JP2010256494A - Lighting device and projection type image display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact lighting device which guides nearly parallel light beams from a pair of light source parts arranged to face each other, to an object to be irradiated, and also aligns optical axes of both light source parts with each other, and to provide a projection type image display apparatus including the same. <P>SOLUTION: The pair of light source parts 2 and 3 is arranged so as to be face each other with their optical axes 2a and 3a aligned with each other, and an optical path changing member 4 is provided between them. The optical path changing member 4 is constituted so as to guide the nearly parallel light beams from the light source parts 2 and 3 to a whole irradiation surface 8 installed in a predetermined direction. An S-polarization wire grid polarizing plate 5 is attached to be inclined at 45 degrees to the optical axis 2a on an emitting side of the light source part 2, and a P-polarization wire grid polarizing plate 6 is attached to be inclined at 45 degrees to the optical axis 3a on an emitting side of the other light source part 3. A reflection part 7 including a 1/4 wavelength plate 7b is attached to a side of the optical path changing member 4 facing the irradiation surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination device using a plurality of light source lamps and a projection display apparatus using the illumination device.

  2. Description of the Related Art Conventionally, as a large screen display device, there is known a projection type video display device that irradiates a liquid crystal panel with powerful light from an illumination device and enlarges and projects an image displayed on the liquid crystal panel on a screen. In recent years, there are cases where projection is performed on a large screen in a bright room or an exhibition hall, and an increase in light output is required. However, when a light source lamp having a large input is used, there is a problem that the lifetime is generally short. Furthermore, in the case of the single lamp type, there is also a problem that when the light source lamp is cut off during projection, the image must be interrupted for replacement of the light source lamp. For this reason, a plurality of light source lamps which are combined as a light source have been put into practical use.

  FIG. 6 is an example of such a lighting device. The illumination device in this example is used as an irradiation device for a projection display apparatus. In addition, this irradiation apparatus is configured such that a pair of light source lamps 101 and 102 face each other and an optical path changing member 103 is disposed between both light source lamps 101 and 102. The optical path changing member 103 reflects the parallel light from both the light source lamps 101 and 102 toward a half region located on the light source lamps 101 and 102 side on one irradiation surface, respectively. 103b is arranged in a mountain shape. The irradiation surface in this case is an integrator lens 104 that constitutes the optical system of the projection display apparatus. Such an illumination apparatus and a projection display apparatus using the illumination apparatus are described in Patent Document 1. .

  7 and 8 show another example of an illumination device that uses two light source lamps and combines the light from the two light source lamps. It is used as an irradiation device.

  In this example, as shown in FIG. 7, a pair of light source lamps 201 and 202 are arranged facing each other with their optical axes 201a and 202a shifted. Three sets of optical path changing members 203 are arranged between the light source lamps 201 and 202. The three sets of optical path changing members 203 apply parallel light from both light source lamps 201 and 202 to a predetermined irradiation surface, in this case, the central region and the peripheral region of the integrator lens 204 constituting the optical system of the projection display apparatus. They are combined and arranged so as to be divided into three parts. Each optical path changing member 203 includes a polarization beam splitter 205 that reflects half of the incident substantially parallel light and transmits the remaining half of the light, a first mirror 206, and a second mirror 207. Yes. The separation film 205a of the polarization beam splitter 205 is disposed with an inclination of 45 ° with respect to the optical axis 201a of the light source lamp 201, and the first mirror 206 is parallel to the separation film 205a (that is, with an inclination of 45 ° with respect to the optical axis 201a). The second mirror 207 is arranged in a direction orthogonal to the first mirror 206. Each optical path changing member 203 receives and synthesizes light beams from regions corresponding to positions of the two light source lamps 201 and 202, respectively, forms a light beam twice as large as the region, and emits light in a predetermined direction. The light emitted from the individual light source lamps 201 and 202 is guided to the entire irradiation surface by being emitted toward the surface. In this case, the irradiation surface is the incident side lens array of the integrator lens 204.

  The polarization beam splitter 205 transmits P-polarized light in the irradiated light and reflects S-polarized light. Therefore, as shown in FIG. 7, each optical path changing member 203 applies S-polarized light, which is half of the light beam emitted from a predetermined region (central region or end region) of one light source lamp 201, to the polarizing beam splitter 205. And reflected in the predetermined direction to form a first light flux. Further, the transmitted P-polarized light that is the remaining half of the light beam is reflected by the first mirror 206 in the predetermined direction, thereby forming a second light beam adjacent to the first light beam. Further, the light emitted from the other light source lamp 202 is reflected by the second mirror 207 and guided in the same direction as the first light flux. Then, the P-polarized light that is half of the light beam emitted from the light source lamp 202 is transmitted through the polarizing beam splitter 205 and superimposed on the first light beam, and the S-polarized light that is the remaining half of the light beam is superimposed on the polarizing beam splitter. The light is reflected by 205 and further reflected by the first mirror 206 in the predetermined direction so as to be superimposed on the second light flux. Note that Patent Document 2 discloses such an illumination device and a projection display apparatus using the illumination device.

Japanese Patent Laid-Open No. 2001-21996 JP 2005-164769 A

  However, although the former illumination device can illuminate the entire illumination object with both the light source lamps 101 and 102, the light emitted from the individual light source lamps 101 and 102 is used as the illumination object (in this case, the integrator lenses 101 and 102). Can not lead to the whole of. Therefore, when any one of the two light source lamps 101 and 102 is cut off in a device such as a projection display apparatus using this illumination device, luminance unevenness and color unevenness due to the luminance unevenness are slightly increased. There is dissatisfaction to remain.

  On the other hand, according to the latter illumination device, since the optical axes 201a and 202a of the two light source lamps 201 and 202 are not matched, there is a problem that the size of the illumination system becomes large under a normal design concept. In addition, there is a problem in that the external dimensions of the apparatus such as a projection display apparatus using such an illuminating device are increased and the cost is increased.

  In view of such a problem, the present invention allows the light emitted from the pair of light source units to be directed to the entire illumination target, and can be miniaturized by matching the optical axes of the two light source units arranged to face each other. An object is to provide a lighting device. Another object of the present invention is to provide a projection display apparatus provided with such an illumination device.

  An illuminating device according to the present invention is made to achieve such an object, and includes a pair of light source portions that emit substantially parallel light, and an optical path changing member disposed between both light source portions. The pair of light source units are arranged to face each other with their optical axes aligned, and the optical path changing member includes a beam splitter unit on the emission side of each light source unit, and beams light emitted from each light source unit. About half of the light beam is reflected by the splitter unit toward the irradiation surface in a predetermined direction, and the remaining half of the light beam is transmitted and reflected by the other beam splitter unit in a direction opposite to the irradiation surface. The light beam reflected in the direction opposite to the irradiation surface is totally reflected with a phase difference of 180 degrees at the reflecting part, and the totally reflected light beam is transmitted through the other beam splitter part. To lead to the irradiated surface Made is characterized in that is.

  According to the above configuration, about half of the light emitted from one light source unit is reflected by the beam splitter unit provided on the emission side of the light source unit, and is a half region on the irradiation surface on the light source unit side. Led to. The remaining half of the light beam that has passed through the beam splitter is reflected by the other beam splitter in a direction facing the irradiation surface. Then, the reflected light beam is converted so as to give a phase difference of 180 degrees at the reflection part, reflected again toward the other beam splitter part, and transmitted through the other beam splitter part to transmit the irradiation surface. In the other half of the light source side.

  Further, the emitted light from the other light source unit also acts in the same manner as described above, so that half of the light beam is guided to the half region on the other light source unit side on the irradiation surface, and the remaining half light beam is directed to the one light source unit. By being guided to the half-irradiated surface on the side, finally, the emitted light emitted from both light source parts is superimposed and guided to the entire irradiated surface. Therefore, according to the illuminating device of the present invention, the emitted light of each light source unit can be guided to the entire irradiation surface while arranging the optical axes of the pair of light source units so as to face each other. The lighting device can be reduced in size. In addition, in the projection display apparatus using the illumination device of the present invention, the size of the device is reduced, and the luminance unevenness and the color unevenness caused by the luminance unevenness are reduced when one of the light source parts is cut off. be able to.

  The optical path changing member has an S-polarized wire grid polarizing plate attached to the output side of one light source unit and a P-polarized wire grid polarizing plate attached to the output side of the other light source unit as the beam splitter unit. At the same time, the S-polarized wire grid polarizer and the P-polarized wire grid polarizer are disposed at an inclination of 45 degrees with respect to the optical axis of the light source unit so as to reflect half of the light emitted from the light source unit to the irradiation surface. It is good also as a structure which is combined with mountain shape, and also the said reflection part is provided with the quarter wavelength plate in the surface part by the side of the said beam splitter of a total reflection plate. Here, the S-polarized wire grid polarizer refers to a wire grid polarizer that reflects S-polarized light and transmits P-polarized light, and the P-polarized wire grid polarizer reflects S-polarized light and reflects S-polarized light. It shall be a wire grid polarizer that transmits light.

  If comprised in this way, as for the emitted light from the light source part irradiated to the S-polarization wire grid polarizing plate, the S-polarization light which is a half light beam in the S-polarization wire grid polarizing plate was predetermined in a fixed direction. The light is guided to a half region on the light source side on the irradiation surface, and the P-polarized light that is the remaining half of the light beam is transmitted. The P-polarized light, which is the remaining half of the light beam, is reflected by the other P-polarized wire grid polarizer and reflected in the direction facing the irradiation surface. This reflected light is converted into circularly polarized light with a phase difference of 90 degrees by passing through a quarter-wave plate constituting the reflecting portion. The circularly polarized light is converted to S-polarized light with a 90-degree phase difference when it is reflected by the total reflection plate and then transmitted through the quarter-wave plate again. Therefore, the remaining half of the luminous flux becomes S-polarized light, passes through the P-polarized wire grid polarizing plate, and is guided to the other light source side half region on the irradiation surface.

  In addition, the outgoing light emitted from the other light source unit toward the P-polarized wire grid polarizing plate is reflected by the P-polarized wire grid polarizing plate as a half luminous flux due to the reverse action. Then, it is irradiated to a half region on the other light source unit side on the irradiation surface and is superimposed on the reflected light beam from the reflection unit. Further, the S-polarized light, which is the remaining half of the light beam, passes through the P-polarized wire grid polarizer and reaches the other S-polarized wire grid polarizer. The direction facing the irradiation surface at the S-polarized wire grid polarizer. Is reflected. This reflected light is converted into P-polarized light by the reflecting portion and reflected again toward the S-polarized wire grid polarizer. Further, since the reflected light beam is converted into P-polarized light, the light beam is transmitted through the S-polarized wire grid polarizing plate and guided to a half region on the one light source side on the irradiation surface. Therefore, this light is superimposed on the light beam emitted from the one light source unit 2 and reflected by the S-polarized wire grid polarizer. As described above, even when configured as in the present invention, the emitted light from both light source parts can be guided to the entire irradiation surface while matching the optical axes of both light source parts.

  In addition, the optical path changing member is attached as a beam splitter unit to the output side of each light source unit so that the polarized beam splitter reflects the S-polarized light of the output light from each light source unit toward the irradiation surface. In addition, a half-wave plate is provided between both the polarizing beam splitters, and the reflection portion is a quarter-wave plate provided on the surface portion of the total reflection plate on the beam splitter side. You may comprise.

  If comprised in this way, the half area | region by the side of the said light source part in the irradiation surface by which the S polarized light which is about half light flux among the emitted light from one light source part was previously decided in the fixed direction by the polarizing beam splitter Led to. Then, the P-polarized light that is the remaining half of the light beam is transmitted through the polarization beam splitter, converted to S-polarized light through a half-wave plate, and disposed on the output side of the other light source unit. The light is reflected toward the reflecting portion installed in the direction facing the irradiation surface. The reflected S-polarized light is converted into P-polarized light by the action of a quarter-wave plate disposed on the surface of the reflecting portion on the beam splitter side, and is incident on the polarizing beam splitter again. The light is transmitted through the polarization beam splitter and guided to the half region on the other light source side on the irradiation surface.

  In addition, the emitted light emitted from the other light source unit is subjected to the same action as described above, and first, the S-polarized light, which is about half the luminous flux, is reflected on the irradiation surface by the polarizing beam splitter on the light source unit side, It is superimposed on the light beam from the reflection part. Further, the P-polarized light, which is the remaining half of the light beam, passes through the polarization beam splitter, is converted to S-polarized light by the half-wave plate, and is incident on the opposite polarization beam splitter. For this reason, the P-polarized light incident on the polarization beam splitter is reflected toward the reflecting portion installed in the direction facing the irradiation surface. The reflected S-polarized light, which is the remaining half of the light beam, is converted into P-polarized light by the action of a quarter-wave plate disposed on the surface of the reflecting portion on the beam splitter side, and is again converted into the polarizing beam splitter. In order to be incident, the light passes through the polarization beam splitter, is guided to a half region on the one light source unit side on the irradiation surface, and is superimposed on the light beam from the one light source unit. Therefore, even if comprised like this invention, the emitted light from both light source parts can be guide | induced to the whole said irradiation surface, making the optical axes of both light source parts correspond.

Further, each of the pair of light source units may include a light source lamp.
If comprised in this way, the light from each light source lamp can be guide | induced to the whole irradiation surface using two light source lamps.

Moreover, at least one light source part of the pair of light source parts may have a configuration similar to that of the lighting device.
If comprised in this way, since at least 3 or more light source lamps can be used, the output of an illuminating device can be enlarged. Moreover, the output of each light source lamp can be made small and the lifetime of a light source lamp can be lengthened.

  Further, a projection display apparatus according to the present invention includes any one of the illumination devices configured as described above, a light valve that modulates light emitted from the illumination device based on a video signal, and the light valve. And a projection lens for enlarging and projecting the light modulated in (1).

  If comprised in this way, since an illuminating device can be reduced in size, the magnitude | size of projection type video display apparatus itself can also be reduced in size. Moreover, since many light source lamps can be used, the output of a light source can be increased. Further, at the expense of an increase in the output of the light source, the life of the lighting device can be extended by reducing the output per light source lamp. In addition, when one of the light source sections is cut off, luminance unevenness and color unevenness due to the luminance unevenness can be reduced.

  Further, in this case, the projection display apparatus according to the present invention separates the light from the illumination device into the three primary colors and guides them to the light valves for the respective color lights, and is modulated by the light valves for the respective color lights. By composing and projecting light, it is possible to reduce the size and increase the output of the three-plate projection display apparatus. In addition, it is possible to reduce luminance unevenness and color unevenness caused by luminance unevenness when one of the light source sections is cut off.

  According to the illuminating device according to the present invention, the optical axes of the two light source units arranged opposite to each other can be made coincident with each other, so that the illuminating device can be reduced in size. Further, it is possible to reduce the size of the projection video display device using the illumination device of the present invention and reduce luminance unevenness and color unevenness caused by the luminance unevenness when one of the light source sections is cut off. it can.

It is explanatory drawing of the illuminating device which concerns on Embodiment 1 of this invention. It is drawing of the wire grid polarizing plate in the same illuminating device, Comprising: (a) It is an external appearance perspective view which shows schematic structure, (b) is arrangement | positioning explanatory drawing as a S polarizing wire grid polarizing plate, (c) is P It is arrangement | positioning explanatory drawing as a polarizing wire grid polarizing plate. It is explanatory drawing of the projection type video display apparatus concerning Embodiment 2 of this invention. It is explanatory drawing of the illuminating device which concerns on Embodiment 3 of this invention. It is explanatory drawing of the illuminating device which concerns on Embodiment 4 of this invention. It is explanatory drawing of the illuminating device which concerns on a prior art example. It is explanatory drawing of the illuminating device which concerns on another prior art example. It is explanatory drawing of the optical path change member in the illumination device.

(Embodiment 1)
Hereinafter, the lighting apparatus according to Embodiment 1 of the present invention will be described with reference to FIG.
The illumination device 1 according to the present embodiment includes a pair of light source units 2 and 3 that emit substantially parallel light, and an optical path changing member 4 that is disposed between the light source units 2 and 3. The pair of light source units 2 and 3 are arranged to face each other so that the optical axes 2a and 3a coincide. As the light source units 2 and 3, general-purpose light source lamps are used.

  The optical path changing member 4 includes an S-polarized wire grid polarizing plate 5 as a beam splitter disposed on the exit side of one light source unit 2 and a P as a beam splitter disposed on the exit side of the other light source unit 3. It comprises a polarizing wire grid polarizer 6 and a reflecting section 7 that totally reflects light and adds a 180-degree phase difference to the light during reflection.

  The wire grid polarizing plate L has a basic structure as shown in FIG. 2A, and a metal material is deposited on the glass substrate L1, and the wire grid L2 is formed by fine etching at the nanometer level. This is a non-absorbing polarizing plate. As shown in FIG. 2B, when natural light is incident from a direction orthogonal to the longitudinal direction of the wire-grid L2, S-polarized light having a vibration direction parallel to the longitudinal direction of the wire-grid L2 is reflected. The P-polarized light having the vibration direction perpendicular to the wire-grid L2 is transmitted. This shows a form in which the wire grid polarizing plate L is used as the S polarizing wire grid polarizing plate 5.

  As shown in FIG. 2C, when natural light is incident on the wire-grid L2 in the longitudinal direction of the wire-grid L2, P-polarized light in a direction perpendicular to the longitudinal direction of the wire-grid L2 is reflected. , Acts to transmit S-polarized light. This shows a form in which the wire grid polarizing plate L is used as the P polarizing wire grid polarizing plate 6.

  In the optical path changing member 4, the S-polarized wire grid polarizing plate 5 is an irradiation surface in which S-polarized light, which is approximately half of the substantially parallel light emitted from one light source unit 2, is set in a predetermined direction. Are inclined by 45 degrees with respect to the optical axis 2a so as to transmit the P-polarized light which is the remaining half of the light flux. Further, the P-polarized wire grid polarizer 6 reflects P-polarized light, which is approximately half of the substantially parallel light emitted from the other light source unit 3, to a half region on the light source unit 3 side of the irradiation surface 8. The other half of the light flux is arranged so as to be inclined by 45 degrees with respect to the optical axis 3a of the other light source unit 3 so as to transmit S-polarized light. Therefore, the S-polarization wire grid polarizer 5 and the P-polarization wire grid polarizer 6 are disposed symmetrically and are combined in a mountain shape so that the top portion is on the irradiation surface 8 side. The illumination device 1 according to this embodiment is assumed to be used in a projection video display device described later, and an incident side lens array of an integrator lens 10 described later is assumed as the irradiation surface 8. ing.

  Further, as described above, the S-polarized wire grid polarizing plate 5 and the P-polarized wire grid polarizing plate 6 are combined in this way, so that the P-polarized light which is about half of the substantially parallel light from the light source unit 2. Is transmitted through the S-polarized wire grid polarizer 5 and irradiated onto the P-polarized wire grid polarizer 6. Then, the P-polarized light is reflected by the P-polarized wire grid polarizing plate 6 toward the direction facing the irradiation surface 8. Further, S-polarized light, which is approximately half of the substantially parallel light emitted from the other light source unit 3 toward the P-polarized wire grid polarizing plate 6, passes through the P-polarized wire grid polarizing plate 6 and passes through the S-polarized light. The wire grid polarizer 5 is irradiated. Then, the S-polarized light is reflected by the S-polarized wire grid polarizer 5 toward the direction facing the irradiation surface 8. In addition, the reflection part 7 is arrange | positioned in the direction facing the irradiation surface 8. As shown in FIG.

  The reflection unit 7 includes a total reflection plate 7a and a quarter-wave plate 7b disposed on the surface portion on the irradiation surface side of the total reflection plate 7a. Therefore, when the P-polarized light is irradiated toward the reflecting unit 7, the P-polarized light is converted into circularly polarized light with a 90-degree phase difference by transmitting through the quarter-wave plate 7b. Then, after being reflected by the total reflection plate 7a, when transmitted through the quarter-wave plate 7b again, a 90-degree phase difference is added and converted to S-polarized light. Further, when the S-polarized light is irradiated toward the reflecting portion 7, the S-polarized light is converted into circularly polarized light with a 90-degree phase difference by passing through the quarter-wave plate 7b. Then, after being reflected by the total reflection plate 7a, when transmitted through the quarter-wave plate 7b again, a 90-degree phase difference is added and converted to P-polarized light.

Since the illumination device according to the present embodiment is configured as described above, it operates as follows.
S-polarized light, which is approximately half of the substantially parallel light emitted from one light source unit 2, is reflected by the S-polarized wire grid polarizing plate 5, and is on the irradiation surface 8 on the one light source unit 2 side. Guided to half the area. Further, the P-polarized light that is the remaining half of the light beam passes through the S-polarized wire grid polarizer 5 and reaches the P-polarized wire grid polarizer 6. Then, this P-polarized light is reflected by the P-polarized wire grid polarizing plate 6 toward the reflecting portion 7, and is converted into S-polarized light by the reflecting portion 7 as described above, and becomes the P-polarized wire grid polarizing plate 6 again. Reflected towards. Accordingly, the S-polarized light reflected by the reflecting section 7 is transmitted through the P-polarized wire grid polarizing plate 6 and guided to a half region on the irradiation surface 8 on the other light source section 3 side. In this way, the emitted light emitted from one light source unit 2 is irradiated to the entire irradiation surface 8.

  Further, the P-polarized light, which is about half of the emitted light emitted from the other light source unit 3, is reflected by the P-polarized wire grid polarizing plate 6, and is on the other light source unit 3 side on the irradiation surface 8. Led to half the area. Further, the S-polarized light that is the remaining half of the light beam passes through the P-polarized wire grid polarizer 6 and reaches the S-polarized wire grid polarizer 5. The S-polarized light is reflected by the S-polarized wire grid polarizing plate 5 toward the reflecting portion 7, converted to P-polarized light by the reflecting portion 7, and reflected again toward the S-polarized wire grid polarizing plate 5. The Therefore, the P-polarized light reflected by the reflecting unit 7 is transmitted through the S-polarized wire grid polarizing plate 5 and guided to a half region on the irradiation surface 8 on the one light source unit 2 side. In this way, the emitted light emitted from the other light source unit 3 is superimposed on the light emitted from the one light source unit 2 described above and irradiated onto the entire irradiation surface 8.

According to the illuminating device which concerns on Embodiment 1, since it is comprised as mentioned above, there can exist the following effects.
(1) Since the light axes 2a and 3a of the pair of light source units 2 and 3 are arranged so as to face each other and face each other, the emitted light of each light source unit 2 and 3 can be guided to the entire irradiation surface 8, so As long as the structural design is performed, the lighting device can be reduced in size.

  (2) Even when any one of the light source units 2 and 3 is cut off, the light is projected on the entire irradiation surface 8. Therefore, when any one of the light source units 2 and 3 is cut off in the apparatus using the illumination device, it is not possible to avoid a decrease in illuminance, but it continues without luminance unevenness and color unevenness caused by the luminance unevenness. Can be used.

  (3) Two light source lamps can be used for each of the pair of light source units 2 and 3. Moreover, the light from each light source lamp can be guided to the whole irradiation surface 8 using two light source lamps.

(Embodiment 2)
Next, a projection display apparatus according to Embodiment 2 will be described with reference to FIG. In addition, the same code | symbol is used for the structure same as Embodiment 1, and the description is abbreviate | omitted.

  The projection display apparatus according to the second embodiment is a three-plate liquid crystal projector, and the lighting apparatus 1 having the configuration of the first embodiment is used. The light emitted from the illumination device 1 is irradiated on the entire incident side lens array of the integrator lens 10 under the action described in the first embodiment. The light that has passed through the integrator lens 10 is converted into a single polarized light by the polarization conversion device 11, and then passes through the condenser lens 12 and is guided to the first dichroic mirror 13a.

  The first dichroic mirror 13a is configured to transmit light in the red wavelength band and reflect light in the cyan (green + blue) wavelength band. The light in the red wavelength band that has passed through the first dichroic mirror 13a is reflected by the total reflection mirror 14a and guided to the transmissive liquid crystal panel 15a as a light valve for red light. Is done. On the other hand, the light in the cyan wavelength band reflected by the first dichroic mirror 13a is guided to the second dichroic mirror 13b.

  The second dichroic mirror 13b is configured to transmit light in the blue wavelength band and reflect light in the green wavelength band. The light in the green wavelength band reflected by the second dichroic mirror 13b is guided to a transmissive liquid crystal panel 15b as a light valve for green light, and is transmitted therethrough to be modulated. The light in the blue wavelength band transmitted through the second dichroic mirror 13b is guided to the transmissive liquid crystal panel 15c as a light valve for blue light through the total reflection mirrors 14b and 14c, and is transmitted therethrough to be modulated. Is done.

  The modulated light (each color video light) obtained through the liquid crystal panels 15a, 15b and 15c as light valves is synthesized by the dichroic prism 16 to become color video light. The color image light is enlarged and projected by the projection lens 17 and is projected and displayed on a screen (not shown).

Since the three-plate liquid crystal projector according to the second embodiment is configured as described above, the following effects can be achieved.
(1) The output can be increased by the illumination device 1 using the pair of light source units 2 and 3. In this case, the size of the lighting device 1 can be reduced, so that the size of the device can be reduced. Further, when any one of the light source units 2 and 3 is cut off, luminance unevenness and color unevenness due to the luminance unevenness can be reduced.

  (2) The light from the lighting device 1 is separated into three primary colors, led to the light valves for each color light, and the light modulated by the light valves for each color light is combined and projected. Therefore, it is possible to reduce the size and increase the output of the three-plate projection display apparatus.

(Embodiment 3)
Next, an illumination device according to Embodiment 3 will be described with reference to FIG. In FIG. 4, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The illumination device according to the third embodiment is obtained by changing the optical path changing member in the first embodiment.
The illumination device according to Embodiment 3 is the same as that of Embodiment 1 in the light source units 2 and 3, and the light source lamps as the light source units 2 and 3 face each other so that the optical axes 2a and 3a are the same. The optical path changing member 4 is arranged between the light source units 2 and 3.

  In the optical path changing member 4, polarization beam splitters 5A and 6A are disposed in front of the light source units 2 and 3 as beam splitters in the present invention, and polarization of light transmitted between the pair of polarization beam splitters 5A and 6A. A half-wave plate 9 is disposed as a polarization mechanism for polarizing the direction from P-polarized light to S-polarized light or from S-polarized light to P-polarized light. Further, the reflecting portion 7 is arranged in a direction facing the irradiation surface 8 of the polarizing beam splitters 5A and 6A arranged in this way.

  As is generally known, the polarization beam splitters 5A and 6A are obtained by applying a dielectric multilayer film or a metal thin film as a separation film 5Aa or 6Aa to a joint surface where two right angle prisms are bonded. When the films 5Aa and 6Aa are irradiated with natural light including P-polarized light and S-polarized light, the P-polarized light is transmitted and the S-polarized light is reflected. In this embodiment, the separation films 5Aa and 6Aa are reflected by the separation film 5Aa and 6Aa in the direction of the irradiation surface 8 so that the S-polarized light out of the substantially parallel light emitted from the light source is reflected by the light source unit 2. The optical axes 2a and 3a are inclined at 45 degrees. The reflecting portion 7 is the same as that in the first embodiment.

The lighting apparatus according to Embodiment 3 is configured as described above and operates as follows.
The substantially parallel light emitted from the two light source units 2 and 3 is a region in which the S-polarized light contained in each light is half of each light source side in the irradiation surface 8 by the polarization beam splitters 5A and 6A on each emission side. It is shot towards. The P-polarized light transmitted through the polarization beam splitters 5A and 6A is converted into S-polarized light with a phase difference of 180 degrees by the half-wave plate 9 disposed between the polarization beam splitters 5A and 6A. The light beams are guided to the polarization beam splitters 5A and 6A on the opposite light source units 2 and 3 side. The S-polarized light converted by the half-wave plate 9 is reflected in the direction of the reflecting portion 7 by the separation films 5Aa and 6Aa of the polarizing beam splitters 5A and 6A, and is polarized into P-polarized light by the reflecting portion 7. And reflected. For this reason, the P-polarized light reflected from the reflecting section 7 passes through the polarizing beam splitters 5A and 6A on the facing light source sections 2 and 3 respectively, and is half on the facing light source section 2 and 3 side on the irradiated surface 8 section. And is superimposed on the light reflected toward the irradiation surface 8 side by the polarization beam splitters 5A and 6A as described above. Therefore, the light emitted from the light source units 2 and 3 is irradiated on the entire irradiation surface 8 as described above.

  According to the illuminating device in the third embodiment, the light emitted from each of the light source units 2 and 3 is entirely irradiated on the irradiation surface 8 set in a predetermined direction in advance. Therefore, even when one of the light source units 2 and 3 breaks down, the luminance unevenness and the color unevenness due to the luminance unevenness hardly occur.

(Embodiment 4)
Next, an illumination device according to Embodiment 4 will be described with reference to FIG. In FIG. 5, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

The illumination device according to the fourth embodiment is intended to further increase the number of light source lamps used, and in this embodiment, four light source lamps are used.
That is, the basic configuration of the lighting apparatus according to the present embodiment is the same as that of the first embodiment, but the configuration of the lighting apparatus 1 described in the first embodiment as the light source units 2 and 3 is the same. It has been adopted. Accordingly, in the light source units 2 and 3, two light source lamps are used for the light source units 20 and 30 as components of the light source units 2 and 3, and these light source lamps are arranged with the optical axes 20a and 30a aligned. ing. Further, an optical path changing member 40 as a component of the light source units 2 and 3 is disposed between the light source lamps that are the light source units 20 and 30. The optical path changing member 40 includes an S-polarized wire grid polarizer 50, a P-polarized wire grid polarizer 60, and a reflector 70 as a beam splitter unit. Similar to the S-polarized wire grid polarizing plate 5 and the P-polarized wire grid polarizing plate 6 in the first embodiment, the S-polarized wire grid polarizing plate 50 and the P-polarized wire grid polarizing plate 60 are emitted from the light source units 20 and 30. Placed and assembled. Moreover, the reflection part 70 is equipped with the quarter wavelength plate 70b arrange | positioned at the surface part by the side of the irradiation surface of the total reflection board 70a, Comprising: It is the same structure as the reflection part 7 in Embodiment 1. FIG. .

  The light path changing member 4 is arranged between the light source units 2 and 3 configured as described above, as in the first embodiment. Therefore, the light emitted from each light source lamp is the light source unit 2 or 2. 3 is emitted as substantially parallel light dispersed on the entire emission surface. Further, the substantially parallel light emitted from each of the light source units 2 and 3 using two light source lamps is irradiated to the entire irradiation surface 8 by the optical path changing member 4 as described above.

  Since the illumination device according to Embodiment 4 is configured as described above, four light source lamps can be used. Therefore, the output as the lighting device can be increased as compared with the first embodiment. Moreover, the output of each light source lamp can be made small and the lifetime of a light source lamp can be lengthened.

(Modification)
The present invention can be modified as follows in the above embodiment.
In the above-described fourth embodiment, the light source units 2 and 3 are both configured to include the same components as the illumination device of the first embodiment, but only one of them is configured as such. May be. For example, when only the light source unit 2 is configured in such an illumination device and the light source unit 3 is a normal light source lamp, three light source lamps are used.

  In addition, in the fourth embodiment, the same lighting device as that in the first embodiment is used as the light source section of the constituent elements in both or either of the light source sections 20 and 30 as the constituent elements in the light source sections 2 and 3. You can also. Thus, if the structure of the illuminating device 1 which concerns on Embodiment 1 is used for the light source part as a component, it can also be made into five or more light source lamps.

The lighting device according to Embodiments 3 and 4 can be applied to the same three-plate liquid crystal projection display apparatus as in Embodiment 2.
In addition, the lighting device according to Embodiment 1 and Embodiments 3 and 4 and the lighting device described in the above-described modification are not limited to such a three-plate liquid crystal projector, and are used as a single-plate liquid crystal projector. You can also. Furthermore, it is good also as a structure using light valves other than a liquid crystal panel.

  The illumination device according to the present invention can be widely used in a projection display apparatus and the like. The projection display apparatus according to the present invention can be used as an image display system in various facilities such as a home theater, a conference room, a training room, a classroom, an amusement hall, various exhibition rooms, and a studio.

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 2, 3, 20, 30 ... Light source part, 2a, 3a, 20a. 30a ... Optical axis, 4, 40 ... Optical path changing member, 5, 50 ... S-polarized wire grid polarizer, 5A, 6A ... Polarized beam splitter, 6, 60 ... P-polarized wire grid polarizer, 7, 70 ... Reflector, 7a, 70a ... Total reflection plate, 7b, 70b ... 1/4 wavelength plate, 8 ... Irradiation surface, 9 ... 1/2 wavelength plate, 15a, 15b, 15c ... Liquid change panel (as a light valve), 17 ... Projection lens.

Claims (7)

A pair of light source portions that emit substantially parallel light, and an optical path changing member disposed between both light source portions,
The pair of light source units are arranged to face each other with their optical axes aligned,
The optical path changing member includes a beam splitter unit on the emission side of each light source unit, and the light emitted from each light source unit directs about half of the light beam toward the irradiation surface in a predetermined fixed direction by the beam splitter unit. The other half of the light beam is reflected and reflected by the other beam splitter unit in a direction facing the irradiation surface, and the light beam reflected in the direction facing the irradiation surface is reflected by the reflection unit. The illumination apparatus is configured so as to be totally reflected with a phase difference of 180 degrees, and to transmit the totally reflected light beam to the irradiation surface through the other beam splitter.   The optical path changing member has an S-polarized wire grid polarizing plate attached to the output side of one light source unit as the beam splitter unit, and a P-polarized wire grid polarizing plate attached to the output side of the other light source unit, These S-polarized wire grid polarizing plate and P-polarized wire grid polarizing plate are disposed at an inclination of 45 degrees with respect to the optical axis of the light source unit so as to reflect half of the light emitted from the light source unit on the irradiation surface. The illumination device according to claim 1, further comprising: a quarter-wave plate provided on a surface portion of the total reflection plate on the beam splitter side of the total reflection plate.   The optical path changing member, as the beam splitter unit, has a polarization beam splitter attached to the emission side of each light source unit so as to reflect the S-polarized light of the emitted light from each light source unit toward the irradiation surface, A ½ wavelength plate is provided between the two polarizing beam splitters, and the reflecting portion is a ¼ wavelength plate provided on the surface portion of the total reflecting plate on the beam splitter side. The lighting device according to claim 1.   It is an illuminating device of any one of Claims 1-3, Comprising: A pair of said light source part consists of a light source lamp, respectively, The illuminating device characterized by the above-mentioned.   The illuminating device according to any one of claims 1 to 3, wherein at least one of the pair of light source portions is the configuration of the illuminating device according to any one of claims 1 to 3. A lighting device comprising:   6. The illumination device according to claim 1, a light valve that modulates light emitted from the illumination device based on a video signal, and an enlarged projection of the light modulated by the light valve. A projection display apparatus comprising a projection lens.   7. The projection display apparatus according to claim 6, wherein the light from the illumination device is separated into three primary colors and led to the light valves for the respective color lights, and the light modulated by the light valves for the respective color lights is synthesized. A projection-type image display device, wherein the projection-type image display device is configured so as to project.

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