JP4162484B2 - Projection display device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an illumination device and a projection display apparatus.
[0002]
[Prior art]
As an illuminating device used for a liquid crystal projector or the like, a lighting device such as a super high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like and a parabolic reflector that collimates the irradiation light is generally used. Further, in such an illuminating device, in order to reduce unevenness in the amount of light on the irradiation surface, an integration function using a pair of fly-eye lenses (a plurality of illumination areas of a predetermined shape sampled and formed in a plane by an optical device on an illumination object) Some have a function of superimposing and condensing). Further, in recent years, attempts have been made to use a light emitting diode (LED) as a light source from the viewpoints of light weight, small size, long life, and the like (see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-186507
[Problems to be solved by the invention]
However, the actual situation is that a practical lighting device has not been obtained using a light emitting diode. In addition, it is conceivable to use a semiconductor laser (LD) instead of the light emitting diode. However, when a plurality of semiconductor lasers (LD) emitting the same wavelength light are used, speckle noise ( Highly coherent light such as laser light, irradiating a rough surface or inhomogeneous medium, and observing the scattered light, a spotted pattern with high contrast that appears in space. Is inconvenient.
[0005]
This invention has been made in view of the above circumstances, and an object thereof is to provide a projection shooting display apparatus that can reduce speckle noise generated in the case of using the record over THE.
[0006]
[Means for Solving the Problems]
Projection display device of the present invention includes a lighting device having a integrated means for guiding the light emitted from the light source and the front chelate chromatography THE formed by arranging a plurality of record over The by Lee Ntegureto, from the lighting device a display panel for generating an image light by modulating the light emitted, in the projection type image display apparatus and a projection lens for enlarging and projecting the image light, provided in the illumination device, before chelate chromatography the characterized in that it comprises a phase shift means to the emitted light of the phase non-uniform with one another.
[0007]
With the above configuration, since a light source having a plurality of semiconductor lasers is used, the amount of light can be increased, and the laser light emitted from each semiconductor laser is integrated and guided to the object to be illuminated. It is possible to prevent the light and darkness corresponding to the semiconductor laser arrangement from being formed on the object. Further, since the phase shift means for making the phases of the laser beams emitted from the semiconductor lasers non-uniform to each other, speckle noise can be reduced.
[0008]
The phase shift means may be composed of a plurality of flat plate transparent portions having different thicknesses arranged on the optical path of the laser light emitted from each semiconductor laser. The phase shift means may be composed of a plurality of flat plate transparent portions having different dielectric constants arranged on the optical path of the laser light emitted from each semiconductor laser. Further, the phase shift means may be a wedge-shaped optical element disposed on the optical path of the laser light emitted from the semiconductor laser.
[0009]
Also, the projection display apparatus of the present invention includes a lighting device having a integrated means for guiding the light emitted from the light source and the front chelate chromatography THE formed by arranging a plurality of record over The by Lee Ntegureto, the illumination a display panel for generating an image light by modulating light emitted from the device, the projection display apparatus and a projection lens for enlarging and projecting the image light, provided in the illumination device, before chelate chromatography characterized in that it comprises a light diffusing hand stage to diffuse light emitted from the.
[0010]
With the above configuration, since a light source having a plurality of semiconductor lasers is used, the amount of light can be increased, and the laser light emitted from each semiconductor laser is integrated and guided to the object to be illuminated. It is possible to prevent the light and darkness corresponding to the semiconductor laser arrangement from being formed on the object. Furthermore, since the light diffusing means for diffusing the laser light emitted from the semiconductor laser is provided, speckle noise can be reduced. As the light diffusing means, an optical element having minute irregularities can be used.
[0011]
Further, in the projection display apparatus according to the present invention, the illumination device includes a first illumination device that emits red light, a second illumination device that emits green light, and a third illumination that emits blue light. And a dichroic prism that is provided between each of the illumination devices and the projection lens and synthesizes each color light emitted from each of the illumination devices .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an illumination device and a projection display apparatus according to an embodiment of the present invention will be described with reference to FIGS.
[0013]
FIG. 1 is a view showing an optical system of a three-plate type projection display apparatus. The projection display apparatus includes three illumination devices 1R, 1G, and 1B (hereinafter, when the individual illumination devices are indicated without being specified, the symbol “1” is used). The illumination device 1R emits red light, the illumination device 1G emits green light, and the illumination device 1B emits blue light. The light emitted from each illuminating device 1 is guided to the liquid crystal display panels 3R, 3G, and 3B for the respective colors by the condenser lens 2 (hereinafter, when the individual liquid crystal display panels are indicated without being specified, the symbol “3” is indicated). Use). Each liquid crystal display panel 3 includes an incident side polarizing plate, a panel portion in which liquid crystal is sealed between a pair of glass substrates (pixel electrodes and alignment films are formed), and an output side polarizing plate. . The modulated light (each color video light) modulated by passing through the liquid crystal display panels 3R, 3G, 3B is synthesized by the dichroic prism 4 to become color video light. This color image light is enlarged and projected by the projection lens 5 and projected and displayed on the screen.
[0014]
The illumination device 1 is emitted from each LD chip 11 and a light source 12 in which LD (laser diode) chips 11 are arranged in an array and lens cells 14 are arranged on the light emitting side of each LD chip 11. The laser beam collimated by the lens cell 14 is integrated with a liquid crystal display panel 3 and guided by a fly-eye lens pair 13. Thus, since the LD chips 11 are arranged in an array, the amount of light can be increased.
[0015]
As shown in FIG. 2, the fly-eye lens pair 13 is composed of a pair of lens groups 13a and 13b, and each lens pair emits laser light emitted from each LD chip 11 to a liquid crystal display panel. 3 is led to the whole surface. That is, since the laser light emitted from the LD chip 11 is integrated and guided to the liquid crystal display panel 3, it is possible to prevent the light and darkness of the array from being formed on the liquid crystal display panel 3 (on the screen image). it can.
[0016]
A phase shift plate 15 is provided between the fly-eye lens pair 13 and the condenser lens 2. As shown in FIGS. 3A and 3B, the phase shift plate 15 includes a plurality of transparent plate portions disposed on the laser light paths of the LD chips 11 and having different thicknesses. Both surfaces of each flat transparent portion are orthogonal to the optical axis. When light is transmitted through the flat transparent portion, the light distance (optical distance (n × d: n is the refractive index, d is the medium thickness)) is changed in proportion to the refractive index. Since the thickness of each flat plate transparent portion is different, the light distance (optical distance) is also different, and the phase of the laser beam transmitted through each flat plate transparent portion is different. As a result, each laser beam emitted from the LD chip 11 has a different phase, and the phase from each LD chip 11 superimposed on the liquid crystal display panel 3 becomes non-uniform, thereby reducing speckle noise. can do.
[0017]
In the above configuration example, the phase shift plate 15 is provided between the fly-eye lens pair 13 and the condenser lens 2, but the present invention is not limited to this, and the space between the LD chip 11 and the liquid crystal display panel 3 is not limited thereto. What is necessary is just to arrange | position in either location.
[0018]
FIG. 4 shows the phase shift plate 16. The phase shift plate 16 is composed of a plurality of flat plate transparent portions (a plurality of flat plate transparent regions) having the same thickness, as shown in FIG. Each flat plate transparent portion (each flat plate transparent region) is disposed on the optical path of the laser light emitted from each LD chip 11. Each flat transparent portion has the same thickness, but as shown in FIG. 4B, its refractive index (refractive index corresponds to dielectric constant) n is n ₀ , n ₁ , n _2. , ... are different from each other. When laser light is transmitted through the flat plate transparent portion, the light distance (optical distance) changes in proportion to the refractive index, so the phase of the laser light transmitted through each flat plate transparent portion is different. As a result, the phase of the laser light itself emitted from the LD chip 11 is the same, but the phase of the laser light of the other LD chip 11 is different, and the phase on the liquid crystal display panel 3 is different. It becomes non-uniform to each other, and speckle noise can be reduced.
[0019]
In FIG. 5, the modification of the illuminating device 1 is shown. In the illuminating device shown in FIG. 5, a plate-shaped wedge-shaped prism 17 is disposed on the optical path of the laser light emitted from the light source 12. When the laser light is incident on the plate-shaped wedge-shaped prism 17, the light distance (optical distance) varies in the thickness change direction of the prism 17, so that the laser light emitted from the LD chip 11 is within the light itself. The phase changes. Also, the LD chips 11... Arranged in the thickness changing direction have different laser light phases. Thereby, speckle noise can be reduced. One plate-shaped wedge-shaped prism 17 is preferably arranged corresponding to one LD chip 11, and the wedge degree (angle) of each plate-shaped wedge-shaped prism 17 is changed. Better.
[0020]
In the above example, the speckle noise is reduced by shifting the phase of the laser light of each LD chip 11, but the speckle noise is reduced by providing a light diffusion means for diffusing the laser light on the optical path. Is possible. As the light diffusing means, frosted glass having minute irregularities can be used. Further, minute irregularities may be formed on the surfaces of the fly-eye lens pair 13 and the condenser lens 2.
[0021]
In the above description, the fly-eye lens pair is shown as the integration means, but a rod integrator may be used. The LD chip is not limited to the edge emitting type, and a surface emitting laser may be used. In addition, a substrate in which a plurality of LDs are formed on a single substrate can be used. Further, in the projection display apparatus, not only the transmission type liquid crystal display panel but also a reflection type liquid crystal display panel may be used, or instead of these liquid crystal display panels, minute mirrors serving as pixels are individually driven. A type of display panel may be used. In addition, the three illumination devices 1R, 1G, and 1B that emit light of each color are provided. However, the illumination device emits white light and is guided to a single-plate color display panel with or without spectral separation using a dichroic mirror or the like. It is good also as a structure. In the case of a lighting device that emits white light, LDs that emit red light, blue light, and green light may be appropriately arranged.
[0022]
Although not shown, a polarization conversion device may be provided at a position before the condenser lens 2 or the like. This polarization conversion device is constituted by a polarization beam splitter array (hereinafter referred to as a PBS array). The PBS array includes a polarization separation film and a phase difference plate (1 / 2λ plate). Each polarization separation film of the PBS array passes, for example, P-polarized light out of the light from the fly-eye lens pair 13, and changes the optical path of S-polarized light by 90 °. The S-polarized light whose optical path has been changed is reflected by the adjacent polarization separation film and emitted as it is. On the other hand, the P-polarized light transmitted through the polarization separation film is converted into S-polarized light by the retardation plate provided on the front side (light emitting side) and emitted. That is, almost all light is converted to S-polarized light.
[0023]
【The invention's effect】
As described above, according to the present invention, an effect of reducing the speckle noise generated in the case of using the record over THE.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an optical system of a projection display apparatus according to an embodiment of the present invention.
FIG. 2 is an explanatory view showing an integration effect by the lighting device of FIG. 1;
3A is a side view of the phase shift plate, and FIG. 3B is a front view.
4A is a side view of the phase shift plate, and FIG. 4B is a front view.
FIG. 5 is an explanatory view showing the operation of a lighting apparatus according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Illuminating device 11 LD chip 12 Light source 13 Fly eye lens pair 14 Lens cell 15 Phase shift plate 16 Phase shift plate 3 Liquid crystal display panel

Claims (3)

An illumination device having a light source formed by arranging a plurality of lasers and a pair of fly-eye lenses that integrate and guide light emitted from the laser, and modulates the light emitted from the illumination device to generate video light In a projection display apparatus comprising: a display panel; a condenser lens that guides light emitted from the illumination device to the display panel; and a projection lens that enlarges and projects the image light.
A plurality of flat plates provided on the optical path of the light emitted from the laser and provided between the illuminating device and the condenser lens and having different thicknesses that make the phases of the light emitted from the laser non-uniform to each other A projection-type image display device comprising phase shift means comprising a transparent portion. An illumination device having a light source formed by arranging a plurality of lasers and a pair of fly-eye lenses that integrate and guide light emitted from the laser, and modulates the light emitted from the illumination device to generate video light In a projection display apparatus comprising: a display panel; a condenser lens that guides light emitted from the illumination device to the display panel; and a projection lens that enlarges and projects the image light.
A plurality of different dielectric constants provided on the optical path of the light emitted from the laser and between the illuminating device and the condenser lens and making the phases of the light emitted from the laser non-uniform to each other A projection-type image display device comprising phase shift means comprising a flat transparent portion. The projection display apparatus according to claim 1 or 2,
The lighting device includes a first lighting device that emits red light, a second lighting device that emits green light, and a third lighting device that emits blue light.
A projection-type image display device comprising: a dichroic prism provided between each of the illumination devices and the projection lens, for combining the color lights emitted from the illumination devices.

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