JP3684926B2 - Illumination optical system and projection display device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination optical system in which light emitted from a light source is divided into a plurality of partial beam bundles, and each of them is substantially superimposed on the same illumination area. The present invention also relates to a projection display device capable of displaying a uniform and bright image using this illumination optical system.
[0002]
[Prior art]
In a projection display device, illumination light from an illumination optical system irradiated on a light modulation device called a “light valve” is modulated according to image information (image signal) to be displayed, and this modulated light is displayed on a screen. Projected images are displayed.
[0003]
The image displayed by such a projection display device is preferably uniform and bright. However, the light emitted from the light source of the illumination optical system usually has the highest light intensity in the vicinity of the optical axis of the light source and tends to decrease as the distance from the optical axis increases. If such light is used as illumination light as it is, a non-uniform image is displayed on the projection display device. In order to solve such a problem, an integrator optical system has been conventionally used as an optical system for uniformly illuminating a light modulation device that is an illumination region.
[0004]
As this integrator optical system, the light emitted from the light source is divided into a plurality of partial beam bundles, and each of the divided partial beam bundles is superimposed on the illumination area, thereby realizing uniform illumination. Things are common.
[0005]
[Problems to be solved by the invention]
The light source lamp used for the light source of the illumination optical system is ideally a point light source, but it is difficult to realize a point light source. For this reason, in the integrator optical system, when the light from the light source is divided into a plurality of partial beam bundles and superimposed on the illumination area, the utilization efficiency of the light emitted from the light source may be reduced.
[0006]
However, it is preferable that the image displayed by the projection display device is brighter, and it is desired that the illumination optical system used for this has higher light utilization efficiency.
[0007]
The present invention has been made to solve the above-described problems in the prior art, and an object thereof is to provide a technique capable of improving the light use efficiency of the illumination optical system. Another object of the present invention is to obtain a uniform and brighter projected image in a projection display device.
[0008]
[Means for solving the problems and their functions and effects]
  In order to solve at least a part of the problems described above, the illumination optical system of the present invention includes:
  An illumination optical system that illuminates a light incident surface of a predetermined optical device as an illumination area,
  A light source;
  A first lens array having a plurality of small lenses for dividing the light emitted from the light source into a plurality of partial beam bundles;
  A second lens array having a plurality of small lenses respectively corresponding to the plurality of small lenses of the first lens array,
  The second lens array is disposed in a vicinity position where a plurality of partial beam bundles emitted from the first lens array are condensed,
  The plurality of small lenses of the second lens array have a polygonal shape other than a substantially rectangular shape according to the contour shape of the partial light bundles collected by the plurality of small lenses of the corresponding first lens array. FormedAnd
The first lens array has M lens rows (M is an integer of 2 or more), and the second lens array has N rows (N is an integer of 1 or more smaller than M). Has a small lens array,
A plurality of partial beam bundles formed by a plurality of small lens rows in the first lens array are collected into a smaller number of rows and made incident on the second lens array. The partial light bundle divided by the M small lens rows is configured to be incident on the N small lens rows of the second lens array,
The plurality of lenslet rows in the first lens array are two lenslet rows,
In the two small lens rows, the position of each of the small lenses on the outer side of the two small lens rows is shifted from the position of each of the small lenses on the inner side along the direction of the rows. Are arranged,
The one small lens row of the second lens array corresponding to the two small lens rows of the first lens array corresponds to the outer small row of lenses of the first lens array. The first small lenses and the second small lenses corresponding to the inner row of small lenses are alternately arranged.It is characterized by being.
[0009]
The partial light bundles emitted from the small lenses of the first lens array may not be used as effective illumination light unless they enter the small lenses of the corresponding second lens array. As a result, the light utilization efficiency of the illumination optical system may be reduced.
[0010]
  In the illumination optical system of the present invention, a polygonal shape other than a substantially rectangular shape is formed according to the contour shape of the partial light bundles collected by the plurality of small lenses of the corresponding first lens array. Accordingly, it is possible to suppress the partial light bundles emitted from the small lenses of the first lens array from entering other small lenses adjacent to the small lenses of the corresponding second lens array. Thereby, the utilization efficiency of the light of an illumination optical system can be improved. The “substantially rectangular shape” is not only a completely rectangular shape (rectangle or square), but also a case where the shape is not completely rectangular due to a design error or a case where chamfering of some corners is added. Including different shapes. That is, the lens design concept means a rectangular shape.
In addition, since the partial light bundle divided by the M small lens rows of the first lens array can be incident on the N small lens rows of the second lens array, the second lens array It is possible to widen the interval between the rows of partial beam bundles emitted from. Thereby, when an optical element corresponding to each column of a plurality of partial beam bundles is provided between the second lens array and a superimposing optical system that superimposes the light emitted from the second lens array on the illumination area. In addition, since the width in the column direction of the optical element corresponding to each column can be increased, the light incident efficiency to the optical element corresponding to each column can be improved. As a result, it is possible to improve the light use efficiency of the illumination optical system.
Furthermore, one small lens array in the second lens array corresponding to two small lens arrays in the first lens array is a first lens array corresponding to one small lens in the outer side of the first lens array. Since the small lenses and the second small lenses corresponding to the inner one row of small lenses are alternately arranged, a plurality of partial beam bundles emitted from the two small lens rows of the first lens array Can be easily incident on the second lens array as a plurality of partial beam bundles arranged in a line.
[0011]
Here, when two reference axes that pass through the center of the second lens array and are perpendicular to each other are defined, at least a part of the dividing lines that divide the plurality of small lenses of the second lens array is: It is preferable that the inclination with respect to the two reference axes increases as the distance from the two reference axes increases.
[0012]
In addition, at least a part of the plurality of small lenses of the second lens array is inclined with respect to two division lines parallel to one of the two reference lines and the other reference line. You may make it have the trapezoid shape divided by the two division lines.
[0013]
If it carries out as mentioned above, the small lens of a 2nd lens array can be formed according to the inclination of the outline shape of the incident partial ray bundle.
[0018]
In the illumination optical system,
It is preferable to provide an afocal optical system that converts an incident light bundle into an outgoing light bundle having a width smaller than the width of the incident light bundle.
[0019]
If the afocal optical system is provided, the width of the light bundle emitted from the illumination optical system can be reduced as compared with the case where the afocal optical system is not provided. Can be reduced. Generally, the light utilization efficiency of the optical element is better when the incident angle of the light beam incident on the optical element is smaller. Therefore, according to the illumination optical system having the above configuration, the light utilization efficiency can be improved.
[0020]
Here, a condensing lens having a condensing function for realizing the afocal optical system is provided in the vicinity of the first lens array,
The plurality of small lenses in the second lens array preferably have a function of collimating light for realizing the afocal optical system.
[0021]
According to the above configuration, an afocal optical system can be easily realized.
[0022]
The projection display device of the present invention is
Any one of the above illumination optical systems;
A light modulation device that has a light incident surface as the illumination region and modulates incident light from the illumination optical system according to an image signal;
A projection optical system that projects the modulated light obtained by the light modulation device;
It is characterized by providing.
[0023]
As described above, the illumination optical system of the present invention can improve the light utilization efficiency as compared with the prior art. Therefore, in the projection display device incorporating the illumination optical system of the present invention, the brightness of the projected image can be improved.
[0024]
Since the illumination optical system of the present invention has an integrator optical system including the first and second lens arrays, the light emitted from the light source has a large light intensity distribution in the cross section of the light beam. Even if there is a bias, it is possible to obtain illumination light with uniform brightness and no brightness or color unevenness. Can be obtained.
[0025]
The projection display device further includes a color light separation optical system that separates light emitted from the illumination optical system into at least two colors of color light, and
A plurality of the light modulation devices that respectively modulate the color lights separated by the color light separation optical system;
A color light combining optical system that combines the modulated light of each color after being modulated by each of the light modulation devices,
The combined light obtained by the color light combining means can be projected through the projection optical system.
[0026]
In this way, it is possible to project and display a color image that is brighter, more uniform and more uniform than in the past.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, unless otherwise specified, the light traveling direction is the z-axis direction (direction parallel to the optical axis), and the 12 o'clock direction as viewed from the z-axis direction is the y-axis direction (vertical). Direction), and the 3 o'clock direction is the x-axis direction (lateral direction).
[0028]
A. Overall configuration of the first embodiment:
FIG. 1 is a schematic configuration diagram of a main part of an illumination optical system 100 as a first example when viewed in plan. The illumination optical system 100 includes a light source 20, a split optical system 30, a polarization conversion optical system 60, and a superimposing optical system (superimposing lens) 70. Each of these optical elements 20, 30, 60, 70 is arranged so that the center axis thereof coincides with the system optical axis 100 ax of the illumination optical system 100. The split optical system 30 and the superimposing optical system 70 constitute an integrator optical system for illuminating the effective illumination area ELA of the illumination area LA substantially uniformly.
[0029]
The light source 20 includes a light source lamp 22 as a radiation light source that emits a radial light beam, and a concave mirror 24 that emits radiation light emitted from the light source lamp 22 as a substantially parallel light beam. As the light source lamp 22, a high pressure discharge lamp such as a metal halide lamp or a high pressure mercury lamp is usually used. As the concave mirror 24, a parabolic mirror is preferably used. In place of the parabolic mirror, an ellipsoidal mirror or a spherical mirror can be used.
[0030]
The split optical system 30 includes a first lens array 40 and a second lens array 50. The first lens array 40 divides substantially parallel light emitted from the light source 20 into a plurality of partial light bundles, and condenses each partial light bundle to form the second lens array 50 and polarization conversion optics. It has a function of forming a condensed image in the vicinity of the system 60.
[0031]
FIG. 2 is an explanatory diagram showing the first lens array 40. FIG. 2A is a front view of the second lens array 50 viewed from the light incident surface side (light source 20 side). FIG. 3B is a plan view, and FIG. 2C is a side view. The first lens array 40 has a configuration in which plano-convex first small lenses 42 having a substantially rectangular outline are arranged in a plurality of rows (M rows) and a plurality of columns (N columns). FIG. 2 shows an example where M = 8 and N = 6. The first small lens 42 has a substantially rectangular outer shape, but the optical axis of the lens is at the center of the lens. Hereinafter, a lens in which the center of the lens and the optical axis coincide with each other is referred to as a “concentric lens”.
[0032]
The external shape of each first small lens 42 viewed in the z-axis direction is normally set to be substantially similar to the shape of the effective illumination area ELA. For example, assuming that a liquid crystal panel is used as the illumination area and the aspect ratio (ratio between horizontal and vertical dimensions) of the image formation area as the effective illumination area is 4: 3, the aspect ratio of the first small lens 42 Is preferably set to 4: 3.
[0033]
FIG. 3 is an explanatory diagram showing the second lens array 50. FIG. 3A is a perspective view of the second lens array 50. FIG. 3B is a front view seen from the light incident surface side (first lens array 40 side). FIGS. 3C and 3D are a plan view and a bottom view, and FIGS. 3E and 3D are a left side view and a right side view. The vertical height H50 and the horizontal length L50 of the second lens array 50 are substantially equal to the vertical height H40 (FIG. 2) and the horizontal length L40 of the first lens array 40. The size of the lens array refers to the size of the plurality of small lenses arranged in a plurality of rows and columns, and does not include other peripheral flat portions. Further, the same number of second small lenses 52 as the first small lenses 42 of the first lens array 40 are arranged in a substantially matrix form. However, the second small lens 52 has a different trapezoidal shape depending on the arrangement position thereof. This shape will be described later.
[0034]
FIG. 4 is a front view showing the second lens array 50 and the first lens array 40 from the z-axis direction. The broken line shown in FIG. 4 indicates the first lens array 40. Further, the + mark indicates the optical axis of each first small lens 42 of the first lens array. The optical axis of each second small lens 52 of the second lens array 50 is configured to coincide with the optical axis of the first small lens 42 of the corresponding first lens array 40.
[0035]
Note that the orientation of the lenses of the first lens array 40 need not be limited to the orientation shown in FIG. 1 and may be arranged so as to have a convex surface on the exit surface side. The second lens array 50 need not be limited to the orientation shown in FIG. 1 and may be arranged to have a convex surface on the exit surface side. Further, the superimposing optical system 70 need not be limited to the orientation shown in FIG. 1, and may be arranged so as to have a convex surface on the incident surface side.
[0036]
The polarization conversion optical system 60 of FIG. 1 includes a first polarization conversion element array 60a on which the respective partial light bundles emitted from the −x-axis direction side of the second lens array 50 with the system optical axis 100ax as the center are incident; And a second polarization conversion element array 60b on which each of the partial beam bundles emitted from the + x-axis direction side is incident.
[0037]
FIG. 5 is a perspective view showing the configuration of the first polarization conversion element array 60a. The first polarization conversion element array 60 a includes a light shielding plate 62, a polarization beam splitter array 64, and a λ / 2 phase difference plate 68 that is selectively disposed on a part of the light exit surface of the polarization beam splitter array 64. I have. In the polarizing beam splitter array 64, a plurality of first light-transmissive members 64a each having a parallelogram-shaped cross section are sequentially bonded to each other, and trapezoidal columnar second and third light-transmissive members having cross-sections at both ends thereof. 64b and 64c are bonded together. The second and third translucent members 64b and 64c may be columnar bodies having the same cross section as that of the first translucent member 64a. Moreover, the cross-section may be a columnar body having a substantially right triangle.
[0038]
Polarization separation films 66a and reflection films 66b are alternately formed on the interfaces of the translucent members 64a, 64b, and 64c. In this polarization beam splitter array 64, a plurality of plate glasses on which these films are formed are bonded to each other so that the polarization separation films 66a and the reflection films 66b are alternately arranged, and obliquely at a predetermined angle. It is produced by cutting. The polarization separation film 66a can be formed of a dielectric multilayer film, and the reflection film 66b can be formed of a dielectric multilayer film or an aluminum film.
[0039]
The λ / 2 phase difference plate 68 is selectively disposed in the x-direction mapping portion of the light exit surface of the polarization separation film 66a or the reflection film 66b. In this example, a λ / 2 phase difference plate 68 is selectively disposed in the x-direction mapping portion of the light exit surface of the polarization separation film 66a.
[0040]
The light shielding plate 62 includes a plurality of light shielding surfaces 62a and a plurality of opening surfaces 62b arranged in a stripe pattern. In this example, a light shielding surface 62a is arranged in the x-direction mapping portion of the light incident surface of the reflection film 66b, and an aperture surface 62b is arranged in the x-direction mapping portion of the light incidence surface of the polarization separation film 66a. . Thereby, the light that has passed through the aperture surface 62b out of the light incident on the first polarization conversion element array 60a is incident only on the polarization separation film 66a. As the light shielding plate 62, a flat transparent body (for example, a glass plate) partially formed with a light shielding film (for example, a chromium film, an aluminum film, and a dielectric multilayer film), or for example, an aluminum plate What provided the opening part in the light-shielding flat plate like this can be used.
[0041]
FIG. 6 is an explanatory diagram showing functions of the first polarization conversion element array 60a. The non-polarized light bundle (s-polarized light + p-polarized light) that has passed through the opening surface 62b of the light shielding plate 62 is incident on the polarization separation film 66a of the polarization beam splitter array 64, and two types of linearly polarized light (s-polarized light and p-polarized light). Most of the p-polarized light passes through the polarization separation film 66a as it is. On the other hand, most of the s-polarized light is reflected by the polarization separation film 66a, further reflected by the reflection film 66b, and emitted in a state substantially parallel to the p-polarized light that has passed through the polarization separation film 66a as it is. The p-polarized light transmitted through the polarization separation film 66a is converted into s-polarized light by the λ / 2 phase difference plate 68 and then emitted. As a result, most of the non-polarized light incident on the first polarization conversion element array 60a is converted into s-polarized light and emitted. Of course, by forming the λ / 2 phase difference layer 68 only on the light emission surface portion reflected by the reflective film 66b, most of the light beam can be converted into p-polarized light and emitted.
[0042]
Here, when non-polarized light is directly incident on the reflection film 66b instead of the polarization separation film 66a, p-polarized light, not s-polarized light, is emitted from the first polarization conversion element array 60a. become. As described above, in this embodiment, the light shielding plate 62 prevents light from entering the reflection film 66b. Therefore, it is possible to prevent unpolarized light from entering the reflective film 66b and emitting unwanted linearly polarized light from the first polarization conversion element array 60a.
[0043]
One block including one adjacent polarization separation film 66a and one reflection film 66b and one λ / 2 phase difference plate 68 can be regarded as one row of polarization conversion elements. The polarization conversion element array 60a is formed by arranging a plurality of such polarization conversion elements in the x direction. In this embodiment, it is composed of three rows of polarization conversion elements.
[0044]
The second polarization conversion element array 60b has a symmetric structure with respect to the polarization conversion element array 60a with the system optical axis 100ax as an axis of symmetry, and has the same function, and thus the description thereof is omitted.
[0045]
The polarization conversion optical system 60 may be provided with one polarization conversion element array instead of the two polarization conversion element arrays 60a and 60b.
[0046]
The light emitted from the light source 20 of FIG. 1 is divided into a plurality of partial beam bundles by the plurality of first small lenses 42 of the first lens array 40. The plurality of divided partial beam bundles are condensed so as to be incident on the corresponding second small lens 52 of the second lens array 50, and in the vicinity of the second lens array 50 and the polarization conversion optical system 60. To form a condensed image. In FIG. 1, the center axis of each partial light bundle is indicated by a solid line for easy explanation. The second lens array 50 has a function of condensing so that light incident on each second small lens 52 is effectively applied to the illumination area LA. The partial light bundles emitted from the respective second small lenses 52 are incident on the polarization separation film 66 a of the polarization conversion optical system 60. As described above, the plurality of partial light bundles incident on the polarization conversion optical system 60 are converted into almost one kind of linearly polarized light, respectively. The plurality of partial light bundles emitted from the polarization conversion optical system 60 are incident on the superimposing optical system 70 and are substantially superimposed on the effective illumination area ELA of the illumination area LA by the superimposing action of the superimposing optical system 70. As a result, the effective illumination area ELA is almost uniformly illuminated with almost one type of linearly polarized light.
[0047]
Note that the second lens array 50, the polarization conversion optical system 60, and the superposition optical system 70 are spaced apart. However, in general, in order to reduce the loss of light at each interface, it is preferable to arrange them closely by bonding them with an adhesive or the like. Further, the superimposing optical system 70 can be omitted.
[0048]
Further, the distance between the second lens array 50 and the polarization separation film 66a of the polarization conversion optical system 60 is very small compared to the distance between the first lens array 40 and the second lens array 50. Therefore, it can be considered that the size of each partial light beam incident on the polarization conversion optical system 60 is equal to the size of each condensed image.
[0049]
The illumination optical system 100 is characterized by the shape of each second small lens 52 of the second lens array 50.
[0050]
B. Condensed image and lens shape in the vicinity of the second lens array:
FIG. 7 is an explanatory diagram showing a focused image formed by the first lens array 40 in the vicinity of the second lens array 50. The condensed image in the figure is represented by the light intensity indicated by the contour lines. FIG. 7 shows only a condensing image of a quarter portion at the upper right part of the second lens array 50. Since the characteristics of the light emitted from the normal light source 20 are symmetric about the optical axis, the left half of the condensed image is symmetrical with respect to the right half of the condensed image, and the lower half of the condensed image. Is vertically symmetric with respect to the upper half of the condensed image.
[0051]
Since the light source lamp 22 constituting the light source 20 is not a point light source, the condensed image of each partial light bundle also has a shape corresponding to the shape of the light source lamp. In this example, it has an elongated shape (substantially elliptical shape or substantially elliptical shape) along the direction connecting the system optical axis 100ax and the position where the condensed image is formed (hereinafter referred to as “radiation direction”). Yes. In addition, since the light emitted from the light source 20 tends to have better parallelism as it is farther from the system optical axis 100ax, the overall size tends to be smaller as the peripheral focused image. In such a case, if the second lens array is composed of the same small lens as the first small lens 42 of the first lens array 40, as shown in FIG. There may be many portions that protrude from the corresponding small lens (indicated by hatching in the figure). The first lens array 40 and the second lens array 50 are set so that the light bundles that have passed through the corresponding small lenses are irradiated to the effective illumination area ELA via the superimposing optical system 70. Therefore, the light beam incident on the lens other than the corresponding small lens may not be effectively irradiated to the effective illumination area ELA. As described above, when there are many protruding portions, the use efficiency of light as an illumination optical system is reduced accordingly.
[0052]
FIG. 8 is an explanatory diagram showing the relationship between the second lens array 50 and a focused image formed in the vicinity of the second lens array 50 by the first lens array 40. The inclination of the long axis of each condensed image with respect to the x axis depends on the angle formed between the radiation direction and the x axis, that is, the angle formed between the system optical axis 100ax and the center of each condensed image and the x axis. Change. For example, the focused image in the first row from the bottom of FIG. 8 is formed so that the long axis is along the x-axis direction, and the focused image in the first column from the left in FIG. It is formed along the direction. In the second and third columns, the condensed images in the second and third rows are formed such that the major axis is inclined according to the position. Therefore, the second lens array 50 has a trapezoidal shape corresponding to each position so as to efficiently classify each condensed image according to the inclination of the long axis of the condensed image formed by each partial beam bundle. The second small lens 52 is used. Specifically, each second small lens 52 of the second lens array 50 is divided as follows.
[0053]
The dividing lines that divide each column of the second lens array 50 are divided by straight lines parallel to the y-axis direction. Note that the dividing line for dividing each column is not necessarily a straight line and may not be parallel to the y-axis. However, it is preferably a straight line parallel to the y-axis direction for the following reasons.
[0054]
In the lower part of FIG. 8, the polarization conversion optical system 60 is shown for reference. The light blocking surface 62 a and the aperture surface 62 b of the polarization conversion optical system 60 are arranged for each column of the second lens array 50. The aperture surfaces 62b in each row are arranged so that the partial beam bundles emitted from the second lens array 50 are incident thereon, and the light shielding surfaces 62a are arranged between the aperture surfaces 62b in each row. Yes. Therefore, the position in the x-axis direction of the dividing line along the y-axis that divides each column is preferably within the width in the x-axis direction of the light shielding surface 62a. Therefore, each column of the second lens array 50 is divided by a straight line parallel to the y-axis direction. In this way, each column can be easily divided.
[0055]
Each row of the second lens array 50 is divided with a different inclination (inclination with respect to the x-axis) according to the inclination of the long axis of the condensed image. For example, since the inclination of the long axis of the condensed image increases as the distance from the system optical axis 100ax increases, the inclination of the dividing line between the lines increases accordingly. However, each condensed image in the first column from the system optical axis 100ax stands so that the major axis thereof is almost along the y-axis, so that the dividing line between the rows is inclined to the major axis of each condensed image. Although there is a slight inclination, it is divided along the x-axis.
[0056]
It can also be seen that the second lens array 50 is divided as follows. That is, if a reference line (reference axis) passing through the system optical axis 100ax and parallel to the x axis is 50x, and a reference line (reference axis) parallel to the y axis is 50y, the first line along the reference line 50x and The dividing lines of the second lenslet other than the dividing line for dividing the second lenslet 52 in the first column along the reference line 50y are separated from the at least two reference lines 50x and 50y by two reference lines 50x. , 50y, the inclination is large.
[0057]
When the second lens array 50 configured as described above is used, it is possible to prevent each condensed image from protruding from the corresponding second small lens 52, so that the second lens array is the second lens array. The efficiency of the illumination optical system can be improved as compared with the case where a lens array having the same shape as that of one lens array is used.
[0058]
In this embodiment, the second small lens 52 constituting the second lens array 50 has a trapezoidal shape, but the present invention is not limited to this. For example, it may be a triangle, pentagon, or rhombus. In the present embodiment, the characteristics of the light emitted from the light source are described as being symmetric with respect to the system optical axis 100ax, but the present invention can also be applied to cases where the characteristics are not symmetric. In short, the second lens array is a small lens having a polygonal shape other than the rectangular shape according to the contour shape such as the size and inclination of the corresponding condensed image so as to efficiently divide each condensed image. What is necessary is just to comprise. The same applies to the following embodiments.
[0059]
In the present embodiment, the configuration including the polarization conversion optical system 60 is described as an example. However, this can be omitted, and the same applies to each of the following embodiments.
[0060]
C. Second embodiment:
FIG. 9 is a schematic configuration diagram of the main part of the illumination optical system 100A as the second embodiment viewed in plan. This illumination optical system 100A is obtained by changing the splitting optical system 30 and the polarization conversion optical system 60 of the first example, and the other configurations are the same as those of the first example.
[0061]
The split optical system 30A of the second example includes a first lens array 40A and a second lens array 50A.
[0062]
FIG. 10 is an explanatory diagram showing the first lens array 40A. FIG. 10A is a perspective view of the first lens array 40A. FIG. 10B is a front view seen from the light incident surface side (light source 20 side). FIGS. 10C and 10D are a plan view and a bottom view, and FIGS. 10E and 10D are a left side view and a right side view. Similarly to the first lens array 40 (FIG. 2) of the first embodiment, the first lens array 40A also includes plano-convex first small lenses 42A having a substantially rectangular outline in a plurality of rows and columns. It has a configuration that is laid out. However, the number of rows in each column (the number of small lenses included in each column) is not necessarily the same.
[0063]
Here, a line passing through the central axis 40Aax and extending along the y-axis direction is taken as a reference line 40Ay, and a line passing through the central axis 40Aax and taken along the x-axis direction is taken as a reference line 40Ax. The plurality of first small lenses 42A are arranged in three rows in both the left and right directions (± x axis directions) around the reference line 40Ay. Eight first small lenses 42A are arranged in the vertical direction around the reference line 40Ax in each of the first and second right columns, and seven first small lenses 42A are arranged in the third right column. The first small lenses 42 are laid out. The first small lenses 42 in each row of the right third column are arranged just between the first small lenses 42 in each row of the right second column. Each column on the left side is the same as each column on the right side. In the following, each column may be indicated by omitting the left side or the right side. In this case, the left or right column is shown.
[0064]
In FIG. 10B,.., X and + marks indicate the position of the optical axis of each first small lens 42A. The position of the optical axis of each first small lens 42A is set to a different position depending on the position where it is arranged. A mark indicates the position of the optical axis of the first small lens 42A in the first row. The + mark indicates the position of the optical axis of the first small lens 42A in the second row, and the x mark indicates the position of the optical axis of the first small lens 42A in the third row.
[0065]
FIG. 11 is an explanatory diagram showing the second lens array 50A. FIG. 11A is a perspective view of the second lens array 50A. FIG. 11B is a front view as viewed from the light incident surface side (first lens array 40A side). 11C and 11D are a plan view and a bottom view, and FIGS. 11E and 11D are a left side view and a right side view.
[0066]
Similarly to the second lens array 50 of the first embodiment, the second lens array 50A has a configuration in which second small lenses 52A having different shapes depending on the arrangement position are arranged in a plurality of rows and a plurality of columns. have. The second lens array 50A has the same number of second small lenses 52A as the first small lenses 42A so as to correspond to the first small lenses 42A of the first lens array 40A. However, the small lenses of the second lens array 50A corresponding to the small lenses in the second and third rows of the first lens array 40A are arranged only in the second row, that is, in one row. . The vertical height H50A and the horizontal length L50A of the lens array 50A are approximately equal to the vertical height H40A (FIG. 10B) and the horizontal length L40A of the lens array 40A. A line passing through the central axis 50Aax and extending along the y-axis direction is referred to as a reference line 50Ay, and a line passing through the central axis 50Aax and along the x-axis direction is referred to as a reference line 50Ax.
[0067]
In FIG. 11B,..., X, + marks indicate the position of the optical axis of each second small lens 52A. The position of the optical axis of each second small lens 52A is set to a different position depending on the position where it is arranged. A mark indicates the position of the optical axis of the second small lens 52A in the first row. The + mark indicates the position of the optical axis of the second small lens 52A in the odd row from the top of the second column, and the x mark indicates the optical axis of the second small lens 52A in the second small lens 52A in the even row. Indicates the position.
[0068]
The polarization conversion optical system 60A includes a polarization conversion element array having polarization conversion elements with the number of columns corresponding to the number of columns of the second lens array 50A symmetrically with respect to the system optical axis 100Aax. In this embodiment, a polarization conversion element array having one column fewer than the polarization conversion element array 60a (FIG. 5) is used.
[0069]
Hereinafter, in order to facilitate the description of the second lens array 50A, first, a case where the virtual second lens array 50B shown in FIG. 12 is used will be described as an example. FIG. 12A shows a front view of the light of the second lens array 50B as viewed from the incident surface side (first lens array 40A side). FIG. 12B shows a bottom view.
[0070]
The second lens array 50B has a configuration in which plano-convex second small lenses 52B having a substantially rectangular outline are arranged in a plurality of rows and a plurality of columns. The second lens array 50B has the same number of second small lenses 52B as the first small lenses 42A so as to correspond to the first small lenses 42A of the first lens array 40A. However, as described below, the small lenses in the second lens array 50B corresponding to the small lenses in the second and third columns of the first lens array 40A are only in the second column, that is, It is arranged in one row. The vertical height H50B and the horizontal length L50B of the second lens array 50B are substantially equal to the vertical height H40A (FIG. 10B) and the horizontal length L40A of the lens array 40A. A line that passes through the central axis 50Bax and extends along the y-axis direction is referred to as a reference line 50By, and a line that passes through the central axis 50Bax and extends along the x-axis direction is referred to as a reference line 50Bx.
[0071]
The plurality of second small lenses 52B are arranged in two rows in both the left and right directions (± x-axis directions) around the reference line 50By. In the first right column, the same number of second small lenses 52B as the first small lenses 42A (FIG. 10B) arranged in the first right column of the first lens array 40A are arranged. Yes. That is, four rows of second small lenses 52B are arranged in both the upper and lower directions around the reference line 50Bx. In the second row on the right side, the same number as the sum of the number of the first small lenses 42A arranged in the second and third columns on the right side of the first lens array 40A, that is, 15 second lenses. Small lenses 52B are arranged. The second small lenses 52B in the odd-numbered rows of the right second column correspond to the first small lenses 42A in the second right column of the first lens array 40A. In addition, the second small lenses 52B in even rows correspond to the first small lenses 42A in the third column on the right side of the first lens array 40A.
[0072]
The entire length of each column on the right side in the y-axis direction is set to be the same. However, the length of each second small lens 52 in the y direction as viewed from the z-axis direction has a different size depending on the position. The second small lens 52A on the left side of the second lens array 50B is the same as that on the right side.
[0073]
In FIG. 12A,..., X, + marks indicate the position of the optical axis of each second small lens 52B. A mark indicates the position of the optical axis of the second small lens 52B in the first row. The + mark indicates the position of the optical axis of the second small lens 52B in the odd row from the top of the second column, and the x mark indicates the optical axis of the second small lens 52B in the second small lens 52A in the even row. Indicates the position. Similarly to the first small lenses 42A of the first lens array 40A, the positions of the optical axes of the second small lenses 52B are also set at different positions according to the arranged positions. This is due to the following reason.
[0074]
FIG. 13 is a plan view showing the positional relationship between the first lens array 40A and the second lens array 50B. Since the −x direction side and the + x direction side are symmetric with respect to the system optical axis 100Aax, the description will be given here on the −x direction side.
[0075]
The second lens array 50B has substantially the same size as the first lens array 40A, but as shown in FIGS. 10 and 12, the first lens array 50B has one column compared to the number of columns of the first lens array 40A. Few. Therefore, the second small lens 52B (52Ba to 52Bc) of the second lens array 50B is smaller than the first small lens 42A (42Aa to 42Ac) of the first lens array 40A. The axial width is large. For this reason, the first small lenses 42Aa to 42Ac in the first to third columns of the first lens array 40A are connected to the second small lenses 52Ba to 52Bc of the corresponding second lens array 50B. Are made up of lenses having optical axes at different positions. Further, the second small lenses 52Ba to 52Bc of the second lens array 50B corresponding to the first small lenses 42Aa to 42Ac of the first lens array 40A are also configured by lenses having optical axes at different positions. ing. Further, as described above, the second small lens 52Bb corresponding to the second column of the first lens array 40A and the second small lens 52Bc corresponding to the third column of the second lens array 50 are as described above. They are arranged in one row so as to constitute the third row. More specifically, the second small lens 52Bc and the second small lens 52Bb are alternately arranged.
[0076]
The partial beam bundles emitted from the first small lenses 42Aa to 42Ac of the first lens array 40A are deflected in accordance with the positions of the lenses, and the corresponding second small lenses of the second lens array 50A. The light enters the lenses 52Ba to 52Bc. Each of the partial light bundles incident on each of the second small lenses 52Ba to 52Bc is deflected so that the central axis thereof is substantially parallel to the system optical axis 100Aax.
[0077]
FIG. 14 is an explanatory diagram showing a focused image formed by the first lens array 40A in the vicinity of the second lens array 50B. FIG. 14 shows only the focused image in the upper right half as in FIG.
[0078]
As shown in FIG. 14, the light collection images formed in the vicinity of the second lens array 50B are arranged in two rows, so that compared to the case where three rows of light collection images are formed within the same width. Thus, the interval between the rows can be increased. This has the following advantages.
[0079]
As described with reference to FIGS. 5 and 6, the polarization conversion optical system arranges polarization conversion elements including adjacent polarization separation films 66 a and reflection films 66 b by the number corresponding to the number of columns of the second lens array. Thus, the light incident on the polarization separation film 66a included in the polarization conversion element is converted into almost one kind of linearly polarized light. Therefore, the higher the light incidence efficiency to the polarization separation film 66a, the better the light utilization efficiency.
[0080]
In the case where the split optical system 30B is configured by the first lens array 40A and the second lens array 50B, it is possible to increase the interval between the columns of the condensed image (the column interval of the partial light bundles). The width in the column direction can be increased. Thereby, since the width of the polarization separation film 66a included in the polarization conversion element can be increased, the incidence efficiency of the light emitted from the second lens array 50B to the polarization conversion optical system 60A can be improved. . As a result, the light use efficiency of the illumination optical system can be improved.
[0081]
Further, if the interval between the columns of the condensed image is the same as the interval between the condensed images when the number of columns is not reduced, the second lens array and the polarization conversion optical system can be reduced. In this case, the incident angle of the light beam incident on the optical element arranged at the subsequent stage can be reduced. When the incident angle of the light beam incident on the optical element is smaller, the light utilization efficiency of the optical element is better, and as a result, the light utilization efficiency of the illumination optical system can be improved.
[0082]
The second lens array 50A of the second embodiment is obtained by adding the function of the second lens array 50 of the first embodiment to the second lens array 50B. That is, as shown in FIG. 14, the condensed image formed in the vicinity of the second lens array 50B may have a portion that protrudes from the corresponding small lens depending on the position. Therefore, as shown in FIG. 15, the second lens array 50A has a polygonal second shape formed so as to segment the condensed image formed by each partial light bundle according to the shape of the condensed image. The small lens 52A is used. As a result, it is possible to prevent the condensed image of each partial light bundle from protruding from the second small lens 52A of the corresponding second lens array 50A, so the virtual second lens array 50B was used. Compared to the case, the light use efficiency of the illumination optical system can be improved.
[0083]
In the illumination optical system 100A of the present embodiment, among the plurality of partial beam bundles divided by the first lens array 40A, the condensed images formed by the two leftmost columns and the two rightmost columns are each in one column. It is arranged. However, it is not limited to this. For example, you may make it arrange the condensing image formed by the partial ray bundle of a several row | line | column of 3 or more rows in 1 row. Further, it is not necessary to combine the two columns at the left and right ends into one column, and only one of them may be combined into one column. Further, it is not necessary that the two rows are at the extreme ends. Further, three columns may be combined into two columns. That is, in general, a plurality of rows of partial light beams formed by a plurality of small lens rows in the first lens array may be combined into a smaller number of rows and incident on the second lens array. The above modification can be similarly applied to the following third embodiment.
[0084]
D. Third embodiment:
FIG. 16 is a schematic configuration diagram of the main part of the illumination optical system 100C as the third embodiment when viewed in plan. This illumination optical system 100C is obtained by changing the split optical system 30A and the polarization conversion optical system 60A of the second embodiment, and the other configurations are the same as those of the second embodiment.
[0085]
The split optical system 30C of the third example includes a first lens array 40C and a second lens array 50C.
[0086]
FIG. 17 is an explanatory diagram showing the first lens array 40C. FIG. 17A is a perspective view of the first lens array 40C. FIG. 17B is a front view seen from the light incident surface side (light source 20 side). 17C and 17D are a plan view and a bottom view, respectively, and FIGS. 17E and 17D are a left side view and a right side view. The first lens array 40C is larger than the first lens array 40A on the side opposite to the surface on which the first small lenses 42A of the first lens array 40A (FIG. 10) of the second embodiment are formed. The configuration includes a condenser lens 44. The condenser lens 44 is a plano-convex lens.
[0087]
The second lens array 50C has a shape obtained by reducing the entire size of the second lens array 50A (FIG. 11) of the second embodiment in accordance with the size of the light bundle collected by the condenser lens 44. ing. However, each second small lens 52C has a function of returning the light collected by the condensing lens 44 to parallel light and a function of each second small lens 52A of the second lens array 50A. It is configured.
[0088]
FIG. 18 is an explanatory diagram showing the function of the condenser lens 44 of the first lens array 40C. FIG. 18 shows a configuration in which the light source 20, the condenser lens 44, the first lens array 40D, and the second lens array 50D are sequentially arranged. Each first small lens 42D of the first lens array 40D is the same concentric lens as the small lens 42 constituting the lens array 40 of the first embodiment. The second lens array 50D includes a second small lens 52D that is smaller than the small lens 42D of the first lens array. Each second small lens 52D has a different optical axis position in accordance with the arrangement position.
[0089]
The substantially parallel light emitted from the light source 20 becomes condensed light by the condensing action of the condensing lens 44. The condensed light emitted from the condenser lens 44 is divided into a plurality of partial beam bundles by the small lenses 42D of the first lens array 40D. The partial beam bundles emitted from each small lens 42D are deflected so that the central axis of each partial beam bundle is inclined in the direction of the system optical axis 100Dax by the condensing action of the condensing lens 44, and the second lens array 50D. The light enters the corresponding second small lens 52D. The second small lens 52D has a function of deflecting so that the central axis of the incident partial beam is parallel to the system optical axis 100Dax. As a result, the entire light emitted from the second lens array 50D is reduced more than the entire width of the light when it enters the condenser lens 44. Thus, the condensing lens 44 and the second lens array 50D function as an afocal optical system that converts the light bundle incident on the condensing lens 44 into a light bundle having a width smaller than the width thereof. The condensing lens 44 has a condensing function for realizing an afocal optical system, and the second lens array 50D has a function for collimating light for realizing an afocal optical system. Yes.
[0090]
Since the light emitted from the afocal optical system is reduced as a whole, the incident angle to the optical system arranged at the subsequent stage can be reduced as compared with the case without the afocal optical system. As described in the second embodiment, the use efficiency of light in the optical element is better when the incident angle of the light beam incident on the optical element is smaller. Therefore, the use efficiency of light can be improved by providing the afocal optical system.
[0091]
The condensing lens 44 of the first lens array 40C of this embodiment corresponds to the condensing function of the afocal optical system, and the second lens array 50C is the second lens array 50B (FIG. 11) of the second embodiment. ) And the function of the second lens array 50D (FIG. 18), that is, the function of collimating the light of the afocal optical system. Therefore, according to the illumination optical system 100C of the present embodiment, the incident efficiency to the polarization conversion optical system 60C arranged at the subsequent stage of the second lens array 50C can be increased as in the second embodiment. In addition, the function of the afocal optical system can improve the light use efficiency in the optical element disposed in the subsequent stage of the second lens array 50C. As a result, also in the illumination optical system of the present embodiment, the light utilization efficiency can be improved.
[0092]
E. Projection display:
FIG. 19 is a schematic configuration diagram of a main part of a projection display apparatus 1000 using the illumination optical system 100C of the present invention when viewed in plan. This projection display apparatus 1000 uses the illumination optical system 100C of the present invention.
[0093]
The projection display apparatus 1000 includes an illumination optical system 100C, a color light separation optical system 200, a relay optical system 220, three liquid crystal light valves 300R, 300G, and 300B, a cross dichroic prism 320, and a projection optical system 340. I have. In the projection display apparatus 1000, the light emitted from the illumination optical system 100C is separated into three color lights of red (R), green (G), and blue (B) by the color light separation optical system 200 and separated. Each color light is modulated in accordance with image information (image signal) through the liquid crystal light valves 300R, 300G, and 300B, and each modulated color light is synthesized by the cross dichroic prism 320 and then on the screen SC via the projection optical system 340. The image is displayed on the screen.
[0094]
As described above, the illumination optical system 100C emits linearly polarized light (in the above example, s-polarized light) whose polarization directions are aligned, and the liquid crystal light valves 300R, 300G, and 300B that are the illumination areas LA. Illuminate. Each of the liquid crystal light valves 300R, 300G, and 300B includes a liquid crystal panel and a polarizing plate disposed on the light incident / exit surface side. The polarizing plate disposed on the light incident surface of the liquid crystal panel is for further increasing the polarization degree of the illumination light, and the polarization direction of the linearly polarized light emitted from the illumination optical system 100C is determined by these polarizing plates. It is arrange | positioned so that it may become the permeation | transmission axis direction. In this way, the purity (degree of polarization) of linearly polarized light included in the illumination light emitted from the illumination optical system 100C can be further increased. If the degree of polarization of the illumination light emitted from the illumination optical system 100C is extremely high, the polarizing plate disposed on the light incident surface side can be omitted.
[0095]
The color light separation optical system 200 includes two dichroic mirrors 202 and 204 and a reflection mirror 208, and separates a light bundle emitted from the illumination optical system 100 into three color lights of red, green, and blue. Has the function of The first dichroic mirror 202 transmits the red light component of the light emitted from the illumination optical system 100 and reflects the blue light component and the green light component. The red light R transmitted through the first dichroic mirror 202 is reflected by the reflection mirror 208 and emitted toward the cross dichroic prism 320. The red light R emitted from the color light separation optical system 200 passes through the field lens 232 and reaches the liquid crystal light valve 300R for red light. The field lens 232 converts each partial light beam emitted from the illumination optical system 100 into a light beam parallel to the central axis. The same applies to the field lenses 234 and 230 provided in front of other liquid crystal light valves.
[0096]
Of the blue light B and green light G reflected by the first dichroic mirror 202, the green light G is reflected by the second dichroic mirror 204 and emitted from the color light separation optical system 200 toward the cross dichroic prism 320. Is done. The green light G emitted from the color light separation optical system 200 passes through the field lens 234 and reaches the liquid crystal light valve 300G for green light. On the other hand, the blue light B transmitted through the second dichroic mirror 204 is emitted from the color light separation optical system 200 and enters the relay optical system 220. The blue light B incident on the relay optical system 220 passes through the incident side lens 222, the relay lens 226, the reflection mirrors 224 and 228, and the emission side lens (field lens) 230 provided in the relay optical system 220. Reach the light valve 300B. Here, the reason why the relay optical system is used for the blue light B is to prevent the light use efficiency from being lowered because the optical path length of the blue light B is longer than the optical path lengths of the other color lights. is there. That is, the blue light incident on the incident side lens 222 is transmitted to the emission side lens 230 as it is. The distances from the superimposing optical system 70 of the illumination optical system 100 to the liquid crystal light valve 300R, the liquid crystal light valve 300G, and the incident side lens 222 are set to be substantially equal.
[0097]
The three liquid crystal light valves 300R, 300G, and 300B have a function as a light modulation device that forms an image by modulating light of three colors according to a given image signal. The cross dichroic prism 320 has a function as a color light combining optical system that combines three color lights modulated through the liquid crystal light valves 300R, 300G, and 300B to form a color image. The cross dichroic prism 320 includes a red light reflecting dichroic surface 321 on which a dielectric multilayer film that reflects red light is formed, and a blue light reflecting dichroic surface 322 on which a dielectric multilayer film that reflects blue light is formed. Is formed in a substantially X shape at the interface of four right-angle prisms. The red light reflecting dichroic surface 321 and the blue light reflecting dichroic surface 322 combine the three color lights to form combined light for projecting a color image. The combined light generated by the cross dichroic prism 320 is emitted in the direction of the projection optical system 340. The projection optical system 340 projects the combined light emitted from the cross dichroic prism 320 and displays a color image on the screen SC. Note that a telecentric lens can be used as the projection optical system 340.
[0098]
Since the projection display apparatus 1000 uses the illumination optical system 100C based on an integrator optical system with high light utilization efficiency, a uniform and bright image can be displayed.
[0099]
In the above embodiment, the case where the illumination optical system 100C is used has been described as an example, but the illumination optical system of another embodiment can also be used.
[0100]
In the projection display apparatus 1000, the illumination optical system 100C of the present invention is described as being applied to a projection display apparatus that projects a color image using three liquid crystal panels (liquid crystal light valves). It is not necessary to be limited to this. The illumination optical system of the present invention can be used as an illumination optical system in various apparatuses. For example, the present invention can also be applied to a projection display device that projects a monochrome image or a color image using a single liquid crystal panel. Further, the present invention can be applied to display devices other than the projection display device.
[0101]
Further, the projection display apparatus 1000 has been described by taking an example in which the illumination optical system of the present invention is applied to a transmissive projection display apparatus. However, the illumination optical system of the present invention is a reflective projection type. The present invention can also be applied to a display device. Here, “transmission type” means that the light modulation device is a type that transmits light, and “reflection type” means that the light modulation device is a type that reflects light. ing. Examples of the reflection type light modulation device include a reflection type liquid crystal panel and a digital micromirror device (trademark of TI). In a reflective projection display device, the cross dichroic prism can be used as a color light separating means for separating light into three colors of red, green, and blue, and is the same by recombining the modulated three colors of light. It can also be used as color light combining means for emitting in the direction of. Even when the present invention is applied to a reflective projection display device, substantially the same effect as that of a transmissive projection display device can be obtained.
[0102]
In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a main part of an illumination optical system 100 as a first embodiment viewed in plan.
FIG. 2 is an explanatory diagram showing a first lens array 40;
FIG. 3 is an explanatory diagram showing a second lens array 50. FIG.
FIG. 4 is a front view showing the second lens array 50 and the first lens array 40 from the z-axis direction.
FIG. 5 is a perspective view showing a configuration of a first polarization conversion element array 60a.
FIG. 6 is an explanatory diagram showing functions of the first polarization conversion element array 60a.
FIG. 7 is an explanatory diagram showing a focused image formed by the first lens array 40 in the vicinity of the second lens array 50;
FIG. 8 is an explanatory diagram showing the relationship between a second lens array 50 and a focused image formed in the vicinity of the second lens array 50 by the first lens array 40;
FIG. 9 is a schematic configuration diagram of a main part of an illumination optical system 100A as a second embodiment viewed in plan.
FIG. 10 is an explanatory diagram showing a first lens array 40A.
FIG. 11 is an explanatory diagram showing a second lens array 50A.
FIG. 12 is an explanatory diagram showing a virtual second lens array 50B.
FIG. 13 is a plan view showing the positional relationship between the first lens array 40A and the second lens array 50B.
FIG. 14 is an explanatory diagram showing a focused image formed by the first lens array 40A in the vicinity of the second lens array 50B.
15 is an explanatory diagram showing a relationship between a second lens array 50A and a focused image formed by the first lens array 40 in the vicinity of the second lens array 50A. FIG.
FIG. 16 is a schematic configuration diagram of a main part of an illumination optical system 100C as a third embodiment viewed in plan.
FIG. 17 is an explanatory diagram showing a first lens array 40C.
FIG. 18 is an explanatory diagram showing the function of the condensing lens 44 of the first lens array 40C.
FIG. 19 is a schematic configuration diagram of a main part of a projection display apparatus 1000 using the illumination optical system 100C of the present invention when viewed in plan.
[Explanation of symbols]
20 ... Light source
22 ... Light source lamp
24 ... concave mirror
30. Split optical system
30A ... Split optical system
30B: Split optical system
30C: Split optical system
40. First lens array
40A ... first lens array
40C ... first lens array
40D ... first lens array
42. First small lens
42A ... 1st small lens
42Aa-42Ac ... 1st small lens
42D ... 1st small lens
44 ... Plano-convex lens
50. Second lens array
50A ... Second lens array
50B ... Second lens array
50C ... Second lens array
50D ... Second lens array
52. Second small lens
52A ... Second small lens
52B ... Second small lens
52Ba-52Bc ... 2nd small lens
52C ... Second small lens
52D ... Second small lens
60: Polarization conversion optical system
60A: Polarization conversion optical system
60C: Polarization conversion optical system
60a, 60b ... Polarization conversion optical system
60a: First polarization conversion optical system
60b ... Second polarization conversion optical system
62: Shading plate
62a ... Light-shielding surface
62b ... Opening surface
64: Polarizing beam splitter array
64a ... 1st translucent member
64b ... 2nd translucent member
64c ... 3rd translucent member
66a ... Polarized light separation membrane
66b ... Reflective film
70: Superimposing optical system
100: Illumination optical system
100A ... Illumination optical system
100C: Illumination optical system
1000: Projection display device
200: Color light separation optical system
202 ... 1st dichroic mirror
204 ... Second dichroic mirror
208 ... Reflection mirror
220: Relay optical system
222: Incident side lens
224, 228 ... Reflection mirror
226 ... Relay lens
230 ... Ejecting side lens (field lens)
232 ... Field lens
234 ... Field lens
300R, 300G, 300B ... Liquid crystal light valve
320 ... Cross dichroic prism
321 ... Red light reflecting dichroic surface
322 ... Blue light reflecting dichroic surface
340 ... Projection optical system

Claims (9)

An illumination optical system that illuminates a light incident surface of a predetermined optical device as an illumination area,
A light source;
A first lens array having a plurality of small lenses for dividing the light emitted from the light source into a plurality of partial beam bundles;
A second lens array having a plurality of small lenses respectively corresponding to the plurality of small lenses of the first lens array,
The second lens array is disposed in a vicinity position where a plurality of partial beam bundles emitted from the first lens array are condensed,
The plurality of small lenses of the second lens array have a polygonal shape other than a substantially rectangular shape in accordance with the contour shape of the partial light bundles collected by the plurality of small lenses of the corresponding first lens array. Formed,
When two reference axes that pass through the center of the second lens array and are perpendicular to each other are defined, at least some of the dividing lines that divide the plurality of small lenses of the second lens array are the two As the distance from the reference axis increases, the inclination with respect to the two reference axes increases .
The first lens array has M lens rows (M is an integer of 2 or more), and the second lens array has N rows (N is an integer of 1 or more smaller than M). Has a small lens array,
A plurality of partial beam bundles formed by a plurality of small lens rows in the first lens array are collected into a smaller number of rows and made incident on the second lens array. The partial light bundle divided by the M small lens rows is configured to be incident on the N small lens rows of the second lens array,
The plurality of lenslet rows in the first lens array are two lenslet rows,
In the two small lens rows, the position of each of the small lenses on the outer side of the two small lens rows is shifted from the position of each of the small lenses on the inner side along the direction of the rows. Are arranged,
The one small lens row of the second lens array corresponding to the two small lens rows of the first lens array corresponds to the outer small row of lenses of the first lens array. An illumination optical system , wherein first small lenses and second small lenses corresponding to the inner row of small lenses are alternately arranged . The illumination optical system according to claim 1,
At least a part of the plurality of small lenses of the second lens array includes two segment lines parallel to one of the two reference lines and two segments inclined with respect to the other reference line. An illumination optical system having a trapezoidal shape separated by lines. The illumination optical system according to claim 1 or 2 ,
An illumination optical system comprising an afocal optical system that converts an incident light bundle into an outgoing light bundle having a width smaller than the width of the incident light bundle. The illumination optical system according to claim 3 ,
A condensing lens having a condensing function for realizing the afocal optical system is provided in the vicinity of the first lens array,
The plurality of small lenses of the second lens array have a function of collimating light for realizing the afocal optical system. A projection display device that projects and displays an image,
An illumination optical system for illuminating a predetermined illumination area;
A light modulation device that has a light incident surface as the illumination region and modulates incident light from the illumination optical system according to image information;
A projection optical system that projects the modulated light obtained by the light modulation device,
The illumination optical system includes:
A light source;
A first lens array having a plurality of small lenses for dividing the light emitted from the light source into a plurality of partial beam bundles;
A second lens array having a plurality of small lenses respectively corresponding to the plurality of small lenses of the first lens array,
The second lens array is disposed in a vicinity position where a plurality of partial beam bundles emitted from the first lens array are condensed,
The plurality of small lenses of the second lens array have a polygonal shape other than a substantially rectangular shape in accordance with the contour shape of the partial light bundles collected by the plurality of small lenses of the corresponding first lens array. Formed,
When two reference axes that pass through the center of the second lens array and are perpendicular to each other are defined, at least some of the dividing lines that divide the plurality of small lenses of the second lens array are the two As the distance from the reference axis increases, the inclination with respect to the two reference axes increases .
The first lens array has M lens rows (M is an integer of 2 or more), and the second lens array has N rows (N is an integer of 1 or more smaller than M). Has a small lens array,
A plurality of partial beam bundles formed by a plurality of small lens rows in the first lens array are collected into a smaller number of rows and made incident on the second lens array. The partial light bundle divided by the M small lens rows is configured to be incident on the N small lens rows of the second lens array,
The plurality of lenslet rows in the first lens array are two lenslet rows,
In the two small lens rows, the position of each of the small lenses on the outer side of the two small lens rows is shifted from the position of each of the small lenses on the inner side along the direction of the rows. Are arranged,
The one small lens row of the second lens array corresponding to the two small lens rows of the first lens array corresponds to the outer small row of lenses of the first lens array. A projection display device , wherein first small lenses and second small lenses corresponding to the inner row of small lenses are alternately arranged . The projection display device according to claim 5 ,
At least a part of the plurality of small lenses of the second lens array includes two segment lines parallel to one of the two reference lines and two segments inclined with respect to the other reference line. A projection display device having a trapezoidal shape separated by lines. The projection display device according to claim 5 or 6 ,
A projection display device comprising an afocal optical system for converting an incident light bundle into an exit light bundle having a width smaller than the width of the incident light bundle. The projection display device according to claim 7 , wherein
A condensing lens having a condensing function for realizing the afocal optical system is provided in the vicinity of the first lens array,
The plurality of small lenses of the second lens array have a function of collimating light for realizing the afocal optical system. A projection display device according to any one of claims 5 to 8 ,
Furthermore, a color light separation optical system that separates light emitted from the illumination optical system into at least two color lights;
A plurality of light modulation devices for modulating each color light separated by the color light separation optical system;
A color light combining optical system that combines the modulated light of each color after being modulated by each of the electro-optical devices,
A projection display device in which the combined light obtained by the color light combining means is projected through the projection optical system.

Images