JP2010066368A - Illumination device, and projection-type display device using the same - Google Patents

Abstract

Conventionally, when a lighting device is configured by combining the radiated light of a plurality of lamps, a lighting device having a large light output is provided by suppressing a combination loss.
Lamps 11 and 12, concave mirrors 13 and 14, and plane mirrors 15 and 16 are provided. The concave mirrors 13 and 14 are arranged to face each other on a common optical axis, and reflecting surfaces 15a of the plane mirrors 15 and 16 are provided. 16a are arranged so that the contact side 18 substantially coincides with the optical axis 17 of the concave mirrors 13,14. The light on the plane mirror 15 side with respect to the optical axis 17 reflected by the reflection surface 13a of the concave mirror 13 and the light on the opposite side of the plane mirror 15 with respect to the optical axis 17 reflected by the reflection surface 14a of the concave mirror 14 overlap. The light on the side opposite to the plane mirror 15 with respect to the optical axis 17 reflected by the reflecting surface 13a of the concave mirror 13 and the light on the side of the plane mirror 15 with respect to the optical axis 17 reflected by the reflecting surface 14a of the concave mirror 14 Overlap. The plane mirrors 15 and 16 reflect incident light on the reflecting surfaces 15a and 16a and emit the combined light in substantially the same direction.
[Selection] Figure 1

Description

  The present invention relates to an illumination device used for illuminating an image forming unit, for example, and a projection display device capable of projecting an optical image formed on the image forming unit onto a screen by a projection lens.

  Conventionally, as one of the methods for displaying a large screen image, a small image forming means for forming an optical image corresponding to a video signal is illuminated with light from a light source such as a lamp, and the optical image is enlarged and projected by a projection lens. A projection display device such as a projector is known, and a projection display device using a liquid crystal panel as a spatial modulation element, a DMD (digital mirror device), or the like as an image forming unit has been put into practical use.

  In such a projection display device, there is a high demand for increasing the brightness of a projected image, and as one method for increasing the brightness, a projection display device in which illumination light is synthesized using a plurality of light sources is disclosed. (For example, refer to Patent Document 1).

  FIG. 4 shows a schematic configuration diagram of such a projection display device. The projection display device includes discharge lamps 71 and 72, ellipsoidal mirrors 73 and 74, UV-IR cut mirrors 75, which are light sources. 76, plane mirrors 77 and 78, a reflecting prism 79, a condensing lens 80, a first lens array 81, a second lens array 82, a beam combining lens 83, a field lens 84, a liquid crystal panel 85, and a projection lens 86. The

  As the discharge lamps 71 and 72, a metal halide lamp, an ultrahigh pressure mercury lamp, a xenon lamp or the like is used.

  In the projection display device configured as described above, the light emitted from the discharge lamps 71 and 72 is reflected by the ellipsoidal mirrors 73 and 74 arranged corresponding to each, and is condensed in the second focal direction. Then, after the ultraviolet light and infrared light components are removed by the UV-IR cut filters 75 and 76, the optical path is bent by the plane mirrors 77 and 78.

  A reflecting prism 79 is disposed near the second focal point of the ellipsoidal mirrors 73 and 74. Thereby, condensing spots of the emitted light of the discharge lamps 71 and 72 are formed in the vicinity of the reflecting surfaces 79a and 79b of the reflecting prism 79, respectively.

  The reflecting surfaces 79a and 79b of the reflecting prism 79 have an aluminum film or a dielectric multilayer film deposited on their surfaces, and reflect visible light efficiently.

  The light reflected by the reflecting prism 79 is divergent light and enters the condenser lens 80. The condenser lens 80 uses, for example, an aspherical biconvex lens, and converts incident light into substantially parallel light.

  The parallel light flux from the condenser lens 80 is incident on the first lens array 81 composed of a plurality of rectangular lenses, and is divided into a large number of minute light fluxes. A large number of minute light beams converge on the corresponding lenses of the second lens array 82 each formed of a plurality of rectangular lenses.

  A large number of images of the discharge lamps 71 and 72 are formed on the second lens array 82. For example, the second lens array 82 may have the same shape as the first lens array 81.

  Each rectangular lens of the second lens array 82 expands a minute light beam incident on the rectangular lens surface of the corresponding first lens array 81 and illuminates the liquid crystal panel 85 that is a spatial modulation element.

  The beam combining lens 83 is used to superimpose the light emitted from each rectangular lens of the second lens array 82 on the liquid crystal panel 85.

  In this way, the incident light flux of the first lens array 81 is divided into a large number of minute light fluxes, which are enlarged and superimposed on the liquid crystal panel 85, so that the liquid crystal panel 85 can be illuminated uniformly.

  The field lens 84 is for condensing the light that illuminates the liquid crystal panel 85 on the pupil plane of the projection lens 86. The projection lens 85 projects an optical image formed on the liquid crystal panel 85 on a screen (not shown).

According to the above configuration, since the liquid crystal panel is illuminated with a plurality of lamps, a bright projection display device can be configured.
JP 2000-3612 A

  In the conventional configuration such as the above-mentioned Patent Document 1, the radiated light of a plurality of lamps is synthesized using a reflecting prism. However, with such a combining method, the optical axes of the lamps cannot be combined on the same axis.

  Specifically, in FIG. 4, since the respective condensed spots of the emitted light from the discharge lamps 71 and 72 are difficult to physically approach on the reflecting surfaces 79 a and 79 b of the reflecting prism 79, the combined optical axis 87. The optical axes 71a and 72a of the discharge lamps 71 and 72 cannot be combined on the same axis. As a result, there has been a problem that optical loss increases in the optical system after synthesis.

  When combining the emitted light of the two lamps, the combined light output is doubled if there is no combination loss. However, generally, the light output after synthesis is about 1.5 to 1.6 times for the above reasons.

  Further, in the above configuration, when one of the two lamps is not lit, the optical axis of the liquid crystal panel and the optical axis of the lamp that illuminates the liquid crystal panel are shifted, resulting in uneven color and uneven brightness. Will occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an illuminating device having a large light output while suppressing a composite loss when a plurality of lamps are used.

  It is another object of the present invention to provide a projection display device that can display a bright projection image using the illumination device.

  In order to solve the above problem, an illumination device of the present invention includes first and second lamps, first and second concave mirrors provided corresponding to each of the first and second lamps, Reflecting means provided between the first and second concave mirrors, and the first and second concave mirrors are arranged opposite to each other on a common optical axis and reflect the radiated light of the corresponding lamp. The light is emitted as light traveling substantially in parallel along the optical axis, and the reflecting means has first and second reflecting surfaces provided corresponding to the first and second concave mirrors, respectively. The first and second reflecting surfaces are arranged so that one side of each of the first and second reflecting surfaces is in contact with a substantially right angle, and the side of the first and second reflecting surfaces substantially coincides with the optical axis of the first and second concave mirrors. The light reflected by the first and second reflecting surfaces is in substantially the same direction. It is characterized in that the Isa.

  In this case, it is preferable if the tangent sides of the first and second reflecting surfaces are arranged so that the midpoints on the optical axes of the first and second concave mirrors substantially coincide.

  The first and second concave mirrors are preferably parabolic mirrors.

  It is preferable that the first and second concave mirrors have an aspherical reflecting surface.

  Further, the lamp is an ultra-high pressure mercury lamp, and it is preferable that the outer surface shape of the arc tube constituting the lamp is an aspherical shape.

  The lamp is an ultra-high pressure mercury lamp, and it is preferable if an antireflection film is vapor-deposited on the outer surface of the arc tube constituting the lamp.

  Furthermore, another illumination device of the present invention includes a plurality of the illumination devices, and further includes light combining means for combining the emitted lights of the plurality of illumination devices so as to be light traveling in substantially the same direction. Is.

  Further, the projection display device of the present invention includes the illumination device, condensing means for condensing the emitted light of the illumination device to form illumination light, and incident the illumination light according to a video signal. A spatial light modulation element that modulates light and a projection lens that projects light modulated by the spatial light modulation element onto a screen are provided.

  The condensing means is preferable if it has two lens array plates composed of a plurality of lenses.

  As described above, according to the present invention, even if a plurality of lamps are used, the optical axes of the lamps can be combined so that the optical axes are coaxial. Can be constructed.

  In addition, the present invention can illuminate the spatial light modulation element that is an image forming means with relatively strong light to increase the brightness of the projected image, and even if one lamp is not lit, A projection display device with little color unevenness and brightness unevenness can be realized.

  Hereinafter, specific embodiments in which the illumination device of the present invention and the illumination device of the present invention are applied to a projection display device will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram showing a first embodiment of a lighting device according to the present invention.

  In FIG. 1, 11 and 12 are lamps, 13 and 14 are concave mirrors, and 15 and 16 are plane mirrors as reflecting means.

  The lamps 11 and 12 are ultra high pressure mercury lamps. An ultra-high pressure mercury lamp has extremely high brightness and excellent light collecting properties, and therefore can collect light efficiently.

  The concave mirrors 13 and 14 are parabolic mirrors, and reflect radiated light from the center of the light source of the lamp as substantially parallel light. On the reflecting surfaces 13a and 14a of the concave mirrors 13 and 14, for example, a dielectric multilayer film that efficiently reflects visible light and transmits infrared light is formed. Of the light emitted from the lamps 11 and 12, The visible light component is efficiently reflected in a desired direction.

  The lamps 11 and 12 are arranged so that the respective light source centers 11 a and 12 a substantially coincide with the focal positions of the concave mirrors 13 and 14.

  As a result, the light incident on the reflecting surfaces 13 a and 14 a of the concave mirrors 13 and 14 is reflected as light traveling substantially in parallel along the optical axis 17.

  Here, the points of the present embodiment will be described. In the present embodiment, the light source centers 11a and 12a of the lamps 11 and 12 and the concave mirrors 13 and 14 are disposed on the common optical axis 17 so as to face each other.

  At the same time, plane mirrors 15 and 16 are provided corresponding to the concave mirrors 13 and 14, respectively, and the reflecting surfaces 15a and 16a of the plane mirrors 15 and 16 are in contact with each other at an angle of intersection of approximately right angles. The tangent side 18 is arranged so as to substantially coincide with the optical axis 17.

  Similarly to the reflecting surfaces 13a and 14a of the concave mirrors 13 and 14, dielectric multilayer films are formed on the reflecting surfaces 15a and 16a of the flat mirrors 15 and 16, respectively.

  The effect | action by the illuminating device of this Embodiment comprised as mentioned above is as follows.

  Of the radiated light from the lamp 11, the light on the plane mirror 15 side with respect to the optical axis 17 is reflected by the reflecting surface 13 a of the concave mirror 13 and then enters the plane mirror 15.

  On the other hand, the light opposite to the plane mirror 15 with respect to the optical axis 17 is reflected by the reflecting surface 13 a of the concave mirror 13, travels substantially parallel to the optical axis 17, and enters the reflecting surface 14 a of the concave mirror 14. .

  The light reflected by the reflecting surface 14 a of the concave mirror 14 passes through the lamp 12, reenters the reflecting surface 14 a of the concave mirror 14, is reflected, becomes substantially parallel light with the optical axis 17, and enters the flat mirror 16.

  Similarly for the lamp 12, the light on the plane mirror 16 side with respect to the optical axis 17 out of the radiated light of the lamp 12 is reflected by the reflecting surface 14 a of the concave mirror 14 and then enters the plane mirror 16.

  On the other hand, the light opposite to the plane mirror 16 with respect to the optical axis 17 is reflected by the reflecting surface 14 a of the concave mirror 14, travels substantially parallel to the optical axis 17, and enters the reflecting surface 13 a of the concave mirror 13. .

  The light reflected by the reflecting surface 13 a of the concave mirror 13 passes through the lamp 11, reenters the reflecting surface 13 a of the concave mirror 13, is reflected, becomes substantially parallel light with the optical axis 17, and enters the flat mirror 15.

  That is, the light on the plane mirror 15 side reflected by the reflecting surface 13a of the concave mirror 13 and the side opposite to the plane mirror 15 with respect to the optical axis 17 reflected by the reflecting surface 14a of the concave mirror 14 are reflected. The light on the opposite side of the plane mirror 15 with respect to the optical axis 17 reflected by the reflecting surface 13a of the concave mirror 13 and the optical axis 17 reflected by the reflecting surface 14a of the concave mirror 14 are overlapped. The light on the plane mirror 15 side overlaps and is combined.

  The plane mirrors 15 and 16 reflect incident light on the reflecting surfaces 15a and 16a and emit the combined light in substantially the same direction.

  With the above-described configuration, the light emitted from the concave mirrors 13 and 14 can be synthesized so as to be light that travels in a substantially coaxial and overlapping manner.

  Therefore, light loss due to the synthesis does not occur, and the radiated light from the lamps 11 and 12 can be synthesized and condensed very efficiently.

  The outer surface shape of the arc tube at the center of the light source of the lamp may be an aspherical shape. In particular, a high-pressure discharge lamp such as an ultra-high pressure mercury lamp has a large thickness of the arc tube in order to obtain a predetermined breakdown voltage, and is often not uniform (uneven thickness).

  In this case, since the light emitted from the light source center of the lamp is refracted by the arc tube, in order to make the reflected light of the concave mirror parallel to the optical axis, the outer surface shape of the arc tube is aspherical. Is preferable.

  Further, it is preferable to deposit an antireflection film on the outer surface of the arc tube of the lamp, because reflection on the outer surface can be reduced and return light from the reflecting surface of the concave mirror can be prevented from diffusing.

  The concave mirror may have an aspherical shape in which the reflecting surface is not limited to a paraboloid, and the same effect as in the present invention can be obtained as long as the reflected light is substantially parallel to the optical axis.

  The tangent of the reflecting surface of the plane mirror can effectively use the radiation of the two lamps facing each other when placed so as to be substantially coincident with the midpoint on the optical axis of the concave mirror, minimizing the loss associated with synthesis. Can be suppressed.

  As described above, according to the present invention, it is possible to realize an illuminating device having a large light output by efficiently combining and condensing radiated light from a plurality of lamps.

(Embodiment 2)
FIG. 2 is a schematic configuration diagram showing a second embodiment of the illumination device according to the present invention.

  In FIG. 2, 21 and 22 are the same illuminating devices as FIG. 1 in Embodiment 1, and 23 and 24 are plane mirrors as a photosynthesis means.

  Light emitted from the illumination devices 21 and 22 is synthesized and reflected by the reflecting surfaces 23a and 24a of the plane mirrors 23 and 24 as light traveling in substantially the same direction.

  That is, in this embodiment, four lamps are used, and a light output almost twice that of the first embodiment using two lamps can be obtained.

  By combining similar configurations, it is possible to obtain a higher output combined light.

  As described above, in the present embodiment, it is possible to achieve high brightness by using multiple lamps with a simple configuration, and by combining the radiated light of the lighting device composed of a plurality of lamps, illumination with a larger light output An apparatus can be realized.

(Embodiment 3)
FIG. 3 is a schematic configuration diagram showing an embodiment of a projection display apparatus according to the present invention.

  In FIG. 3, 31 is an illumination device, 36 is a condensing means, 37 is a spatial light modulation element which is an image forming means, and 38 is a projection lens.

  The illuminating device 31 is the same as that shown in FIG. 1 in Embodiment 1, and efficiently radiates and emits the radiated light of a plurality of lamps.

  The condensing means 36 includes a first lens array 32, a second lens array 33, a beam combining lens 34, and a field lens 35.

  Light emitted from the illumination device 31 is incident on a first lens array 32 composed of a plurality of rectangular lenses, and is divided into a large number of minute light beams. A large number of minute light beams converge on the corresponding lenses of the second lens array 33 each composed of a plurality of rectangular lenses.

  In the present embodiment, the second lens array 33 has the same shape as the first lens array 32.

  Each rectangular lens of the second lens array 33 expands a minute light beam incident on the corresponding rectangular lens surface of the first lens array 32 and illuminates the spatial light modulation element 37.

  The beam combining lens 34 is used to superimpose the light emitted from each rectangular lens of the second lens array 33 on the spatial light modulator 37.

  Since the incident light beam of the first lens array 32 is divided into a large number of minute light beams, which are enlarged and superimposed on the spatial light modulator 37, the spatial light modulator 37 can be illuminated uniformly.

  The field lens 35 is for condensing the light that illuminates the spatial light modulation element 37 onto the pupil plane (not shown) of the projection lens 38.

  The spatial light modulation element 37 is a transmissive liquid crystal panel, and receives illumination light and forms an optical image corresponding to a video signal as a change in transmittance.

  The projection lens 38 projects an optical image formed on the spatial light modulator 37 onto a screen (not shown).

  As described above, according to the present invention, a very bright projection display device can be realized by using an illuminating device that can efficiently combine the emitted lights of a plurality of lamps.

  The projection display device of the present embodiment may be in a cabinet, and a form such as a rear projection display device in which a display image can be observed through a transmissive screen attached to the cabinet may be used.

  The spatial light modulator is not limited to a transmissive liquid crystal panel, and a DMD (digital mirror device), a reflective liquid crystal panel, or the like may be used.

  As described above, in Embodiments 1 to 3, an example in which an ultra high pressure mercury lamp is used as the lamp is shown, but a lamp using a xenon lamp, an LED, or a laser light source may be used.

  The illuminating device according to the present invention can be coaxial when combining the radiated light of a plurality of lamps, so that no light loss occurs due to the synthesis and is effective in realizing a bright illuminating device. Further, the use of the illumination device of the present invention is useful for realizing a bright projection display device.

1 is a schematic configuration diagram showing a first embodiment of a lighting device according to the present invention. The schematic block diagram which shows 2nd Embodiment of the illuminating device of this invention. 1 is a schematic configuration diagram showing an embodiment of a projection display device of the present invention. Schematic configuration diagram showing an example of a conventional lighting device

Explanation of symbols

11, 12 Lamp 11a, 12a Light source center 13, 14 Concave mirror 13a, 14a, 15a, 16a, 23a, 24a Reflective surface 15, 16, 23, 24 Flat mirror 17 Optical axis 18 Tangential 21, 22, 31 Illumination device 32 First 1 lens array 33 second lens array 34 beam combining lens 35 field lens 36 condensing means 37 spatial light modulator 38 projection lens

Claims (10)

First and second lamps;
First and second concave mirrors provided corresponding to each of the first and second lamps;
Reflecting means provided between the first and second concave mirrors,
The first and second concave mirrors are arranged opposite to each other on a common optical axis, reflect the radiated light of the corresponding lamp, and emit it as light traveling substantially parallel along the optical axis,
The reflecting means has first and second reflecting surfaces provided corresponding to the first and second concave mirrors, respectively.
The first and second reflecting surfaces are in contact with each other so that one side thereof has a substantially right angle of intersection, and the contact sides are substantially aligned with the optical axes of the first and second concave mirrors,
The illumination device, wherein the light reflected by the first and second reflecting surfaces is reflected in substantially the same direction. 2. The lighting device according to claim 1, wherein the tangent sides of the first and second reflecting surfaces are arranged so that the midpoints on the optical axes of the first and second concave mirrors substantially coincide with each other. The light source device according to claim 1 or 2, wherein the first and second concave mirrors are parabolic mirrors. The lighting device according to claim 1 or 2, wherein the first and second concave mirrors have reflecting surfaces that are aspherical. 2. The illumination device according to claim 1, wherein the lamp is an ultra high pressure mercury lamp, and an outer surface shape of an arc tube constituting the lamp is an aspherical shape. 2. The lighting device according to claim 1, wherein the lamp is an ultra-high pressure mercury lamp, and an antireflection film is deposited on an outer surface of an arc tube constituting the lamp. A plurality of lighting devices according to claim 1 are provided,
An illuminating device further comprising: a light synthesizer that synthesizes light emitted from the plurality of illuminating devices so as to be light traveling in substantially the same direction. 8. The illumination device according to claim 7, wherein the light combining means is a plane mirror. The lighting device according to claim 1 or 7,
Condensing means for condensing the emitted light of the illumination device to form illumination light;
A spatial light modulator that modulates incident light according to a video signal upon incidence of the illumination light; and
A projection display device comprising: a projection lens that projects light modulated by the spatial light modulator on a screen. The projection display apparatus according to claim 9, wherein the light condensing unit includes two lens array plates each including a plurality of lenses.

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