranged and configured such that its entrance surface substantially coincides with the second reference point of the light source device.

In the first optical fiber lighting device,
It is preferable that a positive lens that reduces the divergence angle of light incident on the optical fiber bundle is disposed near the incident surface of the optical fiber bundle.

A second optical fiber illuminating device according to the present invention includes a light source device for emitting convergent light, a transparent column having a circular or polygonal cross section, and an optical fiber bundle. And a third light source device, wherein the transparent column is disposed so that an incident surface thereof substantially coincides with a second reference point, and the optical fiber bundle has an incident surface which is in close contact with an output surface of the transparent column. Alternatively, they are arranged so as to be close to each other.

In the above second optical fiber lighting device,
It is preferable that a positive lens that reduces the divergence angle of light incident on the transparent column is disposed near the incident surface of the transparent column.
Further, the incident surface of the transparent column may be made convex so that the spread angle of light traveling through the transparent column is reduced.

[0040]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 26.

(Embodiment 1) FIG. 1 is a schematic configuration diagram of a light source device according to Embodiment 1 of the present invention. The light source device according to the present embodiment includes a lamp 21, a concave mirror 22, and a correction lens 23.

The lamp 21 is an ultra-high pressure mercury lamp, the lamp power is 100 W, the length of the luminous body is 1.4 mm, and the diameter of the luminous body is 0.6 mm. The length of the luminous body and the diameter of the luminous body are set to be 50% of the peak luminance.

The concave mirror 22 is formed on the inner surface 2 of the glass substrate 24.
5 is an ellipsoidal mirror in which an optical multilayer film that reflects visible light and transmits infrared light is vapor-deposited on an inner surface 25, where 5 is a spheroid. At the center of the ellipsoidal mirror 22, a window 27 for penetrating the arc tube 26 of the lamp 21 is provided. Elliptical mirror 2
The first focal length (the distance from the vertex 28 of the elliptical surface 25 to the first focal point F ₁ ) is f ₁ = 9.5 mm, and the second focal length (the distance from the vertex 28 of the elliptical surface 25 to the second focal point F _{2) is 2} . Distance) is f ₂
= 130 mm, opening diameter 66 mm, window diameter 13.
4 mm. The lamp 21 is arranged such that the center axis of the light emitter 29 coincides with the optical axis 30 of the ellipsoidal mirror 22, and the center of the light emitter 29 coincides with the first focal point F ₁ of the ellipsoidal mirror 22. A front glass plate 31 is attached to the emission side of the concave mirror 22 to prevent the fragments from scattering when the lamp 21 ruptures.

On the emission side of the front glass plate 31, a correction lens 23 is arranged. The correction lens 23 includes a first lens 34 and a second lens 35 in order from the front glass plate 31 side.
It is composed of The first lens 34 includes an incident side surface 36,
Both the emission side surfaces 37 are spherical biconvex lenses. The second lens 35 is a lens whose entrance side surface 38 is a concave spherical surface and whose exit side surface 39 is an aspheric surface. The aspheric surface has a convex central portion and a concave peripheral portion. An image point F ₃ for forming a luminous body image corresponding to the luminous body 29 is located at a position away from the emission side of the correction lens 23.
Exists. Through the point F _3, the optical axis 30 perpendicular to the plane is the illuminated surface 40.

The numerical data of the light source device shown in FIG.
Shown in In Table 1, R is a concave mirror 22, P is a front glass plate 3.
0 and L1 indicate the first lens 34, and L2 indicates the second lens 35. The reflecting surface 25 of the concave mirror 22 is defined as a first surface, and each surface is numbered consecutively in the order in which the reflected light is encountered. r _i is the paraxial radius of curvature of the i-th surface, and d _i is the
This is the surface interval measured along the optical axis of the (i + 1) surface. n _P ,
ν _P is the refractive index and Abbe number of the front glass plate 30 at the e-line, respectively, and n _j and ν _j are the refractive index and Abbe number of the j-th lens at the e-line, respectively.

The surface marked with * is an aspheric surface, and the amount of sag is represented by the following equation.

[0047]

(Equation 7)

Here, h is the height of the point on the aspherical surface from the optical axis, S is the sag amount of the point at the height h, κ _i is the conic constant, d _i , e
_i , f _i , and g _i are the fourth, sixth, eighth, and first orders of the i-th surface, respectively.
This is the 0th order aspheric coefficient.

S ₁ is the concave mirror 2 from the first reference point of the light source device.
The distance s ₃ from the vertex 28 of the second lens 35 to the second reference point F ₃ of the light source device from the vertex of the exit surface (seventh surface) 39 of the second lens 35.
Is the distance to f _I is the focal length of the first lens 34,
f _II is the focal length of the second lens 35. The first reference point of the light source device is consistent with the first focus F ₁ of the ellipsoidal mirror 22.

[0050]

[Table 1]

Light rays emitted from the first focal point F _{1 of} the ellipsoidal mirror and reflected by the reflection surface 25 of the ellipsoidal mirror 22 are reflected by the ellipsoidal mirror 22.
It proceeds to pass through the second focal point F ₂ of.

When a paraxial ray (a ray having a very small inclination angle) enters the second focal point F ₂ of the ellipsoidal mirror 22, the correction lens 23 emits a ray traveling toward the point F ₃ . When a light beam traveling toward the second focal point F ₂ of the ellipsoidal mirror 22 is incident, the correction lens 23 emits a light beam traveling toward or near the point F ₃ regardless of the inclination angle of the incident light beam. Is emitted. In the configuration shown in FIG. 1, the first reference point of the light source device is consistent with the first focus F ₁ of the ellipsoidal mirror, the point F ₃ is a second reference point of the light source device.
The correction lens 23 is provided at both ends of the light emitting body 29 (the optical axis 30).
Irrespective of the point at which the light rays emitted from both ends of the direction are incident on the reflecting surface 25, the distance from the center of the incident point on the irradiated surface 40 is made as equal as possible. The range of the incident points on the irradiated surface 40 is smaller than the range of the ray height at the point F ₂ when there is no correction lens 23.

Thus, the light emitted from the light emitting body 29 of the lamp 21 is reflected by the reflecting surface 25 of the ellipsoidal mirror 22, and the reflected light is emitted to the second focal point F ₂ of the elliptical mirror 22 corresponding to the light emitting body 29. The light advances to form a body image and enters the correction lens 23. Light emitted from the correcting lens 23 to form an illuminator image 45 corresponding to the light emitter 29 to the point F _3.

The principle of the light source device according to the present invention will be described below.

First, a description will be given of the properties of the illuminant image when the light emitted from the lamp is condensed using an ellipsoidal mirror.

When the reflection surface 25 of the ellipsoidal mirror 22 is a perfect spheroid, as shown in FIG.
There are two special points called focal points on 0, and a ray emitted from _one focal point F ₁ will always pass through the other focal point F ₂ irrespective of the incidence on any point on the reflecting surface 25. There is a property to do. Therefore, the luminous body 2 of the lamp 21
If ask the center of 9 coincides with the focus F ₁ of the ellipsoidal mirror 22 can converge reflected light from the ellipsoidal mirror 22 in the vicinity of the second focal point F _2.

The luminous body 29 is set at the first focal point F ₁ of the ellipsoidal mirror 22.
FIG. 3 shows how light rays emitted from both ends of the luminous body 29 and reflected at a specific point on the reflection surface 25 of the ellipsoidal mirror 22 when are arranged are shown in FIG. The luminous body 29 has an elongated cylindrical shape, the center axis of which coincides with the optical axis 30 of the ellipsoidal mirror 22, and the luminous body 2
Center 9 are arranged to coincide with the first focal point F _1. FIG. 3A shows that the light beam emitted from the light emitting body 29 is
When reflected at a point P ₁ above, FIG. 3 (b) when a line vertical with street light axis 30 a first focus F ₁ is reflected at a point P ₂ intersects the reflecting surface 25, FIG. 3 (c) a case of reflection at a point P ₃ on the open end 44 of the ellipsoidal mirror 22 are shown, respectively.

From FIGS. 3A to 3C, as the distance h from the optical axis 30 to the incident point on the reflection surface 25 increases,
The radius of the luminous body image 45 formed on the second focal point F ₂ is reduced, the divergence angle of the light emitted from the incident point on the reflecting surface 25 is reduced, and the light beam traveling from the incident point toward the center of the luminous body image 45 Angle of inclination (the angle between the ray traveling direction and the optical axis 30)
It can be seen that u increases. From these, the second
Although light passing through the vicinity of the center of the illuminant images 45 formed on the focal point F ₂ have large divergence angle, a small inclination angle of the principal ray,
It can be seen that the light passing through the periphery of the luminous body image 45 has a small divergence angle and a large chief ray inclination angle.

The second focal point F ₂ of the ellipsoidal mirror 22 shown in FIG.
FIG. 4 shows the illuminance distribution of the luminous body image 45 in FIG. The luminous body 29 has a luminous body length of 1.4 mm and a luminous body diameter of 0.6 m.
Illuminance is obtained by numerical calculation as a fully diffused cylindrical light source of m. As can be seen from FIG. 4, the illuminance distribution of the luminous body image 45 has a uniform illuminance area at the center, the illuminance decreases abruptly outside the area, and the illuminance at the periphery is extremely low compared to the center. The lower area is spreading.

In a light source device used for a projection display device or an optical fiber illuminating device, a circular aperture may be arranged at the second focal point F ₂ , and the relationship between the radius of the aperture and the luminous flux of light passing through the aperture may be evaluated. Here, the ratio of the luminous flux of the light passing through the aperture to the luminous flux of the light emitted from the ellipsoidal mirror is referred to as aperture efficiency, and the relationship between the radius of the aperture and the aperture efficiency is referred to as aperture characteristics. FIG. 5 shows aperture characteristics obtained by numerical calculation from the illuminance distribution shown in FIG. When the radius of the aperture is small, the luminous flux of the light passing through the aperture increases almost in proportion to the radius of the aperture.

Next, the operation of the correction lens 23 will be described.

FIG. 6 shows a model of the correction lens. It is assumed that light emitted from a certain optical system to form a circular real image (imaginary object) 46 at point A enters the correction lens 23, and a real image 47 is formed at point B by the correction lens 23.
Each of the correction lenses 23 is a first lens L of a thin lens.
1 and the second lens L2, the light beam traveling toward the point A has the first lens L
1. It is assumed that the light is refracted by the second lens L2 and passes through the point B.

The power of the first lens L1 is φ ₁ , the power of the second lens L2 is φ ₂ , and the air gap between the two lenses L1 and L2 is d. The inclination angle of the light beam entering the first lens L1 is u ₀ , the inclination angle of the light beam exiting the first lens L1 is u ₁ , the height of the refraction point of the first lens L1 is h ₁ , and the refraction of the second lens L2 is The height of the point is h ₂ , and the distance from the second lens L2 to the image point is s.

In the paraxial theory, the following relationship is established with respect to the correction lens 23.

[0065]

(Equation 8)

(Equation 9)

(Equation 10)

For an image to be formed at point B, the following conditions must be satisfied.

[0067]

[Equation 11]

(Equation 8), (Equation 9), (Equation 10), (Equation 1)
The following equation is obtained from 1).

[0069]

(Equation 12)

According to the paraxial theory, the radius of the image (imaginary object) to be formed at the point A is h _A , the radius of the image formed at the point B is h _B , and the inclination angle of the light beam toward the point A Is u _A , and the inclination angle of the light beam toward point B is u _B , the following relationship is established.

[0071]

(Equation 13)

Assuming that the magnification of the image with respect to the imaginary object is m, m
Can be expressed as follows.

[0073]

[Equation 14]

When u _A = u ₀ and u _B = u ₂ and (Equation 8), (Equation 9), (Equation 10), and (Equation 11) are used, (Equation 1)
4) is as follows.

[0075]

(Equation 15)

When d and s are fixed and φ ₁ is changed, φ ₂ is uniquely determined by (Equation 12). Then, when φ ₁ is changed, as can be seen from (Equation 15), the magnification m can be freely selected.

Next, the case where the power of the first lens L1 is positive and the power of the second lens L2 is negative is shown in FIG. 7A. The power of the first lens L1 is negative and the power of the second lens L2 is negative. FIG. 7B shows the case where the power is made positive. Note that FIG. 7A and FIG.
In (b), the positions of point A and point B are the same, that is, d and s are the same. 7A and 7B, it can be seen that the radius of the image 47a in FIG. 7A is larger than the radius of the image 47b in FIG. 7B.

Therefore, for example, as shown in FIG.
The lens L1 has negative power at the central portion and positive power at the peripheral portion, and the second lens L2 has positive power at the central portion and negative power at the peripheral portion, and smoothly changes the power from the central portion to the peripheral portion of each lens. Then, the action shown in FIG. 7B is applied to the light ray passing through the central part of each lens, and the action shown in FIG. 7A is applied to the light ray passing through the peripheral part of each lens. Obtainable. Therefore, in the configuration shown in FIG.
The magnification decreases for light incident on the center of the first lens L1, and increases for light incident on the periphery.

Next, the second focal point F ₂ of the ellipsoidal mirror 22 and the point A of the correction lens 23 coincide with each other so that the correction point shown in FIG. Consider the case where the lens 23 is arranged. The elliptical mirror 22 has a window end 43
Although the magnification is large for the light emitted from the vicinity, this light passes through the central part of each lens of the correction lens 23, and the correction lens 23 has a small magnification with respect to the light passing through the central part.
The correction lens 23 acts to reduce the luminous body image 47. The ellipsoidal mirror 22 has a small magnification with respect to the light emitted from near the opening end 44, but this light is
3 passes through the peripheral portion of each lens, and the correction lens 23 has a large magnification with respect to the light passing through the peripheral portion.
Acts to enlarge the luminous body image 47.

When the concave mirror is a parabolic mirror, it is good to consider that the second focal length of the elliptical mirror is infinite, and when the concave mirror is different from both the elliptical mirror and the parabolic mirror. Consider an ellipsoid or paraboloid closest to the shape of the reflecting surface of the concave mirror. Also, the position of the illuminant images need not be limited to the second reference point F ₃ of the light source device, HU product (details will be described later) may chosen to decrease.

The correction lens 23 of the light source device shown in FIG. 1 is designed according to the following principle.

(1) The light beam emitted from the first reference point F ₁ of the light source device is reflected by the ellipsoidal mirror 22, passes through the correction lens 23, and passes through the second reference point F ₃ of the light source device or its vicinity. To do it.

(2) The rays emitted from both ends of the luminous body 29 and reflected by the ellipsoidal mirror 22 are incident on the edge of the luminous body image as much as possible no matter what point on the reflecting surface 25 is incident. To do.

In order to perform such a design, the correction lens 2
It is preferable that at least one surface of at least one lens constituting the lens 3 is aspherical, and in the light source device shown in FIG. 1, the exit surface 39 of the second lens L2 is aspherical.

When the design is advanced according to the above policy (2), the first
The peripheral portion of the lens 34 and the peripheral portion of the second lens 35 have positive power and negative power, respectively, as shown in FIG. However, the central part of the first lens 34 and the central part of the second lens may not be as shown in FIG.
In the light source device shown in FIG. 1, the central portion of the first lens 34 has positive power, and the central portion of the second lens 35 has negative power. The power at the center of each of the two lenses 34 and 35 may be evaluated based on the focal length determined by the paraxial radius of curvature and the center thickness.

[0086] When the concave mirror 22 is ellipsoidal mirror, the focal length f _I of the first lens 34 and the focal length f _II of the second lens 35, it may be to satisfy the following relation.

[0087]

(Equation 16)

[Equation 17]

When (Equation 16) and (Equation 17) are not satisfied, it seems that the state aimed at by the above policy (2) is not approached.

Thus, according to the light source device shown in FIG. 1, if the divergence angle of the light passing through the center of the illuminant image is the same, the light source image of the illuminant image becomes The radius can be reduced.

A method for evaluating the effect of introducing the correction lens will be described.

As shown in FIG. 9, the point A is a real image (imaginary object).
Consider a case in which light to form 51 enters the positive lens 52 and forms a real image 53 corresponding to the imaginary object 51 at point B. The radius of the imaginary object 51 is H ₁ , the inclination angle of the light beam 54 toward the center of the imaginary object 51 is U ₁ , the radius of a real image 53 formed after passing through the positive lens 52 is H ₂ , and the real image 53
Let U _{2 be} the inclination angle of the light ray 55 incident on the center of the lens, and the following relationship is satisfied if the positive lens 52 is an ideal lens having no aberration.

[0092]

(Equation 18)

Consider a case where the positive lens 52 shown in FIG. 9 is arranged close to the emission side of the second lens 35 of the light source device shown in FIG. Since H ₁ and U ₁ are determined by the characteristics of the light source device, as can be seen from (Equation 18), the positive lens 52
H ₂ sinU ₂ also by changing the power of is constant. Since it is possible to integrate the second lens 35 and the positive lens 52 of the light source device into one lens to make the light refraction characteristics equivalent, to compare the characteristics of the two types of light source devices, The radius of one luminous body image may be corrected using (Equation 18) and compared so that the spread angle of the light emitted from the center of the body image is constant.

Further, the effect of the correction lens can be evaluated in the following manner. Taking the configuration shown in FIG. 1 as an example, it is assumed that a luminous body image is formed at the second focal point F ₂ of the ellipsoidal mirror 22, and the radius of the luminous body image by the ellipsoidal mirror 22 is H ₀ ,
The inclination angle of the light beam emitted from the opening end 44 of the ellipsoidal mirror 22 and passing through the second focal point F ₂ is U ₀ , the radius of the luminous body image formed after passing through the correction lens 23 is H, and the ellipsoidal mirror 22 is Let U be the angle of inclination of the light beam emitted from the opening end 44 of the light-emitting element and passing through the center of the illuminant image. Here, H sinU is H of the light source device.
The U product, H ₀ sinU ₀ , will be referred to as the HU product of the ellipsoidal mirror.

A comparison is made between the light source device of the present invention and a light source device having only an ellipsoidal mirror.

[0096]

[Equation 19]

If the light source device of the present invention has the same size as the light source device having only an ellipsoidal mirror, the light can be efficiently illuminated with a smaller convergence angle. become. In addition, as shown in FIG. 3, when the length of the luminous body of the lamp becomes shorter, the radius of the luminous body image becomes smaller.
If (Equation 19) holds, it means that if the radius of the luminous body image is the same, the length of the luminous body of the lamp can be equivalently reduced by providing the correction lens.

The light source device shown in FIG. 1 has a central light divergence angle of 21.2 °, a luminous body image radius of 5.77 mm, and an HU product of 2.09 mm. On the other hand, with only the elliptical mirror 32,
The central light divergence angle is 21.4 ° and the luminous body image radius is 6.62.
mm and HU product are 2.42 mm. That is, the introduction of the correction lens 23 reduces the HU product. This means that the length of the luminous body of the lamp 21 can be equivalently reduced by introducing the correction lens 23.

FIG. 10 shows the illuminance distribution of the illuminant image formed at the second reference point F ₃ of the light source device shown in FIG. The luminous body 29 is determined by numerical calculation as a cylindrical body having a total length of 1.4 mm and a diameter of 0.6 mm. The solid line is the illuminance distribution of the illuminant image by the light source device of FIG. 1, and the broken line is the illuminance distribution of the illuminant image by the elliptical mirror 22, which is the same as that shown in FIG. By using (Equation 18), the scale of the distance from the center on the irradiated surface 40 is corrected so that the spread angle of the light passing through the center of the illuminant image becomes the same. According to FIG. 10, since the radius where the illuminance is about 13% of the peak is the same, the correction lens 23 increases the illuminance inside the radius where the illuminance is about 13% of the center illuminance of the illuminant image. You can see that In addition, it can be seen that the introduction of the correction lens 23 makes the change in the inclined portion closer to a straight line.

FIG. 11 shows aperture characteristics obtained by numerical calculations based on the illuminance distribution shown in FIG. Also in this case, the scale of the distance from the center is corrected using (Equation 18) so that the spread angle of the light passing through the center of the illuminant image becomes the same. Here, it is assumed that the transmittance of the correction lens 23 is 100%, and that all light emitted from the ellipsoidal mirror 22 is emitted from the correction lens 23.
The light flux of the light emitted from the ellipsoidal mirror 22 and the light flux of the light emitted from the correction lens 23 are the same. FIG. 11 shows that when the aperture radius is the same, the light passing through the aperture increases due to the introduction of the correction lens.

The two lenses 34 and 35 shown in FIG.
Each of them is made of glass because the temperature becomes high and a resin material cannot be used. The second lens 35 having an aspheric emission side surface 39 is formed as follows. A mold for forming an aspherical surface and a plane mold are prepared. The two molds are heated, and the glass material is heated and softened. The softened glass material is put between the two molds and pressed. I do. When the glass material is changed from a high temperature to a room temperature, it shrinks, so that no sink occurs on the aspheric surface, and the surface 3 on the opposite side to the aspheric surface.
8. Make sure that sink marks occur. Finish the sink surface to a spherical surface by post-processing. In this method, since one surface is limited to a spherical surface, the second lens 35 has one surface as an aspheric surface,
The other surface is a spherical surface.

In the configuration shown in FIG. 1, the first lens 34 has a spherical surface on both sides. This is because a spherical lens has a light beam bending angle which is larger than the height from the optical axis. Because they use it.

Thus, the light source device shown in FIG. 1 can efficiently illuminate the illuminated area at a smaller convergence angle if the illuminated area has the same size.

The lamp used in the light source device of the present invention desirably has a luminous body that is rotationally symmetric, and is preferably arranged so that the central axis of the luminous body coincides with the optical axis of the concave mirror. The effect of the present invention that can equivalently shorten the luminous body length can be obtained even when the luminous body length is substantially equal to the luminous body diameter. However, a greater effect is obtained as the luminous body length is larger than the luminous body diameter. As a lamp used in the light source device of the present invention, an arc discharge lamp such as a metal halide lamp and a xenon lamp can be used in addition to the ultra-high pressure mercury lamp.

(Embodiment 2) FIG. 12 shows a schematic configuration of a light source device according to Embodiment 2 of the present invention, wherein 61 is a lamp, 62 is a concave mirror, and 64 is a correction lens.

The light source device shown in FIG. 12 is obtained by replacing the correction lens 23 of the light source device shown in FIG. 1 with a correction lens 64 composed of three lenses. Further, the light source device is designed according to the same policy as the design policy of the light source device shown in FIG.

Lamp 61, concave mirror 62, front glass plate 6
3 is the same as that shown in FIG. Front glass plate 63
A correction lens 64 is disposed on the emission side of the lens. The correction lens 64 includes a first lens 6 in order from the front glass plate side.
5, a second lens 66 and a third lens 67 are arranged. The first lens 65 is a biconvex lens in which both the entrance side surface 68 and the exit side surface 69 are spherical. The second lens 66 has a spherical incident side surface 70 and an aspherical exit side surface 71. The aspheric surface of the emission side surface 71 of the second lens 66 has a convex central portion,
The periphery is concave. The third lens 67 has a convex surface 7
2 is a plano-convex lens with the side facing the incident side.

Table 2 shows numerical data of the light source device shown in FIG. L1 is the first lens 65, L2 is the second lens 6
6, L3 denotes a third lens 67, f _I is the focal length of the first lens 65, the f _II focal length of the second lens 66, the f _III is the focal length of the third lens 67, the other The symbols and conditions are exactly the same as those described in Table 1. The first reference point of the light source device is the first focal point F of the ellipsoidal mirror 62.
Matches ₁ .

[0109]

[Table 2]

In the light source device shown in FIG. 12, the luminous body image has a radius of 3.78 mm, the central light divergence angle is 31.5 °, and the HU
The product is 1.97 mm. Also in this case, the correction lens 64
Has reduced the HU product.

FIG. 13 shows the illuminance distribution of the luminous body image of the light source device shown in FIG. 12, and FIG. 14 shows the aperture characteristics. In each case, the solid line is the characteristic of the luminous body image of the light source device of FIG. It can be seen from FIG. 14 that the introduction of the correction lens 64 increases the aperture efficiency.

Thus, the light source device shown in FIG. 12 can also efficiently illuminate the irradiated area with a smaller convergence angle if the irradiated area has the same size. The light source device shown in FIG. 12 also has the effect that the total length of the light emitter of the lamp can be equivalently reduced by introducing the correction lens 64.

(Embodiment 3) FIG. 15 shows a schematic configuration of a light source device according to Embodiment 3 of the present invention, wherein 81 is a lamp, 82 is a concave mirror, and 84 is a correction lens.

The light source device shown in FIG. 15 is obtained by replacing the correction lens 64 of the light source device shown in FIG. 12 with a correction lens 84 having another three lenses. Further, the light source device is designed according to the same principle as that of the light source device shown in FIG.

Lamp 81, concave mirror 82, whole glass plate 8
3 is the same as that shown in FIGS. On the emission side of the front glass plate 83, a correction lens 84 is arranged. The correction lens 84 includes a front glass plate 83
A first lens 85, a second lens 86, and a third lens 87 are arranged in this order from the side. The first lens 85 is a biconvex lens whose entrance side surface 88 is aspherical and whose exit side surface 89 is spherical. The aspheric surface of the incident side surface 88 of the first lens 85 has a longer radius of curvature from the center to the middle region, and has a shorter radius of curvature at the periphery. The second lens 86 has a concave entrance surface 90 on the entrance side surface 90 and an aspheric surface on the exit side surface 91. Third lens 8
Reference numeral 7 denotes a plano-convex lens with the convex surface 92 facing the incident side.

Table 3 shows numerical data of the light source device shown in FIG. L1 is the first lens 85, L2 is the second lens 8
6, L3 denotes a third lens 87, f _I is the focal length of the first lens 85, the f _II focal length of the second lens 86, the f _III is the focal length of the third lens 87, the other The symbols and conditions are exactly the same as those described in Table 1. The first reference point of the light source device is the first focal point F of the ellipsoidal mirror 82.
Matches ₁ .

[0117]

[Table 3]

The light source device shown in FIG. 15 has a luminous body image with a radius of 3.60 mm, a central light divergence angle of 28.6 °, and an HU
The product is 1.73 mm. Also in this case, the correction lens 84
It can be seen that the HU product is reduced by the introduction of.

FIG. 16 shows the illuminance distribution of the luminous body image of the light source device shown in FIG. 15, and FIG. 17 shows the aperture characteristics. In each case, the solid line is the characteristic of the illuminant image of the light source device of FIG. 15, and the broken line is the characteristic of the illuminant image of the elliptical mirror 82. From FIG. 17, it can be seen that the aperture efficiency is increased by introducing the correction lens 84.

Thus, the light source device shown in FIG. 15 can also efficiently illuminate the irradiated area with a smaller convergence angle if the irradiated area has the same size. The light source device shown in FIG. 15 also has the effect that the total length of the light emitter of the lamp can be equivalently reduced by introducing the correction lens 84.

(Embodiment 4) FIG. 18 shows a schematic configuration of a light source device according to Embodiment 4 of the present invention, wherein 101 is a lamp, 102 is a concave mirror, and 104 is a correction lens.

In the light source device shown in FIG. 18, the concave mirror 22 of the light source device shown in FIG.
The correction lens 23 is replaced with another two-element correction lens 104. Further, the light source device is designed according to the same principle as that of the light source device shown in FIG.

The lamp is the same as that shown in FIG.
The reflecting surface of the concave mirror 102 has a shape slightly shifted from the spheroidal surface with respect to the spheroidal surface. On the emission side of the front glass plate 103, a first lens 105 and a second lens 106 are arranged in order from the front glass plate 103 side. The first lens 105 is a biconvex lens whose entrance side surface 107 is aspherical and whose exit side surface 108 is spherical. The second lens 106 has an entrance side surface 109 having a spherical surface and an exit side surface 110.
Are aspherical concave surfaces.

Table 4 shows numerical data of the light source device shown in FIG. L1 denotes the first lens 105, L2 denotes the second lens 106, f _I denotes the focal length of the first lens 105, f _II denotes the focal length of the second lens 106, and other symbols and conditions are shown in Table 1. It is exactly the same as that described in. The first reference point of the light source device is consistent with the first focus F ₁ of the ellipsoidal mirror 102.

[0125]

[Table 4]

In the light source device shown in FIG. 18, the luminous body image has a radius of 3.55 mm, the central light divergence angle is 26.9 °, and the HU
The product is 1.61 mm. Also in this case, the correction lens 10
It can be seen that the introduction of 4 reduces the HU product.

FIG. 19 shows the illuminance distribution of the luminous body image of the light source device shown in FIG. 18, and FIG. 20 shows the aperture characteristics. In each case, the solid line is the characteristic of the illuminant image of the light source device of FIG. It can be seen from FIG. 20 that the introduction of the correction lens 104 increases the aperture efficiency.

Thus, the light source device shown in FIG. 18 can also efficiently illuminate the irradiated area with a smaller convergence angle if the irradiated area has the same size. The light source device shown in FIG. 18 also has an effect that the total length of the light emitter of the lamp can be equivalently reduced by introducing the correction lens 104.

(Embodiment 5) FIG. 21 shows a schematic configuration of an illumination device according to Embodiment 5 of the present invention, wherein 121 is a light source device, 122 is a rod integrator, and 123 is a relay lens.

In the illumination optical device shown in FIG. 21, a rod integrator 122 is arranged on the emission side of the light source device 121, and a relay lens 123 is arranged on the emission side of the rod integrator 122. The light source device 121 is the same as that shown in FIG.
2. It is composed of a correction lens 23. As shown in FIG. 22, the rod integrator 122 is a quadrangular prism made of quartz glass and has an outer dimension of 5.6 mm × 4.2 mm × 40 m.
m, the six surfaces are mirror-polished, and the entrance surface 124 and the exit surface 1
25 has an anti-reflection film deposited thereon. The rod integrator 122 has its central axis in the longitudinal direction
1 coincides with the optical axis 126 of the light source device 12
It is arranged to coincide with the second reference point F ₃ of 1.
The relay lens 123 is composed of two plano-convex lenses 127 and 128
Are combined.

When the light emitted from the light source device 121 enters the inside from the incident surface 124 of the rod integrator 122, the light incident on the side surface 129 is reflected inward there by total reflection, and proceeds toward the emission surface 125. Incident surface 12
4, the illuminance distribution is not uniform, but the light is reflected on the side surface 129 of the rod integrator 122, and the light having different numbers of reflections is superimposed on the light exit surface 125.
The illuminance distribution at 25 is made uniform. Since the reflectance is 100% in total reflection, the rod integrator 122
Is efficiently emitted to the outside from the emission surface 125. The spread angle of the light emitted from the rod integrator 122 is the same as the spread angle of the light incident on the rod integrator 122.

The light emitted from the rod integrator 122 passes through the relay lens 123 and reaches the irradiated surface 130. By the relay lens 123, a real image corresponding to the emission surface 125 of the rod integrator 122 is formed on the irradiated surface 130. The real image formed on the irradiated surface 130 is similar to the shape of the emission surface 125 of the rod integrator 122.

Output surface 12 of rod integrator 122
5 is D ₁ , the diagonal length of the real image on the irradiated surface 130 is D ₂ , and the emission surface 125 of the rod integrator 122
The maximum inclination angle of the light emitted from the lens is U ₁ , and the relay lens 12
Assuming that the maximum inclination angle of the light emitted from 3 and incident on the center of the irradiated surface 130 is U ₂ , the following relationship holds.

[0134]

(Equation 20)

As can be seen from (Equation 20), the irradiated surface 1
As the real image at 30 increases, the irradiated surface 13
The spread angle of light incident on the center of 0 becomes smaller.

The illumination device shown in FIG. 21 is characterized in that the illuminance distribution on the surface to be irradiated is uniform and the efficiency is high.

If the shape of the irradiation area is not rectangular, the cross-sectional shape of the rod integrator 122 may be similar to the shape of the irradiation area.

The illumination device shown in FIG. 21 is useful when applied to a projection display device using a light valve device.
A projection image with good illuminance uniformity can be obtained on the screen. In this case, the cross-sectional shape of the rod integrator 122 may be similar to the shape of the effective display area of the light valve device. The size of the irradiated area may be slightly larger than the effective display area of the light valve device.

In the lighting device of FIG. 21, the light source device described in Embodiment 1 (FIG. 1) is used as the light source device 121.
However, the lighting device according to the present embodiment is not limited to this configuration, and the light source device 121 is used as the lighting device according to the second, third, or
Alternatively, the four light source devices can be used.

(Embodiment 6) A lighting device according to Embodiment 6 of the present invention will be described.

This lighting device is obtained by replacing the rod integrator 122 in the lighting device shown in FIG. 21 with a rod integrator 133 shown in FIG. FIG. 23 shows the optical axis 126 of the rod integrator 133.
The rod integrator 133 has the incident surface 134 as a convex spherical surface so that the principal ray transmitted through the incident surface 134 is substantially parallel to the optical axis 126 as shown in FIG.

In the lighting device shown in FIG.
In the luminous body image formed at the second reference point F ₃ of 21, since the inclination angle of the principal ray increases as the distance from the optical axis 126 increases at the point F ₃ , the light ray incident on the corner of the incident surface 124 of the rod integrator 122 Of the incident surface 12
4 is larger than the maximum inclination angle of the light ray incident on the center of 4. Therefore, the spread angle of the light emitted from the emission surface 125 of the rod integrator 122 is large. In contrast, FIG.
In the rod integrator 133 shown in FIG. 7, since the principal ray is substantially parallel to the optical axis 126 on the entrance surface 134 of the convex spherical surface, the maximum inclination angle of the light transmitted through the corner of the entrance surface 134 of the rod integrator 133 is Is almost the same as the maximum inclination angle of the light transmitted through the center of. Therefore, FIG.
When the rod integrator 133 shown in FIG. 23 is used for the lighting device shown in FIG. 1, the divergence angle of light emitted from the emission surface 135 of the rod integrator 133 becomes small,
The effective diameter of the relay lens 123 can be reduced.

The rod integrator 13 shown in FIG.
When 3 is used, since no light exits from the window 27 of the concave mirror 22, there is no light with a tilt angle close to 0 ° at any point on the incident surface 134 of the rod integrator 133. For this reason, it is difficult to make the illuminance distribution on the exit surface 135 of the rod integrator 133 uniform compared to the illumination device shown in FIG. However, if the overall length of the rod integrator 133 is increased, the illuminance distribution on the emission surface 135 can be made uniform.

An illumination device using the rod integrator 133 shown in FIG. 23 in the illumination device shown in FIG.
1, the illuminance distribution of the irradiated area 130 is uniform and the efficiency is high.
There is a feature that the maximum inclination angle of the light beam emitted from the emission surface 135 of the rod integrator 133 can be reduced.

The rod integrator 13 shown in FIG.
FIG. 3 shows an example in which instead of forming a convex spherical surface on the incident surface 134, FIG.
Square rod integrator 122 as shown in FIG.
It is also possible to adopt a configuration in which a positive lens is arranged close to the light incident side.

The rod integrator 13 shown in FIG.
When the exit surface 135 of the third lens is also a convex spherical surface and its focal point is located near the relay lens 123, the effective diameter of the relay lens 123 can be further reduced. Also in this case, instead of forming a convex spherical surface on the emission surface 135, a configuration in which a positive lens is arranged near the emission side of a flat rod integrator may be used.

(Embodiment 7) FIG. 24 shows the configuration of a projection display apparatus according to Embodiment 7 of the present invention, wherein 141 is an illumination device, 142 is a lamp, 143 is a concave mirror, and 145 is a correction lens. 146 is a rod integrator, 148 is a relay lens, 171 and 172 are dichroic mirrors, 174, 175 and 180 are field lenses, 176 and 178 are relay lenses, 181, 18
2,183,187,188,189 are polarizing plates,
4, 185 and 186 are liquid crystal panels, 190 is a color combining prism, and 191 is a projection lens.

The illumination device 141 has the same configuration as that shown in FIG. 21, and includes a lamp 142, a concave mirror 143, a front glass plate 144, a correction lens 145, a rod integrator 146, a plane mirror 147, and a relay lens 148. ing. The lamp 142 is an ultra-high pressure mercury lamp, and emits light including red, green, and blue color components. Concave mirror 1
Reference numeral 43 denotes an ellipsoidal mirror, which is an inner surface 1 of a glass base material 149.
50 is a spheroid, reflects visible light on the inner surface 150,
It is obtained by depositing an optical multilayer film that transmits infrared light.
The front glass plate 144 is formed by depositing an optical multilayer film that transmits visible light and reflects infrared light and ultraviolet light on the incident surface of the glass plate, and deposits an antireflection film on the exit surface. In addition to removing infrared light and ultraviolet light from the light radiated from the lamp 142, when the lamp 142 ruptures, scattering of fragments is also prevented. The correction lens 145 includes a first lens 153
And a second lens 154. The visible light contained in the light emitted from the illuminator of the lamp 142 is reflected by the concave mirror 143 and proceeds to form an illuminant image at the second focal point F ₂ (see FIG. 1).

The light emitted from the concave mirror 143 forms an illuminant image at the second reference point F ₃ of the light source device by the correction lens 145. The exit side of the correction lens 145 is a rod integrator 146 is arranged, the entrance surface 157 is arranged to coincide with the point F _3. As described above, the illumination surface 158 of the rod integrator 156 has good illuminance uniformity.

A relay lens 148 is arranged on the emission side of the rod integrator 146. Relay lens 1
Numeral 48 is composed of two plano-convex lenses 160 and 161, and a real image corresponding to the emission surface 158 of the rod integrator 146 is formed at a position distant.

The light emitted from the relay lens 148 enters the blue transmitting dichroic mirror 171, transmits blue light, and reflects red light and green light. The red light and the green light are incident on the green reflecting dichroic mirror 172, the red light is transmitted, and the green light is reflected. The blue light reflected by the blue transmission dichroic mirror 171 is reflected by the plane mirror 173 and enters the field lens 174. The green light reflected by the green reflection dichroic mirror 172 directly enters the field lens 175. The red light transmitted through the green reflection dichroic mirror 172 is transmitted to the first relay lens 176, the plane mirror 177, and the second relay lens 17.
8. The light passes through the plane mirror 179 in order and enters the field lens 180. Each field lens 174, 17
The light emitted from 5,180 is incident on the incident side polarizing plate 18 respectively.
1, 182, 183 and the corresponding liquid crystal panel 1
84, 185 and 186.

The liquid crystal panels 184, 185 and 186 have
An optical image is formed as a change in optical rotation or birefringence according to the video signal. Field lenses 174, 175
Reference numeral 180 is used to make the principal ray incident on the pixels around the liquid crystal panels 184, 185 and 186 perpendicular to the liquid crystal layer.

The respective outgoing lights of the liquid crystal panels 184, 185 and 186 pass through the outgoing side polarizing plates 187, 188 and 189 and enter the color combining prism 190. The color synthesizing prism 190 has a red reflection dichroic multilayer film and a blue reflection dichroic multilayer film on the slopes of the four triangular prisms, and the four triangular prisms have four triangles so that the red reflection dichroic multilayer film and the blue reflection dichroic multilayer film intersect in an X-shape. The prisms are joined. The three primary color lights that have entered the color combining prism 190 are combined into one light by the red reflection dichroic multilayer film and the blue reflection dichroic multilayer film, and the combined light enters the telecentric projection lens 191.

Thus, the three liquid crystal panels 184, 18
The optical images formed at 5, 186 are enlarged and projected by a projection lens 191 on a screen which is arranged at a distance.

The relay lens 148 displays a real image corresponding to the emission surface 158 of the rod integrator 146 on the liquid crystal panel 1.
84, 185 and 186. LCD panel 18
The size of the illuminated area on 4, 185, 186 may be slightly larger than the effective display area of liquid crystal panels 184, 185, 186.

The projection display apparatus shown in FIG. 24 is characterized in that the illuminance distribution of the projected image is uniform and the efficiency is high.

In the projection type display device shown in FIG. 24, the product of the radius of the luminous body image formed by the light source device used and the central light divergence angle is smaller than that of the conventional display device. In comparison, the following effects are obtained.

(1) The same light output can be obtained even when the screen size of the liquid crystal panel is reduced. In this case, the entire device can be made compact.

(2) The light output can be increased by using a lamp having a longer light emitter and a higher light output.

(3) The same light output can be obtained by using a lamp having a longer luminous body length and a longer life.

(4) Even if the F value of the projection lens is increased, the same light output can be obtained. Therefore, the size of the projection lens can be reduced and the cost can be reduced.

(5) The liquid crystal panel has a pixel structure,
The use of a liquid crystal panel in which a lens array having one positive lens corresponding to each pixel on the incident side of the liquid crystal layer is disposed close to each other enables the light output from the projection lens to be improved.

In the above description, a projection type display device using a transmissive liquid crystal panel as the light valve device has been described. However, any light valve device which forms an optical image as a change in optical characteristics according to a video signal. The present invention can be applied to any type including a reflection type.

(Eighth Embodiment) FIG. 25 shows the structure of an optical fiber illuminator according to an eighth embodiment of the present invention. In FIG. 25, reference numeral 201 denotes a light source device, 202 denotes a lamp, 203 denotes a concave mirror, and 205 denotes a concave mirror. Denotes a correction lens, and 209 denotes an optical fiber bundle.

The light source device 201 is the same as the light source device shown in FIG. 1, and includes a lamp 202, a concave mirror 203, a front glass plate 204, and a correction lens 205. The lamp 202 is a halogen lamp, a metal halide lamp,
A xenon lamp, an ultra-high pressure mercury lamp, or the like can be used. The concave mirror 203 is an ellipsoidal mirror, and the lamp 202 is such that the center of the light emitter 206 is the first reference point F ₁ of the light source device 201.
It is arranged to match.

The correction lens 205 includes a first lens 207 and a second lens 208. Optical fiber bundle 2
Reference numeral 09 denotes a bundle of a large number of very thin optical fibers, which can be freely bent to some extent. Fiber optic bundle 209 is incident end 210 is arranged to coincide with the second reference point F ₃ of the light source device 201.

Light emitted from the lamp 202 is reflected by the concave mirror 203.
The process proceeds to to form an illuminator image at a second focal point to form an illuminator image by the correction lens 205 to an image point F _3. The light that has passed through the luminous body image is incident on the incident end 210 of the optical fiber bundle 209, and is repeatedly reflected on the side surface of each optical fiber and is emitted from the emission end 211.

In the optical fiber illuminator shown in FIG. 25, the product of the radius of the luminous body image formed by the light source device used and the central light divergence angle is smaller than in the conventional optical fiber illuminator. The following effects can be obtained as compared with.

(1) By using a lamp having a longer light emitter and a higher light output, the light output from the optical fiber bundle 209 can be increased without increasing the outer diameter of the optical fiber bundle 209.

(2) Even if the outer diameter of the optical fiber bundle 209 is reduced, the same light output can be obtained. In this case, the minimum radius of curvature of the optical fiber bundle 209 can be reduced, and the cost required for the optical fiber bundle 209 can be reduced.

(3) The same light output can be obtained by using a lamp having a long luminous body and a long life.

As the light source device 201, FIGS.
The light source device shown in FIG. 18 can be used.

In the configuration shown in FIG. 25, the optical fiber bundle 20
A positive lens for reducing the divergence angle of light incident on 9 may be arranged. By doing so, the principal ray incident on the periphery of the effective area of the incident end 210 of the optical fiber bundle 209 can be made closer to the direction parallel to the optical axis, and the incident angle of the light incident on the optical fiber can be reduced. Light leaking from the side of the fiber to the outside can be reduced.
9 can be further improved.

(Embodiment 9) FIG. 26 shows the configuration of an optical fiber lighting device according to Embodiment 9 of the present invention. This is a modification of the optical fiber lighting device shown in FIG. 25, in which a rod integrator 221 is arranged between the light source device 201 and the optical fiber bundle 209.

The rod integrator 221 is a transparent cylinder, and the entrance surface 222, the exit surface 223, and the side surface 224 are all mirror-polished. The incident surface 222 is the light source device 2
They are arranged to match the second reference point F ₃ of 01. The optical fiber bundle 209 has the incident end 210 disposed close to the exit surface 223 of the rod integrator 221.

Light emitted from the light source device 201 enters the rod integrator 221, travels while repeating total reflection on the side surface 224, exits from the exit surface 223, and enters the optical fiber bundle 209. The light incident on the optical fiber bundle 209 travels while repeating reflection on the side surface of each optical fiber, and exits from the exit end 211.

The illuminating device shown in FIG. 26 has the same effect as the illuminating device shown in FIG. 25, and can make the illuminance distribution uniform near the exit end 211 of the optical fiber bundle 209.

As the light source device 201, the light source devices shown in FIGS. 12, 15, and 18 can be used.
Further, the rod integrator 221 may be a column having a polygonal cross section. It is preferable that the cross section of the rod integrator 221 has substantially the same shape as the incident end 210 of the optical fiber bundle 209 because light loss is reduced.

In the configuration shown in FIG. 26, in order to reduce the divergence angle of light traveling inside the rod integrator 221, a positive lens is arranged close to the entrance surface 222 or the entrance surface 22 of the rod integrator 221 is reduced.
2 may be a convex spherical surface. By doing so, the divergence angle of the light emitted from the emission surface 223 of the rod integrator 221 is reduced, the light leaking from the side of the optical fiber to the outside can be reduced, and the light output from the optical fiber bundle 209 can be improved. it can.

[0180]

As described above, according to the present invention, by combining a concave mirror with a correction lens having predetermined characteristics, if the size of the irradiated area is the same, the light can be efficiently irradiated with a smaller convergence angle. A light source device capable of illuminating an area can be provided. Further, by using this light source device, a highly efficient lighting device can be provided. Further, by using this lighting device, it is possible to provide a projection type display device having a large light output by using a light valve device having a small screen size to make the entire device compact. Further, by using the light source device of the present invention, it is possible to provide an optical fiber lighting device having a large light output. As described above, the present invention has a very great effect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating a configuration of a light source device according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining properties of an ellipsoidal mirror used in the light source device of the present invention.

FIG. 3 is a diagram for explaining properties of a luminous body image by an ellipsoidal mirror.

FIG. 4 is a characteristic diagram illustrating an illuminance distribution of a luminous body image by an ellipsoidal mirror.

FIG. 5 is a characteristic diagram showing aperture characteristics of a luminous body image by an ellipsoidal mirror.

FIG. 6 is a diagram showing a model of a correction lens of the present invention.

FIG. 7 is a diagram for explaining the operation of the correction lens of the present invention.

FIG. 8 is a schematic configuration diagram illustrating a configuration example of a correction lens of the present invention.

FIG. 9 is a diagram for explaining the operation of an ideal lens.

FIG. 10 is a characteristic diagram illustrating an illuminance distribution of a luminous body image by the light source device according to Embodiment 1 of the present invention.

FIG. 11 is a characteristic diagram showing aperture characteristics of a luminous body image by the light source device according to the first embodiment of the present invention.

FIG. 12 is a schematic configuration diagram illustrating a configuration of a light source device according to Embodiment 2 of the present invention.

FIG. 13 is a characteristic diagram illustrating an illuminance distribution of a luminous body image by the light source device according to Embodiment 2 of the present invention.

FIG. 14 is a characteristic diagram showing aperture characteristics of a luminous body image by the light source device according to Embodiment 2 of the present invention.

FIG. 15 is a schematic configuration diagram illustrating a configuration of a light source device according to Embodiment 3 of the present invention.

FIG. 16 is a characteristic diagram illustrating an illuminance distribution of a luminous body image by the light source device according to Embodiment 3 of the present invention.

FIG. 17 is a characteristic diagram showing aperture characteristics of a luminous body image by the light source device according to Embodiment 3 of the present invention.

FIG. 18 is a schematic configuration diagram illustrating a configuration of a light source device according to Embodiment 4 of the present invention.

FIG. 19 is a characteristic diagram showing an illuminance distribution of a luminous body image by the light source device according to Embodiment 4 of the present invention.

FIG. 20 is a characteristic diagram illustrating aperture characteristics of a luminous body image by the light source device according to Embodiment 4 of the present invention.

FIG. 21 is a schematic configuration diagram showing a configuration of a lighting device according to Embodiment 5 of the present invention.

FIG. 22 is a perspective view showing a configuration of a rod integrator used in the lighting device shown in FIG. 21.

FIG. 23 is a cross-sectional view illustrating a configuration of a rod integrator used in a lighting device according to Embodiment 6 of the present invention.

FIG. 24 is a schematic configuration diagram showing a configuration of a projection display apparatus according to Embodiment 7 of the present invention.

FIG. 25 is a schematic configuration diagram showing a configuration of an optical fiber lighting device according to an eighth embodiment of the present invention.

FIG. 26 is a schematic configuration diagram showing a configuration of an optical fiber lighting device according to Embodiment 9 of the present invention.

[Explanation of symbols]

21, 61, 81, 101, 142, 202 Lamp 22, 62, 82, 102, 143, 203 Concave mirror 23, 64, 84, 104, 145, 205 Correcting lens 121 Light source device 122, 133, 146, 156 Rod integrator 123 , 148 relay lens 141 illuminating device 147 plane mirror 171,172 dichroic mirror 173,177,179 plane mirror 174,175,180 field lens 176,178 relay lens 181,182,183,187,188,189 polarizing plate 184,185 , 186 Liquid crystal panel 190 Color combining prism 191 Projection lens 201 Light source device 206 Light emitting body 209 Optical fiber bundle 221 Rod integrator

Continued on the front page F-term (reference) 2H052 BA02 BA03 BA09 BA14 2H087 KA07 LA24 RA04 RA05 RA26 RA42 TA03 TA06 5C060 BA04 BA08 BC05 EA00 GA01 GB02 GB06 HC20 HC24 HC25 HD00 JA00 JB06 5G435 AA18 BB12 BB17 CC12 DD02 DD05 GG03 GG03 FF03 GG04 GG08 GG18 GG28 9A001 GG03 KK16

Claims (35)

[Claims] 1. An optical system comprising a lamp, a concave mirror, and a correction lens, wherein an optical system combining the concave mirror and the correction lens is rotationally symmetric about an optical axis, and emits light from a first reference point. The lamp has two reference points on the optical axis having such a property that all light rays reflected by the concave mirror and transmitted through the correction lens pass at or near a second reference point. Are arranged so that the central axis of the light-emitting body substantially coincides with the optical axis, and the center of the light-emitting body substantially coincides with the first reference point, and is formed at the second reference point corresponding to the light-emitting body. The radius of the illuminant image is H, the maximum inclination angle of the light beam passing through the center of the illuminant image is U, and the radius of the illuminant image formed corresponding to the illuminant in the configuration in which the correction lens is removed is the minimum. Is defined as an image point, and is formed at the image point. When the radius of the luminous body image is H ₀ , and the angle between the optical axis and a straight line connecting the opening end of the concave mirror and the image point is U ₀ , the concave mirror and the correction lens have the following formula: A light source device characterized by being configured to satisfy. (Equation 1) 2. The light source device according to claim 1, wherein the lamp has a luminous body length longer than a luminous body diameter. 3. The light source device according to claim 1, wherein the concave mirror is an elliptical mirror. 4. The first reference point is a first reference point of the ellipsoidal mirror.
The light source device according to claim 3, wherein the light source device is located at or near the focal point. 5. The spheroid according to claim 1, wherein the reflection surface of the concave mirror is a rotator deformed on the basis of a spheroid, and the first reference point is located at or near a first focal point of the spheroid. The light source device according to claim 1. 6. The light source device according to claim 1, wherein at least one lens surface of at least one of the lenses forming the correction lens is an aspheric surface. 7. An optical system comprising a lamp, a concave mirror, and a correction lens, wherein an optical system combining the concave mirror and the correction lens is rotationally symmetric about an optical axis, and emits light from a first reference point. The lamp has two reference points on the optical axis having such a property that all light rays reflected by the concave mirror and transmitted through the correction lens pass at or near a second reference point. Are arranged so that the center axis of the light-emitting body substantially coincides with the optical axis, and the center of the light-emitting body substantially coincides with the first reference point, and an image corresponding to the light-emitting body is formed at the second reference point. The correction lens includes, in order from the concave mirror side, a first lens and a second lens, wherein the first lens has at least a peripheral portion having a positive power, and the second lens has at least a peripheral portion having a negative power. Light source device characterized by having . 8. The light source device according to claim 7, wherein the lamp has a luminous body length longer than a luminous body diameter. 9. The light source device according to claim 7, wherein the concave mirror is an elliptical mirror. 10. The light source device according to claim 9, wherein the first reference point is located at or near a first focal point of the ellipsoidal mirror. 11. The method according to claim 7, wherein the reflecting surface of the concave mirror is a rotator deformed on the basis of a spheroid, and the first reference point is located at or near a first focal point of the spheroid. The light source device according to claim 1. 12. The focal length of the first lens is defined as f _I , and the focal length of the second lens is defined as f _II. (Equation 3) The light source device according to any one of claims 9 to 11, which satisfies the following. 13. The light source device according to claim 7, wherein the first lens has a convex surface at least in a peripheral portion of an emission side surface. 14. The light source device according to claim 7, wherein the second lens has a concave surface at least in a peripheral portion of an incident side surface. 15. The exit side surface of the second lens is an aspheric surface having a convex central portion and a concave peripheral portion.
The light source device according to item 1. 16. The light source device according to claim 7, wherein a third lens having a positive power is disposed on an emission side of the second lens. 17. An optical system comprising a lamp, a concave mirror, and a correction lens, wherein an optical system combining the concave mirror and the correction lens is rotationally symmetric about an optical axis, and emits light from a first reference point. The lamp has two reference points having a property such that all light rays reflected by the concave mirror and transmitted through the correction lens pass at or near a second reference point. Are arranged so that the center axis of the light-emitting body substantially coincides with the optical axis, and the center of the light-emitting body substantially coincides with the first reference point. The range of the ray height at the reference point 2 is smaller than the range of the ray height at the position where the radius of the illuminant image formed corresponding to the illuminant in the configuration in which the correction lens is removed is the smallest. A light source device characterized by the above-mentioned. 18. The light source device according to claim 17, wherein the lamp has a luminous body length longer than a luminous body diameter. 19. The concave mirror is an elliptical mirror.
8. The light source device according to 7. 20. The light source device according to claim 19, wherein the first reference point is located at or near a first focal point of the ellipsoidal mirror. 21. The concave mirror according to claim 17, wherein the reflecting surface of the concave mirror is a rotator deformed based on a spheroid, and the first reference point is located at or near a first focal point of the spheroid. The light source device according to claim 1. 22. A light source device for emitting convergent light, a transparent column having a circular or polygonal cross section, and a relay lens;
22. The light source device according to claim 1, wherein the transparent column is disposed such that an incident surface thereof substantially coincides with a second reference point of the light source device. The light emitted from the transparent column travels while being reflected inside the transparent column along the longitudinal direction and exits from the output surface, and a real image corresponding to the output surface of the transparent column is separated by the relay lens. Lighting device formed in. 23. The lighting device according to claim 22, wherein a positive lens is arranged close to an incident surface of the transparent column so that a spread angle of light emitted from the transparent column is reduced. 24. The lighting device according to claim 22, wherein the incident surface of the transparent column is convex so that the spread angle of the light emitted from the transparent column is reduced. 25. The illuminating device according to claim 22, wherein a positive lens is arranged close to an emission surface of the transparent column so that a spread angle of light incident on the relay lens is reduced. 26. The lighting device according to claim 22, wherein an exit surface of the transparent column is made convex so that a spread angle of light incident on the relay lens is reduced. 27. An illuminating device, a light valve device to which light emitted from the illuminating device enters to form an optical image according to a video signal, and a light to which the light emitting from the light valve device enters to screen the optical image A projection display device, comprising: a projection lens configured to project an enlarged image thereon; and the illumination device is the illumination device according to any one of claims 22 to 26. 28. A positive lens is arranged on an incident side of the light valve device so that any principal ray incident on the image display surface of the light valve device is substantially perpendicular to the image display surface. A projection display device according to claim 27. 29. The light valve device has two-dimensionally arranged pixels, and has a lens array on the incident side of the light valve device in which minute positive lenses corresponding to the respective pixels are two-dimensionally arranged. 29. The projection display device according to 27 or 28. 30. A sectional shape of a transparent column of the lighting device is substantially similar to an effective display area of the light valve device.
The irradiation area of the light irradiating the light valve device includes an effective display area of the light valve device.
30. The projection display device according to any one of 29. 31. A light source device for emitting convergent light, and an optical fiber bundle, wherein the light source device is the light source device according to any one of claims 1 to 21, wherein the optical fiber bundle has an incident surface. An optical fiber illuminator arranged to substantially coincide with a second reference point of the light source device. 32. The optical fiber illuminating apparatus according to claim 31, wherein a positive lens for reducing a divergence angle of light incident on the optical fiber bundle is disposed near the incident surface of the optical fiber bundle. 33. A light source device for emitting convergent light, a transparent column having a circular or polygonal cross section, and an optical fiber bundle,
The light source device is the light source device according to any one of claims 1 to 21, wherein the transparent column is disposed such that an incident surface thereof substantially coincides with a second reference point of the light source device, and the optical fiber An optical fiber illuminator in which the bundle is arranged such that the light incident surface is in close contact with or close to the light emitting surface of the transparent column. 34. The optical fiber illuminating apparatus according to claim 33, wherein a positive lens that reduces a divergence angle of light incident on the transparent column is arranged near the incident surface of the transparent column. 35. The lighting device according to claim 33, wherein an incident surface of the transparent column is convex so that a spread angle of light traveling through the transparent column is reduced.