JP2000305170A - Illumination device and projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an illumination device capable of illuminating a display element uniformly. SOLUTION: In this illumination device, the rectangular display element 7 is illuminated with luminous flux from lamp units 1 and 2 by using a 1st lens array 3, a 2nd lens array 4 and a lens system RL arranged in turn from this means side. Then, when the length of the effective range of the element 7 in the long-side direction is defined as Dpx, that in the short-side direction is defined as Dpy, the focal distances of individual lenses constituting the 2nd array 4 are defined as (ff2), the focal distance of the lens system is defined as (fr), the width of the lateral aberration of the lens system in the long-side direction with respect to an infinite-point object is defined as (δx) and that in the short-side direction is defined as (δy), the length Dfx of the individual lenses of the 1st array 3 in the long-side direction and the length Dfy thereof in the short-side direction are set so as to satisfy the expressions of Dfx>(Dpx+δx)×ff2/fr and Dfy>(Dpy+δy)×ff2/fr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illumination device and a projection device, and more particularly to a single-panel or three-panel liquid crystal projector capable of realizing illumination with less illuminance unevenness on a projection surface such as a screen or a wall. It is suitable.

[0002]

2. Description of the Related Art Conventionally, liquid crystal display devices (liquid crystal panels,
Various techniques have been proposed for a projector that enlarges and projects an image formed by a display element such as a liquid crystal light valve on a display surface such as a screen.

In a liquid crystal projector, a liquid crystal display element is illuminated by a light beam from an illumination system, and light having image information modulated by a liquid crystal light valve and transmitted through the element is enlarged and projected on a screen by a projection lens. At this time, as means for making the light quantity distribution of the illumination light on the liquid crystal display element uniform, for example, in US Pat. No. 5,098,184, an integrator combining two successive lens arrays as shown in FIG. Was used.

In FIG. 12, reference numeral 101 denotes a white light source,
2 is a condenser lens system combining a mirror and a lens, 10
3 is a first lens array composed of a plurality of lenses,
104 is a second lens array composed of a plurality of lenses, 105 is a condenser lens, 106 is a condenser lens, 107 is a liquid crystal panel, and 108 is a projection lens.
In such an illumination system, the first lens array 10
In 3, the light beam from the condenser lens system 102 is divided into a plurality of light beams, and the divided light beams are divided into a second lens array, a condenser lens 105, and a condenser lens 106.
By superimposing the liquid crystal panel 107 on the liquid crystal panel 107 by using a relay lens system composed of, a substantially uniform illumination area is generated on the liquid crystal panel 107. The shape of this lighting area is
Since the shape of each lens of the first lens array 103 is similar to that of the first lens array 103, the outer shape of each lens of the first lens array 103 is usually made to be a rectangular shape similar to the liquid crystal panel 107, and the illumination area is formed on the liquid crystal panel. They are configured to overlap.

[0005]

In the illumination system shown in FIG. 12, the size of the first fly-eye 103 is Df1, the size of the liquid crystal panel 107 is D1, and the second lens array 104 is the same.
The focal length of each lens is ff2, and the condenser lens 105
Is the focal length of fi, and Mc is the magnification at which the condenser lens 106 acts on the light beam from the condenser lens 105. Df1 = D1 / Mc × ff2 / fi = D1 × ff2 / fr (a1) Have been. Also, fr = Mc × fi, which is the composite focal length of the relay lens system. FIG.
In the illumination system shown in FIG. 2, the condenser lens and the condenser lens are lenses having positive refracting power, respectively. If these are arranged at intervals with a color separation system (not shown), this will occur in this relay lens system. It is difficult to satisfactorily correct field curvature, and lateral aberration occurs around the optical system. At this time, in the configuration such as the formula (a1), there is a problem in that the lateral light flux remaining in the relay lens system causes a shift in the light flux overlapping in the illumination area, resulting in uneven illumination at the edge of the illumination area. is there.

An object of the present invention is to provide an illumination device and a projection device that can illuminate a surface to be illuminated more uniformly than before.

[0007]

According to a first aspect of the present invention, there is provided a rectangular lens having a light beam from a light source through a first lens array and a second lens array arranged in order from the light source side, and a condensing optical system. In the illumination device for illuminating the irradiation surface, the length of the irradiation surface in the long side direction is Dpx, the length in the short side direction is Dpy,
The focal length of each lens constituting the second lens array is ff2, the focal length of the optical system is fr, the width of the lateral aberration in the long side direction with respect to an object at infinity of the optical system is δx,
When the width of the lateral aberration in the short side direction is δy, the first
The length in the long side direction of each lens of the lens array is Df
x, and the length in the short side direction is Dfy, and the following condition is satisfied: Dfx> (Dpx + δx) × ff2 / fr Dfy> (Dpy + δy) × ff2 / fr.

According to a second aspect of the present invention, there is provided illumination for illuminating a rectangular irradiation surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from a light source. In the apparatus, the length of the irradiated surface in the long side direction is Dpx, the length of the short side direction is Dpy, and the light source side of the combined system of the first lens array and the second lens array and the condensing optical system. Let L1 be the distance from the principal point position on the irradiated surface side of the combined system to the irradiated surface, and Sr = L2 / L1. The width of the transverse aberration in the long side direction with respect to an object at infinity is δx, and the width of the transverse aberration in the short side direction is δ
When y is set, the length in the long side direction of each lens of the first lens array is Dfx, and the length in the short side direction is Dfy. Dfx> (Dpx + δx) × Sr Dfy> (Dpy + δy) × Sr It is a lighting device characterized by satisfying the following.

According to a third aspect of the present invention, there is provided an illumination for illuminating a rectangular irradiation surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from the light source. In the apparatus, the length of the irradiation surface in the long side direction is Dpx, the length of the short side direction is Dpy, the focal length of each lens constituting the second lens array is ff2, and the focal length of the optical system is fr, the width of the transverse aberration in the long side direction with respect to an object at infinity of the optical system is δx, the width of the transverse aberration in the short side direction is δy, and the normalized intensity distribution at the entrance pupil of the optical system is Ep, a ray passing through the center of the i-th lens counted from the end in the long side direction among the individual lenses constituting the first lens array and entering the pupil of the light collecting optical system. The lateral aberration amount is δxi, which constitutes the first lens array. δyj lateral aberration of the light rays when the light rays passing through the center of the i-th lens shorter side of each lens is incident on the pupil of the focusing optical system, .DELTA.xi,
The pupil intensity at the pupil position for which δyj was calculated is Epi, Epj
And the average of the weighted lateral aberration widths is

[0010]

[Outside 5] Where Dfx is the length in the long side direction of each lens of the first lens array, and Dfy is the length in the short side direction of each lens of the first lens array.

[0011]

[Outside 6] It is a lighting device characterized by satisfying the following conditions.

According to a fourth aspect of the present invention, there is provided an illumination for illuminating a rectangular irradiation surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from the light source. In the apparatus, the length of the irradiation surface in the long side direction is Dpx, the length in the short side direction is Dpy, and the light source side of the combined system of the first lens array and the second lens array and the condensing optical system. Let L1 be the distance from the principal point position on the irradiated surface side of the combined system to the irradiated surface, and Sr = L2 / L1. The width of the transverse aberration in the long side direction with respect to an object at infinity is δx, and the width of the transverse aberration in the short side direction is δ
Let y be the normalized intensity distribution at the entrance pupil of the condensing optical system, and Ep be the center of the i-th lens of the individual lenses constituting the first lens array counted from the end in the long side direction. Is the lateral aberration of the ray when the ray passing through the pupil of the condensing optical system enters the pupil, and the center of the i-th lens in the short side direction among the individual lenses constituting the first lens array. When the amount of lateral aberration of the passing light beam entering the pupil of the condensing optical system is δyj, and the intensity of the pupil at the pupil position where δxi, δyj is calculated is Epi, Epj, the weighted lateral The average of the width of the aberration is

[0013]

[Outside 7] Where Dfx is the length in the long side direction of each lens of the first lens array, and Dfy is the length in the short side direction of each lens of the first lens array.

[0014]

[Outside 8] It is a lighting device characterized by satisfying the following conditions.

According to a fifth aspect of the present invention, there is provided an illuminating device for illuminating a plurality of light beams by superimposing them on a surface to be illuminated. The lighting device is characterized by being formed outside of the lighting device. There is a method of forming a plurality of secondary light sources (images) by dividing the light from the light sources and obtaining the secondary light sources from the plurality of light beams. To form these secondary light sources, a fly-eye lens group is used. And light pipe (rod type integrator)
And a lens system are required.

According to a sixth aspect of the present invention, there is provided an illumination apparatus for illuminating a surface to be illuminated with a light beam from a light source using a first lens array, a second lens array, and a condensing optical system arranged in this order from the light source side. The illumination unevenness caused by the displacement of the illumination area due to the plurality of light beams from the first and second lens arrays generated due to the lateral aberration of the condensing optical system can be formed outside the illuminated surface (effective range). It is a lighting device characterized by the following.

According to a seventh aspect of the present invention, a display device is illuminated by using the illumination device according to any one of the first to sixth aspects, and an image formed by the display device is projected by a projection optical system. Is a projection device.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a main part of a first embodiment of the present invention in which the illumination optical system of the present invention is applied to a single-panel type liquid crystal projector. The single-panel type liquid crystal projector illuminates a single-panel liquid crystal display element 7 with an illumination optical system to form an image (light) with the faceplate 7 and enlarges and projects the image on a screen or a wall by a projection lens 8.

In FIG. 1, reference numeral 1 denotes a light source such as a metal halide lamp that emits white light, and reference numeral 2 denotes a reflector having a concave reflecting surface such as a spheroid or a paraboloid that efficiently reflects a light beam from the light source 1. The illustrated reflector 2 is a parabolic mirror, reflects the light beam from the light source 1 and converts it into parallel light, and makes this parallel light incident on the first lens array 3. The first lens array 3 has a plurality of lenses having a positive refractive power. Reference numeral 4 denotes a second lens array. Each lens of the lens array 4 is a lens having a positive refractive power corresponding to each lens of the first lens array 3 in a one-to-one correspondence. The first and second lens arrays are lens array plates (fly-eye lenses) in which the front shape of each lens is similar to the illuminated area of the display element 7. A plurality of secondary light sources (light source images) are formed on the second lens array 4 by the first lens array 3.

Reference numeral 5 denotes a condenser lens having a positive refractive power. Reference numeral 6 denotes a condenser lens, which transmits illumination light through a liquid crystal display element 7 to an entrance pupil (aperture stop) of a projection lens 8.
Is condensed. Condensing lens 5 and condenser lens 6
Constitutes a relay lens system (lens system) RL. 7
Is a liquid crystal display element (image display element) comprising a twisted nematic type liquid crystal panel. The projection lens 8 has a positive refractive power, and enlarges and projects an image formed by the display element 7 on a screen or a wall S.

In this embodiment, the second lens array 4
Is located at the rear focal position of the first lens array 3 and the first
Since the lens array 3 is located at the front focal position of the second lens array 4, the light beam condensed by the first lens array 3 forms an image near the second lens array 4, so that the plurality of 2 A plurality of light source images serving as the next light source are formed, and the light emission side of the second lens array 4 is in a telecentric state.

Now, let the length of the liquid crystal display element 7 in the long side direction be D
px, the length in the short side direction is Dpy, the focal length of each lens constituting the second lens array 4 is ff2, and the focal length of the relay lens system (the condenser lens 5 and the condenser lens 6) RL is fr. The imaging magnification Mr by the second lens array 4 and the relay lens system RL can be expressed as Mr = ff2 / fr using respective focal lengths, and the long side of the liquid crystal display element 7 with respect to an infinite object of the relay lens system RL. When the width of the lateral aberration in the direction is δx and the width of the lateral aberration in the short side direction is δy, the length in the long side direction of each lens of the first lens array 3 is Dfx, and the length in the short side direction is Dfy is configured to satisfy the following condition: Dfx> (Dpx + δx) × ff2 / fr = (Dpx + δx) × Mr (1) Dfy> (Dpy + δy) × ff2 / fr = (Dpy + δy) × Mr (2) I have.

As a result, a portion of the illumination unevenness due to a shift of the illumination area caused by the lateral aberration of the relay lens system RL is outside the effective range (image display range) of the liquid crystal display element 7, and the effective area of the display element 7 is made uniform. Can be illuminated. High quality images can be displayed on the screen.

The upper limit of conditional expressions (1) and (2) is preferably 1.15 times the lower limit, more preferably 1.1 times. The same applies to the upper limit values in the following conditional expressions.

In the present embodiment, the length of the irradiated surface on the liquid crystal display element 7 in the long side direction is Dpx, the length in the short side direction is Dpy, and the length of the second lens from the lens surface of the first lens array 3 is Dpy. The distance from the principal point position on the light source 1 side of the combined system of the array 4 and the relay lens system to L1 and the liquid crystal display element from the principal point position on the liquid crystal display element 7 side of the combined system of the second lens array 4 and the relay lens system RL. When the distance to the surface to be irradiated on L7 is L2, Sr = L2 / L1, the width of lateral aberration in the long side direction of the liquid crystal display element 7 with respect to the object at infinity of the relay lens system RL is δx, and the liquid crystal display is When the width of the transverse aberration in the short side direction of the element 7 is δy, the length in the long side direction of each lens of the first lens array 3 is D.
fx, and the length in the short side direction Dfy is such that Dfx> (Dpx + δx) × Sr (3) Dfy> (Dpy + δy) × Sr (4)

As a result, a portion of the illumination unevenness due to a shift of the illumination region caused by the lateral aberration of the relay lens system RL is outside the effective range (image display range) of the liquid crystal display element 7, and the effective range of the display element 7 is made uniform. Can be illuminated. High quality images can be displayed on the screen. Here, the lateral aberration due to the relay lens system RL takes the maximum value when the lateral aberration generated on the edge of the long side and the short side of the liquid crystal panel 7 is divided into components in the long side direction and the short side direction. It is desirable.

Further, when the illumination area outside the effective range is widened, the amount of light for forming an image transmitted through the liquid crystal display element 7 is reduced. 7, the normalized light intensity distribution at the entrance pupil of the relay lens system RL is defined as Ep, and the i-th one of the individual lenses constituting the first lens array 3 is counted from the end in the long side direction. When a ray passing through the center of the lens enters the entrance pupil of the relay lens system RL, the amount of lateral aberration of the ray is δxi, and the number of individual lenses constituting the first lens array 3 is counted from the short side end. A ray passing through the center of the i-th lens is a relay lens system RL.
Δyj, the lateral aberration amount of the light beam when entering the entrance pupil of
When the pupil (light) intensity at the pupil position where δxi, δyj is calculated is defined as Epi, Epj,

[0028]

[Outside 9] Using the width average of the weighted lateral aberration obtained in

[0029]

[Outside 10] It is preferable to configure so as to satisfy the following condition. Note that FIG.
Is the position (i, j) on the xy coordinates set for the plurality of lenses 3a of the first lens array 3 and the entrance pupil of the relay lens system.
Shows the relationship with the lateral aberration amounts δxi and δyj.

If the first lens array 3 is located at a position shifted from the front focal position of the second lens array 4 and the light exit side of the second lens array 4 is not in a telecentric state, the second lens array 3 Dfx> (Dpx + δx) × Mr ′... (11) Dfy> (using the imaging magnification Mr ′ regarding the display element 7 obtained assuming that the lens No. 4 and the relay lens system RL are on the same optical axis. Dpy + δy) × Mr ′ (12) or

[0031]

[Outside 11] May be configured to satisfy the condition.

Further, the liquid crystal display element 7 has a relay lens system R
When the first lens array 3 is located at a position shifted in the optical axis direction from the paraxial image point position of the object at infinity due to L, if the light exit side of the second lens array 4 is in a telecentric state. The liquid crystal display element 7 from the rear focal position of the relay lens system RL corresponding to the paraxial image point position.
Dfx> (Dpx + δx) × ff2 / (fr−σ) = (Dpx + δx) × fr / (fr−σ) × Mr ′ (15) Dfy> (Dpy + δy) ) × ff2 / (fr−σ) = (Dpy + δy) × fr / (fr−σ) × Mr ′ (16) or

[0033]

[Outside 12] Should be satisfied.

Regarding the image formation of the first lens array 3, when the light exit side of the second lens array 4 is not in a telecentric state, the principal point position on the liquid crystal display element 7 side in the optical system including the second lens array 4 Dfx> (Dpx + δx) × fr / (hr−σ) × Mr ″ (19) Dfy> (Dpy + δy) × fr / (hr−σ) × Mr ″ (20) or

[0035]

[Outside 13] Should be satisfied. Here, Mr ′ is an imaging magnification for the display element 7 that is determined assuming that the lens of the second lens array 4 and the relay lens system RL are on the same optical axis, and Mr ′ = fr / (fr−σ) × Mr ″ (23) or Mr ′ = fr / (hr−σ) × Mr ″ (24) can be expressed in the same format as when the display element 7 is placed at the paraxial image point position. it can.

Next, Table 1 shows numerical examples (lens data) of the illumination optical system according to the first embodiment.

[0037]

[Table 1]

In Table 1, r is the radius of curvature of each optical element, and in the first and second lens arrays 3 and 4, it is the radius of curvature of the individual lenses 31 and 41 that compose them.
Is the surface distance on the optical axis o of each optical element, and in the first and second lens arrays 3 and 4, is the distance between the apex of each lens 31 and 41 constituting the respective surface and the next surface, and n is each optical element. It is the refractive index of the material of the element.

The aspherical shapes of the reflector 2 and the condenser lens 5 can be expressed by the following equation (25), where Z is the direction of the optical axis o, and h is the direction perpendicular to the optical axis. K in the above is a parameter in the equation (25).

[0040]

[Outside 14]

The lateral aberration of the liquid crystal display element in the horizontal direction (x direction) and the vertical direction (y direction) with respect to an infinite object of the relay lens system RL including the condenser lens 5 and the condenser lens 6 of this numerical example is shown. The aberration diagram is shown in FIG. The positions of the respective image heights are on the optical axis I0, the vertical edge I1, and the horizontal edge I1 on the liquid crystal display element 7 shown in FIG.
2. The diagonal edge I3. Here, the vertical edge I
1. The lateral and vertical lateral aberration amounts at the lateral edge I2 and the diagonal edge I3 are δ2x, δ3x, and δ1, respectively.
When y and δ3y are set, δ2x = 0.422 mm δ3x = 0.661 mm δ1y = 0.157 mm δ3y = 0.538 mm When the maximum values in the horizontal and vertical directions are δx and δy, δx = 0.661 mm δy = 0.538 mm. Here, the focal length ff2 of the lens 41 constituting the second lens array 4 and the focal length fr of the relay lens system RL are obtained from the lens data as ff2 = 48.3 mm fr = 168.9 mm. The square length is 1.3 inches,
Assuming a vertical and horizontal aspect ratio of 3: 4, the horizontal length Dpx and the vertical length Dpy of the liquid crystal display element are Dpx = 26.41 mm and Dpy = 19.82 mm, respectively. From these data, assuming that the horizontal length is Dfx and Dfy, the size of the first lens array 3 is set as Dfx> 7.74 mm and Dfy> 5.82 mm from the equations (1) and (2). I have.

FIG. 4 is a schematic view of a main part of a second embodiment of the present invention, showing a liquid crystal projector. Embodiment 2 is shown in FIG.
As compared with the first embodiment, the only difference is that the condenser lens 5 is composed of two lenses and no aspheric surface is used, and the other configurations are the same. Table 2 shows lens data in a numerical example of the present embodiment.

[0043]

[Table 2]

The horizontal direction (x direction) and the vertical direction (y direction) of the liquid crystal display element with respect to an object at infinity of the relay lens system RL including the condenser lens and the condenser lens according to the present numerical example.
FIG. 5 shows an aberration diagram of the lateral aberration for (1) and (2). Here, the lateral aberration amount of the relay lens system RL is calculated from Expressions (7) and (8) in consideration of the light intensity distribution at the entrance pupil of the relay lens system RL. The entrance pupil of the relay lens system RL is the light entrance surface of the condenser lens 1, and the light intensity distribution at the entrance pupil is
Is the intensity distribution on the light incident surface. The actual incident intensity distribution of the condenser lens 1 becomes an intensity distribution (solid line) as shown in FIG. 6 based on the light flux condensed by the first lens array 3. Since the lateral aberration is smoothly continuous with respect to the pupil, the actual light intensity distribution at the entrance pupil may be considered as a smoothly approximated curve (broken line in FIG. 6), and the amount of lateral aberration is calculated using this approximated distribution. calculate. From equations (5) and (6), the lateral aberration amount at each image height is: δ2x = 0.676 mm δ3x = 0.911 mm δ1y = 0.545 mm δ3y = 0.746 mm, and the maximum value in the horizontal and vertical directions Let δx, δy be: δx = 0.91 mm δy = 0.746 mm Here, the focal length ff2 of the lens 41 constituting the second lens array 4 and the focal length fr of the relay lens system RL are obtained from the lens data as ff2 = 48.3 mm fr = 168.9 mm. The square length is 1.3 inches,
Assuming a vertical and horizontal aspect ratio of 3: 4, the horizontal length Dpx and the vertical length Dpy of the liquid crystal display element are Dpx = 26.41 mm and Dpy = 19.82 mm, respectively. Based on these data, the size of the lens 31 constituting the first lens array 3 is represented by Dfx, D
Assuming that fy, Dfx> 7.78 mm and Dfy> 5.88 mm are set from equations (7) and (8).

FIG. 7 is a schematic view of a main part of a third embodiment of the present invention, showing a liquid crystal projector. Embodiment 3
1 is different from Embodiment 1 of FIG. 1 only in that the position of the liquid crystal display element is displaced from the paraxial image point position of the relay lens system toward the light source, and other configurations are the same. is there. Next, Table 3 shows lens data in a numerical example of the third embodiment.

[0046]

[Table 3]

In this embodiment, the lateral aberration at the periphery of the screen can be reduced by displacing the liquid crystal display element in the optical axis direction by 4.61 mm toward the light source. On the liquid crystal display element at this position, the lateral aberration of the optical axis I0, the vertical edge I1, the horizontal edge I2, and the diagonal edge I3 is as shown in FIG. Here, when the horizontal and vertical lateral aberration amounts at the vertical edge I1, the horizontal edge I2, and the diagonal edge I3 are δ2x, δ3x, δ1y, and δ3y, respectively, δ2x = 1.924 mm δ3x = 2 .175 mm δ1y = 1.604 mm δ3y = 2.042 mm, and when the maximum values in the horizontal and vertical directions are δx and δy, δx = 2.175 mm δy = 2.042 mm Here, the focal length ff2 of the lens 41 constituting the second lens array 4 and the focal length fr of the relay lens system RL are obtained from the lens data as ff2 = 48.3 mm fr = 177.6 mm. The square length is 1.3 inches,
Assuming a vertical and horizontal aspect ratio of 3: 4, the horizontal length Dpx and the vertical length Dpy of the liquid crystal display element are Dpx = 26.41 mm and Dpy = 19.82 mm, respectively. Based on these data, the size of the lens 31 constituting the first lens array 3 is represented by Dfx, D
Assuming that fy, Dfx> 7.98 mm and Dfy> 6.10 mm are set from Expressions (15) and (16).

FIG. 9 is a schematic view of a main part of a fourth embodiment of the present invention. FIG. 9 shows a case where the present invention is applied to a three-panel color liquid crystal projector.

In the figure, 1 is a light source such as a metal halide lamp which emits white light, and 2 is a reflector having a concave reflecting surface such as a spheroid or a paraboloid which efficiently reflects the light beam from the light source 1. Since the reflector 2 shown is a parabolic mirror, it reflects the light beam from the light source 1 and converts it into parallel light, and makes this parallel light incident on the first lens array 3. The first lens array 3 has a plurality of lenses having a positive refractive power. Reference numeral 4 denotes a second lens array. Each lens of the lens array 4 is a lens having a positive refractive power corresponding to each lens of the first lens array 3 in a 1: 1 ratio. The first and second lens arrays are lens array plates (fly-eye lenses) in which the front shape of each lens is similar to the illuminated area of the display element P.

Reference numeral 51 denotes a polarization conversion element array, which is shown in FIG.
And converts non-polarized light (randomly polarized light) incident on each polarization conversion element into linearly polarized light polarized in a specific direction. As shown in FIG. 11, the polarization directions of the linearly polarized light emitted from each polarization conversion element coincide with each other. Reference numeral 5 denotes a condenser lens having a positive refractive power. M1 to M4 are mirrors.

Reference numeral 52 denotes a dichroic mirror that transmits red light and reflects light of green and blue, and reference numeral 53 denotes a dichroic mirror that transmits blue light and reflects green light. Reference numeral 55 denotes a relay lens system according to the present invention, and the embodiment of FIG. 9 shows a case where the relay lens system includes three lenses (lens groups) G1, G2, and G3. Reference numeral 6 denotes a condenser lens, which collects illumination light on the entrance pupil of the projection lens 8 via the liquid crystal display elements Pr and Pg. The condenser lens 5 and the condenser lens 6 constitute a first relay lens system. Pr is a red-only liquid crystal display element, Pg is a green-only liquid crystal display element, and Pb is a blue-only liquid crystal display element (LCD).

Numeral 54 denotes a color synthesizing means, which has dichroic films 54a and 54b therein and has three liquid crystal display elements P.
The three color image lights from r, Pg, and Pb are combined and emitted from the light emission surface 54c. Reference numeral 8 denotes a projection lens, and the liquid crystal display elements Pr, Pg, Pb synthesized by the color synthesizing means 54.
The image (light) of each color displayed on the screen is enlarged and projected on a screen or a wall.

Next, the configuration of the polarization conversion element array 51 will be described with reference to FIG. Each polarization conversion element of the polarization conversion element array 51 is provided corresponding to each lens of the second lens array 4, and each of these elements is
It has a reflecting surface 51b that bends the optical path of S-polarized light reflected by 1a and the polarization splitting surface 51a, and a quarter-wave plate 51c provided on the optical path of P-polarized light transmitted through the polarization splitting surface 51a. As a result, the emitted light beams are emitted with the same polarization state.

In this embodiment, the illumination light paths for red, green, and blue light are the same for green light and red light, but the illumination light path for blue light is smaller than that of the other two color lights. Since it is long, the second relay lens system 55 is used. In the illumination system including the second relay lens system 55, when the magnifications of the lens 5 and the second relay lens system 55 for the liquid crystal display element Pb are Mr1 and Mr2, respectively, the total magnification is Mr = Mr1 × Mr2; The amount of lateral aberration generated in the optical system including the second relay lens system is δ
Let x 'and δy' be the sizes Dfx 'and Df of the lenses 31 of the first lens array 3 in the same manner as described above.
y ′ satisfies the following condition: Dfx ′> (Dpx + δx ′) × Mr Dfy ′> (Dpy + δy ′) × Mr At this time, the liquid crystal display elements Pr,
Dfx, Dfy and Dfx ', D set for Pg
fy ′ is Dfx = Dfx ′, Dfy = Dfy ′
, But Dfx ′> Dfx, Dfy ′
When> Dfy, the magnification of the second relay lens system 55 is determined from Mr ′ = Dfx / (Dpx + δx ′) or Mr ′ = Dfy / (Dpy + δy ′) such that Mr2 = Mr ′ / Mr1.

Although the projector described above uses a liquid crystal display element as a light modulating element, the present invention is applicable to a projector using a birefringent substance other than liquid crystal or a light modulating element using another structure as a display element. The invention is applicable.

A light pipe (rod type integrator) can also be used as an integrator for each of the above-mentioned uniform illuminations, and a plurality of secondary light sources (images) can be formed by the pipe and the convex lens.

In each of the above embodiments, a portion where illuminance unevenness around illumination light is taken out of the effective range of the display element in consideration of the lateral aberration of the optical system of the illumination device, and the effective range of the display element is changed by the light intensity distribution. We provide a liquid crystal projector that can illuminate with uniform light and project high-quality images.

In place of the dichroic prism used as the color synthesizing means in each of the above-described embodiments, two dichroic mirrors intersecting or a plurality of dichroic mirrors used in the color separating means are arranged in parallel. And a combination of a plurality of prisms as shown in Japanese Patent No. 2505758 can be used.

[0059]

As described above, according to the present invention, it is possible to obtain an illumination device capable of uniformly illuminating a surface to be illuminated, and a projection device capable of uniformly illuminating a light modulation element for displaying an image and projecting a high-quality image. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a main part of a first embodiment of the present invention.

FIG. 2 is an aberration diagram of the relay lens system of FIG. 1;

FIG. 3 is an explanatory diagram of an image plane in FIG. 1;

FIG. 4 is a schematic diagram of a main part of a second embodiment of the present invention.

5 is an aberration diagram of the relay lens system of FIG. 4;

FIG. 6 is an explanatory diagram of the intensity of the entrance pupil of the relay lens system.

FIG. 7 is a schematic diagram of a main part of a third embodiment of the present invention.

8 is an aberration diagram of the relay lens system shown in FIG. 7;

FIG. 9 is a schematic diagram of a main part of a fourth embodiment of the present invention.

FIG. 10 is a diagram illustrating aberrations in the x and y directions.

FIG. 11 is an explanatory view of the polarization conversion element array of FIG. 9;

FIG. 12 is an explanatory diagram of a conventional projection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light source 2 Reflector 3 1st lens array 4 2nd lens array 5 Condensing lens 6 Condenser lens RL Relay lens system 7 Illuminated surface (liquid crystal display element) 8 Projection lens S screen 51 Polarization conversion element array 52, 53 Dichroic mirror 54 Cross dichroic prism 55 Relay lens system Pr, Pg, Pb Liquid crystal panel

Claims (7)

[Claims] An illumination device for illuminating a rectangular illumination surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from a light source, and a condensing optical system. The length of the irradiation surface in the long side direction is Dpx, the length in the short side direction is Dpy, the focal length of each lens constituting the second lens array is ff2, and the focal length of the optical system is f.
r, the width of the transverse aberration in the long side direction with respect to the object at infinity of the optical system is δx, and the width of the transverse aberration in the short side direction is δy, the length of each lens of the first lens array is A lighting device which satisfies the following condition: the length in the side direction is Dfx, and the length in the short side direction is Dfy: Dfx> (Dpx + δx) × ff2 / fr Dfy> (Dpy + δy) × ff2 / fr. 2. An illumination device for illuminating a rectangular surface to be illuminated via a first lens array and a second lens array arranged in order from the light source side with a light beam from a light source, and a condensing optical system. The length of the irradiation surface in the long side direction is Dpx, and the length in the short side direction is Dpy, from the first lens array to the principal point position on the light source side of the combined system of the second lens array and the condensing optical system. Where L1 is the distance from the principal point position of the combined system on the irradiated surface side to the irradiated surface, and Sr = L2 / L1. The width of the transverse aberration in the long side direction is δx, and the width of the transverse aberration in the short side direction is δ
When y is set, the length in the long side direction of each lens of the first lens array is Dfx, and the length in the short side direction is Dfy. Dfx> (Dpx + δx) × Sr Dfy> (Dpy + δy) × Sr A lighting device characterized by satisfying the following. 3. An illumination device for illuminating a rectangular illumination surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from a light source, and a condensing optical system. The length of the irradiation surface in the long side direction is Dpx, the length in the short side direction is Dpy, the focal length of each lens constituting the second lens array is ff2, and the focal length of the optical system is f.
r, the width of the lateral aberration in the long side direction with respect to the object at infinity of the optical system is δx, the width of the lateral aberration in the short side direction is δy, and the normalized intensity distribution at the entrance pupil of the optical system is Ep, a ray passing through the center of the i-th lens counted from the end in the long side direction among the individual lenses constituting the first lens array and entering the pupil of the light collecting optical system. A lateral aberration amount is δxi, and a ray passing through the center of the i-th lens in the short side direction among the individual lenses constituting the first lens array enters the pupil of the condensing optical system. When the pupil intensity at the pupil position at which the aberration amounts δyj, δxi, and δyj are calculated are Epi and Epj, the average width of the weighted lateral aberration is When the length of the first lens array is Dfx, the length of each lens in the long side direction is Dfx, and the length of each lens in the short side direction is Dfy. A lighting device characterized by satisfying the following conditions: 4. An illumination device for illuminating a rectangular irradiation surface via a first lens array and a second lens array arranged in order from the light source side with a light beam from a light source, and a condensing optical system. The length of the irradiation surface in the long side direction is Dpx, and the length in the short side direction is Dpy, from the first lens array to the principal point position on the light source side of the combined system of the second lens array and the condensing optical system. Where L1 is the distance from the principal point position of the combined system on the irradiated surface side to the irradiated surface, and Sr = L2 / L1. The width of the transverse aberration in the long side direction is δx, and the width of the transverse aberration in the short side direction is δ
Let y be the normalized intensity distribution at the entrance pupil of the condensing optical system, and Ep be the center of the i-th lens of the individual lenses constituting the first lens array counted from the end in the long side direction. Is the lateral aberration of the ray when the ray passing through the pupil of the condensing optical system enters the pupil, and the center of the i-th lens in the short side direction among the individual lenses constituting the first lens array. When the amount of lateral aberration of the passing light beam entering the pupil of the condensing optical system is δyj, and the intensity of the pupil at the pupil position where δxi, δyj is calculated is Epi, Epj, the weighted lateral The average of the width of the aberration is When the length is determined by the following formula, the length of the individual lens of the first lens array in the long side direction is Dfx, and the length of the individual lens in the short side direction is Dfy. A lighting device characterized by satisfying the following conditions: 5. An illumination device for illuminating a plurality of light beams by superimposing them on a surface to be illuminated, wherein a portion of illumination unevenness due to a shift of an illumination area due to each of the light beams is the illuminated surface (effective range).
A lighting device characterized in that it can be formed outside the device. 6. An illumination device for illuminating a surface to be illuminated with a light beam from a light source using a first lens array and a second lens array arranged in this order from the light source side, and a condensing optical system. The first occurring due to lateral aberrations of the system
And an illumination device, wherein a portion of illumination unevenness due to displacement of an illumination area due to a plurality of light beams from the second lens array can be formed outside the illuminated surface (effective range). 7. A projection device, comprising: illuminating a display element using the illumination device according to claim 1; and projecting an image formed by the display element by a projection optical system.