JP2009210779A - Optical device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device capable of reducing influences of heat of a polarizing element on an optical modulation device. <P>SOLUTION: A optical device body 45A includes: an optical modulation device 451G; an exit side polarizing plate 453G; a cross dichroic prism 454; a first support member 455; a second support member 457; two spacers 458; and a planar member 459. The first support member 455 and the second support member 457 support the optical modulation device 451G. Each spacer 458 supports the exit side polarizing plate 453G. The second support member 457 and each spacer 458 are fixed via the planar member 459 to an end face 454A in an incident side of the cross dichroic prism 454 and are not in contact with each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical device and a projector.

Conventionally, three liquid crystal panels (light modulation devices) that modulate a plurality of color lights according to image information for each color light, and a cross dichroic prism (color) that combines the light modulated by each liquid crystal panel to form image light 2. Description of the Related Art An optical device including a combining optical device) and a projector including the optical device are known.
In such an optical apparatus, a liquid crystal panel is integrally assembled with a cross dichroic prism to improve assemblability (see, for example, Patent Document 1).
In the optical device described in Patent Document 1, a polarizing plate (polarizing element) that is disposed between a cross dichroic prism and a liquid crystal panel and transmits only light having a predetermined polarization direction among light modulated by the liquid crystal panel. ) And a holding member for fixing the liquid crystal panel to the light incident side end face of the cross dichroic prism.

JP 2003-121931 A

However, according to such a configuration, since the liquid crystal panel, the cross dichroic prism, and the polarizing plate are integrated by the holding member, the heat of the polarizing plate is transmitted to the liquid crystal panel through the holding member, and the temperature of the liquid crystal panel is increased. There are problems such as exceeding the operating temperature range.
In particular, when an inorganic polarizing plate is used as a polarizing plate, it has higher heat resistance than an organic polarizing plate and can be used even at high temperatures. However, since the amount of heat generation is large, the heat of the polarizing plate gives to the liquid crystal panel. The impact is significant.

  An object of the present invention is to provide an optical device and a projector that can reduce the influence of heat of a polarizing element on a light modulation device.

  The optical device according to the present invention includes a plurality of light modulation devices that modulate a plurality of color lights according to image information for each color light, and a plurality of light incident side end faces facing the light modulation devices. A color synthesizing optical device that synthesizes the light modulated by the color synthesizing device to form image light, the light modulating device, and the color synthesizing optical device, and the light modulated by the light modulating device. An optical device including a polarization element that transmits only light having a predetermined polarization direction, a support member for a light modulation device that supports the light modulation device, and a support member for a polarization element that supports the polarization element; The light modulation device support member and the polarizing element support member are respectively fixed to the light incident side end face and are not in contact with each other.

  According to such a configuration, the support member for the light modulation device that supports the light modulation device and the support member for the polarization element that supports the polarization element are independent members, and each support member is a light of the color synthesis optical device. Each is fixed to the incident side end face. Further, since each support member is not in contact, the heat of the polarizing element is transmitted from the polarizing element support member to the light modulation device via the color synthesizing optical device and the light modulation device support member. Therefore, the influence of the heat of the polarizing element on the light modulation device can be reduced. Therefore, the lifetime of the optical device can be extended.

  In the present invention, it is preferable that a heat shield plate that blocks heat transfer from the polarizing element is disposed between the light modulation device and the polarizing element.

Here, as described above, the heat of the polarizing element is transmitted to the light modulation device via each support member and the color synthesizing optical device, as well as the radiant heat of the polarizing element and the air between the polarizing element and the light modulation device. It is also transmitted by convection.
However, according to the present invention, since the heat shield plate is disposed between the light modulation device and the polarizing element, heat transfer from the polarizing element can be blocked, and light modulation of the heat of the polarizing element can be achieved. The influence on the apparatus can be further reduced.

  In the present invention, the light modulation device support member is disposed on the light modulation device side, and is disposed on the color synthesis optical device side, the first support member that supports the light modulation device, and the heat shielding member. It is preferable that the second support member that supports the plate is combined.

Here, the heat shield plate generates heat by blocking heat transfer from the polarizing element.
According to the present invention, since the first support member that supports the light modulation device and the second support member that supports the heat shield plate are independent members, the light modulation device and the heat shield plate are formed by one member. As compared with the case of supporting the heat shield, the influence of the heat of the heat shield plate on the light modulation device can be reduced.

In the present invention, it is preferable that the heat shield plate has a smaller thermal conductivity than the second support member.
According to such a configuration, it is difficult for heat to be transferred from the heat shield plate to the second support member, and therefore the influence of the heat of the heat shield plate on the light modulation device can be further reduced.

In the present invention, it is preferable that the heat shield plate is provided with an antireflection film on at least one of the light modulation device side and the polarizing element side.
According to such a configuration, since the light transmittance in the heat shield plate can be improved by the antireflection film, the heat shield plate is optically disposed by being disposed between the light modulation device and the polarizing element. The influence can be reduced.

  In this invention, it is preferable to provide the plate-shaped member interposed between the said support member for light modulation devices, the said support member for polarizing elements, and the said light-incidence side end surface.

Here, when the support member for the light modulation device and the support member for the polarization element are directly fixed to the light incident side end surface, the heat of the polarization element is transmitted to the color synthesis optical device through the support member for the polarization element, for example, the light modulation There is a problem that the adhesive for fixing the support member for a device, the support member for a polarizing element, and the color synthesis optical device is peeled off, and a pixel shift occurs in image light.
However, according to the present invention, the support member for the light modulation device and the support member for the polarizing element are fixed to the light incident side end face via the plate-like member, so that the heat of the polarizing element to the color synthesizing optical device can be obtained. The influence can be reduced.

A projector according to the present invention includes a light source device, the above-described optical device, and a projection optical device that magnifies and projects image light formed by the optical device.
In the present invention, since the projector includes the optical device described above, the projector can enjoy the same operations and effects as the optical device described above.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a schematic diagram illustrating a schematic configuration of the projector 1.
The projector 1 modulates light emitted from a light source according to image information to form a color image (image light), and enlarges and projects this color image on a projection surface (not shown) such as a screen. As shown in FIG. 1, the projector 1 includes a substantially rectangular parallelepiped outer casing 2, a projection lens 3, an optical unit 4, and the like.
The projection lens 3 as a projection optical device is configured as a combined lens in which a plurality of lenses are combined, and enlarges and projects a color image formed by an optical unit 4 described later on a projection surface such as a screen.

  Although not specifically shown in FIG. 1, a space other than the projection lens 3 and the optical unit 4 in the exterior housing 2 is provided with a cooling fan or the like for cooling each component in the projector 1. A cooling unit, a power supply unit that supplies power to each component in the projector 1, a control unit that controls each component in the projector 1, and the like are disposed.

The optical unit 4 is a unit that forms a color image corresponding to image information by optically processing the light emitted from the light source under the control of the control unit described above. The optical unit 4 includes a light source device 41, an illumination optical device 42, a color separation optical device 43, a relay optical device 44, an optical device 45, and illumination light in which these optical components 41 to 45 are set inside. And an optical component casing 46 disposed at a predetermined position with respect to the axis A.
The light source device 41 includes a light source lamp 411 that emits light and a reflector 412 that aligns the emission direction of the light emitted from the light source lamp 411. Then, the light whose emission direction is aligned by the reflector 412 is emitted toward the illumination optical device 42.

  The illumination optical device 42 includes a first lens array 421, a second lens array 422, a polarization conversion element 423, and a superimposing lens 424. The light emitted from the light source device 41 is divided into a plurality of partial lights by the first lens array 421 and forms an image in the vicinity of the second lens array 422. Each partial light emitted from the second lens array 422 is incident so that its central axis (principal ray) is perpendicular to the incident surface of the polarization conversion element 423, and approximately one type of linearly polarized light is incident on the polarization conversion element 423. As injected. A plurality of partial lights emitted from the polarization conversion element 423 as linearly polarized light and passed through the superimposing lens 424 are superposed on three light modulation devices 451 described later of the optical device 45.

The color separation optical device 43 includes two dichroic mirrors 431 and 432, and a reflection mirror 433, and has a function of separating a plurality of partial lights emitted from the illumination optical device 42 into three color lights of red, green, and blue. Have.
The relay optical device 44 includes an incident side lens 441, a relay lens 443, and reflection mirrors 442 and 444, and color light separated by the color separation optical device 43, for example, red light, which will be described later on the optical device 45. It has a function of leading to the light modulation device 451R.

  The optical device 45 modulates incident light according to image information to form a color image. This optical device 45 includes three light modulation devices 451 (red light side light modulation device 451R, green light side light modulation device 451G, blue light side light modulation device 451B), and each light modulation An incident-side polarizing plate 452 disposed on the upstream side of the optical path of the device 451, an emission-side polarizing plate 453 disposed on the downstream side of the optical path of each light modulation device 451, and a cross dichroic prism 454 as a color combining optical device. . Of these members 451 to 454, each light modulation device 451, each exit-side polarizing plate 453, and cross dichroic prism 454 are integrated to form an optical device body 45A (see FIG. 2). The specific configuration of the optical device main body 45A will be described later.

Each incident-side polarizing plate 452 transmits only light having a polarization direction substantially the same as the polarization direction aligned by the polarization conversion element 423 and absorbs other light. A polarizing film is formed on the translucent substrate. It is affixed and configured.
Each light modulation device 451 has a configuration in which a liquid crystal as an electro-optical material is hermetically sealed between a pair of transparent glass substrates, and is incident by controlling the alignment state of the liquid crystal by a drive signal from the control unit described above. The polarization direction of the light emitted from the side polarizing plate 452 is modulated.
Each exit side polarizing plate 453 as a polarizing element has substantially the same function as the incident side polarizing plate 452, and transmits light having a certain polarization direction among the light modulated by the light modulation device 451. Absorbs other light.

Here, in the present embodiment, since the light source lamp 411 having a spectrum peak in the wavelength range of green light is adopted, the exit side polarizing plate 453G disposed on the downstream side of the optical path of the light modulation device 451G has heat resistance. Adopting a high light absorption type wire grid polarizing plate (inorganic polarizing plate), the exit side polarizing plates 453R and 453B arranged on the rear side of the optical path of the light modulators 451R and 451B are substantially the same as the respective incident side polarizing plates 452. An organic polarizing plate having a configuration is employed.
However, although the inorganic polarizing plate can be used at a higher temperature than the organic polarizing plate, the calorific value is large. Therefore, the light modulation device 451G and the emission-side polarizing plate 453G are connected to the light incident side end surface of the cross dichroic prism 454. The present invention is applied when fixing to 454A (see FIG. 2).

  The cross dichroic prism 454 combines the color lights emitted from the emission-side polarizing plates 453 to form a color image. The cross dichroic prism 454 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and two dielectric multilayer films are formed at the interface where the right-angle prisms are bonded together. These dielectric multilayer films transmit the color light emitted from the light modulation device 451G and pass through the emission side polarizing plate 453, and reflect each color light emitted from the light modulation devices 451R and 451B and passing through the emission side polarizing plate 453. . In this way, the color lights are combined to form a color image. The color image formed by the cross dichroic prism 454 is enlarged and projected by the projection lens 3 described above.

[Configuration of optical device body]
FIG. 2 is an exploded perspective view showing a schematic configuration of the optical device main body 45A. In FIG. 2, the light modulation device 451G and the emission side polarizing plate 453G fixed to the light incident side end surface 454A of the cross dichroic prism 454 are disassembled by applying the present invention, and the light modulation devices 451R and 451B are illustrated. Is omitted.
The optical device main body 45A includes, as shown in FIG. 2, a first support member 455 that constitutes a support member for the light modulation device, in addition to the light modulation devices 451, the exit-side polarizing plates 453, and the cross dichroic prism 454 described above. And the second support member 457, the heat shield plate 456, the two spacers 458, the plate-like member 459, and the support structure 460, and the members 451, 453 to 460 are integrated. .
Here, the exit-side polarizing plates 453R and 453B are respectively fixed to the end surfaces of the light incident side of the cross dichroic prism 454 by an adhesive or the like.

The first support member 455 is a metal member that supports the light modulation device 451G, and is formed in a rectangular frame shape having an opening 455A for allowing light modulated by the light modulation device 451G to pass through at a substantially central portion. ing. The light modulation device 451G is fixed to the surface of the first support member 455 opposite to the cross dichroic prism 454 with an adhesive, a screw, or the like.
The first support member 455 is formed with substantially rectangular insertion holes 4551 at four corner positions for inserting four pins 4574 described later of the second support member 457. Further, the first support member 455 is formed with protrusions 4552 that protrude toward the cross dichroic prism 454 at positions near the four corners of the opening 455A. The protruding amount of each protruding portion 4552 is set to be larger than the thickness of the heat shield plate 456 in the direction of the illumination optical axis A (see FIG. 1).

  The heat shielding plate 456 is a substantially rectangular plate-shaped glass member, and is disposed between the light modulation device 451G and the emission side polarizing plate 453G, and blocks heat transfer from the emission side polarizing plate 453G. That is, the heat shield plate 456 shields the radiant heat of the emission side polarizing plate 453G, and also reduces heat transfer to the light modulation device 451G due to convection of air around the emission side polarizing plate 453G. In addition, an antireflection film is provided on both surfaces of the heat shield plate 456. Note that the thermal conductivity of the heat shield plate 456 is smaller than the thermal conductivity of the second support member 457.

  The second support member 457 is a metal member that supports the heat shield plate 456, and is formed in a rectangular frame shape having an opening 457A for allowing the light modulated by the light modulation device 451G to pass through in a substantially central portion. ing. The second support member 457 includes a support portion 4571 located on the left and right sides in FIG. 2 in the opening 457A, a contact portion 4572 located on the upper and lower sides in each support portion 4571, and a fixed portion located on the upper and lower sides in the opening 457A. 4573 and pins 4574 protruding from both ends of each fixing portion 4573 in the left-right direction toward the light modulation device 451G side.

Each support portion 4571 is a portion having a support surface 4571A for supporting the heat shield plate 456, and the heat shield plate 456 is fixed to the support surface 4571A with an adhesive or the like. In addition, the length in the up-down direction of each support part 4571 is set longer than the length in the up-down direction of the exit side polarizing plate 453G.
Each contact portion 4572 is formed at a position facing the protrusion portion 4552 of the first support member 455, and is a portion that contacts the protrusion portion 4552 in a state where the first support member 455 and the second support member 457 are combined. is there.

  Each fixing portion 4573 is a portion having a fixing surface 4573A fixed to the plate-like member 459 with an adhesive or the like, and protrudes toward the cross dichroic prism 454 side with respect to each support portion 4571 and each contact portion 4572. It is formed at the position. Note that the protruding amount of each fixed portion 4573 from each support portion 4571 is set to be larger than the total thickness of the exit-side polarizing plate 453G and the spacer 458 in the direction of the illumination optical axis A.

Each pin 4574 is a portion that is formed at a position corresponding to the insertion hole 4551 of the first support member 455 and is inserted through each insertion hole 4551 when the first support member 455 and the second support member 457 are combined. . That is, the first support member 455 and the second support member 457 are combined by inserting each pin 4574 through the insertion hole 4551 and fixing it with an adhesive or the like.
Here, as described above, the protrusion amount of each protrusion portion 4552 of the first support member 455 is set to be larger than the thickness of the heat shield plate 456 in the direction of the illumination optical axis A. Therefore, the first support member 455, and In the state where the second support member 457 is combined, the first support member 455 and the heat shield plate 456 are not in contact with each other.

  Each spacer 458 as a polarizing element support member is a resin member that is formed in a rectangular column shape with a rectangular cross section and supports the exit-side polarizing plate 453G. The exit-side polarizing plate 453G is fixed to the surface of each spacer 458 on the second support member 457 side with an adhesive or the like. The vertical length of each spacer 458 is set to be shorter than the vertical length of the exit-side polarizing plate 453G.

  The plate-like member 459 is a rectangular plate-like member interposed between the second support member 457 and each spacer 458 and the light incident side end face 454A. The second support member 457 and each spacer 458 The plate-like member 459 is fixed to the surface of the light modulation device 451G side by an adhesive or the like. The surface of the plate-like member 459 on the cross dichroic prism 454 side is fixed to the light incident side end surface 454A with an adhesive or the like.

  Here, as described above, the length in the vertical direction of each support portion 4571 of the second support member 457 is set longer than the length in the vertical direction of the exit-side polarizing plate 453G, and the protrusion amount of each fixing portion 4573 is as follows. Since it is set to be larger than the total thickness of the exit-side polarizing plate 453G and the spacer 458 in the illumination optical axis A direction, the second support member 457 and each spacer 458 are fixed to the plate-like member 459. The second support member 457, the exit-side polarizing plate 453G, and the spacers 458 are not in contact with each other.

The support structure 460 is a member that is attached to an upper surface that is an end surface that intersects each light beam incident side end surface of the cross dichroic prism 454 and supports the entire optical device main body 45A.
The support structure 460 is formed with arm portions 4601 that extend outward from the four corner portions and connect to the optical component casing 46. Then, by connecting the arm portion 4601 to the optical component casing 46, the entire optical device main body 45 </ b> A is fixed to the optical component casing 46.

According to the present embodiment as described above, the following effects are obtained.
(1) In the optical device main body 45A, the first support member 455 and the second support member 457 that support the light modulation device 451G, and the spacers 458 that support the emission-side polarizing plate 453G are independent members. The members 455, 457, and 458 are fixed to the light incident side end surface 454A of the cross dichroic prism 454, respectively. Further, since the support members 455, 457, and 458 are not in contact with each other, the heat of the exit-side polarizing plate 453G is transferred from the spacers 458 to the plate-like member 459, the second support member 457, and the first support member 455. Therefore, the influence of the heat of the exit side polarizing plate 453G on the light modulation device 451G can be reduced. Therefore, the lifetime of the optical device can be extended.

(2) In the optical device main body 45A, the heat-shielding plate 456 that shields the radiant heat of the exit-side polarizing plate 453G is disposed between the light modulation device 451G and the exit-side polarizing plate 453G. The radiant heat of the plate 453G can be shielded. Further, by disposing the heat shield plate 456, it is possible to reduce heat transfer to the light modulation device 451G due to convection of air around the emission side polarizing plate 453G. Therefore, it is possible to further reduce the influence of the heat of the emission side polarizing plate 453G on the light modulation device 451G.
(3) In the optical device main body 45A, the first support member 455 that supports the light modulation device 451G and the second support member 457 that supports the heat shield plate 456 are independent members. The influence of heat on the light modulation device 451G can be reduced.
(4) In the optical device main body 45 </ b> A, the heat shield plate 456 has a smaller thermal conductivity than the second support member 457, so that heat is not easily transmitted from the heat shield plate 456 to the second support member 457. Thus, the influence of the heat of the heat shield plate 456 on the light modulation device 451G can be further reduced.

(5) In the optical device main body 45A, since the antireflection films are provided on both surfaces of the heat shield plate 456, the light transmittance in the heat shield plate 456 can be improved. The optical influence by disposing between 451G and the exit-side polarizing plate 453G can be reduced. Moreover, since the antireflection film is provided on both surfaces of the heat shield plate 456, a higher effect can be obtained as compared with the case where it is applied on one surface.
(6) In the optical device main body 45A, the second support member 457 and the spacers 458 are fixed to the light incident side end face 454A via the plate-like member 459, so that the thermal cross dichroic prism of the exit side polarizing plate 453G The influence on 454 can be reduced.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the antireflection film is applied to both surfaces of the heat shield plate 456. However, the antireflection film may be applied to only one surface, or the antireflection film may not be applied to any surface. .
In the above-described embodiment, the heat shield plate 456 is made of glass having a lower thermal conductivity than the metal second support member 457, but may be made of other materials. In short, the polarizing element It is only necessary that the radiant heat can be shielded.
In the above embodiment, the heat shield plate 456 is disposed between the light modulation device 451G and the emission-side polarizing plate 453G. However, the heat shield plate may not be disposed.

In the embodiment, the support member for the light modulation device is configured by combining the first support member 455 and the second support member 457, but may be configured by one member. In short, the support member for the light modulation device may be a member that is fixed to the light incident side end face of the color synthesis optical device and supports the light modulation device.
In the embodiment, the second support member 457 and the spacers 458 are fixed to the light incident side end face 454A via the plate-like member 459. However, the light modulation device can be provided without interposing the plate-like member 459. The support member for polarization and the support member for polarizing element may be directly fixed to the light incident side end face.

In the above embodiment, the first support member 455 and the second support member 457 made of metal and the spacers 458 made of resin are used. However, the material of the support member for the light modulation device and the support member for the polarizing element is used. May be other materials.
In the embodiment, the present invention is applied when the light modulation device 451G and the emission side polarization plate 453G among the light modulation devices 451 and the emission side polarization plates 453 are fixed to the light incident side end surface 454A. However, the present invention may be applied when fixing each of the other light modulation devices 451R and 451B and each of the exit side polarizing plates 453R and 453B to the light incident side end face.

In the embodiment, the optical device main body 45A includes the three light modulation devices 451. However, the optical device main body 45A may be configured as an optical device including two light modulation devices or an optical device including four or more light modulation devices. .
In the above embodiment, the projector 1 including the optical device main body 45A has been exemplified. However, for example, the optical device of the present invention may be applied to other optical devices such as a rear projector.

  INDUSTRIAL APPLICABILITY The present invention can be used for an optical device, and in particular, can be suitably used for an optical device including a polarizing element that generates a large amount of heat.

1 is a schematic diagram showing a schematic configuration of a projector according to an embodiment of the invention. The disassembled perspective view which shows schematic structure of the optical apparatus main body in the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 3 ... Projection lens (projection optical apparatus), 41 ... Light source device, 45 ... Optical apparatus, 45A ... Optical apparatus main body, 451 ... Light modulation apparatus, 453 ... Ejection side polarizing plate (polarization element), 454 ... Cross Dichroic prism (color synthesizing optical device), 454A ... light incident side end surface, 455 ... first support member (support member for light modulator), 456 ... heat shield plate, 457 ... second support member (support member for light modulator) ) 458 spacer (polarizing element support member), 459 plate member.

Claims (7)

A plurality of light modulation devices that modulate a plurality of color lights according to image information for each color light, and a plurality of light incident side end faces facing the light modulation devices, light modulated by the light modulation devices A color combining optical device that combines and forms image light, the light modulating device, and the color combining optical device, and has a predetermined polarization direction among the light modulated by the light modulating device. An optical device comprising a polarizing element that transmits only light,
A light modulation device support member for supporting the light modulation device;
A polarizing element support member for supporting the polarizing element,
The optical device, wherein the light modulation device support member and the polarizing element support member are fixed to the light incident side end surface and are not in contact with each other. The optical device according to claim 1.
An optical device, wherein a heat shield plate that blocks heat transfer from the polarizing element is disposed between the light modulation device and the polarizing element. The optical device according to claim 2.
The support member for the light modulator is
A first support member disposed on the light modulation device side and supporting the light modulation device;
An optical apparatus comprising a second support member disposed on the color synthesis optical apparatus side and supporting the heat shield. The optical device according to claim 3.
The optical apparatus, wherein the heat shield plate has a smaller thermal conductivity than the second support member. The optical device according to any one of claims 2 to 4,
An optical device, wherein the heat shield plate is provided with an antireflection film on at least one of the light modulation device side and the polarizing element side. The optical device according to any one of claims 1 to 5,
An optical device comprising: a plate-like member disposed between the light modulation device support member, the polarizing element support member, and the light incident side end surface.   A projector comprising: a light source device; the optical device according to any one of claims 1 to 6; and a projection optical device that enlarges and projects image light formed by the optical device.

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