JPH11271669A - Illumination means, and illumination optical device and projection type display device using the means - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more uniformly and brightly illuminate the area at a low cost in an illumination means for illuminating the prescribed area and an illumination optical device including the means and to provide a projection type display device capable of presenting the brighter projection images of more uniform brightness by using the illumination optical device. SOLUTION: This illumination optical device 204 is provided with a light source (lamp 101), a first lens array 104 in which at least a part thereof is arrayed in zigzag and a second lens array 105 in which the opening of at least a part of lenses is made almost hexagonal. Then by reducing the real images of the light source projected from the opening of the second lens array 105, high light availability is obtained. Also, this projection type display device is provided with the illumination optical device 204, an optical modulation element (liquid crystal panel 202) and a projection lens 203 to project the more uniform and uniform and bright images on a screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly uses an illuminating means for illuminating a predetermined area in advance, an illuminating optical device using the illuminating device, an illuminating optical device, a spatial light modulator, and a projection lens. The present invention relates to a projection display device that projects a large-screen image on a screen.

[0002]

2. Description of the Related Art Conventionally, a projection display device using various light modulation elements has been known as a video device for a large screen. These use, for example, a transmissive or reflective liquid crystal panel as a light modulation element, illuminate the light modulation element with a light source, and form an optical image corresponding to a video signal supplied from the outside on the light modulation element, and project the light image. The optical image is enlarged and projected on a screen by a lens.

FIG. 12 shows an example of a basic configuration of a projection display device using a transmission type liquid crystal panel. Lamp 901, concave mirror 902, UV-IR cut filter 903,
It comprises a field lens 904, a liquid crystal panel 905, and a projection lens 906.

The white light emitted from the lamp 901 is condensed by the concave mirror 902 to become a light beam traveling along the optical axis 907, and illuminates the display area of the liquid crystal panel 905 via the field lens 904. UV-IR cut filter 9
03 is used for removing unnecessary and harmful infrared light (IR) and ultraviolet light (UV) from illumination light. The field lens 904 is used to effectively guide the light transmitted through the liquid crystal panel 905 to the entrance pupil of the projection lens 906.

As the lamp 901, a metal halide lamp is widely used because of its excellent color reproducibility and luminous efficiency. In addition, a mercury lamp or a xenon lamp in which the inside of the arc tube at the time of lighting is set to an extremely high pressure is used from the viewpoint that a luminous body with high luminance can be obtained.

[0006] Light emitted from the lamp is condensed mainly using a concave mirror having a large solid angle such as a parabolic mirror or an ellipsoidal mirror because the light condensing rate can be increased. Therefore, (FIG. 1
The illumination optical device combining the lamp and the concave mirror shown in 2) is common in this application. However, this illumination optical device can increase the light collection rate, but has the disadvantage that illumination unevenness on the light receiving surface is large.

On the other hand, there has been proposed an illumination optical apparatus in which an optical element called an integrator combining two lens arrays is added to improve the uniformity of illumination light.

For example, the configuration disclosed in Japanese Patent Application Laid-Open No. 3-111806 combines two lens arrays in which a plurality of lenses having the same rectangular opening are two-dimensionally arranged. This configuration has the advantages that the configuration of the lens array is simple, the lens array can be easily formed, and the cost is low. On the other hand, part of the partial light beam converged on the opening of the second lens array is changed from the rectangular opening. If it protrudes, there is a problem that the light is lost and cannot be used effectively. This poses a greater problem as the size of the illuminant used for the light source increases.

When light loss occurs in the illumination optical system,
In order to make the projected image dark or bright, it is necessary to use a lamp with large power consumption, which causes problems such as large heat generation and large set.

On the other hand, the configuration disclosed in Japanese Patent Application Laid-Open No. Hei 5-346557 uses a lens array in which a plurality of lenses having appropriately different apertures are combined. This has an advantage that light that is lost from the opening and is lost can be reduced, and illumination with high efficiency can be realized. On the other hand, such a lens array has a problem that the configuration of the lens array is complicated and difficult to mold, a mold for molding is complicated and expensive, a high lens array, and difficult to mold when the lens array is small. . As a result, there are problems that the projection display device becomes expensive and has low mass productivity, and that it is difficult to reduce the size of the optical system used in the projection display device.

[0011]

The means for illuminating the light modulation element and the optical device for illuminating the light modulation element have high uniformity with little unevenness in brightness and color, which reduces light loss and increases light use efficiency. There is a problem of realizing lighting and realizing high mass productivity and low cost by using cheap and easy-to-make components.

In particular, in an illumination optical apparatus using a lens array which is known as a method for improving the uniformity of brightness, a light component which passes through an opening of a lens of the lens array and is likely to be generated, and the light use efficiency is reduced. There is a problem such as lowering. If the aperture shape of the lens array is complicated to improve light loss, there are problems that the lens array is difficult to form, mass production is difficult, cost is high, and miniaturization of the lens array is difficult.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the illuminating means of the present invention illuminates a predetermined area and comprises a light source and a plurality of first lenses arranged. A first lens array and a second lens array in which a plurality of second lenses are arranged; the first lens array divides a light beam emitted from a light source to form a plurality of partial light beams; Each causes each of the corresponding partial light beams to converge on the corresponding aperture of the second lens, and each of the second lenses causes each aperture of the corresponding first lens to be substantially conjugate with the defined area, and is divided by the first lens array. The cross section of each of the divided partial light beams is guided and illuminated in a superimposed manner on the defined area, at least a part of the plurality of first lenses is arranged in a staggered lattice shape, and at least a part of the plurality of second lenses has an opening thereof. It is good to be substantially hexagonal.

In order to solve the above problems, an illumination optical device according to the present invention is an optical device for illuminating a predetermined area, and comprises a first light source and a plurality of first lenses arranged.
A second lens array having a plurality of second lenses arranged therein;
A first lens array that divides a light beam emitted from the light source to form a plurality of partial light beams, and each of the first lenses places each of the corresponding partial light beams on an opening of the corresponding second lens. By converging, each of the second lenses substantially conjugates the defined area illuminated with each aperture of the corresponding first lens, and guides the cross section of each partial light beam divided by the first lens array to the defined area in a superimposed manner. It is preferable that at least a part of the plurality of first lenses is arranged in a staggered lattice shape, and at least a part of the plurality of second lenses has a substantially hexagonal opening.

In order to solve the above problems, a projection type display device according to the present invention comprises a light source, a first lens array having a plurality of first lenses arranged therein, and a first lens array having a plurality of second lenses arranged therein. A first lens array that divides a light beam emitted from a light source; a two-lens array, a light modulation element that spatially modulates light to form an optical image, and a projection lens that projects the optical image onto a screen. Forming a plurality of sub-beams, each of the first lenses converging each of the corresponding sub-beams onto the corresponding aperture of the second lens, and each of the second lenses is coupled to the respective aperture of the corresponding first lens. The display area of the modulation element is made substantially conjugate, and the cross section of each partial light beam divided by the first lens array is guided and illuminated in a superimposed manner on the display area, and at least a part of the plurality of first lenses is staggered. Arranged in
At least a part of the plurality of second lenses preferably has a substantially hexagonal opening in the lens.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an illuminating means of the present invention, an illuminating optical apparatus using the illuminating means, and a projection display apparatus will be described.
Specific embodiments will be described with reference to the drawings.

(Embodiment of Illumination Means and Illumination Optical Device)
(FIG. 1) shows an example of the configuration to be implemented of the illumination means and the illumination optical device of the present invention. Lamp 101, parabolic mirror 10
2. UV-IR cut filter 103, first lens array 104, second lens array 105, auxiliary lens 12
1, a light receiving surface 108. The first lens array 104 has a plurality of first lenses 109 arranged two-dimensionally, and an example of the configuration is shown in FIG. 2. The second lens array 105 has a plurality of second lenses 110 arranged two-dimensionally, and an example of the configuration is shown in FIG. 3.

FIG. 2 shows a case where 30 first lenses 109 having an opening shape similar to the specified area to be illuminated are arranged. 30 first lenses 109
Have the same opening shape and are arranged in a houndstooth check pattern. The houndstooth check is, for example,
Regarding the first lens arranged in the height direction of the rectangular opening,
This figure shows a state in which they are arranged so as to be shifted in the horizontal direction by の of the horizontal opening length. This is the same even if the arrangement is performed by shifting the opening length by １ ／ in the vertical direction.

The first lens array 1 shown in FIG.
FIG. 3 shows a configuration of the second lens array 105 corresponding to the configuration of the second lens array 105. Thirty second lenses 110, each having a hexagonal opening shape, are arranged in a two-dimensional array. The center of gravity 109A of the first lens 109 (FIG. 2)
And the center of gravity 110A of the second lens 110 in FIG. 3 is at the same position for the corresponding lens pair.

The operation of the illumination optical device shown in FIG. 1 will be described with reference to FIG. Light emitted from the light emitting body 106 formed by the lamp 101 is condensed by the parabolic mirror 102 and becomes a light beam that travels substantially parallel along the optical axis 107. This is indicated by 111. The single light beam 111 is divided by the first lens array 104 into a plurality of partial light beams.
The focal length of each of the first lenses 109 is selected such that the focal point substantially matches the center of gravity 110A of the corresponding second lens 110, and each partial light beam incident on the first lens 109 is
It converges on the corresponding opening of the second lens 110. As a result, a plurality of real images of the luminous bodies 106 corresponding to the number of the first lenses 109 are formed on the openings of the second lens array 105.

Each of the plurality of second lenses 110 enlarges a light beam passing therethrough and guides the light beam onto light receiving surface 108. Each of the light receiving surface 108 and the opening of the first lens 109 has a conjugate relationship with each of the second lens 110 and the auxiliary lens 121. Therefore, if the opening shape of the first lens 109 is similar to the shape of the light receiving surface, it is possible to guide a light beam having a cross section corresponding to the shape of the light receiving surface. By adding the auxiliary lens 121, a plurality of partial light beams emitted from the second lens array 105 are guided onto the light receiving surface in a superimposed form. Alternatively, without using the auxiliary lens 121, the second lens 110
Even if each of them is appropriately decentered, each partial light beam can be superimposed on the light receiving surface.

The illuminating means and the illuminating optical device of the present invention comprise a first lens array 104 having the structure shown in FIG. 2 (FIG. 3).
By using the second lens array 105 having the configuration shown in (1), the following operation and effect can be obtained.

First, problems in the conventional illumination optical device will be described. When an illumination optical device is used in a conventional projection display device, in a specified area to be illuminated, for example, when a liquid crystal panel generally used as a light modulation element is used, a vertical direction similar to the liquid crystal panel is used. The first lens having a rectangular opening shape having a long horizontal direction is arranged. Also, the second
In general, the lenses have the same shape and the same arrangement as the first lens in order to match the center of gravity of each lens of the first lens array.

In this case, a plurality of real images 153 of the light emitters are formed radially from the center 152 of the lens array on the conventional second lens array 151 shown in FIG. Even if sufficient openings are provided, not enough openings are provided in the vertical direction. A part of the real image protruding from the opening is not used because it loses light passing therethrough.

FIG. 5 illustrates the case where the display area having the aspect ratio of 4: 3 is illuminated. However, the case where the display area corresponding to the wide image having the aspect ratio of 16: 9 is illuminated is more remarkable. Problem.

On the other hand, the second lens array 1 of the present invention
A real image of the illuminant is formed on 54 as shown in FIG. The first lens array is arranged in a staggered lattice pattern, and the second
Since the aperture shape of each lens of the lens array 154 is substantially hexagonal, the actual image of the luminous body formed radially is compared with the conventional configuration regardless of the position of each lens in the second lens array. Thus, a more optimal opening shape can be provided. The hexagonal opening shape can provide the same sufficient opening for the real images of the respective luminous bodies spread in the horizontal direction, the vertical direction, and the oblique direction. Further, in order to densely combine the second lenses having a hexagonal opening shape in an array form, it is necessary to arrange the first lens arrays in a staggered lattice form.

According to the above configuration, the illumination optical device of the present invention can suppress loss of light without passing through the opening of the second lens as compared with the conventional configuration. Thus, an illumination optical device having high light use efficiency can be realized, and a great effect is obtained.

(Embodiment of Projection Display Device) (FIG. 7)
1 shows an example of a configuration of the projection display device to be implemented according to the present invention. As shown in FIG. 7, the illumination optical device 204
And a field lens 201, a liquid crystal panel 202, and a projection lens 203 to form a projection display device.

In this case, with the illumination optical device 204 of the present invention, the liquid crystal panel 202 as the light receiving section is illuminated more uniformly, with higher light use efficiency, and brighter than the conventional illumination optical device. . This makes it possible to present a projected image that is brighter and has more uniform brightness as compared with the related art. If the light efficiency of the projection display device is high, a lamp with lower power consumption can be used to obtain the same brightness. If the power of the lamp is small, heat generation in the set is small, and a smaller projector can be realized.

(Other Embodiments) Another embodiment of the above-described illumination means of the present invention and the configuration of a lens array in an illumination optical device and a projection display device using the illumination means will be described.

FIG. 8 shows the number of lenses in the lens array.
An example in which the first lens array and the second lens array are both 14 is shown in FIG.
This is shown in the second lens array 302 (FIG. 8b). At this time,
In the first lens 303 and the second lens 304, according to the configuration of the present invention, the first lenses are arranged in a zigzag pattern, and the aperture of the second lens is substantially hexagonal.

When the number of lenses in the lens array is reduced,
Compared to the case where the number of lenses is large, the configuration of the lens array is simple, the lens array is easy to mold, the cost is low,
There is an advantage. On the other hand, as compared with the case where the number of lenses is large, in general, the degree of brightness uniformity is reduced, and the light use efficiency is also reduced. On the other hand, as a result of examining various design examples, if the number of lenses is at least 14 or more, the loss of light protruding from the aperture of the second lens is reduced, and the light use efficiency is high and the brightness is sufficiently high. It has been found that illumination with high uniformity can be realized.

FIG. 9 shows the first lens array 311 and the second lens array 31 when the number of lenses is 50.
2 is an example of the configuration. Similarly, FIG. 10 shows the first lens array 321 when the number of lenses is 59,
2 is an example of a configuration of a second lens array 322.

When the lens array having the configuration described in FIGS. 9 and 10 is used, the number of lenses is sufficiently large, so that illumination with extremely high brightness uniformity can be realized. at the same time,
By making the opening of the second lens hexagonal, light that goes out of the opening and is lost is greatly reduced, and extremely efficient illumination can be realized. Furthermore, since the lens array of the present invention has the same lens aperture and regular array,
Despite the large number of lenses, the configuration of the lens array is relatively simple and easy to mold. Therefore, an illumination optical device and a projection display device having excellent performance can be configured without increasing the cost.

FIG. 11 shows the first lens array 331 and the second lens array 3 when the number of lenses is 108.
32 is shown. In this case, it is possible to form an illumination optical device having extremely good light utilization efficiency and brightness uniformity. Further, even when the number of lenses is large, the lens array according to the configuration of the present invention can mold a molding die according to a regular procedure, so that a lens array can be produced at a practical cost. There are advantages.

[0036]

As described above, the illuminating means or the illuminating optical device of the present invention can be used for the first lens array and the second optical system without largely changing the configuration of the conventional optical system using the lens array.
By changing the lens array to an appropriate shape, the light use efficiency of the entire optical system can be increased.

Therefore, if a projection type display device is constituted by using the illumination means or the illumination optical device of the present invention, the configuration of the conventional optical system is not changed so much, the light use efficiency is high, and the decrease in light quantity is small. , An optical system can be provided. Thereby, the brightness uniformity is high and a bright projection image can be presented on the screen, so that a very large effect is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an illumination optical device of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an example of a configuration of a first lens array.

FIG. 3 is a schematic configuration diagram illustrating an example of a configuration of a second lens array.

FIG. 4 is a schematic diagram illustrating the operation of the illumination optical device of the present invention.

FIG. 5 is a schematic diagram illustrating the effect of a conventional lens array.

FIG. 6 is a schematic diagram illustrating the effect of an example of the lens array of the present invention.

FIG. 7 is a schematic configuration diagram showing an embodiment of the projection display device of the present invention.

FIG. 8 is a schematic configuration diagram illustrating an example of a configuration of a first lens array and a second lens array.

FIG. 9 is a schematic configuration diagram illustrating an example of a configuration of a first lens array and a second lens array.

FIG. 10 is a schematic configuration diagram illustrating an example of a configuration of a first lens array and a second lens array.

FIG. 11 is a schematic configuration diagram illustrating an example of a configuration of a first lens array and a second lens array.

FIG. 12 is a schematic configuration diagram showing an embodiment of a conventional projection display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Lamp 102 Parabolic mirror 103 UV-IR cut filter 104,301,311,321,331 Example of 1st lens array of this invention 105,302,312,322,332 Example of 2nd lens array of this invention 106 Light-emitting body 108 Light-receiving surface 109, 109A, 303, 313, 323, 333
Example of the first lens of the present invention 110, 110A, 304, 314, 324, 334
Example of second lens of the present invention 121 Auxiliary lens 151 Example of conventional second lens array 152 Center of lens array 153 Real image of light emitter 154 Example of second lens array of the present invention 201 Field lens 202 Liquid crystal panel 203 Projection lens 204 Illumination optical device of the present invention

Claims (3)

[Claims] 1. An illuminating means for illuminating a predetermined area, comprising: a light source; a first lens array in which a plurality of first lenses are arranged; and a second light in which a plurality of second lenses are arranged. A first lens array that divides a light beam emitted from the light source to form a plurality of partial light beams, wherein each of the first lenses corresponds to each of the corresponding partial light beams to the corresponding second light beam. The second lens converges on the opening of the lens, and each of the second lenses substantially conjugates the defined area to be illuminated with the corresponding opening of the first lens.
A cross section of each partial light beam divided by the lens array is guided and illuminated in a superimposed manner on the specified region, and the plurality of first light beams are illuminated.
At least a part of the lenses is arranged in a staggered pattern, and at least a part of the plurality of second lenses has a substantially hexagonal opening. 2. An illumination optical device for illuminating a predetermined area, comprising: a light source; a first lens array in which a plurality of first lenses are arrayed; and a first lens array in which a plurality of second lenses are arrayed. A second lens array, wherein the first lens array divides a light beam emitted from the light source to form a plurality of partial light beams, and each of the first lenses corresponds to each of the corresponding partial light beams to the corresponding first light beam. Each of the second lenses is made to converge on the aperture of the two lenses, and each of the second lenses makes each of the apertures illuminated with the corresponding aperture of the first lens substantially conjugate, and each partial light beam divided by the first lens array. The cross section of the first lens is illuminated by being guided to the specified area in a superimposed form, and at least a part of the plurality of first lenses is arranged in a staggered lattice pattern,
An illumination optical device, wherein at least a part of the plurality of second lenses has a substantially hexagonal opening. 3. A light source, a first lens array in which a plurality of first lenses are arranged, a second lens array in which a plurality of second lenses are arranged, and an optical image obtained by spatially modulating light. And a projection lens for projecting the optical image on a screen, wherein the first lens array divides a light beam emitted from the light source to form a plurality of partial light beams, Each of the lenses causes each of the corresponding partial light beams to converge on the corresponding aperture of the second lens;
Each of the second lenses makes each aperture of the corresponding first lens and a display area of the light modulation element substantially conjugate, and superposes a cross section of each partial light beam divided by the first lens array on the display area. And illuminating in a form, wherein at least a part of the plurality of first lenses are arranged in a staggered pattern, and at least a part of the plurality of second lenses has a substantially hexagonal opening in the lens. Projection type display device.