KR20080107277A - Projection display - Google Patents

Abstract

A projection display system is provided to prevent non-uniform illumination by simplifying the continuous control of the intensity of radiation and display images with a sufficient gray level all the time. A light source(3a) generates light to be radiated to a light valve(2). An integrator lens(4) is disposed on a light path between the light source and the light valve for making the distribution of the intensity of light radiated to the light valve from the light source uniform. Light blocking elements(9a) are disposed on the light path for controlling the intensity of light radiated from the light source to the light valve. The light blocking elements rotate in the shape of a pair of double doors, each being curved in the shape of V in the direction for reducing the intensity of light.

Description

Projection display device {PROJECTION DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device having a light amount adjusting mechanism for adjusting the light amount of light irradiated to a light valve in accordance with an image signal.

In the projection display device, light leaked from various optical elements constituting an optical system such as an induction optical system or a projection lens, and stray light (unnecessary light) generated by the optical element are caused, and dark images are not sufficiently dark. Therefore, it is difficult to obtain high gradation. In particular, when projecting an image on a screen in a dark room, if the dark image is not sufficiently dark, the viewer gives an impression of lack of gradation. In particular, in the projection display device using the liquid crystal light valve, although the liquid crystal light valve blocks the transmitted light according to the polarization characteristic of the light, it is not possible to completely block the transmitted light, so that there is a limit in the correspondence by the image signal processing, so that the improvement of the gray scale is improved. It is required.

As a countermeasure for such a problem, a light shield plate is disposed between the first lens array and the second lens array, and the light shield plate is rotated in accordance with an image signal to control the amount of light irradiated to the light valve, thereby controlling The gradation is improved (see Patent Document 1, for example).

[Patent Document 1] Publication WO2005-026835

In Patent Document 1, when the shape of the tip of the light shielding plate has a rectangular surface in the vertical direction with respect to the light shielding plate, the tip of the light shielding plate is positioned near the first lens array at the position of the center of curvature of the second lens array in the rotational direction of the light shielding plate. If this exists, the rectangular surface of the light shielding plate forms an image on the light valve, and thus there is a problem that the roughness of the line shape is generated in the direction perpendicular to the rotational direction and the optical axis direction on the light valve. In addition, depending on the tip shape of the light shielding member, there is a problem that sufficient gradation cannot be obtained.

SUMMARY OF THE INVENTION The present invention has been made to solve these problems, and a projection display device capable of continuously adjusting the amount of light that does not cause illuminance unevenness of light irradiated to a light valve in accordance with an image signal and capable of always displaying an image having sufficient gradation is provided. It aims to provide.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the projection display device which concerns on this invention is arrange | positioned on the light valve, the light source which produces the light irradiated to a light valve, and the light path between a light source and a light valve, and irradiates a light valve from a light source. And an integrator lens for equalizing an illuminance distribution of light to be made, and a light amount adjusting mechanism having a light shielding body arranged on the optical path and rotating in a pair of double door shapes for adjusting the amount of light irradiated from the light source to the light valve. The light shielding body is bent in a V-shape in a direction of reducing light quantity during rotation.

According to the present invention, an integrator lens is disposed on an optical path between the light source and the light valve and uniformizes an illuminance distribution of light irradiated from the light source to the light valve, and an amount of light of the light disposed on the optical path and irradiated to the light valve from the light source is adjusted. And a light amount adjusting mechanism having a light shielding body that rotates in a pair of double door shapes, and the light shielding body is bent in a V-shape in a direction of decreasing light quantity at the time of rotation, and according to a video signal. It is easy to continuously adjust the amount of light that does not cause illuminance unevenness of the light irradiated to the light valve, and it is possible to always display an image with sufficient gradation.

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

(Example 1)

1 is a configuration diagram of an illumination optical system 1 of a projection display device according to Embodiment 1 of the present invention. As shown in FIG. 1, the illumination optical system 1 includes an integrator lens 4, a polarization conversion element 5, a condenser lens 6, and a field lens between the light source system 3 and the light valve 2. 7) and the polarizing plate 8. In addition, the projection display device according to the first embodiment of the present invention includes a projection lens (not shown) for projecting light emitted from the light valve 2 onto the screen. In addition, the light valve 2 is provided on each optical path of RGB, and the illumination optical system 1 shown in FIG. 1 typically represents one of each optical path of RGB.

In the embodiment of the present invention, the light valve 2 uses a liquid crystal light valve. However, in the case of using a lens array, the light valve 2 may be a digital micro-mirror device (DMD) or a reflective liquid crystal display element.

The light source system 3 is provided in order to irradiate light to the light valve 2, and the reflector 3b which irradiates the integrator lens 4 with light emitted from the light source 3a and the light source 3a by reflection. It is composed of The light source 3a is generally a high-pressure mercury lamp, a halogen lamp, or a xenon lamp. Any light emitting device such as an LED (Light Emitting Diode), a laser, an electrodeless discharge lamp, or the like may be used. Although the reflecting mirror 3b is formed in a parabolic surface or an ellipsoidal surface, any shape and structure may be sufficient as light condensing on the polarization conversion element 5, and is not specifically limited. For example, when the light incident on the integrator 4 is made substantially parallel to the optical axis C, in order to make the shape of the reflecting mirror 3b a parabolic surface or to make the light almost parallel when the elliptic surface is used, the light source system ( What is necessary is just to arrange a concave lens between 3) and the integrator lens 4 (refer FIG. 32).

The integrator lens 4 is disposed on the light path between the light source system 3 and the light valve 2, and is provided to uniformize the illuminance distribution of light irradiated from the light source system 3 to the light valve 2, And a second lens array 4b spaced apart from the first lens array 4a and the first lens array 4a. The first lens array 4a and the second lens array 4b have a plurality of convex lenses arranged vertically and horizontally. The convex lenses of the first lens array 4a and the convex lenses of the second lens array 4b are Corresponding to each other, they are arranged facing each other.

The polarization conversion element 5 converts and inject | emits the light beam which injected into the polarization conversion element 5 into one kind of linearly polarized light, and is arrange | positioned with the space | interval appropriate at the x-axis direction. 2 is a configuration diagram of a polarization conversion element 5 according to Embodiment 1 of the present invention. As shown in FIG. 2, the polarization conversion element 5 includes a plurality of polarization separation films 5a and a polarization separation film 5a which are arranged inclined (for example, 45 °) with respect to the optical axis C direction (z direction). On the surface of the light valve 2 side of the some reflective film 5b arrange | positioned inclined (for example, 45 degrees) with respect to the optical axis C direction (z direction), and the polarization conversion element 5 between, and a polarization separation film The part to which the light which permeate | transmitted (5a) is irradiated is comprised by the (lambda) / 2 phase difference plate 5c. Light incident on the polarization conversion element 5 is separated into s-polarized light and p-polarized light by the polarization separation film 5a. The p-polarized light is transmitted through the polarization separating film 5a, converted into s-polarized light by the λ / 2 phase difference plate 5c, and emitted from the polarization converting element 5. On the other hand, the s-polarized light reflects the polarization splitting film 5a and is emitted from the polarization converting element 5 after reflecting the reflecting film 5b. Therefore, almost all of the light beams emitted from the polarization conversion element 5 become s-polarized light.

The light quantity adjusting system 9 (light quantity adjusting mechanism) is disposed on the optical path and rotates as a light shielding body that rotates in a pair of double door shapes for adjusting the amount of light emitted from the light source system 3 to the light valve 2. A rotating mechanism 9a having a mechanism 9a disposed between the first lens array 4a and the second lens array 4b and a video signal input to the light valve 2 is detected, and from the detection result. Rotation control part which controls rotation of the rotation mechanism 9a based on the signal detection part 9b which calculates the relative light quantity ratio of the light quantity irradiated to the light valve 2, and the relative light quantity ratio computed by the signal detection part 9b. It consists of (9c). As shown in Fig. 3 (b), the rotation mechanism 9a is composed of light shields 9T and 9B, and the light shields 9T and 9B have a V shape in a direction of decreasing (light shielding) the amount of light. It is bent and formed. Further, the tip portions of the light shielding bodies 9T and 9B are formed by being cut out by the concave portion 9g which restricts the passage of light. The concave portion 9a may be any shape such as a concave curved shape, a parabolic shape, a semi-elliptic shape, and a triangular shape.

Next, the improvement of gradation is demonstrated. When the relative light amount ratio of the video signal is 100%, the adjustment is performed at a relative light amount of 100% without blocking by the rotating mechanism 9a. For example, when the relative light quantity ratio of the video signal is 20%, by adjusting the relative light quantity ratio to 20% by the rotating mechanism 9a, the fine video signal can be adjusted approximately five times. In addition, by lowering the relative light quantity ratio by shielding the rotation mechanism 9a, it is possible to make the black darker when the relative light quantity ratio of the video signal is 0% than when the light is not shielded. That is, since the transmittance of the light valve 2 is substantially constant, the amount of light irradiated to the light valve 2 is reduced by the rotation mechanism 9a, which makes it possible to darken the image projected on the screen and to improve the gradation. can do.

Fig. 4A shows the rotational operation of the light shields 9T and 9B of Fig. 3A, and Fig. 4B shows the rotational operation of the light shields 9T and 9B of Fig. 3B, respectively. It is a figure which shows the rotation operation | movement at the time of every rotation. As shown in Figs. 4A and 4B, the movement amount in the z direction at the tips of the light shielding bodies 9T and 9B is the movement amount Zb in Fig. 4B than the movement amount Za in Fig. 4A. Since it is small (Za> Zb), it turns out that the movement amount of the light shielding bodies 9T and 9B in the y direction per rotation angle is large in FIG.4 (b). Therefore, the relative light quantity ratio becomes illuminance of 100% at the rotation angle with the smaller shape of the light shielding bodies 9T and 9B shown to FIG. 4 (b).

FIG. 5 is a diagram illustrating a relationship between the rotation angle and the relative light quantity ratio when the rotation mechanism 9a has the shape of FIG. 3. In (b), (gamma) T and (gamma) B were made into 20 degrees, and the rotation angle of each rotation mechanism 9a was set to 2 degrees. Incidentally, the rotation angle of 0 ° is when the light shields 9T and 9B are completely closed, that is, when the light shields 9T and 9B are in the states of 41a and 41b in Fig. 4. Curve 50 shows the results of the respective simulations of the rotation mechanism 9a in the shape of FIG. 3 (a), and curve 51 shows the rotation mechanism 9a in the shape of FIG. 3 (b). As shown in Fig. 5, the curve 51 rises faster when the relative light quantity ratio is lower than the curve 50, and the relative light quantity ratio is 100% at a rotation angle of about 75 degrees. Since the operating angle range is narrow, the shape of FIG. 3 (b) can be controlled more responsively than the shape of FIG. 3 (a). Further, it can be seen from the curves 50 and 51 that the change in the relative light quantity ratio with respect to the rotation angle except for the portion where the relative light quantity ratio is low is approximately the same. From the above, as described later in FIG. 14, when the relative light quantity ratio is low, the roughness unevenness can be reduced by bending the ends of the light shields 9T and 9B in a V-shape in the rotational radial direction. In addition, from FIG. 5, it can be seen that it is possible to continuously adjust the amount of light by forming two concave portions 9g at the distal ends of the light shields 9T and 9B as shown in FIG. In addition, in the Example of this invention, although (gamma) T and (gamma) B were made into 20 degrees, arbitrary angles may be sufficient and the same effect can be acquired even if it is not a relationship of (gamma) T = (gamma) B. In addition, the relationship between the rotation angle of the rotation mechanism 9a and the relative light quantity ratio on the light valve 2 shown in the embodiment of the present invention indicates when the relative light quantity ratio is 100% of the signal input. Only the characteristic of the mechanism 9a is shown.

FIG. 6 shows the position in the z direction of the tips of the light shields 9T and 9B when the relative light quantity ratio in FIG. 5 is 20%. As shown in Fig. 6 (a), the angle of rotation in the shape of Fig. 3 (a) is about 24 °, and the angle of rotation in the shape of α1 ≒ 24 ° and the shape of Fig. 3 (b) is about 34 °. It is α2 ≒ 34 °. In addition, (alpha) 3 = (gamma) T of FIG. 6 (b) is 20 degrees. The length of the light shields 9T and 9B of FIG. 6 (a) is d1, and the length from the rotational axis of the light shields 9T and 9B of FIG. 6 (b) to the bent portion is d2, the length from the bend to the tip. Let d3 be. Based on the above conditions, the position of the z direction of the front-end | tip of the light shielding bodies 9T and 9B of FIG. 3 (b) is calculated.

6 (a) and (b), the movement amounts Zc and Zd in the z direction of the light shielding bodies 9T and 9B are represented by the following equations (1) and (2).

 4 (b), d1 is represented by Formula (3).

Therefore, since Zc is represented by equation (4), the condition of Zc> Zd is satisfied by equation (5).

Therefore, by making the length of d2 shorter than d3, the shape of FIG. 3 (b) can reduce roughness unevenness than the shape of FIG. 3 (a). Since the cause of the roughness spot is not only the moving distance of the tip ends of the light shielding bodies 9T and 9B, the condition of the formula (5) is preferable, but it does not necessarily have to be satisfied.

FIG. 7: is a figure which shows the illuminance distribution of the light irradiated to the light valve 2 when it completely shields in the shape of FIG. 3 (b). In the total light shielding, the light incident on the second lens array 4b is irradiated by uniformly overlapping substantially the entire region (region 7a) of the light valve 2 and the peripheral portions 7 region in both directions in the x direction. Because of that, roughness does not occur. The region of 7a represents the illuminance distribution of the light irradiated to the light valve 2 from the cell (region 30 of FIG. 3 (b)) when the entire opening of the cell of the second lens array 4b is approximately opened. , Region 7b indicates the illuminance distribution of light irradiated to the light valve 2 from the cell (region 31 in FIG. 3 (b)) when the opening of the cell of the second lens array 4b is about half opening. It is shown.

Fig. 8 is a diagram showing the relationship between the rotation angle and the relative light quantity ratio when no concave portions are formed in the light shielding bodies 9T and 9B without the bent portion. The rotation angle was simulated every 2 degrees. From the curve 80, it is understood that the change in the relative light quantity ratio with respect to the rotation angle is not continuous, and four flat portions 8a, 8b, 8c, and 8d exist.

9 is a diagram illustrating a light source image in the vicinity of the second lens array 4b. 9 shows a gray scale of 256 gradations. From Fig. 9, each of 9a, 9b, 9c, and 9d represents a dark portion between light source images in the + y direction. The flat parts of four places 8a, 8b, 8c, and 8d in FIG. 8 correspond to the dark areas 9a, 9b, 9c, and 9d between the four light source images shown in FIG. It can be confirmed that this is an influence of the flat portion of FIG. 8. Therefore, in order to continuously change the amount of light, it is necessary to shield light and shade between light source images simultaneously. As shown in Fig. 3, when the concave portions are formed in the light shielding bodies 9T and 9B, the amount of light can be continuously changed as shown in Fig. 5, so that the concave portions are formed in the light shielding bodies 9T and 9B. It is possible to shield light and dark between the light source phases at the same time.

FIG. 10: is a figure which shows an example of the shape of light shielding bodies 9T and 9B, One recessed part 9g is formed symmetrically with respect to the optical axis C. As shown in FIG. When completely shielding in such a shape, the irradiation distribution on the light valve 2 is substantially uniform.

FIG. 11 is a diagram showing the relationship between the rotation angle and the relative light quantity ratio when the light shields 9T and 9B have the shape of FIG. 10. (Gamma) T and (gamma) B of the light shielding bodies 9T and 9B in FIG. 10 are set to 20 degrees. Curve 110 is a simulation result of the rotating mechanism 9a having the shape of FIG. 10. Curve 80 shows the simulation result of the rotating mechanism 9a of the shape which did not form the recessed part of FIG. 8, Comparing the effect with or without formation of the recessed part 9g. For ease of comparison, curve 80 is shifted to overlap curve 110. 11, even when one recessed part 9g is formed in the light shielding bodies 9T and 9B, light quantity can be adjusted continuously rather than the light shielding bodies 9T and 9B which do not form the recessed part. That is, forming at least one concave portion 9g in the light shielding bodies 9T and 9B is effective for continuous light amount adjustment. However, from the curve 51 of FIG. 5 and the curve 110 of FIG. 11, when two concave parts are formed, the light quantity changes more smoothly than when one concave part is formed, and in order to perform smoother light quantity adjustment, It is preferable to form a plurality of concave portions.

FIG. 12 shows lens cells positioned in the most + y direction of the light trajectory, in particular, the first lens array 4a when the light shielding bodies 9T and 9B rotate to the first lens array 4a side at the time of light shielding. It is a figure which shows the trajectory of the light which passes. Although only the light shield 9T is described here, the same is true for the light shield 9B. 120a represents the trajectory of light passing from the center of the lens cell to the + y side, 120b represents the trajectory of light passing through the center of the lens cell, and 120c represents the trajectory of light passing from the center of the lens cell to the -y side. As shown in FIG. 12, when the bending angle of the light shield 9T is small or the bending position is far from the rotational axis, unnecessary light reflected by the light shield 9T passes through the second lens array 4b. Therefore, there is a possibility of appearing on the screen by multiple reflection of the inside of the housing (not shown) of the illumination optical system 1. Therefore, it is preferable that the light shields 9T and 9B rotate to the second lens array 4b side at the time of light shielding, rather than the opening and closing directions of the light shields 9T and 9B as shown in FIG.

FIG. 13A is a diagram showing the trajectory of light when the dimensions of the light blocking bodies 9T and 9B in the x direction and the y direction are smaller than the first lens array 4a and the second lens array 4b. FIG. 13B is a view comparing dimensions of the light blocking bodies 9T and 9B in the x direction and the y direction with dimensions of the second lens array 4b in the x direction and the y direction. 9T and 9B) show that the dimension of the x direction and the y direction is smaller than the dimension of the x direction and the y direction of the 2nd lens array 4b. Although only the light shield 9T is described here, the same is true for the light shield 9B. 130a is a trajectory of light passing through the center of the lens cell located fifth in the + y direction from the optical axis C of the first lens array 4a, and 130b is 2 in the + y direction from the optical axis C of the first lens array 4a. The second also shows the trajectory of the light passing through the + x direction from the center of the lens cell located in the third in the + x direction. As shown in FIG. 13 (a), the light passing through the first lens array 4a located on the + y side of the rotation axes of the light blocking bodies 9T and 9B is not in contact with the light blocking bodies 9T and 9B. You can see that it goes through the + y side without it. Therefore, in order to adjust the amount of light emitted from the first lens array 4a by the light shielding bodies 9T and 9B, the dimensions of the light shielding bodies 9T and 9B in the x-direction and the y-direction are determined by the first lens array 4a. ) And larger than the second lens array 4b. When the dimension of the second lens array 4b is larger than that of the first lens array 4a, the dimensions of the light shielding bodies 9T and 9B in the x direction and the y direction are larger than the second lens array 4b. Although it is preferable, it is possible to provide a light shielding plate between the second lens array 4b and the polarization conversion element 5 to shield unnecessary light that has passed through the second lens array 4b. For this reason, the dimensions of the light shielding bodies 9T and 9B in the x direction and the y direction are not necessarily larger than the first lens array 4a and the second lens array 4b.

FIG. 14 is a diagram showing the trajectory of light when the backlight trace is performed from the center of the light valve 2. 140 denotes a light trajectory, and an area 141 represents a position where the light of 140 is focused. As shown in FIG. 14, since it is possible to confirm that an image in the vicinity of the first lens array 4a is formed in the light valve 2, the light valve 2 and the first lens array 4a are separated. The vicinity of the entrance surface is in the airspace relationship. Therefore, when the front ends of the light shields 9T and 9B are located in the vicinity of the region 141, the front ends of the light shields 9T and 9B are formed in the light valve 2 and near the center on the light valve 2. As a result, line roughness unevenness occurs in the x direction. Therefore, it is preferable to bring the tip ends of the light shields 9T and 9B closer to the second lens array 4b, that is, to place the rotational axis in the vicinity of the second lens array 4b.

In addition, when attention is paid to the front end portions of the light shielding bodies 9T and 9B, the ones formed by bending the light shielding bodies 9T and 9B in a V-shape in a direction of decreasing (shielding) the amount of light are formed in the y direction than when there is no bending. Since the width to form (see dy1 of FIG. 15 and dy2 of FIG. 16) becomes narrow, it becomes possible to reduce the roughness unevenness generate | occur | produced on the light valve 2. As shown in FIG. Therefore, by forming the light shields 9T and 9B in a V-shape in a direction of decreasing (light shielding) the amount of light, it is possible to reduce roughness unevenness generated on the light valve 2.

15 and 16 show a light shielding body 9T when the imaging of the tip of the light shielding bodies 9T and 9B occurs on the light valve 2 in the shape of FIGS. 3A and 3B. It is a figure which shows the rotation position of 9B). As a condition under which image formation occurs on the light valve 2, the front ends of the light shielding bodies 9T and 9B have a center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array 4b. As the same position, it is located near the first lens array 4a. 150, 151, 160, and 161 all represent axes passing through the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array. Both 152 and 162 have shown the front-end | tip part of 9T of light shielding bodies.

The reason why the front ends of the light shielding bodies 9T and 9B are set to the same position as the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array 4b will be described. First, at the same position as the curvature center position of the first lens cell in the + or -y direction from the optical axis C of the second lens array 4b, the illuminance unevenness generated on the light valve 2 is difficult to confirm. Further, at the same position as the center of curvature of the third lens cell in the + or -y direction from the optical axis C of the second lens array 4b, the first lens cell and the second lens cell in the + or -y direction from the optical axis C Since light without illuminance unevenness is superimposed on the light valve 2, illuminance unevenness on the light valve 2 by the third lens cell becomes relatively low, making it difficult to confirm. Therefore, as a condition in which imaging of the front ends of the light shielding bodies 9T and 9B is easy to be confirmed on the light valve 2, the front ends of the light shielding bodies 9T and 9B are + or + from the optical axis C of the second lens array 4b. It positioned at the same position as the center of curvature of the second lens cell in the -y direction.

FIG. 17A shows a simulation result of illuminance distribution on the light valve 2 in the state of FIG. 15 without the concave portion 9g of FIG. 3A, and FIG. 17B. Shows the simulation result of the illuminance distribution on the light valve 2 in the state of FIG. 16 as a shape without the concave part of FIG. As shown in FIG. 17, 170a and 170b represent the low illuminance area | region, and 171a and 171b have shown the y-axis which passes through the center of the light valve 2. As shown in FIG. Comparing 170a and 170b, it can be seen that the side of 170b has less roughness unevenness. This is because the relationship between dy1 in FIG. 15 and dy2 in FIG. 16 is dy1> dy2. Therefore, by forming the light shields 9T and 9B in a V-shape in a direction of decreasing (light shielding) the amount of light, it is possible to reduce roughness unevenness generated on the light valve 2. For this reason, even if it does not satisfy | fill the condition of Formula 5 mentioned above, if light-shielding bodies 9T and 9B are formed by bending, the roughness unevenness can be reduced.

FIG. 18: shows the result of the simulation of the illuminance distribution on the light valve 2 in the state of FIG. 16 as a shape of FIG. 3 (b). As shown in FIG. 18, there is hardly a region with low illuminance in the x direction from the center of the light valve 2. 180 denotes a region in which the illuminance in the y direction is low from the center of the light valve 2, and 181 denotes a y axis passing through the center of the light valve 2. Although the concave portions 9g of the light shielding bodies 9T and 9B become the condensing positions of the second lens array 4b, slight uneven illuminance can be confirmed in the region of 180, but the illuminance distribution of the entire light valve 2 is Because it is approximately uniform, there is no problem. Therefore, the light shields 9T and 9B are bent in a V-shape in a direction of decreasing (light shielding) the amount of light, so that at least one concave portion is formed at the tip end of the light shields 9T and 9B, and the concave at the tip end is formed. By reducing the flat portions other than the shape portion, the overlap of the tip shape formed on the light valve 2 is reduced, and the roughness unevenness can be greatly reduced.

FIG. 19 is a view showing the relative light quantity ratios in the y direction on the top of 171a, 171b, and 181 which are the y-axis shown in FIGS. 17A, 17B, and 18, respectively. The horizontal axis corresponds to the vertical axis of the light valve 2 shown in FIG. As shown in FIG. 19, 190 represents the relative light quantity ratio on 171a, 191 represents the relative light quantity ratio on 171b, and 192 represents the relative light quantity ratio on 181, respectively. 19, when comparing the value of the relative light quantity ratio in 0.5Y which is the center of the y-valve of the light valve 2, it becomes 190 <191 <192, and also the roughness unevenness is reduced in order of 190, 191, 192. I can confirm that there is. Therefore, roughening spots can be reduced by bending the light shields 9T and 9B in a V-shape in a direction of decreasing (light shielding) the light quantity, and forming the tip portion in the concave shape.

In the embodiment of the present invention, in the case of 41b of FIG. 4B, the angle shown in FIG. 6 is γT = α2 = α3. However, by setting α3> α2 = γT, the dy2 shown in FIG. Since the width can be further reduced, roughness unevenness can be reduced more than the shape shown in Fig. 4B. In addition, although there are only one bending of the light shielding bodies 9T and 9B, as long as the width | variety of dy2 shown in FIG. 16 becomes small, two bending may be sufficient. By doing so, the roughness spot can be reduced. In Fig. 3B, the bend position is set to the position near the second lens cell in the y direction centering on the optical axis C of the second lens array 4b, but the bend may be bent at any position.

From the above, the light shields 9T and 9B of the rotation mechanism 9a are formed by bending the V-shape in the direction of decreasing (light shielding) the amount of light, and forming the tip by cutting at least one concave shape. Continuous light amount adjustment is possible without causing illuminance spots on the light valve 2.

(Example 2)

20 is a configuration diagram of an illumination optical system 1b of the projection display device according to the second embodiment of the present invention. In Example 2 of this invention, the front-end | tip part of the light shielding bodies 9T and 9B of the rotation mechanism 9a is cut off, and is formed, It is characterized by the above-mentioned. Since the structure and operation | movement about other parts are the same as that of Example 1, description is abbreviate | omitted here.

FIG. 21 is the same view as FIG. 15, and FIG. 22 is the same as the arrangement position of FIG. 15 and light shielding bodies 9T and 9B. Further, 210, 211, 220, and 221 all represent axes passing through the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array. As shown in FIG. 22, the front-end | tip part of light shielding bodies 9T and 9B is cut | disconnected rather than 220, and is formed in the blade-shaped part. By doing in this way, the width | variety of dy is made small. In addition, the width | variety t of the light shielding bodies 9T and 9B is about 0.5 mm normally in consideration of the intensity | strength of the light shielding body with respect to rotation of the rotation mechanism 9a. 212 and 222 have shown the front-end | tip part of 9T of light shielding bodies.

FIG. 23A shows a simulation result of the illuminance distribution on the light valve 2 in the state of FIG. 21 without the concave portion 9g of FIG. 3A, and FIG. 23B. Shows the simulation result of the illuminance distribution on the light valve 2 in the state of FIG. 22 as a shape without the concave part of FIG. Here, t = 0.5 mm. As shown in FIG. 23, 230a and 230b represent regions of low illuminance, and 231a and 231b represent the y-axis passing through the center of the light valve 2. Comparing 230a and 230b, it can be confirmed that roughness unevenness is greatly improved at 230b. Therefore, as shown in FIG. 22, the front end portions of the light shielding bodies 9T and 9B are positioned on the optical axis C side rather than the axis passing through the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array. It is possible to greatly reduce roughness unevenness by cutting and forming the blade shape.

FIG. 24 is a view showing the relative light quantity ratios in the y-direction on the y-axis 231a and 231b shown in FIGS. 23 (a) and 23 (b), respectively. As shown in FIG. 24, 240 has shown the relative light quantity ratio on 231a, and 241 has shown the relative light quantity ratio on 231b, respectively. From FIG. 24, when comparing the value of the relative light quantity ratio in 0.5Y which is the center of the y-direction of the light valve 2, it turns out that 241 is higher than 240, and illumination intensity unevenness is greatly reduced. Therefore, rough spots are formed by cutting the optical axis C side with the blade-shaped portion rather than the axis passing through the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array in the direction of the light shields 9T and 9B. It is possible to greatly reduce.

FIG. 25 is a diagram illustrating the shapes of the tip portions of the light shielding bodies 9T and 9B. 250 and 251 represent the axis passing the center of curvature of the second lens cell in the + or -y direction from the optical axis C of the second lens array. 25, it is preferable that the angle of the front-end | tip part of light shielding bodies 9T and 9B is smaller than (beta).

From the above, at least one concave portion is formed by cutting away the tip portions of the light shielding bodies 9T and 9B, and the tip portion is formed by cutting the blade portion into a blade portion, so that the continuous light amount is not generated on the light valve 2 without causing roughness unevenness. It is possible to carry out the adjustment.

(Example 3)

Fig. 26 is a configuration diagram of the illumination optical system 1c of the projection display device according to the third embodiment of the present invention. In Example 3 of this invention, the shape of the front-end | tip part of light shielding bodies 9T and 9B can make high gradation high enough, without generating the roughness spot on the light valve 2 in a small opening area, It is characterized by the above-mentioned. do. Since the structure and operation | movement about other parts are the same as that of Example 1, description is abbreviate | omitted here.

Light 270 emitted from the second lens array 4b enters the light valve 2 at a large incident angle. At this time, due to the characteristics of the light valve, the gradation decreases as the angle of light incident on the light valve 2 increases (see FIG. 29), so that the shape of the light shielding bodies 9T and 9B is determined with respect to the light valve 2. It is preferable to shield light with a large incident angle, particularly incident light in the x direction.

An example of the front view (a) and the side view (b) of the xy plane of the 2nd lens array 4b and the polarization conversion element 5 are shown in FIG. FIG. 28C is a view showing FIG. 2 in more detail. 28C shows the trajectory of the light incident on the second lens array 4b. Here, the dotted line portion represents the polarization conversion element 5, and the gray color represents the lambda / 2 phase difference plate 5c. Usually, polarization conversion condenses light only in the area | region of (lambda) / 2 phase difference plate 5c, and performs polarization conversion efficiently. Therefore, the light rays 270, 271, 272, 273, 274, and 275 become light rays to be polarized-converted. From Fig. 28 (c), the incident p + s linearly polarized light enters the p-polarized light since it is converted into the s-polarized light by the λ / 2 phase difference plate 5c after it is incident on the polarization conversion element 5. The polarization conversion element 5 can be emitted at the same x-direction position as the position, but is emitted at a position dx (distance between 275a-275b) from the optical axis as compared with s-polarized light. Therefore, blocking light incident from the optical axis in the x direction is indispensable for improving the gradation. In other words, the light rays 270 and 275 become light that affects the gradation. In other words, incidence of light rays on a position in the x-direction close to the optical axis C is a condition of gray scale improvement.

30 illustrates the shapes of the light shields 9T and 9B. The concave portions at the tips of the light shielding bodies 9T and 9B include two concave portions having different areas, 9g and 9h, and 9g has a smaller opening area than 9h. In addition, 9g and 9h are formed in the light shielding bodies 9T and 9B at the point symmetrical position with respect to the optical axis C, when the light shielding bodies 9T and 9B are closed.

FIG. 31 is a diagram showing the amount of light passing through each cell of the second lens array 4b by simulation, and showing the calculation result numerically for each cell. By setting it as the shape like FIG. 30, the difference of the gradation of a x direction is reduced. In addition, in FIG. 31, since the 2nd lens array 4b is symmetrical in up, down, right and left, the 1st upper limit part is represented.

FIG. 32 is a diagram showing the simulation of the state in which light emitted from the light source 3a is reflected by the reflector 3b. The reflecting mirror 3b is an ellipsoidal surface, and the light emitted from the light source system 3 is made parallel by the concave lens 310. Usually, the valve of a light source exists in the optical axis C vicinity, and 311 has shown the opening part.

As shown in FIG. 32, since the opening part is 311, the cell of V1H1 shown in FIG. 31 has a small amount of light emitted from the light source system 3. As shown in FIG. When completely shielding in the shape of FIG. 30, the recessed part 9g irradiates the both ends of the x direction of the light valve 2, and the recessed part 9h is irradiating the center part of the light valve 2. As shown in FIG. . That is, by making the relative light quantity of the light irradiated to the both ends and center part of the x direction of the light valve 2 the same, it will be uniform illumination distribution. For example, when the shape of the concave portion 9g and the concave portion 9h are the same, as shown in FIG. 33, the illuminance of the central portion of the light valve 2 is lowered to generate roughness unevenness. Therefore, the concave portion 9h needs to have a larger opening area than the concave portion 9g. In FIG. 33, light emitted from the concave portion 9g irradiates an area of 32b on the light valve 2, and light emitted from the concave portion 9h is an area of 32a above the light valve 2. Investigate.

34 shows the shapes of the light shielding body 9T and the light shielding body 9B in consideration of the gradation. The concave portion 9i is formed in the cell V1H1 with an opening in a right triangle shape, so that the illuminance distribution on the light valve 2 is uniform. However, since the amount of light passing through the cell V1H1 is small by FIG. 31, when the 100% video signal is displayed on the screen, the light amount is small, and thus the gradation of the image projected on the screen cannot be obtained sufficiently.

In view of the above, in order not to generate roughness unevenness on the light valve 2, about 8 cells of openings are usually required. However, by considering the relative light quantity ratio incident on the shape and the opening, it is possible to prevent roughness unevenness on the light valve 2 in about 4 cells. That is, the vertex of the concave part 9h with a large opening area is made into the x direction center of the cell V1H1 closest to the optical axis C, and the vertex of the concave part 9g with a small opening area is made into the optical axis. By making the junction portion of the cell V1H1 closest to C and the cell V2H1 adjacent to the upside adjacent to the optical axis C, it is possible to improve the gradation without generating roughness unevenness on the light valve 2 by about 4 cells.

FIG. 35 is a diagram illustrating a relationship between the rotation angle and the relative light quantity ratio when the light shields 9T and 9B have the shape of FIG. 30. Curve 331 is a simulation result of the rotation mechanism 9a of the shape of FIG. Curve 330 shows the simulation result of the rotation mechanism 9a of the shape which does not form the recessed part of FIG. For ease of comparison, curve 330 is shifted to overlap curve 331. It can be seen from FIG. 35 that the light shielding bodies 9T and 9B have the same shapes as those in FIG. 30, so that the amount of light to the light valve 2 can be adjusted substantially continuously with respect to the rotation angle. Therefore, by making the shape of the front-end | tip part of light shielding bodies 9T and 9B like FIG. 30, light quantity adjustment can be carried out continuously without generating roughness unevenness on the light valve 2, and gradation can be improved.

In the present embodiment, the elliptical shape is shown. However, similarly to the present embodiment, the same effect can be obtained with respect to the triangular shape in consideration of the opening area and the vertex position.

36 shows the shapes of the light shields 9T and 9B. The concave portions at the tips of the light shielding bodies 9T and 9B are formed in a triangular shape. 36 is characterized in that light quantity adjustment can be finely executed when the relative light quantity ratio is 30% or less. By arranging the concave portion 9g in both the x-directions of the second lens array 4b, it becomes possible to finely control the portion having the low relative light quantity ratio. In addition, although the number of cells used by the 2nd lens array 4b when it is completely light-shielded is small, it becomes a triangle shape like FIG. 36, and the illumination intensity distribution on the light valve 2 becomes uniform by overlapping an irradiation area. Therefore, roughness spots do not occur.

FIG. 37 is a diagram illustrating a relationship between the rotation angle and the relative light quantity ratio when the light shields 9T and 9B have the shape shown in FIG. 36. Curve 351 is a simulation result of the rotation mechanism 9a having the shape of FIG. 36. Curve 350 shows the simulation result of the rotation mechanism 9a having the shape of FIG. 38. For ease of comparison, curve 350 is shifted to overlap curve 351. From FIG. 37, when the light shields 9T and 9B are made the same shape as FIG. 36, the inclination becomes a gentle curve in the relative light quantity ratio around 10%-30%. The reason for such a gentle curve is that the lens cell of V1H1 shown in FIG. 31 is shielded when the rotation angle of the rotation mechanism 9a is low, so that the illuminance change can be reduced. In the region where the relative light quantity ratio is 10% to 30%, since the sensitivity of the change of the relative light quantity ratio by the human eye is particularly high, fine light amount adjustment by the rotation mechanism 9a is important. Therefore, by making it the shape like FIG. 36, it becomes possible to finely control the light quantity adjustment in the relative light quantity ratio lower than 30%.

From the above, by making the light shields 9T and 9B into a shape as shown in FIG. 36, it is possible to finely adjust the light amount when the relative light amount ratio is low.

1 is a configuration diagram of an illumination optical system of a projection display device according to Embodiment 1 of the present invention;

2 is a configuration diagram of a polarization conversion element according to Embodiment 1 of the present invention;

3 is a view showing an example of the shape of the rotation mechanism according to the first embodiment of the present invention;

4 is a view showing a rotating operation of the rotating mechanism according to the first embodiment of the present invention;

5 is a view showing a relationship between a rotation angle and a relative light quantity ratio when the rotation mechanism according to Embodiment 1 of the present invention is in the shape of FIG. 3;

Fig. 6 is a diagram showing the position in the z direction of the tip of the rotating mechanism when the relative light quantity ratio according to the first embodiment of the present invention is 20%,

FIG. 7 is a view showing an illuminance distribution of light irradiated onto a light valve when the rotation mechanism according to Embodiment 1 of the present invention is completely shielded in the shape of FIG. 3 (b);

8 is a view showing a relationship between a rotation angle and a relative light quantity ratio when a concave portion is not formed in a light shielding body according to an embodiment of the present invention;

9 is a view showing a light source image in the vicinity of a second lens array according to Embodiment 1 of the present invention;

10 is a view showing an example of the shape of the rotation mechanism according to the first embodiment of the present invention;

11 is a view showing a relationship between a rotation angle and a relative light quantity ratio when the rotation mechanism according to Embodiment 1 of the present invention is in the shape of FIG. 10;

12 is a view showing the trajectory of light with respect to the shape of the rotating mechanism according to the first embodiment of the present invention;

FIG. 13 is a view showing the trajectory of light when the dimension of the rotation mechanism according to Embodiment 1 of the present invention is smaller than that of the lens array; FIG.

FIG. 14 is a view showing the trajectory of light when the backlight trace is executed from the center of the light valve according to the first embodiment of the present invention; FIG.

FIG. 15 is a view showing a rotation position of the rotation mechanism when an imaging occurs in the light valve according to the first embodiment of the present invention; FIG.

Fig. 16 is a diagram showing the rotational position of the rotation mechanism when an imaging occurs in the light valve according to the first embodiment of the present invention;

17 is a view showing an illuminance distribution of light irradiated to a light valve according to Embodiment 1 of the present invention;

18 is a view showing an illuminance distribution of light irradiated to a light valve according to Embodiment 1 of the present invention;

19 is a view showing a relative light quantity ratio on each y-axis of FIGS. 17 and 18 according to Embodiment 1 of the present invention;

20 is a configuration diagram of an illumination optical system of a projection display device according to a second embodiment of the present invention;

Fig. 21 is a view showing the rotational position of the rotating mechanism when the imaging occurs in the light valve according to the second embodiment of the present invention;

Fig. 22 is a view showing the rotational position of the rotation mechanism when an imaging occurs in the light valve according to the second embodiment of the present invention.

FIG. 23 is a view showing an illuminance distribution of light irradiated to a light valve according to Embodiment 2 of the present invention;

24 is a view showing a relative light quantity ratio on each y-axis of FIG. 23 according to Embodiment 2 of the present invention;

25 is a view showing the tip shape of the rotation mechanism according to the second embodiment of the present invention;

26 is a configuration diagram of an illumination optical system of a projection display device according to a third embodiment of the present invention;

27 is a view showing an optical path of light incident on a light valve according to Embodiment 3 of the present invention;

28 is a view showing a trajectory of light passing through a second lens array and a polarization conversion element according to Embodiment 3 of the present invention;

Fig. 29 is a relation diagram of the angle of incidence of light to the light valve and the gray scale according to the third embodiment of the present invention;

30 is a view showing an example of the shape of the rotation mechanism according to the third embodiment of the present invention;

31 is a view showing the amount of light passing through each cell of the second lens array 4b according to Embodiment 3 of the present invention;

32 is a view showing the trajectory of the light emitted from the light source 3 according to the third embodiment of the present invention;

33 is a view showing an illuminance distribution of light irradiated to a light valve according to Embodiment 3 of the present invention;

34 is a diagram showing an example of the shape of the rotation mechanism according to the third embodiment of the present invention;

35 is a view showing a relationship between a rotation angle and a relative light quantity ratio when the rotation mechanism according to the third embodiment of the present invention is in the shape of FIG. 30;

36 is a view showing an example of the shape of the rotation mechanism according to the third embodiment of the present invention;

37 is a view showing the relationship between the rotation angle and the relative light quantity ratio when the rotation mechanism according to the third embodiment of the present invention is in the shape of FIG. 35;

Fig. 38 is a diagram showing an example of the shape of the rotation mechanism according to the third embodiment of the present invention.

Explanation of symbols for the main parts of the drawings

DESCRIPTION OF SYMBOLS 1 Illumination optical system, 2: Light valve, 3: Light source system, 3a: Light source, 3b: Reflector, 4: Integrator lens, 4a: 1st lens array, 4b: 2nd lens array, 5: Polarization conversion element, 5a : Polarizing separator, 5b: reflecting film, 6: condenser lens, 7: field lens, 8: polarizing plate, 9: light amount adjusting system, 9a: rotating mechanism, 9b: signal detecting unit, 9c: rotating control unit, 9B: light shielding body, 9T: Shading body

Claims (17)

With light valve, A light source generating light to irradiate the light valve; An integrator lens disposed on an optical path between the light source and the light valve and equalizing an illuminance distribution of light irradiated from the light source to the light valve; A light amount adjusting mechanism disposed on the optical path and having a light shielding body rotating in a pair of a double door shape for adjusting the amount of light irradiated from the light source to the light valve. And The light shielding body is formed by bending in a V shape in a direction of decreasing light quantity Projection type display device characterized in that. The method of claim 1, And wherein the light blocking member is formed by cutting a tip portion into a concave portion. The method according to claim 1 or 2, And wherein the light blocking member is formed by cutting a tip portion into a blade-shaped portion. With light valve, A light source generating light to irradiate the light valve; An integrator lens disposed on an optical path between the light source and the light valve and equalizing an illuminance distribution of light irradiated from the light source to the light valve; A light amount adjusting mechanism disposed on the optical path and having a light shielding body rotating in a pair of double door shapes for adjusting the amount of light emitted from the light source to the light valve. And The light shielding body is formed by cutting a tip portion into a blade-shaped portion Projection type display device characterized in that. The method of claim 4, wherein And wherein the light shield is formed by cutting a tip portion into a concave portion. The method according to claim 1 or 4, The integrator lens includes a first lens array provided on the light source side, and a second lens array provided on the light valve side. The light shielding body is disposed between the first lens array and the second lens array, and rotates in a direction of opening and closing toward the first lens array; Projection type display device characterized in that. The method of claim 6, And a rotation axis of the light shielding body is disposed between the first lens array and the second lens array, in the vicinity of the second lens array. The method according to claim 1 or 4, And a dimension of both rotational radial directions of the pair of light shielding bodies is larger than that of the integrator lens. The method according to claim 2 or 5, And the concave portion is formed in a concave curve. The method according to claim 2 or 5, And the concave portion is formed in a parabolic shape. The method according to claim 2 or 5, And the concave portion is formed in a semi-ellipse shape. The method according to claim 2 or 5, And the concave portion is formed in a triangular shape. The method according to claim 2 or 5, And a plurality of concave portions are formed in the light shielding body. The method of claim 13, And wherein the concave portions include two concave portions having different areas, and the two concave portions are formed in the light shields at points symmetrical with respect to the optical axis when the light shield is closed. The method of claim 14, The area at the time of assuming the xyz coordinate system which consists of the z-axis which is the said optical axis direction, the x-axis which is orthogonal to the z-axis, and the horizontal direction, and the y-axis which is orthogonal to the z-axis and the x-axis is perpendicular | vertical In the two concave portions, The vertex of the concave portion of the larger opening area is located in the y-axis direction from the center of the lens cell in the x-axis direction closest to the optical axis of the second lens array, and is the vertex of the concave portion of the smaller opening area. Is located in the y-axis direction from the engaging portion of the lens cell and the lens cell on the x-axis and opposite to the optical axis side of the lens cell; Projection type display device characterized in that. With light valve, A light source generating light to irradiate the light valve; An integrator lens disposed on an optical path between the light source and the light valve and equalizing an illuminance distribution of light irradiated from the light source to the light valve; A light amount adjusting mechanism disposed on the optical path and having a light shielding body rotating in a pair of double door shapes for adjusting the amount of light emitted from the light source to the light valve. And The light shielding body is formed by distal end portion of a concave curved portion, the concave portion including two concave portions having different areas, and the two concave portions with respect to the optical axis when the light shielding body is closed. Formed on the light shielding body in a point symmetrical position Projection type display device characterized in that. The method of claim 16, The area at the time of assuming the xyz coordinate system which consists of the z-axis which is the said optical axis direction, the x-axis which is orthogonal to the z-axis, and the horizontal direction, and the y-axis which is orthogonal to the z-axis and the x-axis is perpendicular | vertical In the two concave portions, The vertex of the concave portion of the larger opening area is located in the y-axis direction from the center of the lens cell in the x-axis direction closest to the optical axis of the second lens array, and is the vertex of the concave portion of the smaller opening area. Is located in the y-axis direction from the junction of the lens cell with the lens cell on the x-axis and opposite to the optical axis side of the lens cell; Projection type display device characterized in that.

Images