JP4211969B2 - Illumination optical system and projection display device using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an illumination optical system that illuminates an object to be illuminated using a light source unit that includes a light emitter and a reflector, and in particular, modulates an illumination light beam with a light valve and uses the projected light beam to image an image on a screen. The present invention relates to an illumination optical system suitable for a projection display device that performs enlarged projection, and a projection display device using the illumination optical system.
[0002]
[Prior art]
As a light source unit of a projection display device, a configuration including a light source and a reflector is generally used. This light source preferably has a small light emission distribution and high light emission efficiency. At present, a light source such as an ultrahigh pressure mercury lamp, a metal halide lamp, or a xenon lamp is generally used. In addition, a parabolic mirror or an ellipsoidal mirror is usually used as the reflector that reflects the light from the light source and emits the light forward.
[0003]
17 to 19 show the structure of a well-known light source unit. 17 and 18 show a type in which the arc tube 101 is positioned at the rear part of the reflectors 104 and 105. Further, FIG. 19 shows a configuration in which the anode 103 is disposed at the rear part of the reflector 104 and the cathode 102 is disposed from the light emitting side of the reflector 104 in a configuration often used as a xenon lamp. FIG. 19B is a cross-sectional view of the light source unit, and FIG. 19A is a diagram of the light source unit viewed from the light emitting side. The cathode part having the cathode 102 is welded to a transparent member 106 for enclosing xenon gas and held on the outer periphery of the reflector, and a rod-like holding member having wiring for applying a voltage to the cathode 102 on the transparent member 106 107 is arranged.
[0004]
In FIG. 17 and FIG. 19, the reflector 104 is a parabolic mirror, and is arranged so that the light emitting point of the light source is located at the focal position. Is emitted. In FIG. 18, the reflector 105 is an ellipsoidal mirror, and is arranged so that the light emitting point of the light source is positioned at the first focal position. The illumination light beam emitted from the light source unit is the second focal point of the ellipsoidal mirror. Focused on the position.
[0005]
By the way, in the light source unit composed of the light sources 101 to 103 and the reflectors 104 and 105, a space with low light intensity is formed in the vicinity of the optical axis of the light beam emitted from the reflectors 104 and 105 due to its structure. (For example, refer to Patent Document 1). As described in FIG. 6A of Patent Document 1 and paragraph number 0038, light is not reflected due to the hole provided in the rear part of the reflector, or light is blocked due to the size of the arc tube itself. Because it is. In order to arrange the arc tube 101 or the anode 107, there is a range that is not mirror-finished at the rearmost part of the reflector. If this diameter is A, at least in the central part of the light beam emitted from the light source part, FIG. 17 and FIG. In FIG. 18, there is a space through which light hardly passes in the range of the diameter A in the plane orthogonal to the optical axis, and in FIG. 18, in the range of the angle B ° around the second focal point of the reflector. become.
[0006]
In Patent Document 1, in the multi-lens array downstream from the light source unit, the number of lens cells near the optical axis of the multi-lens array on the illuminated object side is reduced, the lens cell size is increased, and these lens cells are decentered. Thus, there has been proposed a technique for improving the light utilization efficiency of the entire optical system without using light in the vicinity of the optical axis having a low light intensity.
[0007]
[Patent Document 1]
JP 2001-56435 A
[0008]
[Problems to be solved by the invention]
However, in recent years, development of bright projection display devices has been advanced so that projection display devices can be used without problems even in projection in a bright place. As an element that greatly contributes to the improvement of brightness, along with the light valve, a new device is also required for the configuration of the light source part of the illumination optical system.
[0009]
The present invention has been made in view of such circumstances, and pays attention to the light amount distribution in the vicinity of the optical axis of the light beam emitted from the light source unit composed of the light source and the reflector, and has a large design compared to the conventional light source unit of this type. It is an object of the present invention to provide an illumination optical system that can perform bright and uniform illumination with high illumination efficiency and a projection display device using the illumination optical system, without being changed.
[0010]
[Means for Solving the Problems]
  An illumination optical system according to the present invention includes a main light source unit including a light emitter and a reflector that reflects light emitted from the light emitter toward the illuminated body, and a light beam near the center of the light beam emitted from the main light source unit. An auxiliary light source unit that emits a light beam so as to supplement the light beam in the low-density part, and a first integrator unit having two fly-eyes is provided to achieve uniform light quantity of the light beam from the main light source unit.And
  The light beam emitted from the auxiliary light source unit is introduced into the light beam low-density part before the fly eye on the main light source unit side or between the two fly eyes,
  A second integrator unit different from the first integrator unit is provided in the light beam low-density unit to equalize the amount of light from the introduced auxiliary light source unit.It is characterized by this.
[0012]
In addition, at least one of the two fly eyes of the first integrator unit includes a lens that collects or diverges the light beam from the auxiliary light source unit in the vicinity of the optical axis through which the light beam from the auxiliary light source unit passes. You may have.
[0014]
  Also, the aboveThe second integrator section2 fly eyesIt is madeIt is preferable. Further, at least one fly eye of the two fly eyes of the second integrator section is formed on the same member as at least one fly eye of the two fly eyes of the first integrator section. Is more preferable.
[0015]
  Also, the aboveThe second integrator sectionHas a rod integratorIt is madeIt is preferable.
[0016]
Further, the light emitter of the main light source unit generates a randomly polarized light beam, and the light beam is converted into linearly polarized light by a polarization conversion optical system to illuminate the object to be illuminated. A light beam with a polarization direction that is substantially the same as the light beam from the main light source unit that has been converted to linearly polarized light by the polarization conversion optical system is emitted, and the light beam from the auxiliary light source unit is polarized The illumination target may be illuminated without being illuminated.
[0017]
Further, the light emitter of the main light source unit generates a randomly polarized light beam, which is converted into linearly polarized light by the first polarization conversion optical system to illuminate the illuminated body, and the auxiliary light source unit The luminous body generates a randomly polarized light beam, and the polarization direction substantially coincides with the light beam from the main light source unit converted into linearly polarized light by the first polarization conversion optical system by the second polarization conversion optical system. It may be configured to illuminate the object to be illuminated after being converted into linearly polarized light.
[0018]
A projection display device according to the present invention includes the illumination optical system, and illuminates at least one light valve that performs light modulation of the illumination light beam based on predetermined image information with the light beam from the illumination optical system. A light beam carrying image information from a light valve is projected through a projection optical system.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIG. 1A showing a schematic configuration of an illumination optical system according to Example 1 of the present invention described later. The illumination optical system includes a main light source unit 1, an auxiliary light source unit 2, a deflection mirror 3, a first integrator unit 4 having two fly eyes 15 and 16, and a second integrator unit 5.
[0020]
The main light source unit 1 includes a light source 11 made of an arc tube such as a xenon lamp or a metal halide lamp, and the light emitting point is arranged at the focal point of a reflector 12 made of a parabolic mirror, and the light emitted from the light source 11 is emitted. A substantially parallel light beam is emitted from the opening of the reflector 12 that reflects toward the illuminated body.
[0021]
By the way, as described above, the light amount distribution in the cross section perpendicular to the optical axis of the light beam emitted from the main light source unit 1 is a portion having a low light intensity (hereinafter referred to as a light beam low-density portion) in a predetermined range near the optical axis. Present). Paying attention to this, the illumination optical system is configured to include an auxiliary light source unit 2 that emits a light beam so as to supplement the light beam in a light beam dense portion near the center of the light beam emitted from the main light source unit 1. ing. In FIG. 1A, the auxiliary light source unit 2 is composed of a laser light source 31 made of a semiconductor laser LD, and the light beam from the auxiliary light source unit 2 made into a parallel light beam by the collimator lens 35 is deflected by the deflecting mirror 3, and the main light source unit. 1 is introduced into the low-density portion of the light beam emitted from 1.
[0022]
The configuration of supplementing the light beam from the auxiliary light source unit 2 to the light beam low density portion of the light beam emitted from the main light source unit 1 not only increases the light amount as the entire light source unit, but also contributes to the improvement of the brightness of the illumination optical system, Even in the light amount distribution, it is possible to enhance the light intensity of the light-dense portion in the vicinity of the center of the light beam that should originally have the highest light intensity. Further, even if a member such as a deflecting mirror 3 is provided in order to supplement the light flux in the light flux density portion, since the light intensity of the light flux from the main light source portion 1 is weak, the main light source portion 1 The light beam from the main light source unit 1 can be used efficiently without substantially blocking the light beam. Moreover, according to such a structure, with respect to the light source part provided with the reflector generally used conventionally, this can be made into the main light source part 1, and a brightness can be improved with few design changes and compactness.
[0023]
In addition, this illumination optical system includes two fly eyes 15 and 16 as the first integrator section 4 for uniformizing the light amount distribution in a cross section perpendicular to the optical axis. In FIG. 1A, the luminous flux emitted from the main light source unit 1 is distributed in light quantity distribution by the first integrator unit 4 in which the second fly eye 15 and the first fly eye 16 are arranged in order from the main light source unit side. It is made uniform and emitted from the illumination optical system as an illumination light beam. That is, the second fly eye 15 divides the substantially parallel light beam from the main light source unit 1 into the same number of partial light beams as the number of lens cells of the second fly eye 15, and in the vicinity of each lens cell constituting the first fly eye 16. By forming a secondary light source image of the light source 11, the light quantity distribution is made uniform.
[0024]
In the present embodiment, in addition to the above-described configuration, it is preferable that a second integrator unit 5 for further uniforming the light amount distribution in a cross section perpendicular to the optical axis of the light beam from the auxiliary light source unit 2 is preferably provided. In the following description, when the action of the first and second integrator sections 4 and 5 is described as “uniform light quantity distribution”, it is assumed to be in the above cross section.
[0025]
In FIG. 1A, the light flux emitted from the auxiliary light source unit 2 can be made uniform in light quantity distribution by the rod integrator 36 as the second integrator unit 5. The rod integrator 36 is disposed between the two fly eyes 15 and 16, and the light beam from the auxiliary light source unit 2 is transmitted from the auxiliary light source unit 2 in the fly eye 15 when passing through the second fly eye 15. The light is incident on the rod integrator 36 at a predetermined angle by the action of the condenser lens 37 provided at the position where the light beam is incident. Therefore, the light is reflected and emitted a plurality of times on the inner wall surface of the rod integrator 36, and the light quantity distribution is made uniform.
[0026]
Examples 1 to 6 will be described below as specific examples of the illumination optical system according to the present invention. In each embodiment, the same components are denoted by the same reference numerals unless otherwise specified, and detailed description of the matters already described is omitted.
[0027]
<Example 1>
A sectional view of a schematic configuration of the illumination optical system according to the present embodiment is shown in FIG. In FIG. 1 (a) and the following FIGS. 2, 3 (a), 4 (a), 5, 7 (a), 8, 12, 13, 15, and 16, each member emphasizes its cross-sectional shape. In some cases, the description of the far end face is omitted.
[0028]
The configuration of the present embodiment and the operational effects thereof are as described above, but a more detailed configuration will be described below. In the present embodiment, the light beam from the auxiliary light source unit 2 is introduced into the light beam from the main light source unit 1 by the deflection mirror 3 in the front stage of the second fly eye 15. When the light source of the auxiliary light source unit 2 is the semiconductor laser 31, this light source usually needs to be used while being cooled, so that the light source from the main light source unit 1 is arranged and deflected in this way. It is preferably introduced by light guiding means such as a mirror 3.
[0029]
Next, the fly eyes 15 and 16 of the first integrator unit 4 in this embodiment will be described. FIG. 1B schematically shows the first fly's eye 16 of FIG. 1A viewed from the illuminated object side (in the direction of arrow A). The fly eye 16 has a plurality of lens cells 18 formed by minute convex lenses having a rectangular outline arranged vertically and horizontally. The light beam from the auxiliary light source unit 2 is incident on the fly eye 16 at the center. A condensing lens 38 having a shape different from that of the lens cell 18 is provided at the position. In FIG. 1B, the portion corresponding to the lens cell 18 is indicated by hatching.
[0030]
Further, the fly eye 15 has a shape including a lens cell 17 corresponding to each lens cell 18 of the fly eye 16 and a condenser lens 37 corresponding to the condenser lens 38 of the fly eye 16. The condensing lens 37 has a refractive power that refracts the light beam in a direction suitable for entering the rod integrator 36, and the condensing lens 38 refracts the light beam emitted from the rod integrator 36 in a desired direction. Has refractive power. The illumination optical system used in the projection display device is preferably refracted so that the light beam from the auxiliary light source unit 2 is superimposed on the subsequent light valve in the same manner as the light beam from the main light source unit 1. The fly eye 15 is disposed so that the convex surface of the lens cell 17 faces the main light source unit, and the fly eye 16 faces the convex surface of the lens cell 18 toward the illuminated body. It is advantageous in terms of cost that the fly eyes 15 and 16 have the same shape.
[0031]
In the present embodiment, the light beam emitted from the auxiliary light source unit 2 has a small beam diameter emitted so as to supplement the light beam in the light beam dense portion near the center of the light beam emitted from the main light source unit 1. Therefore, the second integrator unit 5 for making the light quantity distribution of the light beam emitted from the auxiliary light source unit 2 uniform has a simple configuration using a rod integrator 36. The arrangement position of the rod integrator 36 is between the two fly eyes 15 and 16, and a compact configuration is achieved by effectively using space. Further, the light beam from the auxiliary light source unit 2 is introduced on the main light source unit side from the second fly eye 15, and the rod integrator 36 is disposed between the two fly eyes 15, 16, so that the fly eyes 15, 16 The condenser lenses 37 and 38 are integrally formed to achieve a compact configuration.
[0032]
In this embodiment and the following embodiments, the rod integrator includes a solid rod rod prism made of glass, a hollow prism whose inner surface is a mirror surface by a reflective coating, and a rod rod prism arranged on the light beam incident side. A so-called hybrid integrator in which a hollow prism is arranged on the light beam exit side and both are combined can be used. The light beam incident on the rod integrator is guided to the light beam output end of the rod-shaped rod prism while being totally reflected a plurality of times on the inner wall surface and reflected by the mirror surface of the inner wall surface a plurality of times on the hollow prism. The light beam emitted from the rod integrator is a light beam having a substantially uniform light beam density at the emission end of the rod integrator. When this illumination optical system is used in a projection display device, the exit end of the rod integrator and the subsequent light valve are in an imaging relationship (conjugate relationship) with each other via a relay lens.
[0033]
<Example 2>
FIG. 2 shows a cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment. The present embodiment is configured to include a main light source unit 1, an auxiliary light source unit 2, a first integrator unit 4, a second integrator unit 5, and a collimator lens 35 similar to those of the first embodiment. However, the present embodiment is different from the first embodiment in that the deflecting mirror 3 deflects the light beam from the main light source unit 1. A portion near the optical axis of the deflecting mirror 3 where the light flux from the main light source is irradiated is a space, and the light from the auxiliary light source is introduced into the light flux through the space. . Even when the deflecting mirror 3 deflects the light beam from the main light source unit 1 as in this embodiment, the light beam emitted from the auxiliary light source unit 2 is emitted from the main light source unit 1. Since the light beam is introduced so as to be located in the light beam low density portion in the vicinity of the center of the light beam, the same effect as that of the first embodiment can be obtained.
[0034]
<Reference example 1>
  BookreferenceA cross-sectional view of a schematic configuration of an illumination optical system according to an example is shown in FIG. BookreferenceThe example main light source unit 1 is the same as that of the first embodiment.
[0035]
  BookreferenceThe auxiliary light source unit 2 in the example is a light source in which the luminous flux emitted from the auxiliary light source unit 2 is emitted and the light amount distribution is substantially uniform. For example, a laser light source 32 can be used. Since the light flux from the auxiliary light source unit 2 having such a light source does not need to be uniformed by the integrator,referenceIn the example, the means for making the light amount of the light flux from the auxiliary light source unit 2 uniform is omitted, and the configuration is simpler.
[0036]
  BookreferenceThe first integrator unit 4 in the example includes two fly eyes 15 and 16 as in the first embodiment. FIG. 3B schematically shows the first fly eye 16 of FIG. 3A as viewed from the illuminated body side (in the direction of arrow B). Similar to the first embodiment, the fly eye 16 has a plurality of lens cells 18 each having a rectangular outline and a minute convex lens arrayed vertically and horizontally, and the auxiliary light source unit 2 in the fly eye 16 at the center. Unlike in the first embodiment, a condensing lens 38 having the same shape as the lens cell 18 is provided at a position where the light beam from the light beam enters. In FIG. 3B, a portion corresponding to a lens having the same shape as the lens cell 18 is indicated by hatching.
[0037]
Further, the fly eye 15 has a shape including a lens cell 17 corresponding to each lens cell 18 of the fly eye 16 and a condenser lens 37 corresponding to the condenser lens 38 of the fly eye 16. The condenser lens 37 has a refractive power that refracts the light beam from the auxiliary light source unit 2 in the same direction as the parallel light beam from the main light source unit 1, and forms a secondary light source image in the vicinity of the first fly's eye. Can be made. The condensing lens 38 is similar to the light beam from the main light source unit 1 divided into the partial light beams by the second fly eye 15 with respect to the light beam from the auxiliary light source unit 2 collected by the condensing lens 37. It has a refractive power that refracts in the direction. The illumination optical system used in the projection display device is preferably refracted so that the light beam from the auxiliary light source unit 2 is superimposed on the subsequent light valve in the same manner as the light beam from the main light source unit 1. Similar to the first embodiment, the fly eye 15 is arranged so that the convex surface of the lens cell 17 faces the main light source unit, and the fly eye 16 faces the convex surface of the lens cell 18 toward the illuminated body. It is advantageous in terms of cost that the fly eyes 15 and 16 have the same shape.
[0038]
  BookreferenceIn the example, a light beam having a uniform light amount distribution from the auxiliary light source unit 2 is introduced to the main light source unit side from the second fly eye 15 through the collimator lens 35 and the deflection mirror 3. Therefore, a condensing lens 37 having the same shape as that of the lens cell 17 is integrally formed in the fly eye 15, and a condensing lens 38 having the same shape as that of the lens cell 18 is integrally formed in the fly eye 16. Have achieved.
[0039]
<Example 4>
FIG. 4A is a cross-sectional view of a schematic configuration of the illumination optical system according to the present example. The main light source unit 1 of this embodiment is the same as that of the first embodiment.
[0040]
The auxiliary light source unit 2 of the present embodiment has a configuration in which a light source 33 is disposed at a focal position of a reflector 34 formed of a parabolic mirror. The auxiliary light source unit 2 of the illumination optical system according to the present invention is not limited to a laser light source, and may use a reflector 34 as in this embodiment. In this case, the auxiliary light source unit 2 can be made at low cost and with a large amount of light. In the present embodiment, the light beam emitted from the auxiliary light source unit 2 is substantially parallel light having a nonuniform light amount distribution.
[0041]
The first integrator unit of the present embodiment includes two fly eyes 15 and 16 as in the first embodiment. FIG. 4B schematically shows the first fly eye 16 of FIG. 4A viewed from the illuminated object side (in the direction of arrow C). Similar to the first embodiment, the fly eye 16 has a plurality of lens cells 18 each having a rectangular outline and a minute convex lens arrayed vertically and horizontally, and the auxiliary light source unit 2 in the fly eye 16 at the center. Unlike the first embodiment, fly eyes 41 and 42 constituting a second integrator section to be described later are provided at the positions where the light beams from the first and second beams are incident. The fly eye 15 includes a lens cell 17 corresponding to each lens cell 18 of the fly eye 16. Similar to the first embodiment, the fly eye 15 is arranged so that the convex surface of the lens cell 17 faces the main light source unit, and the fly eye 16 faces the convex surface of the lens cell 18 toward the illuminated body.
[0042]
In the present embodiment, the two fly eyes are arranged such that the light beam emitted from the auxiliary light source unit 2 is positioned in the light beam dense portion near the center of the light beam emitted from the main light source unit 1 via the deflection mirror 3. 15 and 16 are introduced. For this reason, it is not necessary to provide a lens in the portion corresponding to the light beam low density portion in the vicinity of the center of the light beam emitted from the main light source unit 1 in the center portion of the second fly eye 15.
[0043]
In addition, since the light beam emitted from the auxiliary light source unit 2 is introduced between the two fly eyes 15 and 16, a member inserted into the light beam from the main light source unit 1 such as the deflection mirror 3 or the like. However, it is difficult to block the light from the main light source unit 1, and the light use efficiency can be improved. In the vicinity of both the fly eyes 15, 16, particularly in the vicinity of the first fly eye 16, the light from the main light source unit 1 is collected as each partial light beam by the second fly eye 15. For this reason, a member can be arranged in the gap between the partial light beams so as not to block the condensed partial light beams, and the deflection mirror 3 for deflecting the light from the auxiliary light source unit 2 is supported and fixed. A member for this can be arranged in this way. Unlike the present embodiment, in the configuration in which the deflection mirror 3 is arranged in front of the second fly eye 15 and light from the auxiliary light source unit 2 is to be introduced, the support fixing member of the deflection mirror 3 is separated from the main light source unit 1. It is inevitable to block the light.
[0044]
As described above, in the present embodiment, the light beam emitted from the auxiliary light source unit 2 is substantially parallel light having a nonuniform light amount distribution. Therefore, in order to make the light quantity of the light flux from the auxiliary light source unit 2 uniform, a second integrator unit having two fly eyes 41 and 42 is provided. In the present embodiment, the fly eyes 41 and 42 are provided on both sides of the first fly eye 16 at a position where the light beam from the auxiliary light source unit 2 is incident on the fly eye 16 at the center of the first fly eye 16. Is formed.
[0045]
FIG. 4B shows a first fly eye 42 corresponding to the auxiliary light source unit 2 formed on the illuminated body side of the first fly eye 16. The fly eye 42 is formed by arranging a plurality of lens cells 49 each having a rectangular contour having a size different from that of the lens cells 17 and 18 and formed by a minute convex lens. Further, as shown in FIG. 4A, the surface of the first fly eye 16 on the auxiliary light source unit side includes lens cells 48 corresponding to the lens cells 49 respectively, and corresponds to the auxiliary light source unit 2. A second fly eye 41 is formed. The parallel light beam from the auxiliary light source unit 2 is divided into each partial light beam and condensed by the second fly eye 41 corresponding to the auxiliary light source unit 2 formed on the auxiliary light source unit side of the first fly eye 16. Further, the light is refracted in a desired direction and emitted by the first fly eye 42 corresponding to the auxiliary light source unit 2 formed on the illuminated body side of the first fly eye 16. As an illumination optical system used in the projection display device, it is preferable that the light beam from the auxiliary light source unit 2 is refracted so as to be superimposed on the light valve at the rear stage in the same manner as the light beam from the main light source unit 1.
[0046]
As described above, in this embodiment, the fly eyes 41 and 42 on the two surfaces of the second integrator unit that equalize the light quantity distribution of the light emitted from the auxiliary light source unit 2 are the same members as the fly eyes 16 of the first integrator unit. By being formed above, the number of members is reduced and a simple and compact configuration is achieved. In the present invention, even if fly eyes are provided on both surfaces of the same member as in the present embodiment, each of the partial light beams is divided by the second fly eye so that the second fly eye is in the vicinity of the first fly eye. The configuration of “having two fly eyes” that forms the next light source image can be regarded as equivalent to “having two fly eyes”.
[0047]
As a modification of the present embodiment, the light beam from the auxiliary light source unit 2 is configured to be introduced into the light beam low-density part of the light beam from the main light source unit 1 before the second fly eye 15, and the second fly eye You may form the 2nd fly eye 41 corresponding to the auxiliary light source part 2 on the same member as the fly eye 15 in the position where the light beam from the auxiliary light source part 2 of 15 center part passes. As described above, at least one of the two fly eyes 41 and 42 of the second integrator section is the same member as at least one of the two fly eyes 15 and 16 of the first integrator section. By being formed above, the number of members can be reduced and a simple and compact configuration can be obtained.
[0048]
As a modification of the present embodiment, the auxiliary light source unit 2 may be configured to use a reflector made of an ellipsoidal mirror.
[0049]
<Example 5>
FIG. 5 shows a cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment. The auxiliary light source unit 2 including the main light source unit 1 and the laser light source 31 of the present embodiment is the same as that of the first embodiment. In addition, the configuration of the fly eyes 15 and 16 as the first integrator unit is also the portion corresponding to the light flux density portion of the light beam from the main light source unit 1 at the center of the second fly eye 15, and the first fly eye 16. Except for the portion where the light beam from the auxiliary light source unit 2 in the central part is incident, it is the same as in the first embodiment.
[0050]
In the present embodiment, the light beam emitted from the auxiliary light source unit 2 is not introduced into the light beam from the main light source unit 1 by the deflecting mirror, but the auxiliary light source unit 2 has two fly as the first integrator unit. Arranged between the eyes 15 and 16. Since the auxiliary light source unit 2 is disposed in the light beam dense portion near the center of the light beam emitted from the main light source unit 1, there is no possibility of deteriorating the utilization efficiency of the light emitted from the main light source unit 1.
[0051]
As in the fourth embodiment, the present embodiment is configured such that a second integrator section having two fly eyes 41 and 42 is provided in order to make the amount of light from the auxiliary light source section 2 uniform. . In this embodiment, the light beam emitted from the auxiliary light source unit 2 is converted into a parallel light beam by the collimator lens 35, and then divided into individual partial light beams by the second fly eye 41 corresponding to the auxiliary light source unit 2. Further, the light is refracted and emitted in a desired direction by the first fly eye 42 corresponding to the auxiliary light source unit 2 formed on the surface of the first fly eye 16 on the illuminated body side. As an illumination optical system used in the projection display device, it is preferable that the light beam from the auxiliary light source unit 2 is refracted so as to be superimposed on the light valve at the subsequent stage in the same manner as the light beam from the main light source unit 1.
[0052]
Similarly to the fourth embodiment, the two fly eyes 41 and 42 have lens cells 48 and 49 formed by minute convex lenses having a rectangular outline having a size different from the lens cells of the fly eyes 15 and 16 vertically and horizontally. A plurality of the lens cells 48 and 49 of the two fly's eyes 41 and 42 are in a one-to-one correspondence with each other. Also in the present embodiment, since the fly eye 42 is formed on the same member as the fly eye 16, the number of members can be reduced and a simple and compact configuration can be achieved.
[0053]
By the way, as an illumination optical system used in a projection display device, for example, when the light valve of the device is a liquid crystal panel, the light emitted from the illumination optical system is substantially parallel light with the polarization direction aligned. In some cases, it may be preferable. Therefore, in the present embodiment, the first polarization conversion optical system 6 for converting the light beam from the main light source unit 1 that generates random polarized light into linearly polarized light, and the random number after the first and second integrator units. The light beam from the auxiliary light source unit 2 that generates polarized light is converted into linearly polarized light that has a polarization direction substantially coincident with the light beam from the main light source unit 1 converted into linearly polarized light by the first polarization conversion optical system 6. The illumination optical system includes the second polarization conversion optical system 7.
[0054]
FIG. 6A is a view of the first and second polarization conversion optical systems 6 and 7 formed integrally in the present embodiment as viewed from the illuminated body side, and FIG. It is a side view of a). The first polarization conversion optical system 6 aligns the polarization direction of the light beam from the main light source unit 1 emitted from the first integrator unit. The well-known polarization beam splitter array and the light emission of this array are well-known. A plurality of λ / 2 phase films 21 arranged on the surface side are composed of λ / 2 phase plates arranged in stripes. In FIG. 6A, the hatched portion is a portion where the λ / 2 phase film 21 is disposed.
[0055]
In the polarization beam splitter array, the polarization separation film 19 and the reflection film 20 are alternately formed so as to have an angle of about 45 degrees with respect to the optical axis. A light beam from the main light source unit 1 that is randomly polarized light is incident from a corresponding lens cell of the fly eye 16 and is separated into two types of polarized light of P-polarized light and S-polarized light having different polarization directions by the polarization separation film 19. One polarized light passes through the polarization separation film 19 and is emitted from the prism surface 22. The other polarized light is reflected by the polarization separation film 19 and the reflection film 20 adjacent thereto, and finally is emitted from the polarization beam splitter array at an angle substantially parallel to the light beam that has been transmitted through the polarization beam splitter array in a straight line. When passing through the two-phase film 21, the light is converted into a polarization direction substantially coincident with the light beam that has been transmitted straight through the polarization beam splitter array by the rotating action of the polarization plane, and is emitted.
[0056]
In addition, the second polarization conversion optical system 7 is formed at the center of the first polarization conversion optical system 6 at a position where the light beam emitted from the auxiliary light source unit 2 passes. The second polarization conversion optical system 7 has substantially the same configuration as the first polarization conversion optical system 6 although the size is different, and includes a polarization beam splitter array in which a polarization separation film 43 and a reflection film 44 are formed, and a plurality of polarization beam splitter arrays The λ / 2 phase film 45 is composed of a λ / 2 phase plate arranged in a stripe shape. The light source emitted from the prism surface 46 and the light beam that passes through the λ / 2 phase film 45 and is emitted after the polarization direction is converted are converted into linearly polarized light by the first polarization conversion optical system 6. Is emitted with the polarization direction substantially coincident with the luminous flux of.
[0057]
In the present embodiment, the first polarization conversion optical system 6 is divided into two members in the vertical direction of FIG. 6 in order to facilitate the formation of the second polarization conversion optical system 7 at the center. The internal polarization separation film 19 and the reflection film 20 are disposed so as to be symmetric with respect to the optical axis.
[0058]
As described above, when the light source of the auxiliary light source unit 2 generates random polarized light, the second polarization conversion optical system 7 for aligning the polarization direction of light from the light source is disposed in the subsequent stage. It is preferable. According to the illumination optical system in which the illumination light beam is converted and emitted so that the polarization directions are substantially matched by the first and second polarization conversion optical systems 6 and 7, the projection in which the light valve of the apparatus is a liquid crystal panel The illumination optical system used in the type display device can also have high illumination efficiency.
[0059]
In the configuration in which the second integrator unit having two fly eyes 41 and 42 is provided in order to make the light amount of the light beam from the auxiliary light source unit 2 uniform as in the fourth embodiment and the present embodiment, the auxiliary In the case where the light source of the light source unit 2 emits a light beam having a uniform polarization direction, the second polarization conversion optical system is not necessary. That is, the light source of the main light source unit 1 generates random polarized light, and this light beam is converted into linearly polarized light by the first polarization conversion optical system 6 to illuminate the object to be illuminated, and the auxiliary light source unit 2 receives the first polarized light. A light beam having a polarization direction that is substantially the same as the light beam from the main light source unit 1 converted into linearly polarized light by the conversion optical system 6 is emitted, and this light beam is subjected to polarization conversion without being subjected to polarization conversion. By configuring the illumination body to illuminate, the configuration can be simplified.
[0060]
Further, as a modification of the present embodiment, the auxiliary light source unit 2 and the collimator lens 35 are disposed on the main light source unit side of the second fly eye 15 and correspond to the auxiliary light source unit 2 in the center of the second fly eye 15. It is also possible to form the second fly eye 41 to be formed. In this embodiment as well as in this modified example, a deflecting mirror may be provided so that the light beam from the auxiliary light source unit 2 may be introduced.
[0061]
<Example 6>
FIG. 7A shows a cross-sectional view of a schematic configuration of the illumination optical system according to the present example. The illumination optical system according to the present embodiment is an illumination optical system including the first polarization conversion optical system and the second polarization conversion optical system 7 as in the fifth embodiment. As will be described later, the first polarization conversion optical system includes a birefringence diffraction type polarization separation plate 26 and a λ / 2 phase plate in which a plurality of λ / 2 phase films 21 are arranged in a stripe shape.
[0062]
The configuration other than the polarization conversion optical system is substantially the same as that of the first embodiment in which the second integrator unit is the rod integrator 36, and the light flux from the auxiliary light source unit 2 is the first fly eye 16 and the second one. The difference is that it is introduced by the deflection mirror 3 arranged between the fly eye 15. For this reason, in this embodiment, the condensing lens 37 is not formed at the center of the second fly's eye 15 as in the first embodiment, but is a single lens and is incident on the rod integrator 36. It has a refractive power that refracts in a suitable direction. Even when the light beam from the auxiliary light source unit 2 is introduced into the light beam from the main light source unit 1 in the subsequent stage of the fly eye 15, the light beam is introduced into the light beam dense portion near the center of the light beam emitted from the main light source unit 1. Therefore, there is no possibility that the utilization efficiency of the light emitted from the main light source unit 1 is deteriorated.
[0063]
The first polarization conversion optical system according to the present embodiment includes a birefringence diffraction type polarization separation plate 26 and a λ / 2 phase plate in which a plurality of λ / 2 phase films 21 are arranged in a stripe shape. Is converted into linearly polarized light. The light beam from the main light source unit 1 passes through the birefringence diffraction type polarization separation plate 26 and is deflected and separated in two different directions according to the polarization direction. In FIG. 7A, one polarized light beam is indicated by a solid line, and the other polarized light beam is indicated by a dotted line. As shown in the figure, the polarized light beams deflected in two different directions form a light source image twice the number of fly-eye divisions on the first fly eye 16 by the action of the second fly eye 15. Of these light source images, a λ / 2 phase film 21 that changes the polarization direction is disposed in the vicinity of the light source image of a light beam having one of the polarization directions, so that the light beam emitted from the main light source unit 1 is linear. Convert to polarized light. In FIG. 7A, the λ / 2 phase plate is the main light source of the first fly's eye 16 so that the λ / 2 phase film 21 is arranged at a position where the polarization direction of the polarized light beam indicated by the dotted line can be changed. It is attached to the plane on the part side.
[0064]
The second polarization conversion optical system 7 of this embodiment is a block-shaped polarization conversion system composed of prisms, and the light beam from the auxiliary light source unit 2 that generates random polarization is converted into linearly polarized light by the first polarization conversion optical system. The light is converted into linearly polarized light that has a polarization direction substantially coinciding with the converted light flux from the main light source unit 1. This prism includes a prismatic prism having a polarization separation film 43 formed therein, an isosceles triangular prism having a reflection film 44 formed on a hypotenuse, and the polarization separation film 43 and the reflection film 44 are parallel and light. They are joined so as to form an angle of about 45 degrees with respect to the axis.
[0065]
A light beam from the auxiliary light source unit 2, which is randomly polarized light, enters the polarization conversion optical system 7 from the rod integrator 36 via the condenser lens 38. This light beam is separated into two types of polarized light having different polarization directions by the polarization separation film 43 inside the prism. One polarized light travels straight through the polarization separation film 43 and is emitted from the light beam exit surface 46 of the prism. The other polarized light is reflected by the polarization separation film 43 and the reflection film 44, and finally is emitted from the light beam emission surface of the prism at an angle substantially parallel to the light beam that has been transmitted through the polarization separation film 43 in a straight line. When passing through the λ / 2 phase film 45 formed on the surface, the light is converted into a polarization direction substantially coincident with the light beam that has been transmitted through the polarization separation film 43 by the rotating action of the polarization surface, and is emitted. The main light source unit in which the light beam from the auxiliary light source unit 2 is converted into linearly polarized light by the first polarization conversion optical system by appropriately setting the separation characteristics of the polarization separation film 43 and the arrangement position of the λ / 2 phase film 45 1 can be converted into linearly polarized light that has a polarization direction substantially coincident with the luminous flux from 1. FIG. 7B schematically shows the fly eye 16 and the second polarization conversion optical system 7 of FIG. 7A as viewed from the illuminated body side. In FIG. 7B, the portion corresponding to the second polarization conversion optical system 7 is indicated by hatching.
[0066]
As described above, when the light source of the auxiliary light source unit 2 generates random polarized light, the second polarization conversion optical system 7 for aligning the polarization direction of light from the light source is disposed in the subsequent stage. It is preferable. According to the illumination optical system in which the illumination light beam is converted and emitted so as to have the polarization directions substantially coincident with each other by the first and second polarization conversion optical systems, the projection display device in which the light valve of the device is a liquid crystal panel The illumination optical system used in the above can also have high illumination efficiency.
[0067]
In the present embodiment, similarly to the fifth embodiment, when the light source of the auxiliary light source unit 2 emits a light beam having the same polarization direction, the second polarization conversion optical system is not necessary. . By using such a light source, the configuration can be simplified.
[0068]
<Example 7>
FIG. 8 shows a cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment. Although the configuration of the illumination optical system of the present embodiment is often the same as that of the first embodiment, the difference is that the polarization conversion optical system 6 is disposed after the first and second integrator sections, and The light beam from the auxiliary light source unit 2 is introduced by the deflection mirror 3 disposed between the first fly eye 16 and the second fly eye 15. This difference will be described.
[0069]
In the present embodiment, since the light beam from the auxiliary light source unit 2 is introduced by the deflection mirror 3 disposed between the first fly eye 16 and the second fly eye 15, the condenser lens 37 is used in the first embodiment. In this way, the lens is not formed at the center of the second fly eye 15 but is formed as a single lens and has a refractive power that refracts in a direction suitable for incidence on the rod integrator 36.
[0070]
In addition, the polarization conversion optical system 6 of the present embodiment is a well-known polarization beam splitter array, and a plurality of λ / 2 phase films 21 are arranged in a stripe pattern on the light exit surface side of the array. The λ / 2 phase plate is made. In the present embodiment, unlike the fifth and sixth embodiments, the first polarization converting optical system that aligns the polarization direction of the light beam from the main light source unit 1 is used to align the polarization direction of the light beam from the auxiliary light source unit 2. Cost reduction can be achieved by using a conventional polarization conversion optical system without providing a two-polarization conversion optical system.
[0071]
When such a polarization conversion optical system 6 is used, the laser light source 31 of the auxiliary light source unit 2 may generate random polarized light or may have good polarization characteristics for emitting a light beam with a uniform polarization direction. Any of them can be used. In the former light source, the light beam from the auxiliary light source unit 2 is converted into linearly polarized light by the polarization conversion optical system 6 from both the λ / 2 phase film 21 and the prism surface 22 of the corresponding polarization conversion optical system 6. The direction of polarization is approximately the same as the luminous flux from the light source unit 1 and is emitted. In other words, the polarization conversion optical system 6 also plays the role of the second polarization conversion optical system 7 in Examples 5 and 6 in which the polarization direction of the light beam from the auxiliary light source unit 2 is aligned.
[0072]
In the case of the latter light source, the light beam from the auxiliary light source unit 2 is only the light beam emitted from either the λ / 2 phase film 21 or the prism surface 22 of the corresponding polarization conversion optical system 6 by the polarization conversion optical system 6. The polarization direction is substantially the same as the luminous flux of the main light source unit 1 converted into linearly polarized light, and is emitted.
[0073]
In addition, when the laser light source 31 of the auxiliary light source unit 2 has good polarization characteristics for emitting a light beam with a uniform polarization direction, the polarization conversion optical system 6 is as shown in FIGS. It is possible to change. 9-11, (a) is the figure which looked at the polarization conversion optical system 6 from the to-be-illuminated body side, (b) is the side view of the polarization conversion optical system 6. FIG. In each figure (a), the hatched portion is a portion where the λ / 2 phase film 21 is disposed.
[0074]
The polarization conversion optical system 6 shown in FIG. 9 includes a polarization beam splitter array in which a polarization separation film 19 and a reflection film 20 are alternately formed so as to have an angle of about 45 degrees with respect to the optical axis. The λ / 2 phase film 21 is composed of a λ / 2 phase plate arranged in a stripe shape, and this phase plate has a λ / 2 phase film 21 only in the central portion where the light beam from the auxiliary light source unit 2 passes. Has been deleted. If the light beam from the laser light source 31 has a polarization characteristic that transmits the polarization separation film 19, most of the light beam is emitted from the prism surface 22. Even if a certain amount of light beam is reflected by the separation efficiency of the polarization separation film 19, the λ / 2 phase film 21 is deleted from this portion of the light beam reflected and emitted from the reflection film 20 as well. The light is emitted from the prism surface 25 with the polarization direction substantially coincident with the light beam emitted from the light beam 22. That is, the light from the auxiliary light source unit 2 is obtained by using a low-cost method of bonding a λ / 2 phase plate from which only the λ / 2 phase film 21 at a predetermined position in the center is deleted to the polarization beam splitter array. Utilization efficiency can be increased.
[0075]
In this way, when the light source of the auxiliary light source unit 2 is made to have the same polarization, there is no need for further polarization conversion of this light beam. It is not inconvenient if the light is emitted from the illumination optical system via the polarization conversion optical system 6 that performs polarization conversion.
[0076]
FIGS. 10 and 11 show that the laser light source 31 of the auxiliary light source unit 2 has good polarization characteristics for emitting a light beam with a uniform polarization direction, so that this light beam passes through the polarization conversion optical system 6. The space to be used is a space, and the light quantity is to be utilized to the maximum without being transmitted through the prism of the polarization conversion optical system 6. In order to form this space in the central portion of the polarization conversion optical system 6, for example, as shown in FIG. 10, two polarization conversion optical systems 6a having the same shape (one is indicated by a solid line and the other is indicated by a dotted line). ) Can be combined to reduce the manufacturing cost. Further, as shown in FIG. 11, two polarization conversion optical systems 6b having the same shape and two polarization conversion optical systems 6c having the same shape (one is shown by a solid line and the other is shown by a dotted line). Even when the members are combined, the manufacturing cost can be reduced. The method for forming the space in the central portion of the polarization conversion optical system 6 is not limited to the above.
[0077]
According to the illumination optical system in which the illumination light beam is converted and emitted by the polarization conversion optical system 6 so as to have substantially the same polarization direction as in the present embodiment, the projection type in which the light valve of the apparatus is a liquid crystal panel The illumination optical system used for the display device can also have high illumination efficiency.
[0078]
<Example 8>
A cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment is shown in FIG. The feature of the present embodiment is that the auxiliary light source unit is composed of a plurality of light sources. Other configurations are substantially the same as those of the embodiment already described. For example, the main light source unit 1 is the same as that of the first embodiment. Further, the first integrator part is constituted by two fly eyes 15 and 16, and the second integrator part is constituted by a rod integrator 36, which is substantially the same as that of the sixth embodiment. The deflection conversion optical system 6 is the same as that shown in FIG. 9 as a modification of the seventh embodiment, except that the λ / 2 phase film is deleted only at the center.
[0079]
The illumination optical system of the present embodiment includes two light sources 31a and 31b having similar spectral distributions as auxiliary light source units. The light beams from these light sources 31a and 31b pass through the collimator lenses 35a and 35b and the deflecting mirror 3 that reflects and synthesizes both light beams, and the light beams enter the light beam dense part near the center of the light beam emitted from the main light source unit 1. It is introduced into this luminous flux so as to compensate. Thereafter, the light beams from the light sources 31a and 31b are incident on the rod integrator 36 as the second integrator section via the lens 37 to make the light quantity distribution uniform, and are incident on the deflection conversion optical system 6 via the lens 38. Is done. The lens 38 is different from the lens of the seventh embodiment, and is a lens different from the lens cell of the first fly's eye 16, and is a space provided in the first fly's eye 16 at a position where the light beam from the auxiliary light source unit passes. The operation is the same as that of the sixth embodiment.
[0080]
In the present embodiment, the deflection conversion optical system 6 uses the one in which the λ / 2 phase film is deleted only in the central portion shown in FIG. Therefore, the light sources 31a and 31b of the auxiliary light source unit emit light beams having the same polarization direction so as to have a polarization direction substantially coincident with the light beam from the main light source unit 1 converted into linearly polarized light by the deflection conversion optical system 6. It is preferable to emit light. In this case, the light beam from the auxiliary light source unit 2 is also emitted from the deflection conversion optical system 6 as an illumination light beam having a polarization direction substantially coincident with the light beam from the main light source unit 1 converted into linearly polarized light. Can be good. However, in a configuration in which the auxiliary light source unit is composed of a plurality of light sources, it is not always necessary to use a light source that emits a light beam with the polarization direction aligned as described above. Also, the configuration of the polarization conversion optical system 6 can be appropriately selected according to the light source characteristics and other configurations.
[0081]
In this embodiment, two light sources are used as the auxiliary light source unit, but it is also possible to use two or more light sources. By providing a plurality of light sources as the auxiliary light source unit, it is possible to increase the amount of light supplemented to the light flux density portion of the main light source unit 1.
[0082]
<Example 9>
FIG. 13 shows a cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment. The present embodiment is different from the eighth embodiment in that the plurality of light sources constituting the auxiliary light source unit are composed of two types of light sources 31a and 31b having different spectral distributions, and is the same as the eighth embodiment in other points.
[0083]
  In this embodiment, since two types of light sources 31a and 31b having different spectral distributions are used, a cross prism is used as a means for combining light beams emitted from these light sources 31a and 31b.8Is arranged. The light flux from the light sources 31a and 31b passes through the collimator lenses 35a and 35b and is a cross prism.8The light is reflected and deflected by the dichroic films 51a and 51b, and is introduced into the light flux so as to supplement the light flux in the light flux density portion near the center of the light flux emitted from the main light source section 1. Thereafter, the light beams from the light sources 31a and 31b are incident on the rod integrator 36 as the second integrator section via the lens 37 to make the light quantity distribution uniform, and are incident on the deflection conversion optical system 6 via the lens 38. Is done.
[0084]
Also in the present embodiment, as in the eighth embodiment, the light sources 31a and 31b of the auxiliary light source section have a polarization direction substantially coincident with the light beam from the main light source section 1 converted into linearly polarized light by the deflection conversion optical system 6. In addition, it is preferable to emit a light beam having a uniform polarization direction. In this case, the light beam from the auxiliary light source unit 2 is also emitted from the deflection conversion optical system 6 as an illumination light beam having a polarization direction substantially coincident with the light beam from the main light source unit 1 converted into linearly polarized light. Can be good. In the configuration in which the auxiliary light source unit is composed of light sources having different spectral distributions, it is not always necessary to use a light source that emits light beams having the same polarization direction as described above, as in the eighth embodiment. Also, the configuration of the polarization conversion optical system 6 can be appropriately selected according to the light source characteristics and other configurations.
[0085]
  In this embodiment, two light sources are used as the auxiliary light source unit, but it is also possible to use two or more light sources. By providing a plurality of light sources as the auxiliary light source unit, it is possible to increase the amount of light supplemented to the light flux density portion of the main light source unit 1. In this embodiment, the cross prism8By combining the light beams of the auxiliary light source unit, the range in which the light beam from the main light source unit 1 is shielded is smaller than in the case where the deflection mirror 3 of the eighth embodiment is arranged.
[0086]
Furthermore, an illumination optical system using at least two types of light sources having different spectral distributions as an auxiliary light source unit is useful when used as an illumination optical system of a color projection display device. For example, two different color lights of the three primary color lights may be combined by emitting one from the light source 31a and the other from the light source 31b, and supplementing the light flux from the main light source unit 1 with a light-dense portion. it can.
[0087]
As described above, Examples 1 to 9 have been described as specific examples of the illumination optical system according to the present invention. In each of the embodiments, since the light beam from the auxiliary light source unit 2 is supplemented to the light beam low-density portion of the light beam emitted from the main light source unit 1, a bright and compact illumination optical system is provided. Since two fly eyes are provided as a part, it is possible to emit an illumination light beam with a uniform light amount distribution.
[0088]
By the way, examples of the light source used in the main light source unit of the illumination optical system according to the present invention include an ultra-high pressure mercury lamp, a metal halide lamp, and a xenon lamp. These light sources each have a specific spectral distribution depending on the type. Therefore, it does not have a uniform light amount distribution in the visible light region. For the projection display device that is the main application of the illumination optical system according to the present invention, an image with good color reproducibility is required in addition to the request for brightness. Variations in the spectral distribution of the light source may be a problem. This is because, depending on the light source, the amount of light in the wavelength range necessary for good color reproducibility is insufficient, or the amount of light in the unnecessary wavelength range is excessive.
[0089]
For example, FIG. 14 is a diagram showing the spectral distribution of wavelengths in the visible region of an ultra-high pressure mercury lamp, and the vertical axis shows the light intensity. As shown in the figure, in this light source, the red wavelength region of the three primary color lights has a smaller amount of light than the wavelength region corresponding to the other color components, while the light source has a light intensity peak in the yellow wavelength region. When light is used, a yellowish color image is formed as a whole. Therefore, conventionally, as a measure for improving the color reproducibility of the apparatus, illumination was performed by removing light in the wavelength region near 580 nm from the light emitted from the light source. It becomes contrary to the demand for improvement.
[0090]
The illumination optical system according to the present invention includes the auxiliary light source unit that emits the light beam so as to supplement the light flux density portion near the center of the light beam emitted from the main light source unit, and is emitted from the main light source unit. A light beam having an intensity peak in a wavelength range desired to be increased in the spectral distribution of the light beam can be emitted from the auxiliary light source unit. For example, when the light emitter of the main light source unit is the ultra-high pressure mercury lamp, the auxiliary light source unit emits a light beam having an intensity peak in the red wavelength region. As a light source of the auxiliary light source unit, for example, an inexpensive and small red semiconductor laser can be used. According to such a configuration, the light intensity in the red wavelength region as a whole of the illumination light beam increases, and the light in the vicinity of 580 nm from the ultra-high pressure mercury lamp, which conventionally had an adverse effect on the color reproducibility, can be used without being excluded. It becomes like this. The amount of light that has been excluded so far corresponds to 20% of the total amount of light from the ultra-high pressure mercury lamp, and the effect of increasing this amount of light is high.
[0091]
By configuring the light source having an intensity peak in the wavelength range to be increased in the spectral distribution of the light beam emitted from the main light source unit to be emitted from the auxiliary light source unit, the amount of light from the auxiliary light source unit only increases. In addition, the luminous flux from the main light source, which has been excluded for color reproducibility, can be captured without degrading the color reproducibility, and a bright illumination system with good color reproducibility can be obtained. Can do. The intensity peak of the light beam emitted from the auxiliary light source unit is not limited to the red wavelength region, and the wavelength region can be set as appropriate according to the spectral distribution of the light source of the main light source unit.
[0092]
The illumination optical system of the present invention is not limited to the one described above, and various modifications can be made. For example, the main light source unit, the auxiliary light source unit, the deflection unit, the first integrator unit, the second integrator unit, the polarization conversion optical system, etc. used in Examples 1 to 9 may be taken out and combined. In each of the above embodiments, similarly to the second embodiment, the deflecting mirror deflects the light beam from the main light source unit, and the light beam low-density part of the light beam from the main light source unit is irradiated on the deflecting mirror. It is possible to change to a configuration in which a portion is formed as a space, and a light beam from the auxiliary light source unit is introduced into the light beam low-density portion through this space.
[0093]
The positions where the light beam from the auxiliary light source unit is introduced into the light beam from the main light source unit are the front and rear stages of the first and second integrator units, and the two fly eyes that constitute the first integrator unit. It may be any, including the middle. In addition, a deflection mirror for introducing the light beam from the auxiliary light source unit into the light beam low-density part of the light beam from the main light source unit is not essential. The configuration in which the auxiliary light source unit is disposed in the light beam low density portion as shown in the fifth embodiment is possible in any case.
[0094]
In addition, the main light source unit may be configured not only to have the arc tube shown in each example but also to have the configuration in which the electrodes shown in FIG. 19 are disposed. In addition, the auxiliary light source unit can use a configuration including a reflector or a laser light source, and can also be a light source with uniform light intensity spectroscopy or a light source with good polarization characteristics. The auxiliary light source unit achieves its intended purpose, such as increasing the amount of light in the illumination optical system, making the light amount distribution uniform, and optimizing the color reproducibility (including when you want to strengthen or weaken the specified color). It is preferable to obtain. Moreover, the shape of each lens arranged in the optical path of the light beam from the lens cell of each fly eye and the main light source unit and the auxiliary light source unit can be set as appropriate.
[0095]
In addition, the illumination optical system according to the present invention has a number of conventionally proposed illumination optical systems simply having a plurality of light sources in order to increase the light amount as a total amount. Is different. A conventional illumination optical system including a plurality of light sources is intended to increase the amount of light as a total amount by disposing a plurality of light source portions having a size corresponding to the main light source portion of the present invention. These do not have the idea of supplementing the light beam from another light source to the light beam low density portion of the light beam emitted from the light source unit including the reflector as in the present invention.
[0096]
In order to solve the above-described problem of color reproducibility of the projection display device, an illumination optical system using a plurality of light source portions having different light emission distributions has already been proposed (see, for example, Japanese Patent Application Laid-Open No. 2001-166383). However, in this case as well, as in the illumination optical system including the plurality of light sources, the light flux from another light source is supplemented to the low-density portion of the light flux emitted from the light source portion including the reflector as in the present invention. It has no idea. According to the illumination optical system according to the present invention, high color reproducibility can be achieved by the illumination optical system that is much more compact than the conventional example.
[0097]
Next, examples 10 and 11 will be described as specific examples of the projection display apparatus according to the present invention.
[0098]
<Example 10>
FIG. 15 shows a schematic configuration of the projection display apparatus according to the present embodiment. This apparatus is an apparatus using the illumination optical system according to the first embodiment as a representative of the illumination optical system according to the present invention. The polarization conversion optical system 6 of the illumination optical system is well known in the past as shown in Example 7 (FIG. 8).
[0099]
This apparatus illuminates a light valve composed of a transmissive image display element that performs light modulation of an illumination light beam based on predetermined image information with an illumination light beam from an illumination optical system, and carries image information from the light valve. The light beam is projected through the projection optical system 67. The illumination light beam is emitted from the illumination optical system of the present invention in a state where the light quantity distribution is made uniform by the first and second integrator sections 4 and 5 and the polarization direction is made uniform by the polarization conversion optical system 6. Then, as shown below, the illumination light beam is decomposed into three primary color lights, light-modulated by the liquid crystal panels 64a to 64c which are transmissive image display elements for the respective color lights, and after the projection light beams are synthesized, The projection optical system 67 projects and forms a full color image on a screen (not shown). The first to third color light components shown below can correspond to the three primary color lights of blue, green and red in any order.
[0100]
That is, the illumination light beam emitted from the illumination optical system is subjected to color light decomposition by the dichroic mirrors 62a and 62b, and irradiated to the liquid crystal panels 64a to 64c on which images for the first to third color light components are displayed, respectively. The dichroic mirror 62a separates the illumination light beam into the first color light component light beam and the combined light beam of the second and third color light components, and the dichroic mirror 62b combines the second and third color light components separated by the dichroic mirror 62a. The light beam is separated into a second color light component and a third color light component. On the optical path of the illumination light beam, total reflection mirrors 63a to 63d for deflection and condensing lenses 61a to 61f are arranged, and emitted from the fly eye of the first integrator unit 4 on the liquid crystal panels 64a to 64c. Each of the partial light fluxes and the light flux from the auxiliary light source unit 2 emitted from the second integrator unit 5 are superimposed. The first to third color light component light beams, which are projection light beams that are transmitted through the liquid crystal panels 64a to 64c and are light-modulated based on predetermined image information, are internally reflected by the dichroic film 65a and the third color light components that reflect the first color light component. It is synthesized by a cross prism 66 having a dichroic film 65b that reflects color light components.
[0101]
According to the present embodiment, by including the illumination optical system according to the present invention, it is possible to obtain a projection display apparatus that is compact and can perform bright and uniform illumination with high illumination efficiency.
[0102]
Further, as described above, the illumination optical system according to the present invention emits a light beam having an intensity peak in the wavelength region to be increased in the spectral distribution of the light beam emitted from the main light source unit 1 from the auxiliary light source unit 2. Can be configured. For example, in this case, when the light beam from the auxiliary light source unit 2 is not white light but the light intensity is biased to a specific wavelength region, the light beam from the auxiliary light source unit 2 color-decomposes the illumination light beam to each color An apparatus configured to perform color composition after image information is carried by each light valve for each light may be configured to illuminate only some of the light valves. For example, when the main light source unit 1 emits white light and the light source of the auxiliary light source unit 2 is a red semiconductor laser, the light from the auxiliary light source unit 2 is configured to illuminate only the red component light valve. May be.
[0103]
<Reference example 2>
  BookreferenceFIG. 16 shows a schematic configuration of a projection display apparatus according to an example. This apparatus illuminates a light valve composed of a reflective image display element that performs light modulation of an illumination light beam based on predetermined image information with an illumination light beam from an illumination optical system, and carries image information from the light valve. The light beam is projected through the projection optical system 88. This deviceOnRecordReference example 1It is set as the apparatus using the illumination optical system concerning.
[0104]
  The illumination light flux is in a state where the light quantity distribution is made uniform by the first integrator unit 4 and the polarization direction is aligned by the polarization conversion optical system 6.Reference example 1 aboveFrom the illumination optical system. Then, this illumination light beam is incident on a color quad 89 through condensing lenses 81a and 81b and a total reflection mirror 82 for deflection as shown below, and is split into three primary color lights in this color quad 89, and each color light Light is modulated by reflection type liquid crystal panels (hereinafter referred to as LCOS) 85a to 85c, which are image display elements for use, and these projected light beams are synthesized and then emitted from the color quad 89 and projected by the projection optical system 88. Thus, a full color image is formed on a screen (not shown). The first to third color light components shown below can correspond to the three primary color lights of blue, green and red in any order.
[0105]
The color quad 89 has first to fourth LCOSs 85a to 85c corresponding to the first to fourth PBSs 83a to 83d and the first to third color light components arranged so that the polarization separation films 84a to 84d therein are X-shaped. , First to fourth specific wavelength polarization conversion elements 86a to 86d, and first to second polarizing plates 87a and 87b. The polarizing plate 87a is arranged to align the polarization direction of the incident illumination light beam (in the following description, this polarization direction is S-polarized light), and the polarizing plate 87b is arranged to align the polarization direction of the projected light beam to P-polarized light, To improve the contrast of projected images. The specific wavelength polarization conversion elements 86a to 86d are elements that rotate predetermined color light by a predetermined angle and convert S-polarized light into P-polarized light. The specific wavelength polarization conversion elements 86a and 86d convert the first color light from S polarization to P polarization, and the specific wavelength polarization conversion elements 86b and 86c convert the third color light from S polarization to P polarization.
[0106]
By these actions, the first color light is transmitted through the PBSs 83a and 83b to irradiate the LCOS 85a that modulates the first color light, and the second color light is reflected inside each of the PBSs 83a and 83c to be the second color light. The third color light is reflected inside the PBS 83a, passes through the PBS 83c, and is irradiated with the LCOS 85c that modulates the third color light. The first color light is reflected after the projection light beam corresponding to the ON state of the first LCOS 85a is converted into S-polarized light and reflected inside the PBS 83b and 83d, and the second color light corresponds to the ON state of the second LCOS 85b. The projected luminous flux is converted to P-polarized light and reflected, passes through the PBSs 83c and 83d, and the third color light is reflected and converted to S-polarized light corresponding to ON of the third LCOS 85c, and reflected inside the PBS 83c. Then, the three color light components are combined and emitted from the color quad 89 through the PBS 83d.
[0107]
  BookreferenceAccording to the exampleReference example 1 aboveBy providing the illumination optical system according to the above, it is possible to obtain a projection display device that is compact and can perform bright and uniform illumination with high illumination efficiency. In addition, as in Example 10, thisreferenceAlso in the example, when the light beam from the auxiliary light source unit 2 is not white light but the light intensity is biased to a specific wavelength range, the light beam from the auxiliary light source unit 2 color-separates the illumination light beam for each color light. An apparatus configured to perform color composition after image information is carried by each light valve may be configured to illuminate only some of the light valves.
[0108]
The projection display device of the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, as the projection display device of the present invention, the illumination optical system of the present invention can be arbitrarily used. The apparatus configuration at the subsequent stage is not limited depending on whether the second integrator unit is a fly eye, a rod integrator, or not provided. However, these combinations are arbitrary, but consistency as the whole apparatus is necessary.
[0109]
In the projection display device of the present invention, the light valve is not limited to that of the embodiment. For example, an apparatus configuration using a digital micromirror device as a light valve may be employed. Also in this case, by providing the illumination optical system according to the present invention, it is possible to obtain a projection display device that is compact and can perform bright and uniform illumination with high illumination efficiency.
[0110]
The projection display device of the present invention is not necessarily limited to a color image display device, and may be a monochrome image display device.
[0111]
【The invention's effect】
As described above, according to the illumination optical system and the projection display apparatus using the illumination optical system according to the present invention, the light beam emitted from the main light source unit composed of the light source and the reflector, The auxiliary light source unit that emits the light beam so as to supplement the light beam is provided, and the first integrator unit having two fly eyes is provided, so that the illumination efficiency is high and the illumination is bright and uniform. An illumination optical system to be obtained and a projection display device using the illumination optical system can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an illumination optical system according to Embodiment 1 of the present invention.
FIG. 2 is a schematic configuration diagram of an illumination optical system according to a second embodiment of the present invention.
FIG. 3 of the present inventionReference example 1Schematic configuration diagram of illumination optical system according to
FIG. 4 is a schematic configuration diagram of an illumination optical system according to Example 4 of the present invention.
FIG. 5 is a schematic configuration diagram of an illumination optical system according to a fifth embodiment of the present invention.
6 is a schematic configuration diagram of the first and second polarization conversion optical systems in FIG. 5;
FIG. 7 is a schematic configuration diagram of an illumination optical system according to Example 6 of the present invention.
FIG. 8 is a schematic configuration diagram of an illumination optical system according to Example 7 of the present invention.
9 is a schematic configuration diagram of a first modification of the polarization conversion optical system in FIG. 8;
10 is a schematic configuration diagram of a second modification of the polarization conversion optical system in FIG. 8. FIG.
11 is a schematic configuration diagram of a third modification of the polarization conversion optical system in FIG. 8;
FIG. 12 is a schematic configuration diagram of an illumination optical system according to Example 8 of the present invention.
FIG. 13 is a schematic configuration diagram of an illumination optical system according to Example 9 of the present invention.
FIG. 14 is a spectral distribution diagram of wavelengths in the visible region of an ultra-high pressure mercury lamp.
FIG. 15 is a schematic configuration diagram of an illumination optical system according to Example 10 of the present invention.
FIG. 16 shows the present invention.Reference example 2Schematic configuration diagram of illumination optical system according to
FIG. 17 is a schematic configuration diagram of a first conventional light source unit including a reflector.
FIG. 18 is a schematic configuration diagram of a second conventional light source unit including a reflector.
FIG. 19 is a schematic configuration diagram of a third conventional light source unit including a reflector.
[Explanation of symbols]
  1 Main light source
  2 Auxiliary light source
  3 Deflection mirror
  4 First integrator section
  5 Second integrator section
  6 Polarization conversion optical system
  7    Second polarization conversion optical system
  8, 66 Cross prism
11, 33 Light source
12, 34, 104 Parabolic reflector
15 Second Fly Eye
16 First fly eye
17, 18, 48, 49 Lens cell
19, 43, 84 Polarization separation membrane
20, 44 Reflective film
21, 45 λ / 2 phase film
22, 25, 46 Prism surface
26 Birefringence diffractive polarization separator
31, 32 Semiconductor laser
35 Collimator lens
36 Rod Integrator
37, 38, 61, 81 Condensing lens
41 Second fly eye corresponding to the auxiliary light source
42 First fly eye corresponding to the auxiliary light source
51, 65 Dichroic membrane
62 Dichroic Mirror
63, 82 Total reflection mirror
64 transmissive LCD panel
67, 88 Projection optical system
83 PBS
85 Reflective liquid crystal panel (LCOS)
86 Specific wavelength polarization conversion element
87 Polarizing plate
89 Color Quad
101 arc tube
102 cathode
103 anode
105 Ellipsoidal reflector
106 Transparent member
107 Rod holding member

Claims (8)

A main light source unit including a light emitter and a reflector that reflects the light emitted from the light emitter toward the illuminated body, and a light flux density portion near the center of the light beam emitted from the main light source unit so as to supplement the light flux An auxiliary light source unit that emits a light beam, and a first integrator unit having two fly-eyes for achieving uniform light quantity of the light beam from the main light source unit is provided ,
The light beam emitted from the auxiliary light source unit is introduced into the light beam low-density part before the fly eye on the main light source unit side or between the two fly eyes,
An illumination optical system characterized in that a second integrator unit different from the first integrator unit is provided in the light beam low-density unit for uniformizing the amount of light beam from the introduced auxiliary light source unit. . At least one of the two fly eyes of the first integrator unit includes a lens for condensing or diverging the light beam from the auxiliary light source unit in the vicinity of the optical axis through which the light beam from the auxiliary light source unit passes. claim 1 Symbol placement illumination optical system characterized by comprising. The second integrator unit, according to claim 1 or 2 illumination optical system according to, characterized in that formed by perforated two fly-eye. At least one fly eye of the two fly eyes of the second integrator section is formed on the same member as at least one fly eye of the two fly eyes of the first integrator section. The illumination optical system according to claim 3 . The second integrator unit, according to claim 1 or 2 Symbol placement illumination optical system, characterized in that it is made by have a rod integrator. The light emitter of the main light source unit generates a randomly polarized light beam, which is converted into linearly polarized light by a polarization conversion optical system to illuminate the illuminated body, and the auxiliary light source unit is the polarization conversion A light beam having a polarization direction that is substantially the same as the light beam from the main light source unit converted into linearly polarized light by the optical system is emitted, and the light beam from the auxiliary light source unit is subjected to polarization conversion. The illumination optical system according to any one of claims 1 to 5 , wherein the illumination object is illuminated. The luminous body of the main light source unit generates a randomly polarized light beam, which is converted into linearly polarized light by a first polarization conversion optical system to illuminate the illuminated body, and the light emission of the auxiliary light source unit The body generates a randomly polarized light beam, and the light beam has a polarization direction substantially coincident with the light beam from the main light source unit converted into linearly polarized light by the first polarization conversion optical system by the second polarization conversion optical system. such illumination optical system of any one of claims 1-5, characterized in that it is converted into linearly polarized light to illuminate the object to be illuminated. An illumination optical system according to any one of claims 1 to 7 , wherein at least one light valve that performs light modulation of the illumination light beam based on predetermined image information is illuminated by the light beam from the illumination optical system. A projection display device that projects a light beam carrying image information from the light valve through a projection optical system.

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