JP2002189213A - Lighting system and projection liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system or a projection liquid crystal display device capable of miniaturizing the device while retaining other characteristics. SOLUTION: The projection liquid crystal display device 1 is provided with a first lens array 12, a second lens array 13, a first condensing lens 15 and a second condensing lens 23 successively arranged from the light source 11 side. The incident plane 151 of the first condensing lens 15 is in a shape of a convex spherical face divided into a plurality of micro regions 150. A micro beam emitted from respective lens elements of the second lens array 13 passes through the respective micro regions 150 of the first condensing lens 15 and does not pass through difference in level 155 between the micro regions 150. Consequently the first condensing lens 15 is miniaturized while condensing efficiency is maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for irradiating an object with light, and a projection type liquid crystal display device for projecting an image on a screen using the lighting device.

[0002]

2. Description of the Related Art There has been known a projection type liquid crystal display device in which an image formed by a liquid crystal panel is enlarged and projected on a screen by a projection optical system. FIG.
Represents a basic configuration of a general projection-side liquid crystal display device. The projection type liquid crystal display device includes a liquid crystal panel 106,
A lighting device 110 for irradiating the liquid crystal panel 106 with light
The image formed by the liquid crystal panel 106 on the screen 10
8 is provided with a projection optical system 107 for projecting light.

An illumination device 110 has a light source 101 such as a halogen lamp, and further includes a first lens array 102 and a second lens array 102 along a traveling direction of light emitted from the light source 101.
A lens array 103, a first condenser lens 104, a second
And a condenser lens 105. First lens array 1
Numeral 02 divides the light emitted from the light source 101 into a plurality of small light beams and emits them. The second lens array 103 emits small light beams incident through the first lens array 102, respectively. First lens array 102 and second lens array 1
The small light flux passing through the liquid crystal panel 1 is superimposed by the first condenser lens 104 and the second condenser lens 105.
06.

[0004]

Here, in recent years, in order to improve the portability and the like of the projection type liquid crystal display device, the size of the illumination device 110 has been required to be reduced. Since the first condenser lens 104 has the largest size among the optical components of the illumination device 110, it is strongly required to reduce the size of the first condenser lens 104.

As a method of reducing the size of the first condenser lens 104, it is conceivable to use a Fresnel lens.
The Fresnel lens is a lens that is thinned by providing a step portion on an incident surface or an exit surface. However, when a Fresnel lens is used as the first condenser lens 104, light incident on the step portion is scattered,
There is a problem that the light collecting ability is reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lighting device or a projection type liquid crystal display device which can reduce the size of the device while maintaining other characteristics. .

[0007]

An illumination device according to the present invention comprises a light source for emitting a light beam, and a plurality of first lens elements which divide the light beam emitted from the light source into a plurality of small light beams and emit the light beams, respectively. A second lens array in which a first lens array arranged in a parallel manner and a plurality of second lens elements each emitting a small light beam incident through the first lens element of the first lens array are arranged in a plane. And an incident surface on which the small light beam emitted from the second lens array is incident, and an emission surface from which the small light beam incident from the incident surface is emitted, and at least one of the incident surface and the emission surface is a continuous one. A condensing lens configured to divide the curved surface into a plurality of small regions and to move at least one of the small regions in a direction in which a distance between the entrance surface and the exit surface is reduced; Light len Small area is characterized in that it is arranged to capable of condensed by passing at least one of the beamlets passing through each a plurality of second lens element in the second lens array.

A projection type liquid crystal display device according to the present invention comprises a liquid crystal display means for forming an image using a liquid crystal display element, an illumination means for irradiating the liquid crystal display means with light, and an image formed by the liquid crystal display means. A projection type liquid crystal display device comprising projection means for projecting onto a predetermined projection surface, wherein the illumination means divides a light beam emitted from the light source into a plurality of small light beams and emits the light beam. A first lens array in which a plurality of first lens elements are arranged in a plane, and a plurality of second lens elements each of which emits a small light beam incident through the first lens element of the first lens array. A second lens array, which is arranged in a parallel manner, an incident surface on which the small light beam emitted from the second lens array is incident, and an exit surface on which the small light beam incident from the incident surface is emitted, and the incident surface or the exit surface. surface At least one is configured to divide a continuous curved surface into a plurality of small regions and to move at least one of the small regions in a direction in which a distance between the entrance surface and the exit surface is reduced. And a condensing lens, wherein the small area of the condensing lens is arranged so that at least one of the small light beams that has passed through each of the plurality of second lens elements in the second lens array can be condensed. It is characterized by the following.

In the lighting device or the projection type liquid crystal display device according to the present invention, at least one of the entrance surface and the exit surface is
Since the continuous curved surface is divided into a plurality of small regions and at least one of the small regions is moved in a direction to reduce the distance between the entrance surface and the exit surface, the size of the condensing lens in the optical axis direction Becomes shorter. Furthermore, since each small light beam emitted from the second lens array passes through each small area of the condenser lens, even if there is a step between adjacent small areas, light may pass through the step. There is no.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Structure of Projection Type Liquid Crystal Display Device] FIG. 1 shows the whole structure of a projection type liquid crystal display device according to an embodiment of the present invention. Projection type liquid crystal display device 1 of the present embodiment
Is a so-called single-panel projection type liquid crystal display device which performs image display using one transmission type liquid crystal panel. The projection type liquid crystal display device 1 has a light source 11 that emits light. The light source 11 is, for example, a luminous body 11 that emits white light.
A, and a concave mirror 11B that reflects light emitted from the light emitting body 11A and emits the light as substantially parallel light. As the illuminant 11A, for example, a halogen lamp, a metal halide lamp, a xenon lamp, or the like is used. The concave mirror 11B desirably has a shape with high light-collecting efficiency, and has a rotationally symmetric surface shape such as a spheroidal mirror or a paraboloidal mirror.

Along the direction of the optical axis 10 from the light source 11, U
V (ultraviolet) / IR (infrared) cut filter 11C
, A first lens array 12 and a second lens array 13 are sequentially arranged. The optical axis 10 is defined by a lens center of a first condenser lens 15 described later.

The UV / IR cut filter 11C removes ultraviolet light and infrared light contained in the white light emitted from the light source 11. First lens array 1
Each of the second and second lens arrays 13 is for uniformizing the in-plane intensity distribution of light applied to the liquid crystal panel unit 24 described later.

FIG. 2 is a plan view showing the planar structure of the first lens array 12 as viewed from the emission side (the second lens array 13 side). FIG. 3 is a line segment III-III in FIG.
FIG. 3 is a cross-sectional view illustrating a cross-sectional structure of a first lens array 12 taken along a line. As shown in FIG. 2, the first lens array 12
Has a plurality of first lens elements 120 having a positive refractive power arranged in a plane orthogonal to the optical axis 10. The first lens array 12 includes, for example, a plurality of first lens elements 120 having the same rectangular shape and arranged in two directions orthogonal to each other. The planar shape of each first lens element 120 is, for example, a rectangle substantially similar to an effective area (illuminated area) of the liquid crystal panel section 24 described later, and the ratio of the long side to the short side is, for example, 4 to 3. Has become. The plurality of first lens elements 120 divide incident light into a plurality of small light beams and emit the light beams. As shown in FIG.
In each of the first lens elements 120 of the first lens array 12, the incident side surface 121 is a flat surface orthogonal to the optical axis 10, and the exit side surface 122 is a convex spherical surface protruding toward the exit side. .

FIG. 4 is a plan view showing a planar structure of the second lens array 13 as viewed from the exit side (the first condenser lens 15 side). FIG. 5 is a view taken along line VV in FIG. FIG. 3 is a cross-sectional view illustrating a cross-sectional structure of a second lens array 13 according to the first embodiment. As shown in FIG. 4, the second lens array 13 has a plurality of second lens elements 130 having a negative refractive power arranged in a plane orthogonal to the optical axis 10. Like the first lens element 120 of the first lens array 12, the planar shape of each second lens element 130 of the second lens array 13 is a rectangle substantially similar to the effective area of the liquid crystal panel section 24 described later, and has a long shape. The ratio between the side and the short side is, for example, 4 to 3. The second lens elements 130 emit small light beams incident from the first lens elements 120 of the first lens array 12, respectively.

The image indicated by reference numeral 3 in FIG. 4 is an image of the light source 11 as viewed from the emission side of the second lens array 13 (hereinafter referred to as a light source image 3). Since each small light beam emitted from the light source 11 and divided by the first lens array 12 is incident on each lens element 130 of the second lens array 13, the light source image 3 is seen in each lens element 130.

As shown in FIG. 5, the second lens array 1
In each of the second lens elements 130 of FIG.
Reference numeral 1 denotes a convex spherical surface protruding toward the incident side, and a surface 132 on the exit side is a flat surface orthogonal to the optical axis 10. The focal position of each first lens element 120 of the first lens array 12 is configured to be substantially located on the main plane of each second lens element 130 of the second lens array 13.
That is, each first lens element 1 of the first lens array 12
The small luminous flux passing through the second lens array 13
Light is condensed near the main plane of the lens element 130. 1 to 5, the first lens array 1
The second lens element 120 and the lens element 130 of the second lens array 13 are shown in small numbers for simplicity, but may be larger.

A first condenser lens 15 and a second condenser lens 23 are arranged in order from the second lens array 13 along the optical axis 10. The first condenser lens 15 and the second condenser lens 23 constitute a condenser optical system for condensing light on the liquid crystal panel unit 24. The optical axis of the first condenser lens 15 and the second condenser lens 23 is the optical axis 10. Here, in the transmission type liquid crystal display device 1, the second
The portion up to the condenser lens 23 corresponds to a specific example of “illuminating device” or “illuminating means” in the present invention.

FIG. 6 shows a planar structure of the first condenser lens 15 as viewed from the exit side (the second condenser lens 23 side). FIG. 7 is a sectional view taken along line VII-VII in FIG. 3 shows a sectional structure of the first condenser lens 15. FIG.
As shown in (1), the first condenser lens 15 is divided into a plurality of small regions 150 arranged corresponding to each second lens element 130 of the second lens array 13. Each of the small regions 150 of the first condenser lens 15 is adapted to pass a small light beam incident through each of the second lens elements 130 of the second lens array 13.

The image denoted by reference numeral 5 in FIG. 6 is an image of the light source 11 as viewed from the emission side of the second lens array 13 (hereinafter, referred to as a light source image 5). The small luminous flux emitted from the second lens array 13 enters each of the small regions 150 of the first condenser lens 15, so that the light source image 5 can be seen in each of the small regions 150.

As shown in FIG. 7, the first condenser lens 15
Is a flat surface orthogonal to the optical axis. On the other hand, the surface on the incident side (referred to as an incident surface 151) of the first condenser lens 15 is a convex curved surface protruding toward the incident side, and the incident surface 151 is divided into the plurality of small regions 150 described above. ing.

The entrance surface 151 of the first condenser lens 15 divides one continuous virtual sphere 156 into a plurality of small regions 150 and directs at least one of the small regions 150 toward the emission surface 152 ( (Along the optical axis 10). Thereby, the dimension of the first condenser lens 15 in the optical axis direction is reduced. Here, the incident surface 151 has a shape such that the smaller the region 150 near the optical axis 10, the greater the amount of movement H from the virtual spherical surface 156. A step 155 in the direction parallel to the optical axis 10 is formed between two adjacent small regions 150.

Here, each lens element 13 of the second lens array 13 is provided in each small area 150 of the first condenser lens 15.
Since the small luminous fluxes emitted from 0 are respectively incident, little luminous fluxes pass through the step 155 between the small areas 150. That is, it is possible to reduce the size of the first condenser lens 15 without lowering the condenser ability due to scattering of light at the step 155. 1 and 6
7 and FIG. 7, the small area 15 of the first condenser lens 15 is shown.
Although 0 is shown in a small number for simplicity, it may be larger.

A liquid crystal panel section 24 and a projection lens 26 are sequentially arranged from the second condenser lens 23 along the optical axis 10. The liquid crystal panel unit 24 includes the second condenser lens 23
The light that has passed through and is spatially modulated according to image information. The projection lens 26 projects light emitted from the liquid crystal panel unit 24 toward a screen 27 placed at a remote position. Here, the projection lens 26 corresponds to a specific example of “projection unit” in the present invention. The light source 11, the UV / IR cut filter 11C, the first lens array 12, the second lens array 13, the liquid crystal panel unit 24, and the projection lens 26
Are located on the optical axis 10 of the first condenser lens 15 and the second condenser lens 23.

FIG. 8 shows a main configuration of the liquid crystal panel section 24. The liquid crystal panel section 24 is arranged such that, in order from the incident side of light (indicated by an arrow L in FIG. 8), the incident side polarizing plate 31
, A liquid crystal display element 32, optical compensation elements 33 and 34,
An output side polarizing plate 35 is provided. The light incident surface and the light outgoing surface of each optical element of the liquid crystal panel section 24 correspond to the optical axis 1.
It is orthogonal to 0. In FIG. 6, the light incident direction is Z
Shown as direction. Also, for simplicity, the incident side polarizing plate 3
1, the liquid crystal display element 32, the optical compensating elements 33 and 34, and the output side polarizing plate 35 are shown separated from each other.

The incident side polarizing plate 31 is the first of the incident lights.
(X direction in FIG. 8) has a transmission axis 31A that transmits a light component that oscillates in the direction
(The Y direction in FIG. 6). On the other hand, the exit-side polarizing plate 35 has a transmission axis 35A that absorbs a light component that vibrates in the second direction, of the incident light, and absorbs a light component that vibrates in the first direction. . Thus, the arrangement relationship in which the transmission axis 31A of the incident-side polarization plate 31 and the transmission axis 35A of the emission-side polarization plate 35 are orthogonal to each other is also referred to as an orthogonal Nicol relationship.

FIG. 9 shows a detailed configuration of the liquid crystal display element 32. The liquid crystal display element 32 includes a pixel electrode substrate 4
0B and the liquid crystal layer 4 on the incident side of the pixel electrode substrate 40B.
And a counter substrate 40 </ b> A that is disposed to face with the counter substrate 4 interposed therebetween.

The pixel electrode substrate 40B is a glass substrate 47
And a plurality of pixel electrode portions 45 and a plurality of black matrix portions 46 stacked on the light incident surface side of the glass substrate 47. The pixel electrode substrate 40B has an alignment film 49 laminated between the liquid crystal layer 44 and the pixel electrode portion 45 and the black matrix portion 46. Each of the pixel electrode portions 45 is made of a transparent member having conductivity. The black matrix section 46 is formed between adjacent pixel electrode sections 45. Each black matrix section 46 is shielded from light by, for example, a metal film. A switching element such as a thin film transistor (TFT) is formed inside the black matrix unit 46, for example.

The surface of the alignment film 49 on the side in contact with the liquid crystal layer 44 is subjected to a rubbing treatment in order to align the alignment direction of the liquid crystal molecules existing in the emission side region (near the interface with the alignment film 49) in the liquid crystal layer 44. Have been. By the rubbing process, a plurality of grooves are formed on the surface of the alignment film 49 in the same direction.
Are oriented in a certain direction along the grooves formed on the surface of the substrate. Hereinafter, the direction of the groove formed by performing the rubbing process is referred to as a “rubbing direction”.

The counter substrate 40A includes a glass substrate 41, a micro lens 42, and a counter electrode 43 in this order from the incident side.
And an alignment film 48. The alignment film 48 is provided so that the surface on the emission side is in contact with the liquid crystal layer 44. The surface of the alignment film 48 on the side in contact with the liquid crystal layer 44 is formed on the pixel electrode substrate 40 in order to align the alignment direction of the liquid crystal molecules existing in the incident side region (near the interface with the alignment film 48) in the liquid crystal layer 44.
The rubbing treatment is performed in the same manner as the B alignment film 49. As shown in FIG. 8, the rubbing direction R2 of the alignment film 49 on the output side and the rubbing direction R2 of the alignment film 48 on the incident side.
1 are orthogonal to each other.

The counter electrode 43 is laminated on the surface of the alignment film 48 on the incident side. The counter electrode 43 is for generating an electric potential between the counter electrode 43 and the pixel electrode portion 45, and is formed of, for example, a transparent conductive film such as ITO (Indium Tin Oxide). The counter electrode 43 is usually fixed at a constant potential (for example, a ground potential). Micro lens 42
Are laminated on the incident side surface of the counter electrode 43. A plurality of microlenses 42 are provided corresponding to the pixel electrode portions 45.

Each micro lens 42 has a convex shape on the incident side and a planar shape on the exit side. Each microlens 42 has a positive refractive power, and condenses light incident through the glass substrate 41 toward the corresponding pixel electrode unit 45. For example, as shown by L2 in the figure,
If there is no micro lens 42, the black matrix 46
Even if the incident light is incident on the micro lens 4
The light is condensed on the pixel electrode part 45 by the action of 2. The efficiency of light incidence on the pixel electrode unit 45 is increased by the microlenses 42.

The transmission axis 31 A of the incident-side polarizing plate 31 is aligned with the rubbing direction R 1 of the alignment film 48 on the incident side of the liquid crystal display element 32.
Are orthogonal to. On the other hand, the transmission axis 35A of the exit side polarizing plate 35 is orthogonal to the rubbing direction R2 on the exit side of the liquid crystal display element 32.

FIGS. 10 and 11 are perspective views showing the structure of the liquid crystal layer 44, which correspond to a state where no voltage is applied and a state where a voltage is applied, respectively. The liquid crystal layer 44 is called a nematic liquid crystal, and includes a plurality of rod-like liquid crystal molecules 40. As shown in FIG. 10, when no voltage is applied, the liquid crystal molecules 4
Numerals 0 are arranged such that their molecular long axes are orthogonal to the optical axis 10. The direction of the molecular long axis of the liquid crystal molecules 40 near the alignment film 48 and the direction of the molecular long axis of the liquid crystal molecules near the alignment film 49 are orthogonal to each other. The liquid crystal molecules 40 are arranged such that the molecular major axis is twisted by 90 ° from the incident side to the emission side. When light is incident on the liquid crystal layer 44 in a non-energized state, optical rotation occurs due to the twist of the liquid crystal molecules 40, and the light oscillation direction rotates 90 ° along the twist direction of the liquid crystal. On the other hand, as shown in FIG.
When a voltage is applied to the liquid crystal layer 44, the liquid crystal molecules 40 rise up except for the vicinity of the alignment films 48 and 49.
That is, the arrangement state of the liquid crystal molecules 40 changes so that the molecular long axis is parallel to the optical axis 10.

As shown in FIG. 8, the optical compensating element 33,
Each has a function of compensating for an optical phase difference caused by the liquid crystal molecules 40 in the vicinity of the exit surface and the entrance surface of the liquid crystal layer 44. The optical compensating element 33 has an optical axis 33A whose orientation film 49
In the same direction as the rubbing direction R2. The optical compensation element 34 has an optical axis 34A
The rubbing direction R1 of the incident side alignment film 48 is the same as the rubbing direction R1. A detailed description of the structure and operation of the optical compensation elements 33 and 34 will be omitted.

[Operation of Projection Type Liquid Crystal Display Device] Next, the operation of the projection type liquid crystal display device having the above configuration will be described.

First, the overall operation of the projection type liquid crystal display device will be described with reference to FIG. The white light emitted from the light source 11 is first transmitted to the UV / IR cut filter 11.
By transmitting C, light components in the ultraviolet region and the infrared region are removed. The light transmitted through the UV / IR cut filter 11C is transmitted to the first lens array 12, the second lens array 13, the first condenser lens 15, and the second condenser lens 23.
And enters the liquid crystal panel unit 24. In the liquid crystal panel section 24, when light is incident on the incident-side polarizing plate 31, only light components that vibrate in the same direction as the transmission axis 31A pass through the incident-side polarizing plate 31. The light component transmitted through the incident side polarizing plate 31 then enters the liquid crystal display element 32.

In a state where no voltage is applied to the liquid crystal layer 44 in the liquid crystal display element 32 (FIG. 10), the liquid crystal molecules 4
Optical rotation is caused by the zero twist, and the direction of light oscillation is rotated by 90 ° along the twist of the liquid crystal. This allows
The oscillation direction of the light emitted from the liquid crystal display element 32 is parallel to the transmission axis 35A of the emission-side polarizing plate 35, and passes through the emission-side polarizing plate 35 via the optical compensation elements 33 and 34. The light transmitted through the output side polarizing plate 35 is projected on a screen 27 by a projection lens 26. At this time, the display state of the image is a so-called white level display. On the other hand, when a voltage is applied to the liquid crystal layer 44 in the liquid crystal display element 32 (FIG. 11), the liquid crystal molecules 40 are oriented in a direction substantially parallel to the optical axis 10, so that the light oscillation direction does not change. Accordingly, the light emitted from the liquid crystal display element 32 has a vibration direction perpendicular to the transmission axis 35A of the emission-side polarizing plate 35, and is thus absorbed by the emission-side polarizing plate 35 and not transmitted. At this time, the display state of the image is a so-called black level display. Thus, the image on the liquid crystal panel unit 24 is projected on the screen 27.

Next, a characteristic operation of the present embodiment will be described with reference to FIGS. First
The lens array 12 has a UV-I
A substantially parallel single light beam transmitted through the R-cut filter 11C enters. The single light beam incident on the first lens array 12 is split into small light beams by the first lens elements 120 and emitted. Since each first lens element 120 of the first lens array 12 has a positive refractive power, the small light beam emitted from each first lens element 120 becomes convergent light,
The light converges near the main plane of each second lens element 130 of the lens array 13.

As shown in FIG. 12, each small light beam incident on each first lens element 130 of the second lens array 13 is
The light is incident on each small area 150 of the first condenser lens 15. The small luminous flux emitted from each lens element 130 of the second lens array 13 is applied to each small area 15 of the first condenser lens 15.
0, so that the step 15
5 hardly passes a small light beam. Therefore, step 15
5 is prevented from deteriorating the light-collecting ability due to light scattering or the like.

Each small light beam transmitted through the first condenser lens 15 passes through the second condenser lens 23 and then enters the liquid crystal panel section 24. Since each lens element 120 of the first lens array 12 and the illuminated area of the liquid crystal panel section 24 are in a conjugate relationship, the illuminated area of the liquid crystal panel section 24 is superimposedly illuminated, and the illuminated area of the liquid crystal panel section 24 is superimposed. , The in-plane intensity distribution becomes uniform.

As described above, in the illumination device and the projection type liquid crystal display device 1 according to the present embodiment, the shape of the incident surface 151 of the first condenser lens 15 divides a spherical surface into a plurality of small regions 150. In addition, since at least one of the small regions 150 is moved toward the emission surface 152, the size of the first condenser lens 15 can be reduced in the optical axis direction. Further, each small light beam emitted from each second lens element 130 of the second lens array 13 is allowed to pass through each small region 150, and the small light beam is prevented from passing through the step 155. Can be prevented. That is, the first condenser lens 1 can be used without lowering the condenser ability.
5 can be reduced in size and weight.

In addition, since the curved surface can be optimally designed for each of the small regions 150, the light condensing ability can be further improved.

In particular, since each small light beam emitted from the second lens array 13 is made to enter the first condenser lens 15 without straddling the boundaries of the plurality of small areas 150, the light is condensed. A decrease in performance can be prevented more reliably.

Further, the first condenser lens 15 located closest to the second lens array 13 in the condenser optical system (that is, the largest lens in the condenser optical system) is reduced in size. Therefore, it can contribute most to miniaturization of the illumination device and the projection type liquid crystal display device 1.

Since the arrangement of the plurality of small areas 150 in the first condenser lens 15 is made to correspond to the arrangement of the second lens elements 130 in the second lens array 13, light is emitted from each second lens element 130. Each small light beam can be easily guided to a plurality of small regions 150.

As described above, the present invention has been described with reference to the above embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made. For example, the first condenser lens 1
Instead of dividing the entrance-side surface 151 of FIG. 5 into a plurality of small regions 150, the exit-side surface 152 may be divided into a plurality of small regions.

Further, in the above-described embodiment, the entrance surface of each small region 150 of the first condenser lens 15 is spherical, but the entrance surface of each small region 150 may be aspheric.

In the above-described embodiment, the first condenser lens 15 and the second condenser lens 23 constitute a condenser optical system. However, three or more or one lens constitutes a condenser optical system. A system may be configured. When the condensing optical system is constituted by three or more lenses, it is preferable to divide the lens arranged closest to the second lens array 13 into a plurality of small areas. This is because the effect of reducing the size of the lens is great.

In the light source 11, the parabolic mirror 11B
May be replaced by an elliptical mirror, and an LED (Laser Emitting Diode) may be used instead of the light emitter 11A.

[0051]

As described above, the lighting device according to any one of claims 1 to 4 or the lighting device according to claim 5
According to the projection type liquid crystal display device described in the above, at least one of the shape of the entrance surface and the exit surface of the condensing lens divides a continuous curved surface into a plurality of small regions and at least one of the small regions is defined as an entrance surface. Since the shape is such that the space between the light emitting surface and the light exit surface is narrowed, it is possible to reduce the size and weight of the condenser lens in the optical axis direction. Furthermore, since each small light beam emitted from the second lens array passes through each small area of the condenser lens, even if a step is generated between adjacent small areas, light can pass through the step. Therefore, there is almost no decrease in the light collecting ability of the light collecting lens. That is, it is possible to reduce the size and weight of the condenser lens without lowering the condenser ability.

In particular, according to the lighting device of the second aspect,
Since each small light beam emitted from the second lens array is made to enter the condenser lens without straddling the boundaries of the plurality of small areas, it is possible to more reliably prevent a decrease in the condenser ability.

Further, according to the illumination device of the fourth aspect, the condensing lens is a lens closest to the second lens array in the condensing optical system. The effect of miniaturization is the greatest.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an overall configuration of a projection type liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view illustrating a planar shape of a first lens array.

FIG. 3 is a cross-sectional view illustrating a cross-sectional shape of a first lens array illustrated in FIG.

FIG. 4 is a plan view illustrating a planar shape of a second lens array.

5 is a cross-sectional view illustrating a cross-sectional shape of a second lens array illustrated in FIG.

FIG. 6 is a plan view illustrating a planar shape of a first condenser lens.

FIG. 7 is a cross-sectional view illustrating a cross-sectional shape of the first condenser lens illustrated in FIG.

8 is a sectional view showing a schematic configuration of a liquid crystal panel in the projection type liquid crystal display device shown in FIG.

9 is a cross-sectional view illustrating a schematic configuration of a liquid crystal panel unit in the projection type liquid crystal display device illustrated in FIG.

FIG. 10 is an explanatory diagram illustrating an alignment state of liquid crystal molecules when a voltage is not applied to a liquid crystal layer in the liquid crystal panel unit illustrated in FIG.

FIG. 11 is an explanatory diagram showing an alignment state of liquid crystal molecules when a voltage is applied to the liquid crystal layer shown in FIG.

FIG. 12 is a diagram for explaining a characteristic operation in one embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating a configuration example of a liquid crystal panel peripheral portion in a general projection type liquid crystal display device.

[Explanation of symbols]

3, 5: light source image, 10: optical axis, 11: light source, 11C: U
V-IR cut filter, 12 first lens array, 1
20: first lens element, 13: second lens array, 13
0 ... second lens element, 15 ... first condenser lens, 150 ...
Small area, 155 steps, 23 second condenser lens, 24
Liquid crystal panel, 26 ... Projection lens, 27 ... Screen,
31: incident side polarizing plate, 32: liquid crystal display element.

Claims (5)

[Claims] 1. A first lens array in which a light source that emits a light beam and a plurality of first lens elements that split the light beam emitted from the light source into a plurality of small light beams and emit the light beams are planarly arranged. A plurality of second lens elements each of which emits a small light beam incident through the first lens element of the first lens array;
A second lens array in which the small light beams emitted from the second lens array are incident, and an emission surface from which the small light beams incident from the incident surface are emitted, At least one of the entrance surface and the exit surface divides one continuous curved surface into a plurality of small regions, and moves at least one of the small regions in a direction in which a distance between the entrance surface and the exit surface is reduced. And a condensing lens configured to have a shape formed by forming at least one of the small light beams that have passed through the plurality of second lens elements in the second lens array, respectively. An illumination device characterized by being arranged so as to be able to pass through and condense light. 2. The method according to claim 1, wherein each of the small light beams emitted from the second lens array is incident on the condenser lens without straddling boundaries of the plurality of small regions. The lighting device according to claim 1. 3. The lighting device according to claim 1, wherein the curved surface is a spherical surface or an aspherical surface. 4. The condensing lens belongs to a condensing optical system that condenses a small light beam emitted from the second lens array, and the condensing lens is at least in the condensing optical system. The illumination device according to claim 1, wherein the lens is closest to the second lens array. 5. A liquid crystal display means for forming an image using a liquid crystal display element, an illuminating means for irradiating the liquid crystal display means with light, and a projection for projecting an image formed by the liquid crystal display means on a predetermined projection surface. A light source that emits a light beam; and a plurality of first lenses that divide the light beam emitted from the light source into a plurality of small light beams and emit the light beams. A first lens array in which elements are arranged in a plane, and a plurality of second lens elements each of which emits a small light beam incident through the first lens element of the first lens array;
A second lens array in which the small light beams emitted from the second lens array are incident, and an emission surface from which the small light beams incident from the incident surface are emitted, At least one of the entrance surface and the exit surface divides one continuous curved surface into a plurality of small regions, and moves at least one of the small regions in a direction in which a distance between the entrance surface and the exit surface is reduced. And a condensing lens configured to have a shape formed by forming at least one of the small light beams that have passed through the plurality of second lens elements in the second lens array, respectively. A projection type liquid crystal display device, which is arranged so as to be able to pass through and collect light.