JP3826528B2 - Display device provided with optical device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device including an optical device capable of efficiently irradiating light to a light modulation element (display device) such as a liquid crystal display panel.
[0002]
[Prior art]
Recently, display devices such as projector devices, television receivers, and computer displays using optical elements such as liquid crystal display panels, which are light modulation elements called light valves, have become widespread in a wide range of fields. .
A display device using such a liquid crystal display panel or the like splits light emitted from a light source into three primary colors, enters the liquid crystal display panel, and synthesizes the light after being modulated by a video signal input in the liquid crystal display panel. Thus, a color video signal is generated. The color video signal is enlarged and projected onto a screen via a projection lens.
[0003]
By the way, such an optical system is required to efficiently and uniformly irradiate a liquid crystal display panel with a light beam emitted from a light source. However, since the light emitting surface of the light source has a surface area, it is difficult to use the light source as an ideal point light source, and a light beam generated by an actual light source has a large divergence angle. For this reason, it is difficult to efficiently irradiate the liquid crystal display panel with the light beam emitted from the light source.
As a means for efficiently irradiating the liquid crystal display panel with the light beam emitted from the light source having such a large divergence angle, for example, using a lens array having a structure in which a large number of small lenses are arranged in a lattice shape, It is generally known to converge the luminous flux reaching the liquid crystal display panel and to make the illuminance distribution uniform.
[0004]
A general example using this type of lens array will be described with reference to FIG. In the light source 510, for example, a metal halide lamp 510a is disposed at the focal position of the parabolic mirror, and a light beam substantially parallel to the optical axis of the parabolic mirror is emitted from the opening. In the luminous flux emitted from the light source 510, unnecessary rays in the infrared region (IR) and ultraviolet region (UV) are blocked by the UV-IR cut filter 511, and only effective rays are passed to the first optical block 501 behind. Led.
[0005]
The first optical block 501 includes a plurality of convex cell lenses 512a having an outline substantially similar to the aspect ratio of the effective aperture of the liquid crystal display panels 517, 521, and 527 which are light modulation elements (light spatial modulation elements). An optical element including a first lens array 512 arranged in a shape.
[0006]
The second lens array 513 of the second optical block 502 disposed behind the first optical block 501 forms a plurality of convex cell lenses 513a on the incident side, and serves as a first condensing component on the output side. It has at least one convex surface 513b.
Dichroic mirrors 514 and 519 for separating the light emitted from the light source 510 into red, green, and blue colors are disposed between the effective apertures of the second lens array 513 and the liquid crystal display panels 517, 521, and 527. .
In the example shown in this figure, first, the dichroic mirror 514 reflects the red light R and transmits the green light G and the blue light B. The red light R reflected by the dichroic mirror 514 is bent by 90 ° in the traveling direction by the mirror 515, converged by the condenser lens 516, and enters the red liquid crystal display panel 517.
[0007]
On the other hand, the green light G and the blue light B transmitted through the dichroic mirror 514 are separated by the dichroic mirror 519. That is, the green light G is reflected and bent in the traveling direction by 90 ° and guided to the green liquid crystal display panel 521 through the condenser lens 520. The blue light B passes through the dichroic mirror 519 and travels straight, and is guided to the blue liquid crystal display panel 527 through the relay lenses 522 and 524, the condenser lens 526, and the mirrors 523 and 525.
[0008]
On the incident side of the liquid crystal display panels 517, 521, and 527, there is a polarizing plate (not shown) for aligning the polarization direction of the incident light in a certain direction, and light having a predetermined polarization plane of the emitted light behind. A polarizing plate (not shown) that only transmits light is arranged, and is configured to modulate the intensity of light by the voltage of a circuit that drives the liquid crystal.
[0009]
The light of each color light-modulated by the liquid crystal display panels 517, 521, and 527 is combined by a dichroic prism 518 as a light combining unit. In the dichroic prism 518, the red light R is reflected by the reflecting surface 518a, and the blue light B is reflected by the reflecting surface 518b in the direction in which the projection lens 530 is disposed. The green light G passes through the reflecting surfaces 518a and 518b, so that the RGB lights are combined into one optical axis and enlarged and projected onto a screen (not shown) by the projection lens 530.
[0010]
Next, the configuration of the lens arrays 512 and 513 of the first optical block 501 and the second optical block 502 will be described in more detail with reference to FIGS.
First, FIG. 18 mainly shows an example of forming a light beam by the optical characteristics of the first optical block 501, and the light beam L emitted from the light source is divided by each cell lens 512a of the first lens array 512, and the first After exiting the optical block 501, an image corresponding to each cell lens 512a of the first lens array 512 is formed in the vicinity of the second optical block 502.
Thereafter, the light beam is guided to the condenser lens 520 which is the second condensing component by the first condensing component 513b.
At this time, the image point imaged by the outer peripheral cell of the first lens array 512 is an object point of the peripheral angle of view with respect to the condenser lens 520 that is the second condensing component. Thus, the image formed in the vicinity of the second optical block 502 by each cell lens 512a of the first lens array 512 is in the vicinity of the entrance pupil E of the projection lens 530 by the condenser lens 520 as the second condensing component. Re-imaged.
[0011]
FIG. 19 mainly shows an example of light beam formation by the second optical block 502, and the second lens array 502 appropriately sets the external dimension of each cell lens 513a and the distance between the first lens array 512. Thus, the divergence angle θ that can be taken in by the illumination system is controlled.
The captured light flux within the divergence angle is guided to the condenser lens 520 as the second condensing component by the convex surface 513b as the first condensing component, and the first condensing component and the second condensing component are combined. The liquid crystal display panel 521 is efficiently and uniformly irradiated by the combined light collecting component.
However, this action causes the following problems. That is, the light beam passing through the central portion of the convex surface 513b is focused at the position P1 close to the liquid crystal display panel 521, while the light beam passing through the peripheral portion of the convex surface 513b is focused at the position P2 close to the second lens array 502. That is, the position where the image is formed shifts from the liquid crystal display panel 521 side to the second optical block 502 side as it goes from the central part to the peripheral part of the convex surface 513b.
[0012]
As described above, for example, the light beam applied to the liquid crystal display panel 521 is modulated by the liquid crystal display panel 520 having polarizing plates on the front and rear surfaces, and then enters a color composition element such as a dichroic prism 518.
Note that light that enters the condenser lens 520 that is the second condensing component via the convex surface 513b that is the first condensing component is red light R, green light G, and blue light by an optical element such as a dichroic mirror (not shown). It is the green light G among the rays separated into B.
The dichroic prism 518 is formed by bonding four prisms via reflection surfaces 518a and 518b formed of a thin film having a predetermined reflection characteristic.
[0013]
Only the optical path of the green light G is indicated by a solid line, but the red light R and the blue light B are similarly light-modulated by the liquid crystal display panels of the respective colors, and then, as indicated by arrows, the cross dichroic prism 518 On the other hand, the light enters from different directions.
[0014]
The green light G modulated by the liquid crystal display panel 521 passes through the dichroic prism 518 as it is, the red light R incident on the dichroic prism 518 is reflected by the reflecting surface 518a, and the incident blue light B is reflected by the reflecting surface 518b. In other words, the RGB lights are combined by the cross dichroic prism 518 to generate a color video signal and enter the projection lens 530.
[0015]
As described above, by providing the lens arrays 512 and 513 in which the convex lenses 512a and 513a are arranged in a lattice pattern behind the light source, the light emitted from the light source is more efficiently and uniformly than when only the condenser lens is arranged. In addition, the effective opening of the liquid crystal display panel 521 can be irradiated.
[0016]
[Problems to be solved by the invention]
However, in such a conventional first optical block 501 and second optical block 502, each of the first lens array 512 and the second lens array 513 is configured by disposing lens cells having exactly the same shape in a lattice pattern. is doing.
As a problem in the case of using the lens array having such a configuration, first, as shown in FIG. 18, the imaging position of each cell lens 512a of the first lens array 512 and its aberration are exactly the same. is there. At this time, the light beam imaged by each cell lens 512a of the first lens array 512 is guided to the condenser lens 520 as the second condensing component by the convex surface 513b as the first condensing component. Since the angles of light beams incident on the condenser lens 520 are different as indicated by the broken line and the solid line, the pupil of the projection lens 530 is affected by the off-axis aberration caused by the condenser lens 520 as shown in FIGS. In the vicinity of E, for example, as indicated by the areas AR1 and AR2, the luminous flux does not have uniform imaging performance, and loss of light quantity and unevenness of light quantity occur.
[0017]
As a second problem, as shown in FIG. 19, each cell lens 513a of the second lens array 513 is composed of a convex surface 513b that is a first condensing component and a condenser lens 520 that is a second condensing component. Due to the light condensing component, only the light beams in different ranges among the light beams formed near the liquid crystal display panel 521 act. As a result, as shown in FIGS. 19 and 20B, each cell lens 513a of the second lens array 513 is affected by different aberrations due to the combined light condensing component, and the liquid crystal display panel 521 forms a uniform image. Loss of light amount and unevenness of light amount occur without performance.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a display device including an optical device that can solve the above-described problems and obtain uniform imaging performance while preventing loss of light amount and unevenness of light amount.
[0018]
[Means for Solving the Problems]
According to the present invention, there is provided a display device including a light source, a light modulation element that emits a light beam from the light source through an optical device for illumination, and a projection lens that projects the modulated light beam. The illumination optical device corresponds to a first optical block including a first lens array having a plurality of cell lenses substantially similar to the light modulation element, and a first lens array of the first optical block. A second optical block including a second lens array having a plurality of cell lenses, and a first condensing component that condenses the light beam that has passed through the second lens array toward the light modulation element; A second condensing component disposed in the vicinity of the light modulation element to form an image of the emitted light beam at a predetermined position, and the cell lens of the first lens array of the first optical block is different Aspherical Thus, a plurality of light beams that pass through the plurality of cell lenses of the first lens array and travel in different directions due to the second condensing component via the second optical block are imaged on the pupil plane of the projection lens. to correct This is achieved by a display device comprising an optical device characterized in that.
[0019]
In the present invention, the light modulation element of the display device is irradiated with the light beam from the light source via the optical device for illumination. The projection lens of the display device projects the modulated light beam.
The first optical block of the illumination optical device includes a first lens array. The first lens array has a plurality of cell lenses.
The second optical block has a second lens array. The second lens array has a plurality of cell lenses. This second lens array corresponds to the first lens array of the first optical block. The first condensing component of the second optical block condenses the light beam that has passed through the second lens array toward the light modulation element side.
The second condensing component is disposed in the vicinity of the light modulation element in order to form an image of the light beam emitted from the second optical block at a predetermined position, for example, the position of the pupil of the projection lens.
In this case, the cell lenses of the first lens array of the first optical block are made from different aspheric surfaces.
As a result, since the cell lenses of the first lens array are not made of the same spherical surface but are made of different aspherical surfaces, the first lens array, the second lens array, the first condensing component, and the second condensing component pass through. For example, the light flux can be uniformly imaged in the vicinity of the pupil of the projection lens. Thereby, loss of light quantity and unevenness of light quantity in the projection lens can be prevented.
[0020]
According to the present invention, there is provided a display device including a light source, a light modulation element that emits a light beam from the light source through an optical device for illumination, and a projection lens that projects the modulated light beam. The illumination optical device corresponds to a first optical block including a first lens array having a plurality of cell lenses substantially similar to the light modulation element, and a first lens array of the first optical block. A second optical block including a second lens array having a plurality of cell lenses, and a first condensing component that condenses the light beam that has passed through the second lens array toward the light modulation element; A second condensing component disposed in the vicinity of the light modulation element to form an image of the emitted light beam at a predetermined position, and the cell lens of the second lens array of the second optical block is different. Aspherical Thus, a plurality of light beams collected from the cell lenses of the plurality of first lens arrays through the corresponding cell lenses of the second lens array and condensed by the first light collection component are transmitted through the second light collection components. Correction is performed so that an image is formed at a predetermined position on the display surface of the modulation element This is achieved by a display device comprising an optical device characterized in that.
[0021]
In the display device of the present invention, the light modulation element of the display device is irradiated with the light beam from the light source through the illumination optical device. The projection lens of the display device projects the modulated light beam.
The first optical block of the irradiation optical apparatus includes a first lens array. The first lens array has a plurality of cell lenses having a substantially similar shape to the light modulation element.
The second optical block has a second lens array. The second lens array has a plurality of cell lenses. This second lens array corresponds to the first lens array of the first optical block. The first condensing component of the second optical block condenses the light beam that has passed through the second lens array toward the light modulation element side.
The second light collecting component is disposed in the vicinity of the light modulation element in order to form an image of the light beam emitted from the second optical block at a predetermined position.
In this case, the second lens array of the second optical block is made of different aspheric surfaces.
Thereby, since the second lens array of the second optical block is made of different aspherical surfaces instead of the same spherical surface, the first lens array, the second lens array, the first condensing component, and the second condensing component. The light flux that has passed through the component can be imaged well and uniformly on the light modulation element, for example, not at a distance from the light modulation element.
In the present invention, it is preferable that the first lens array of the first optical block and the second lens array of the second optical block are both different aspherical surfaces to obtain both of the above-described uniform imaging functions. Can do.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.
The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.
[0023]
FIG. 1 is an external view showing a projection television set 100 including a projection display device having a preferred embodiment of the optical device of the present invention, and FIG. 2 is a liquid crystal including the projection display device 1 of FIG. 1 shows a rear projection television set 100 of the type, which is also called a liquid crystal projector device. FIG. 2 shows the internal structure of the television set 100.
First, the schematic structure of the television set 100 will be described. In FIG. 1 and FIG. 2, the television set 100 includes a cabinet 101, a screen 102, a mirror 103, and a projection display device 1. The projection light 5 to be projected by the projection display device 1 using the light from the light source 3 is reflected by the mirror 103 and projected from the back surface 104 of the screen 102.
The image projected on the screen 102 can be viewed on the screen 102 as a color image or a monochrome image by the user U.
[0024]
In the following description of the embodiment, a case where a color image can be displayed on the screen 102 will be described.
The projection display device 1 shown in FIGS. 3 and 4 includes an optical device 11, a light source 3, and a projection lens 13. The light source 3 and the projection lens 13 are detachably attached to the main body 11a of the optical device 11.
[0025]
As shown in FIG. 4, the light source 3 has a parabolic reflecting mirror 3a and a lamp 3b, for example. The lamp 3b can be a metal halide lamp or a halogen lamp. On the other hand, the projection lens 13 has a mechanism capable of adjusting the focus of the combined light (color image light) 13A guided from the optical device 11 with respect to the back surface 104 of the screen 102 in FIG.
[0026]
Next, the optical system in the optical device 11 will be described with reference to FIG.
A filter 15, a first optical block 1, and a second optical block 2 are disposed near the light source 3. The filter 15, the first optical block 1, and the second optical block 2 are arranged orthogonal to and parallel to the optical axis OP of the light (light beam) LP emitted from the light source 3.
[0027]
The first optical block 1 and the second optical block 2 are, for example, a planar assembly of a large number of rectangular lenses. The light LP that has passed through the filter 15 is equalized to obtain liquid crystal display panels 45, 49, Illumination light is supplied to the 53 side and sent to the projection lens 13.
The light L that has passed through the filter 15, the first optical block 1 and the second optical block 2 contains red light (R), green light (G), and blue light (B). By the system, the light L is divided into red light (R), green light (G), and blue light (B), and then given predetermined light modulation so that these three primary colors are formed again. The synthesized light 13A, which is color image light, is synthesized on the lens 13 side.
[0028]
Dichroic mirrors 25 and 27, a relay lens 29, and a mirror 31 are arranged along the optical axis OP. A mirror 37 is arranged corresponding to the dichroic mirror 25 along another optical axis OP1 in a direction orthogonal to the optical axis OP. A mirror 37, a condenser lens (second condensing component) 51, and a liquid crystal display panel 53 as a light modulation member are arranged along an optical axis OP2 parallel to the optical axis OP.
[0029]
A condenser lens (second condensing component) 47 and a liquid crystal display panel 49 as a light modulation member are arranged along the optical axis OP3 parallel to the optical axis OP1 corresponding to the dichroic mirror 27.
A relay lens 33 and a mirror 35 are arranged corresponding to the mirror 31 along the optical axis OP4 parallel to the optical axis OP1 and the optical axis OP3. An optical axis OP5 passing through the mirror 35 coincides with the optical axis OP2, and along this optical axis OP5, a condenser lens (second condensing component) 43 and a liquid crystal display panel 45 as a light modulation member are provided. Has been placed.
[0030]
Corresponding to these liquid crystal display panels 53, 49, 45, dichroic prisms (also referred to as light combining members, combining optical elements, or cross prisms) 41 are arranged. The projection lens 13 is positioned corresponding to the dichroic prism 41.
The dichroic mirrors 25 and 27 are mirrors having a light reflection characteristic that reflects light according to a wavelength and a light transmission characteristic that transmits light.
[0031]
The red light (R) of the light L in FIG. 4 is reflected by the dichroic mirror 25 and sent to the mirror 37 side, and the green light (G) and the blue light (B) of the light L are transmitted through the dichroic mirror 25. Are sent to the dichroic mirror 27 side. Green light (G) is reflected by the dichroic mirror 27 and sent to the condenser lens 47 and the liquid crystal display panel 49. The blue light (B) passes through the dichroic mirror 27, passes through the relay lens 29, is reflected by the mirror 31, and then passes through the relay lens 33 and is reflected by the mirror 35, so that the condenser lens 43 and the liquid crystal display panel are reflected. Go through 45.
[0032]
On the other hand, red light (R) is reflected by the mirror 37 and passes through the condenser lens 51 and the liquid crystal display panel 53.
[0033]
Next, the dichroic prism 41 shown in FIG. 4 will be described. The dichroic prism 41 is a prism that combines the red light (R), the blue light (B), and the green light (G) to produce the combined light 13A. This dichroic prism 41 is a prism formed by adhering four prisms 41A, 41B, 41C, 41D having a triangular cross section with an adhesive. Optical thin films 41a and 41b having light transmission characteristics and light reflection characteristics are formed on one or two surfaces of each prism 41A, 41B, 41C and 41D. Optical thin films (optical multilayer films) 41a and 41b having such predetermined light transmission characteristics and light reflection characteristics are formed on the surfaces to which the prisms 41A, 41B, 41C, and 41D are to be bonded.
Each of the prisms 41A to 41D of the dichroic prism 41 is made of a plastic or glass and has a triangular cross section.
[0034]
Next, a path until the light LP generated by the lamp 3b of the light source 3 reaches the screen 102 in FIG. 4 will be briefly described.
The light LP generated by the lamp 3b passes through the filter 15 to remove unnecessary light (infrared and ultraviolet) and becomes light L. The red light R of the light L is reflected by the dichroic mirror 25, reflected by the mirror 37, passes through the condenser lens 51 and the liquid crystal display panel 53, and is reflected by the optical thin film 41 a of the dichroic prism 41.
[0035]
On the other hand, the green light G and blue light B components of the light L pass through the dichroic mirror 25, and the green light G is reflected by the dichroic mirror 27, passes through the condenser lens 47 and the liquid crystal display panel 49, and the optical of the dichroic prism 41. It passes through the thin films 41a and 41b.
The blue light B that has passed through the dichroic mirror 27 passes through the relay lens 29, is reflected by the mirror 31, passes through the relay lens 33, and is further reflected by the mirror 35. The blue light B is reflected by the optical thin film 41 b of the dichroic prism 41 through the condenser lens 43 and the liquid crystal display panel 45.
[0036]
As described above, the red light R, the green light G, and the blue light B gathered in the dichroic prism 41 are combined by the light transmission characteristics and the light reflection characteristics of the optical thin films 41a and 41b, and the liquid crystal display panels 53 and 49 are combined as the combined light 13A. , 45 are enlarged and projected from the projection lens of the projection lens 13 onto the rear surface of the projection screen 102 so as to include information on the displayed image.
[0037]
Next, the first optical block 1 and the second optical block 2 described above will be described with reference to FIGS.
First, referring to FIGS. 4, 5, and 6, the first optical block 1 and the second optical block 2 are arranged perpendicular to and spaced from the optical axis OP. The first optical block 1 and the second optical block 2 are arranged in parallel with the filter 15 and are located between the filter 15 and the dichroic mirror 25.
The light LP generated by the lamp 3 b of the light source 3 in FIG. 4 enters the filter 15 and the first optical block 1 as substantially parallel light. When this light LP passes through the first optical block 1 and the second optical block 2, it reaches the dichroic mirror 25 as light L.
[0038]
As shown in FIGS. 4 to 6, the first optical block 1 has a first lens array 21. For example, as shown in FIG. 7A, the first lens array 21 has cell lenses 21a to 21d arranged in a lattice pattern. The plurality of cell lenses 21a to 21d are composed of at least two different aspheric surfaces. For example, the aspherical shapes of the cell lenses 21a and 21d are different from the aspherical shapes of the cell lenses 21b and 21c. However, the aspheric shapes of all the cell lenses 21a to 21d may be different from each other depending on the positions of the cell lenses.
[0039]
On the other hand, the second optical block 2 has a second lens array 23 as shown in FIGS. The second lens array 23 has a plurality of cell lenses 23a to 23d as shown in FIG. The cell lenses 23a to 23d are located at positions corresponding to the cell lenses 21a to 21d of the first lens array 21 in FIG. As shown in FIG. 9B, the cell lenses 23a to 23d are composed of at least two different aspheric surfaces, for example. For example, the aspheric shapes of the cell lenses 23a and 23d are different from the aspheric shapes of the cell lenses 23b and 23c. However, the aspherical shapes of all the cell lenses 23a to 23d may be different from each other depending on the positions of the cell lenses.
[0040]
The aspect ratio (the ratio of the horizontal length to the vertical length) of the cell lenses 21a to 21d in FIG. 7A is set to 16: 9, for example. The aspect ratio of the cell lens 21a is approximately the same as the aspect ratio of the liquid crystal display panels 45, 49, and 53 shown in FIG. 4, which are light modulation elements, and the aspect ratio of the screen 102 shown in FIG.
[0041]
The cell lenses 21a to 21d and 23a to 23d shown in FIGS. 8 and 9 are preferably composed of at least two different aspheric surfaces, and more preferably, the cell lenses 21a to 21d and 23a to 23d are different from each other. If it is an aspherical surface, as illustrated in FIGS. 5 and 6, a uniform imaging state can be obtained by freely controlling the aberration of the imaging position of the light beam.
The second optical block 2 has a first light collection component 23f in addition to the second lens array 23 described above. The first condensing component 23 f is convex and is formed integrally with the second lens array 23. Between the second optical block 2 and the liquid crystal display panels 45, 49, 53, condenser lenses 43, 47, 51 as second condensing components are respectively arranged.
[0042]
FIGS. 5 and 6 show an example for explaining that a uniform imaging state is obtained by the optical functions of the first optical block 1 and the second optical block 2 as described above.
In FIG. 5, the cell lenses 21a, 21b, 21c and 21d of the first lens array 21 of the first optical block 1 are mainly composed of at least two different aspheric surfaces, and more preferably aspheric surfaces having different shapes. This indicates that uniform imaging can be performed at the entrance pupil E of the projection lens 13.
On the other hand, in FIG. 6, the cell lenses 23a, 23b, 23c, and 23d of the second lens array 23 of the second optical block 2 are aspherical surfaces that are composed of at least two different aspherical surfaces and have different shapes. Thus, an example in which the imaging position FP can be formed on the liquid crystal display panel 49 is shown.
5 and 6 show an example of the green light G as an example, and the optical system includes the first optical block 1, the second optical block 2, the condenser lens 47, the liquid crystal display panel 49, and the dichroic prism 41. ing.
[0043]
Since the imaging characteristics and the like by the first optical block 1 and the second optical block 2 to be described below can be exhibited in the red light R and the blue light B in addition to those related to the green light G, the green light G is representative. The characteristic functions of the first optical block 1 and the second optical block 2 will be described with reference to FIGS.
In FIG. 5, the aspherical shapes of the cell lenses 21a to 21d of the first optical block are corrected for the aberration generated in the optical system after the first optical block 1 mainly due to the condenser lens 47 which is the second condensing component. By optimizing the image to be erased, an image formed in the vicinity of the second lens array by the first lens array can be formed on the pupil E of the projection lens 13 as indicated by a solid line or a broken line in FIG. .
Thereby, it is possible to obtain a more uniform imaging state with respect to the entrance pupil E of the projection lens 13, and it is possible to obtain an efficient and uniform illumination with no loss of light quantity and without unevenness of light quantity.
[0044]
Next, the function of the cell lens 23a of the second optical block 2 will be mainly described with reference to FIG. After the light L passes through the cell lens 21a of the first optical block 1, passes through the cell lenses 23a to 23d of the second optical block 2, and is condensed by the first condensing component 23f, then passes through the condenser lens 47. An image is formed on the liquid crystal display panel 49.
In this way, unlike the conventional case, the liquid crystal display is optimized by optimizing the aspherical shape of the cell lenses 23a to 23d of the second optical block 2 to a shape that corrects the spherical aberration of the first condensing component 23f. It is possible to form a uniform image on the panel 49.
[0045]
As a result, the conventional first lens array and the second lens array are configured by the same spherical cell lens, but compared with this conventional configuration, the aspherical surface of the second lens array 23 in the embodiment of FIG. By using the cell lenses 23a to 23d, the aberration generated by the combined light condensing component synthesized by the first light condensing component 23f and the condenser lens 47 is corrected well, and the result corresponding to each cell lens of the second lens array is obtained. The image position FP can be uniformly determined on the liquid crystal display panel 49.
As a result, a uniform imaging state can be obtained in the vicinity of the liquid crystal display panel 49, and it is possible to obtain efficient and uniform illumination with no loss of light amount and no unevenness in light amount.
Each of the cell lenses 23a to 23d of the second lens array 23 has at least two different aspheric surfaces and has different aspheric shapes depending on their positions.
[0046]
In FIGS. 5 and 6, the cell lenses 21a to 21d and 23a to 23d in the first optical block 1 and the second optical block 2 are each composed of at least two types of aspheric surfaces, and more preferably adjacent to each other. The cell lenses 21a to 21d or the adjacent cell lenses 23a to 23d have different aspheric shapes.
However, the present invention is not limited to this, and only the cell lenses 21a to 21d of the embodiment of the present invention can be adopted only for the first optical block. Conversely, the cell lens of the embodiment of the present invention can be used only for the second optical block. 23a-23d can also be employed. In any case, the embodiment shown in FIGS. 5 and 6 is the best combination of the most preferable first optical block 1 and second optical block 2.
[0047]
6 and 7, the green light G has been described, but the same applies to the red light R and the blue light B, and such a function can be exhibited for the three primary colors (RGB).
[0048]
FIG. 10 is an optical path diagram simply shown by combining FIGS. 6 and 7. Again, when an image is formed on the pupil (incidence pupil) E of the projection lens 13, the cell lens 21a of the first optical block 1 mainly functions. Conversely, when an image is formed on the liquid crystal display panel 49, the cell lens 23a of the second lens array 23 of the second optical block 2 functions.
[0049]
Next, another embodiment of the present invention will be described with reference to FIGS.
11 includes a polarization conversion element 131 between the first optical block 1 and the second optical block 2 of the optical device 11 shown in the embodiment of FIG. This polarization conversion element 131 is, for example, the combined light of the P wave and the S wave after the light LP from the light source 3 passes through the filter 15 and the first optical block 1, for example, only the P wave is transmitted to the second optical block. 2 is irradiated.
By doing in this way, the light beam from the light source 3 can be irradiated to the liquid crystal display panel which is a light valve more efficiently and uniformly. This polarization conversion element 131 is for separating and converting one of the two types of polarization planes of the light LP emitted from the normal light source 3. That is, the polarization plane can be generally divided into a P-polarized component (P wave) and an S-polarized component (S wave). In this type of display device, before the light beam emitted from the light source 3 enters the liquid crystal display panel, such a polarization conversion element 131 is used to correspond to the polarizing plate provided on the front surface of the liquid crystal display panel. Then, the light is converted into only light having a polarization plane of either P wave or S wave and irradiated.
[0050]
As a polarization conversion element that is a means for obtaining a P wave or an S wave, a polarizing beam splitter (hereinafter referred to as PBS) is used. Then, for example, randomly polarized light (P + S wave) is incident on the PBS disposed in the prism at a predetermined angle, and for example, the P wave is transmitted and the S wave is reflected. Then, there is a method in which the S wave is reflected by the end face of the prism and returned to parallel light, and for example, only the S wave is converted to a P wave by passing through a 1 / 2λ plate.
By using such a polarization conversion element, the light that has been absorbed by the conventional polarizing plate can be used effectively, and the light emitted from the light source can be efficiently and uniformly irradiated onto the liquid crystal display panel. It is like that.
[0051]
Next, FIGS. 12A, 12B, and 12C are referred to. In the second optical block 2 in FIG. 12A, the cell lenses 23a to 23d of the second lens array 23 are formed on the light source 3 side in FIG. Each of the cell lenses 23a to 23d shown in FIG. 12A is integrally formed with a first condensing component 23f.
The cell lenses 23a to 23d of the second lens array 23 of the second optical block 2 in FIG. 12B are integrally formed with respect to one large first condensing component 23f. The cell lenses 23a to 23d of the second lens array 23 of the second optical block 2 face the first optical block 1 side.
FIG. 12C shows still another embodiment of the second optical block 2, and an air space is provided between the second lens array 23 of the second optical block 2 and the first condensing component 23f. H is formed.
[0052]
Next, FIG. 13 shows an example of the light source 3, the polarization conversion element 231, the first optical block 1, the second optical block 2, the condenser lens (second condensing component) 47, the liquid crystal display panel 49 and the dichroic prism 41. Yes. In this example, the polarization conversion element 231 is disposed between the first optical block 1 and the light source 3. This polarization conversion element 231 has the same function as the polarization conversion element 131 shown in FIG. 11, and can convert the light LP into only the P wave or S wave and transmit it to the first optical block 1 side.
[0053]
In the embodiment of FIG. 14, the polarization conversion element 331 is disposed between the first optical block 1 and the second optical block 2. In the embodiment of FIG. 15, the second lens array 23 of the second optical block 2 and the first condensing component 23 f are arranged with an air interval H, and the polarization conversion element 431 is in the air space H. Is arranged.
[0054]
Next, FIGS. 16A, 16B, and 16C show examples of light combining means that can be used in place of the dichroic prism 41 as the light combining element of FIG. 4, for example. FIG. 16A shows so-called L-shaped light combining means, which is a combination of prisms 400, 401, and 402. The light modulation element or the liquid crystal display panel 403 corresponds to these prisms 400, 401, and 402. , 404, 405 are arranged.
The light combining means shown in FIG. 16B is similarly composed of prisms 600, 601, and 602. Three liquid crystal display panels 700, 701, 702 are arranged corresponding to these prisms 600, 601, 602. The light combining means shown in FIG. 16C includes two dichroic mirrors 800 and 801 and three liquid crystal display panels 900, 901 and 902.
[0055]
In the embodiment of the present invention, it is also possible to replace the light combining means shown in FIGS. 16A to 16C with the dichroic prism 41 shown in FIG. 4 or the like.
[0056]
By the way, the present invention is not limited to the above embodiment.
In the above-described embodiment, an example of a so-called three-plate type display device using three liquid crystal display panels, particularly a rear projection type display device is shown. However, the present invention is not limited to this, and a so-called single-plate type panel in which only one liquid crystal display panel is used can also be adopted. The light valve or the light modulation element is not limited to the liquid crystal display panel, and other types of display panels can be used.
The present invention can be applied not only to a rear projection type display device that projects synthesized light from the rear side of the screen as shown in FIG. 1 but also to a projector called a front projector that projects synthesized light directly on the screen. .
[0057]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the loss of the light amount and the unevenness of the light amount and obtain uniform imaging performance.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an example of a display device of the present invention.
FIG. 2 is a diagram showing an internal structure of the display device of FIG.
3 is a diagram showing a projection type display device provided in the display device of FIGS. 1 and 2. FIG.
FIG. 4 is a diagram showing a structure of an optical device of a projection display device.
FIG. 5 is a diagram illustrating a state in which the first optical block, the second optical block, and other optical elements are mainly formed by the first optical block.
FIG. 6 is a diagram illustrating a state in which a second optical block mainly forms an image on the liquid crystal display panel side.
FIG. 7 is a diagram illustrating an arrangement example of cell lenses of a first optical block and cell lenses of a second optical block.
FIG. 8 is a diagram illustrating an example in which the cell lenses of the first optical block, the liquid crystal display panel, and the screen have the same aspect ratio.
FIG. 9 is a cross-sectional view showing the shapes of a cell lens of a first optical block and a cell lens of a second optical block.
FIG. 10 is a diagram showing an example of a light beam formed by a first optical block and a second optical block and its image formation.
FIG. 11 is a diagram showing another embodiment of the present invention.
FIG. 12 is a diagram showing another embodiment of the present invention.
FIG. 13 is a diagram showing another embodiment of the present invention.
FIG. 14 is a diagram showing another embodiment of the present invention.
FIG. 15 is a diagram showing another embodiment of the present invention.
FIG. 16 is a diagram showing another embodiment of the present invention.
FIG. 17 is a diagram showing an example of an optical system of a conventional projection type projector.
18 is a diagram showing problems in the conventional optical system of FIG.
FIG. 19 is a diagram showing problems in the conventional optical system of FIG.
FIG. 20 is a diagram illustrating a problem in a conventional optical system.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... 1st optical block, 1 ... Projection type display apparatus, 2 ... 2nd optical block, 3 ... Light source, 13 ... Projection lens, 21 ... 1st lens array, 21a ˜21d... Cell lens, 23... Second lens array, 23a to 23d... Cell lens, 23f... First condensing component of the second optical block, 45, 49, 53. Display panel (light modulation element, light valve), 131... Polarization conversion element

Claims (19)

The display device includes a light source, a light modulation element on which a light beam from the light source is irradiated via an optical device for illumination, and a projection lens that projects the modulated light beam. A first optical block including a first lens array having a plurality of cell lenses substantially similar to the modulation element, and a second lens array having a plurality of cell lenses corresponding to the first lens array of the first optical block. And a second optical block including a first condensing component that condenses the light beam that has passed through the second lens array toward the light modulation element, and forms an image of the light beam emitted from the second optical block at a predetermined position to, and a second condensing component is disposed in the vicinity of the light modulation element, the cell lenses of the first lens array of the first optical block, Ri Do from different aspherical, the first lens Multiple cells in an array It passes through the display in which a plurality of light beams toward the second direction different from the converging component through the second optical block comprises an optical device and correcting to image on the pupil plane of the projection lens apparatus. 2. A display device comprising the optical device according to claim 1, wherein the cell lens of the first lens array of the first optical block comprises at least two types of aspherical surfaces or different aspherical surfaces. The display device includes a light source, a light modulation element on which a light beam from the light source is irradiated via an optical device for illumination, and a projection lens that projects the modulated light beam. A first optical block including a first lens array having a plurality of cell lenses substantially similar to the modulation element, and a second lens array having a plurality of cell lenses corresponding to the first lens array of the first optical block. And a second optical block including a first condensing component that condenses the light beam that has passed through the second lens array toward the light modulation element, and forms an image of the light beam emitted from the second optical block at a predetermined position to, and a second condensing component is disposed in the vicinity of the light modulation element, the cell lenses of the second lens array of the second optical block, Ri Do from different aspherical, the plurality of first Cell array lens A plurality of light beams that have passed through the corresponding cell lens of the second lens array and have been condensed by the first condensing component are imaged at predetermined positions on the display surface of the light modulation element via the second condensing component. And a display device comprising an optical device.   The display device including the optical device according to claim 3, wherein the cell lens of the second lens array of the second optical block includes at least two types of aspherical surfaces or different aspherical surfaces. The display device comprising the optical device according to claim 1, wherein the cell lens of the second lens array of the second optical block is formed of different aspheric surfaces. The cell lens of the second lens array of the second optical block has a different aspherical surface, and passes through the corresponding cell lens of the second lens array from the cell lens of the plurality of first lens arrays, and the first condensing component The optical apparatus according to claim 1, wherein the optical device is corrected so that the plurality of light beams collected by the light beam are imaged at a predetermined position on the display surface of the light modulation element via the second light collection component. A display device provided. 7. The optical device according to claim 6, wherein the cell lens of the first lens array of the first optical block and the cell lens of the second lens array of the second optical block comprise at least two types of aspherical surfaces or different aspherical surfaces. A display device comprising:   The display device including the optical device according to claim 2, wherein the cell lens of the second lens array of the second optical block includes at least two types of aspherical surfaces or different aspherical surfaces.   The display device including the optical device according to claim 4, wherein the cell lens of the first lens array of the first optical block includes at least two types of aspherical surfaces or different aspherical surfaces.   A display device comprising the optical device according to claim 1, wherein the first light collection component of the second optical block is formed integrally with the second lens array.   A display device comprising the optical device according to claim 3, wherein the first condensing component of the second optical block is formed integrally with the second lens array.   The display device comprising the optical device according to claim 1, wherein the first condensing component of the second optical block is formed integrally with each cell lens of the second lens array.   The display device comprising the optical device according to claim 3, wherein the first condensing component of the second optical block is formed integrally with each cell lens of the second lens array.   The display device comprising the optical device according to claim 1, wherein the second lens array of the second optical block and the first light-collecting component are spaced apart from each other.   The display device comprising the optical device according to claim 3, wherein the second lens array of the second optical block and the first condensing component are spaced apart from each other.   A display device comprising the optical device according to claim 1, wherein a polarization conversion element is disposed between the light source and the first optical block.   A display device comprising the optical device according to claim 3, wherein a polarization conversion element is disposed between the light source and the first optical block.   A display apparatus comprising the optical device according to claim 1, wherein a polarization conversion element is disposed between the first optical block and the second optical block.   A display apparatus comprising the optical device according to claim 3, wherein a polarization conversion element is disposed between the first optical block and the second optical block.

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