JP2002174854A - Optical device for projection and projection type picture display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically improve the utilization efficiency of luminous flux from a white light source in an illumination optical device separating the luminous flux from the white light source into three primary colors and compositing them. SOLUTION: This rear projection type picture display device using the optical device for projection is equipped with an auxiliary light source 16 emitting the light of two primary colors complementing color light having minimum spectral energy in the case of spectrally splitting the luminous flux from the white light source 17 into three primary colors, and light is synthesized on a display element 11 by a multi-lens array 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates white light from a light source into three primary colors, and modulates each color light with a display element.
A projection optical device having projection means for projecting a light beam modulated by a display element, a projection display device for enlarging and projecting a projection image obtained by the projection optical device onto a screen by a return mirror, and a projection television The present invention relates to a projection type image display device such as a television set.

[0002]

2. Description of the Related Art With the diversification of video sources, projection-type image display devices have become widespread in the market because of their light weight, low cost, and compactness as large-screen projection optical devices. Under these circumstances, in addition to the conventional projection tube, a liquid crystal display element (hereinafter referred to as a liquid crystal panel) is used as an image source.
In recent years, a projection type image display device using a reflection type image display device (DMD: Digital Micromirror Device) having a plurality of micromirrors has begun to appear on the market in recent years.

[0003] Among them, the liquid crystal panel and the reflection type image display element do not emit light by themselves unlike the conventional projection type cathode-ray tube, so that a separate light source is required. For this reason, in a projection type image display apparatus using a display element which does not emit light by itself, means for separating white light from a white light source into three primary colors is required.

The liquid crystal panel modulates the light transmittance in accordance with a video signal, and enlarges an original image displayed on the liquid crystal panel on a screen by a projection lens device to display a full-color video. . The optical system of the projection type image display device using this liquid crystal panel includes a three-panel system using three liquid crystal panels according to three primary colors of red, blue and green;
There is a single-panel system using only one liquid crystal panel.

FIG. 15 is a cross-sectional view showing a main part of an example of a conventional three-plate type illumination optical device using three transmission type liquid crystal panels. In FIG. 15, 1 is a projection lens, 2, 3,
Reference numerals 4 and 15 are folding mirrors, 5, 6 and 7 are field lenses, 10 is a condenser lens, 12 is a photosynthetic prism, and 8 and 9 are dichroic mirrors for separating a white light beam into three primary color lights. Reference numeral 11 denotes a liquid crystal panel, 13 denotes a polarizing plate, and 17 denotes a lamp as a white light source.
Reference numeral 14 denotes an integrator optical system (hereinafter, referred to as a multi-lens array) disclosed in, for example, Japanese Patent Application Laid-Open No. H8-304739, which includes a plurality of rectangular lens elements that arrange incident light beams in a matrix. A first multi-lens array 14a for splitting into a plurality of light beams, and a plurality of light beams split by the first multi-lens array by a plurality of rectangular lens elements arranged in a matrix are respectively enlarged on a liquid crystal panel. And a polarization conversion function of emitting a desired polarized wave by a plurality of polarizing beam splitters and a 1 / 2λ retardation plate provided for each of the plurality of lens elements. A polarized light illuminating device that includes a multi-lens array 14b and emits a desired polarized wave component is formed by the white light source 17 and the multi-lens array 14. To have.

The plurality of polarizing beam splitters of the second multi-lens array 14b have a shape in which a plurality of columnar translucent plate members each having a parallelogram-shaped cross section are alternately bonded to each other. Has a polarization separation film and a reflection film formed alternately. The light emitted from the plurality of lens elements of the second multi-lens array 14b enters the polarization beam splitter of the polarization beam splitter. The P-wave component that can pass through the polarization splitting film is reflected, and the S-wave component is reflected, reflected again by the adjacent reflection film, and emitted. P transmitted through the polarization separation membrane
The wave component is converted into an S wave by a 1 / 2λ retardation plate formed on the emission surface portion and emitted. In this way, a desired vibration direction component is selected. In the above example, the outgoing light is an S-wave, but is not limited to this.

The operation of FIG. 15 will be described below. The white light beam from the lamp 17 is emitted by the multi-lens array 14 as a light beam having a desired polarized wave component, and is reflected by the turning mirror 15.
And is incident on the condenser-lens 10. The condenser lens 10 superimposes and condenses the light beams split by the multi-lens array on the liquid crystal panel 11 to perform uniform illumination. The luminous flux passing through the condenser lens 10 is converted into R, G, B light by dichroic mirrors 8 and 9.
The light is color-separated and enters the liquid crystal panel 11. The color light that enters the liquid crystal panel 11 through the return mirrors -2 and 3 has a longer optical path than the other color lights, and is corrected by the field lenses 5, 6, and 7. LCD panel 11
The color light incident on is transmitted after undergoing light modulation by a video signal (not shown), and is color-combined by the light-combining prism 12.
The light is projected on a screen (not shown) by the projection lens 1.

On the other hand, a reflection type image display device having a plurality of micromirrors is turned on per unit time by the angle of the micromirrors with respect to incident light according to an input video signal.
An image is formed on the element by modulating light by controlling the number of times / OFF. This element also does not emit light by itself unlike a conventional projection type cathode-ray tube, and therefore requires a separate light source. For this reason, a projection-type image display device using a reflection-type image display device also needs a means for separating white light from a white light source into three primary colors. The optical system of the projection type image display device using this reflection type image display device is also a three-chip type using three reflection type image display devices according to three primary colors of red, blue and green, and a reflection type image display device. 1
There is a one-chip system using only one chip.

FIG. 16 is a sectional view showing a main part of an example of a conventional one-chip type illumination optical apparatus using only one reflection type image display element. In FIG. 16, reference numeral 24 denotes a projection lens, reference numerals 18 and 19 denote folding mirrors, reference numeral 10 denotes a condenser lens, and reference numeral 23 denotes a color wheel in which dichroic mirrors for separating a white light beam into three primary color lights are combined in a disk shape. Reference numeral 22 denotes a motor for rotating the color wheel at a predetermined rotation speed, and reference numeral 20 denotes a reflection type image display device. Reference numeral 21 denotes a prism (not shown) for distinguishing between ON light and OFF light. 140 is described, for example, in JP-A-3-11.
No. 1806, Japanese Patent Application Laid-Open No. H11-281923 discloses a multi-lens array in which an incident light beam is divided into a plurality of light beams by a plurality of rectangular lens elements arranged in a matrix. A multi-lens array and a plurality of luminous fluxes divided by the first multi-lens array are respectively enlarged by a plurality of rectangular lens elements arranged in a matrix, and are superimposedly irradiated onto the reflective image display element 20. It is a uniform illumination means comprising two multi-lens arrays. Unlike the multi-lens array 14 of FIG. 15, it does not include a polarizing beam splitter and a 1 / 2λ retardation plate. This is because the reflective image display element does not use a polarized wave.

The operation of FIG. 16 will be described below. Light from the light emitting portion 17c of the lamp 17 is reflected by the main reflector 17a and the sub reflector 17b, and is emitted so as to converge near the color wheel 23. The luminous flux from the lamp 17 is bent at approximately 90 degrees by a return mirror 18 and is rotated in a time division manner by a color wheel 23 rotated by a motor 22.
The light is color-separated into G and B lights. The color light that has been subjected to the time-division color separation is substantially parallel to the optical axis by the condenser lens 10 and enters the multi-lens array 140. Multi-lens array 14
0 makes the incident light spatially uniform and emits it. The light emitted from the multi-lens array 140 is bent by the turning mirror 19 and enters the prism 21. The light incident on the prism 21 is bent by the internal reflection surface, and
The light enters the reflective image display element 20 disposed below the light-emitting element 1. The light reflected by the reflection type image display element 20 is again incident on the prism 21 and only the desired light (ON light) is enlarged and projected by a projection lens 24 on a screen (not shown).

In the projection type image display apparatus using the liquid crystal panel and the reflection type image display element described above, since there is no projection type cathode ray tube neck as compared with the case of using a projection type cathode ray tube as shown in FIG. Even with a single 104 configuration, a sufficiently compact set can be realized not only by the depth but also by the set height.

FIG. 21 is a configuration diagram showing the configuration of the set when the depth is further reduced. 20 and 21.
In the figure, 100 denotes an illumination system including a light source, 1 denotes a projection lens, 102 denotes a transmission screen, and 103 denotes a housing. As the transmissive screen 102 used at this time, a two-screen screen composed of a Fresnel sheet made of a Fresnel lens and a lenticular lens sheet is mainly used.

[0013]

In the above-mentioned projection type image display apparatus using the liquid crystal panel and the reflection type image display element according to the prior art, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp is used as a white light source used in an illumination optical system. Lamps and the like were used. Particularly, in recent years, an ultra-high pressure mercury lamp having a spectral energy distribution shown in FIG. 11 has become mainstream because of its superior luminous efficiency as compared with other lamps (FIG. 12 is a characteristic diagram extracted only in the visible region).
As shown in the characteristic diagram of FIG. 11, this ultra-high pressure mercury lamp has a relative energy in the red wavelength region extremely inferior to other color lights. Further, in order to prevent deterioration of the display element itself due to ultraviolet rays present in a wavelength region of 400 nm or less, a filter for completely blocking ultraviolet rays is provided between the lamp and the display element.

Therefore, the white luminous flux from the lamp is changed to red, green,
The brightness of a white image obtained after spectral separation / synthesis with the three primary colors of blue (there is no prism for synthesizing light in the one-chip type illumination optical device using only one reflective image display element in FIG. 16). Is determined by the overall efficiency of each dichroic mirror whose example is shown in FIG. FIG.
FIG. 4 is a characteristic diagram showing a spectral energy distribution in consideration of the overall efficiency when a light beam from a white light source is spectrally separated / combined by an illumination optical device. Since the color light distribution of each of the three primary colors of the combined white light is based on the red light having the smallest spectral energy, it is necessary to discard a part of the green light having the largest spectral energy. For this reason, in the conventional illumination optical device, it has not been possible to effectively use all the luminous flux diverging from the lamp.

For example, Japanese Patent Application Laid-Open No. 2000-305040 discloses a projection display device provided with a red rope light source.

[0016]

According to the present invention, when a white light beam is split into three primary colors of red, green, and blue, green light having the largest spectral energy is compensated for the insufficient color light. An auxiliary light source for generating primary color light is provided, and the auxiliary light source for generating the two primary color lights makes effective use of all light beams diverging from the lamp. A first multi-lens array for dividing an incident light beam into a plurality of light beams by a plurality of lens elements arranged in a matrix between the white light source and the auxiliary light source to a display element; and a first multi-lens array arranged in a matrix. A multi-lens array, which is a uniform illuminating means, including a second multi-lens array for enlarging a plurality of light beams divided by the first multi-lens array by a plurality of lens elements and superimposing and irradiating the light beams on the display element Deploy. The white light from the white light source is incident on the first multi-lens array close to the light source, and the light from the auxiliary light source for generating the two primary colors is also incident on the first multi-lens array. The light beam is expanded by the lens array and is incident on the display element.

In particular, when the display element is a liquid crystal panel, the incident light flux is arranged in a matrix between the white light flux from the white light source and the auxiliary light source for generating the two primary colors from the display element. A first multi-lens array that divides the light into a plurality of light beams by a plurality of lens elements, and a plurality of light beams that are divided by the first multi-lens array by a plurality of lens elements arranged in a matrix. It has a polarization conversion function of irradiating a superimposed light onto the display element and emitting a desired polarized wave by a plurality of polarizing beam splitters and a λλ phase difference plate respectively provided for the plurality of lens elements. The second
And a multi-lens array composed of the multi-lens array of FIG.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of an illumination optical device as an example of an embodiment of the present invention. In FIG. 1, 1 is a projection lens, 2, 3, 4, and 15 are folding mirrors, 5, 6, and 7 are field lenses,
Is a condenser lens, 12 is a photosynthetic prism, 8,
9 is a dichroic mirror, 11 is a liquid crystal panel, 13
Is a polarizing plate, 17 is a lamp as a white light source, and 16 is a light emitting diode as an auxiliary light source.

A multi-lens array 14 is an integrator optical system. The first multi-lens array 14a divides an incident light beam into a plurality of light beams by a plurality of rectangular lens elements arranged in a matrix. A plurality of rectangular lens elements arranged in a matrix form
A plurality of light beams split by the multi-lens array are enlarged and irradiated onto a liquid crystal panel in a superimposed manner, and a plurality of polarizing beam splitters respectively corresponding to the plurality of lens elements are combined with a 1 / 2.lambda. The white light source 17 and the multi-lens array 14 form a polarization illuminating device that emits a desired polarized wave component with the second multi-lens array 14b having a polarization conversion function of emitting a desired polarized wave by the phase difference plate. are doing. Reference numeral 16 denotes a light emitting diode as an auxiliary light source, which includes a plurality of light emitting diodes as described later. FIG.
FIG. 15 is obtained by adding a light emitting diode 16 as an auxiliary light source to FIG. 15, and the same reference numerals are given to common parts, and detailed description is omitted.

First, the necessity of the red auxiliary light source, which is the first auxiliary light source, will be described. The white light source 17 is an ultra-high pressure mercury lamp having the spectral energy distribution shown in FIG. 11 (FIG. 12 is a characteristic diagram extracted only in the visible region). As shown in the characteristic diagram of FIG. 11, this ultra-high pressure mercury lamp has a relative energy in the red wavelength region extremely inferior to other color lights.
Therefore, the light of the red light emitting diode 16 having the directional characteristic (generating a substantially parallel light beam) as shown in FIG. 2 and having the relative light emission intensity shown in FIG.

In FIG. 3, the peak of the red light emitting diode 16 is shown.
The peak wavelength is 645 nm, but is not limited thereto, and may be any peak wavelength between 590 nm and 700 nm. FIG. 6 shows the white light flux of the lamp 17 and the auxiliary light source 16.
(In this embodiment, a red light beam having a peak wavelength of 645 nm) is incident on each lens element of the multi-lens array 14.

A light beam from the auxiliary light source 16 for generating a red light beam is incident on a lens element having an R display in FIG. When a rectangular reflector is used for the lamp 17 (FIG. 1), the light beam from the lamp 17 is incident on the hatched region. When a round reflector is used, a light beam enters a region shown by a circle in FIG. In FIG. 6, four red light emitting diodes 16 as auxiliary light sources are used.

Next, the necessity of the blue auxiliary light source as the second auxiliary light source will be described. The ultra-high pressure mercury lamp 17 is shown in FIG.
As shown in the characteristic diagram, a light beam in a wavelength region (ultraviolet region) of 400 nm or less is also generated. Ultraviolet light has a high energy and deteriorates the characteristics of the liquid crystal panel and the DMD element itself. For this reason, in the illumination optical device, a filter for completely blocking ultraviolet rays is provided between the lamp and the element. Due to the characteristics of the ultraviolet cutoff filter and the overall characteristics of the blue light selection filter (efficiency Blue in FIG. 13), the amount of blue light flux that can be used effectively decreases. For this reason, if the light amount of the green light beam is used as a reference, the light amount of the blue light beam is also insufficient after the red light beam.

Therefore, the blue light-emitting diode 16 having the directional characteristics (generating a substantially parallel light beam) as shown in FIG. 2 and having the relative light emission intensity shown in FIG.
Is incident on the multi-lens array 14. In FIG. 4, the peak wavelength of the blue light emitting diode 16 is 447 nm.
However, the present invention is not limited to this, and it is sufficient if the peak wavelength is between 420 nm and 470 nm.

FIG. 7 shows the white light flux of the lamp 17 and the auxiliary light source 1.
6 shows where the light beam from No. 6 (a blue light beam having a peak wavelength of 447 nm in this embodiment) is incident on each lens element of the multi-lens array 14. A light beam from the auxiliary light source 16 for generating a blue light beam is incident on a lens element having a B display in FIG. Lamp 17 as in FIG.
When a rectangular reflector is used (FIG. 1), the light flux from the lamp 17 is incident on a region indicated by oblique lines. Also,
When a round reflector is used, a light beam enters a region shown by a circle in FIG.

FIG. 8 shows a case in which a rectangular reflector is used as a lamp 17 and four red light emitting diodes 16 are used as auxiliary light sources.
An example including R and four blue light emitting diodes 16B is shown. Red light emitting diode 16R and blue light emitting diode 1
6B are arranged at respective symmetrical positions to achieve equalization.

FIG. 9 shows an example in which six red light emitting diodes 16R and six blue light emitting diodes 16B are provided as auxiliary light sources. Each light emitting diode is arranged at a symmetrical position to achieve equalization.

FIG. 10 shows an example in which a large number of red light emitting diodes and blue light emitting diodes are used.

FIG. 5 shows one embodiment of the reflection type image display device of the present invention.
It is sectional drawing which shows the principal part of an example of the one-chip type illumination optical device which uses only one piece. In FIG. 5, reference numeral 24 denotes a projection lens, reference numerals 18 and 19 denote folding mirrors, reference numeral 10 denotes a condenser lens, and reference numeral 23 denotes a color wheel in which dichroic mirrors for separating a white light beam into three primary colors are combined in a disk shape. Reference numeral 22 denotes a motor for rotating the color wheel at a predetermined rotation speed, and reference numeral 20 denotes a reflection type image display device. Reference numeral 21 denotes a prism (not shown) for distinguishing between ON light and OFF light.

Reference numeral 140 denotes a multi-lens array which is an integrator optical system. The first multi-lens array 140 divides an incident light beam into a plurality of light beams by a plurality of rectangular lens elements arranged in a matrix. And a second multi-lens for enlarging and irradiating a plurality of light fluxes divided by the first multi-lens array with a plurality of rectangular lens elements arranged in a matrix form onto the reflective image display element 20 in a superimposed manner. This is a uniform illumination means comprising a lens array. Unlike the multi-lens array 14 of FIG. 1, it does not have a polarizing beam splitter and a 1 / 2λ retardation plate. This is because the reflective image display element does not use a polarized wave.
Reference numeral 16 denotes a light emitting diode as an auxiliary light source.
FIG. 5 is obtained by adding a light-emitting diode 16 as an auxiliary light source to FIG. 16, and the common parts are denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 17 shows an example of the arrangement of red light emitting diodes 16R and blue light emitting diodes 16B, which are auxiliary light sources.

In the embodiment of the present invention, the white light beam from the lamp 17 is converted into a substantially parallel light beam by the condenser lens 10 with the convergent light, and is incident on the multi-lens array 140. The separation into the three primary colors is performed by rotating the color wheel 23.

In the projection type image display apparatus using the liquid crystal panel and the reflection type image display element of the present invention described above, a compact illumination optical apparatus can be realized.
As shown in (1), even with a single folding mirror 104, a sufficiently compact set can be realized not only by the depth but also by the setting height.

FIG. 21 is a configuration diagram showing the configuration of the set when the depth is further reduced. 20 and 21.
In the figure, 100 denotes an illumination optical device including a light source, 1 denotes a projection lens, 102 denotes a transmission screen, and 103 denotes a housing.

The transmissive screen used in the projection type image display device of the present invention is a two-screen screen composed of a Fresnel sheet 32 composed of Fresnel lenses and a lenticular lens sheet 36 shown in FIG. The Fresnel sheet 32 includes the antireflection film 30 on the incident surface 40,
It has a Fresnel lens 31 on the exit surface.

The lenticular lens sheet 36 has a lenticular lens 33 arranged on the incident surface in the horizontal direction of the screen with the vertical direction of the screen as the longitudinal direction. A lenticular lens 37 arranged in the horizontal direction of the screen is provided, a projection 41 is provided at a portion where light from the lenticular lens 33 is not converged, and a light absorbing layer is provided on the surface to prevent a decrease in contrast due to the influence of external light. ing. The diffusing material 42 is diffused inside the lenticular lens sheet 36, and mainly diffuses incident light in the vertical direction of the screen to improve the vertical viewing angle.

The image light projected from the projection lens onto the screen 102 becomes substantially parallel by the Fresnel sheet 32, is condensed in the horizontal direction by the lenticular lens 33, and is substantially in the vicinity of the exit surface of the lenticular sheet 36. Form an image. The formed image light is diffused in the horizontal direction, but is further diffused in the horizontal direction by the lenticular lens 37, so that the horizontal viewing angle is widened. By providing the lenticular sheet 36 with a wavelength-selective filter described later, the contrast performance can be improved.

FIG. 18 shows another embodiment. As shown in FIG. 18, the lenticular lens sheet 36 is composed of two components. 34 is a first component,
A lenticular lens 33 whose longitudinal direction is the screen screen vertical direction is continuously arranged in the screen horizontal direction on the incident surface, and a light passing window 43 through which an image light flux passes near the focal point of each lenticular lens. Is provided. Further, between adjacent light passing windows, a light absorbing layer 3 is provided.
5 is provided to prevent a decrease in contrast due to the influence of external light. The thickness of the first component 34 in the optical axis direction is about 1.5 times the lens pitch when the lens shape is an ellipse, and is about 5 times even if the focal position is shifted using an aspheric surface. . For this reason, if the lens pitch is made smaller, the thickness becomes thinner and the mechanical strength is reduced.

Therefore, in this embodiment, the first component is bonded or adhered to the second component 38 (a thermoplastic resin is generally used in terms of cost).
The writer mixes the second component 38 with a dye or a pigment and adds wavelengths of 485 nm to
A trial production of a transmission screen having absorption characteristics in the range of 75 nm to 595 nm confirmed that the contrast performance was improved. Further, when the antireflection film 39 is provided on the image viewing side surface of the second component 38, the reduction in contrast performance when external light is incident on the screen can be greatly improved.

By using the transmission type screen provided with the above-described wavelength selective filter, even if external light is incident on the screen surface, the contrast performance of the obtained image does not easily deteriorate. In addition, by mixing a diffusing material into the above-described second component 38, the diffusion of the video light in the vertical direction of the screen and a part of the diffusion of the video light in the horizontal direction of the screen are shared. As a result, there is another effect that it is not necessary to mix a diffusing material into the first component, the light flux blocked by the light absorbing layer is reduced, and the brightness is improved.

[0041]

According to the present invention, in an illumination optical device, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like is used as a white light source, and a white light beam is emitted by red light.
By providing an auxiliary light source that generates two primary colors to compensate for the lack of color light for the green light having the largest spectral energy when spectrally separated into three primary colors of green and blue, the entire light flux from the lamp is effectively used. be able to. Further, since the illumination optical device is smaller than the projection type cathode ray tube, a compact rear projection type display device can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of an illumination optical system according to the present invention.

FIG. 2 is a characteristic diagram showing directional characteristics of an auxiliary light source according to the present invention.

FIG. 3 is a characteristic diagram showing the spectral relative emission intensity of the auxiliary light source of the present invention.

FIG. 4 is a characteristic diagram showing the spectral relative emission intensity of the auxiliary light source of the present invention.

FIG. 5 is a configuration diagram showing a main part of the illumination optical system of the present invention.

FIG. 6 is an explanatory diagram used to describe a state of incidence of a light beam on a multi-lens array.

FIG. 7 is an explanatory diagram used to describe a state of incidence of a light beam on a multi-lens array.

FIG. 8 is an explanatory diagram used to describe a state of incidence of a light beam on a multi-lens array.

FIG. 9 is an explanatory diagram used to describe a state of incidence of a light beam on a multi-lens array.

FIG. 10 is an explanatory diagram used to describe a state of incidence of a light beam on a multi-lens array.

FIG. 11 is a graph showing a spectral energy distribution of an ultra-high pressure mercury lamp.

FIG. 12 is a graph showing a spectral energy distribution of an ultra-high pressure mercury lamp.

FIG. 13 is a graph showing the overall efficiency of the three primary colors of the illumination optical device.

FIG. 14 is a graph showing a relative energy distribution of three primary colors that can be used in the illumination optical device.

FIG. 15 is a configuration diagram showing a main part of a conventional illumination optical system.

FIG. 16 is a configuration diagram showing a main part of a conventional illumination optical system.

FIG. 17 is an explanatory view showing an arrangement of an auxiliary light source according to the present invention.

FIG. 18 is a configuration diagram showing a configuration of a transmission screen of the present invention.

FIG. 19 is a configuration diagram showing a configuration of a transmission screen of the present invention.

FIG. 20 is a vertical sectional view showing a main part of a rear projection type image display apparatus equipped with the projection optical system of the present invention.

FIG. 21 is a vertical sectional view showing a main part of a rear projection type image display device equipped with the projection optical system of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Projection lens 2, 3, 4, 15 Folding mirror 5, 6, 7 Field lens 8, 9 Dichroic mirror 10 Condenser lens 11 Liquid crystal panel 12 Photosynthetic prism 13 Polarizer 14 Multi-lens array 14a First multi-lens array 14b Second Multi-lens array 16 Auxiliary light source 17 Lamp 17a Main reflector 17b Sub-reflector 17c Light-emitting section 18, 19 Folding mirror 20 Reflective image display element 21 Prism 22 Motor 23 Color wheel 24 Projection lens 30 Anti-reflection film 31 Fresnel lens 32 Fresnel Lens sheet 33 Lenticular lens (incident surface) 34 First component 35 Light absorbing layer 36 Lenticular lens sheet 37 Lenticular lens (emission surface) 38 Second component 39 Reflection Tomemaku 40 Fresnel lens sheet of the incident surface 41 protrusions 42 diffusing material 43 light passage window 100 illumination optical system 102 transmission screen 103 housing 104 folding mirror 140 multi-lens array

Continued on the front page (72) Inventor Nobuo Masuoka 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Digital Media System Division of Hitachi, Ltd. 2H088 EA15 HA13 HA15 HA21 HA24 HA25 HA28 MA05 2H091 FA05Z FA11Z FA14Z FA26X FA29Z FA41Z FA45Z FD21 LA16 MA07

Claims (8)

[Claims] 1. A white light source, means for dispersing a white light beam from the white light source into three primary colors of red, green, and blue, and generating two primary color lights other than the color light having the largest spectral energy among the three primary colors. A first auxiliary light source for splitting an incident light beam into a plurality of light beams by a plurality of lens elements arranged in a matrix between the white light source and the auxiliary light source for generating the two primary color lights and the display element; A multi-lens array, and a second multi-lens array for enlarging and irradiating a plurality of light beams divided by the first multi-lens array with a plurality of lens elements arranged in a matrix form onto the display element. An illumination optical system comprising a multi-lens array as a uniform illumination means comprising: and a projection means for projecting a light beam modulated by the display element. Projection optical system according to claim. 2. A white light source, means for dispersing a white light beam from the white light source into three primary colors of red, green and blue, and generating two primary color lights other than the color light having the largest spectral energy among the three primary colors. A first auxiliary light source for splitting an incident light beam into a plurality of light beams by a plurality of lens elements arranged in a matrix between the white light source and the auxiliary light source for generating the two primary color lights and the display element; A multi-lens array; a plurality of light fluxes divided by the first multi-lens array by a plurality of lens elements arranged in a matrix; A second polarization beam splitter having a polarization conversion function of emitting a desired polarized wave by a plurality of polarization beam splitters and a λλ phase difference plate respectively corresponding to
A projection optical device, comprising: an illumination optical system including a multi-lens array including the multi-lens array described above; and a projection unit configured to project a light beam modulated by the display element. 3. The projection optical device according to claim 1, wherein the auxiliary light source includes a plurality of light emitting diodes. 4. An auxiliary light source for generating said two primary color lights.
The peak wavelength of the light beam generated from the
4. The projection optical device according to claim 1, wherein a peak wavelength of a light beam generated from the other auxiliary light source is 0 nm or less and 590 nm or more and 700 nm or less. 5. The multi-lens array according to claim 1, wherein the light flux from the auxiliary light source for generating the two primary color lights is incident on a part of the multi-lens array. Projection optical device. 6. The projection according to claim 5, wherein a light beam from the auxiliary light source for generating the two primary color lights is incident on a lens element arranged at a peripheral portion of the multi-lens array. Optical device. 7. A white light source and means for dispersing a white light beam from the white light source into three primary colors of red, green and blue, and two units other than the color light having the largest spectral energy among the three primary colors.
An auxiliary light source for generating primary color light; and a plurality of light beams divided by a plurality of lens elements arranged in a matrix between the white light source and the auxiliary light source for generating the two primary color lights to a display element. A first multi-lens array to be expanded and a plurality of luminous fluxes divided by the first multi-lens array by a plurality of lens elements arranged in a matrix form, each of which is enlarged and irradiated onto the display element in a superimposed manner. An illumination optical system including a multi-lens array that is a uniform illumination unit including a multi-lens array; and a projection lens as a projection unit that projects a light beam modulated by the display element, and projection light from the projection lens. Projection image display, comprising a folding mirror that folds the light, and a transmission screen that projects light from the folding mirror. Location. 8. A white light source and means for splitting a white light beam from the white light source into three primary colors of red, green and blue, and two light sources other than the color light having the largest spectral energy among the three primary colors.
An auxiliary light source for generating primary color light; and a plurality of light beams divided by a plurality of lens elements arranged in a matrix between the white light source and the auxiliary light source for generating the two primary color lights to a display element. A first multi-lens array, and a plurality of luminous fluxes divided by the first multi-lens array by a plurality of lens elements arranged in a matrix are respectively enlarged and irradiated onto the display element in a superimposed manner. A second polarizing beam splitter having a function of emitting a desired polarized wave by using a plurality of polarizing beam splitters and a 1 / 2λ retardation plate respectively provided for a plurality of lens elements;
An illumination optical system comprising a multi-lens array comprising: a multi-lens array; and a folding mirror comprising: a projection lens as a projecting means for projecting a light beam modulated by the display element; and a projection mirror from which the projection light from the projection lens is folded. And a transmissive screen for projecting light from the folding mirror.