JP6503816B2 - projector - Google Patents

Description

  The present invention relates to a projector.

2. Related Art A projector is conventionally known that includes a light source device, a light modulation device that modulates the light emitted from the light source device, and a projection optical device that projects the modulated light. As such a projector, for the purpose of improving the contrast of a projected image, a projector provided with two light modulation devices optically connected in series has been proposed (for example, see Patent Document 1).

In the projector described in Patent Document 1, light emitted from the light source unit is separated into red, green and blue color lights by a plurality of dichroic mirrors after passing through a uniform illumination system and a reflection mirror. Then, the respective color lights are modulated by the liquid crystal light valve (color modulation light valve) which is the corresponding first modulation means, and are synthesized by the cross dichroic prism. After this, the light synthesized by the cross dichroic prism passes through a relay optical system having both-side telecentricity in which optical members such as the front lens group, the aperture stop, and the rear lens group are linearly arranged, and luminance modulation is performed. It is incident on the part. The brightness modulation unit is a liquid crystal light valve (
The light amount (image light formed by the color modulation light valve) is modulated by the luminance modulation light valve to adjust the light amount for each pixel. Then, the light passing through the luminance modulation unit is projected by the projection lens. With such a configuration, the gradation of the image to be projected can be broadened, and the contrast can be improved.

JP 2007-218946 A

However, in the projector described in Patent Document 1, each optical member of the relay optical system is linearly disposed, the color modulation light valve is disposed at one end side, and the luminance modulation light valve is disposed at the other end side. A projection optical device is disposed on the light emission side of the brightness modulation light valve. In such a configuration and arrangement, there is a problem that the configuration of the relay optical system is large and the projector tends to be large.

An object of the present invention is to solve at least a part of the above-mentioned problems, and an object thereof is to provide a projector which can be miniaturized.

A projector according to an aspect of the present invention includes an image forming apparatus for forming an image, and a projection optical apparatus for projecting the formed image, the image forming apparatus including: an illumination apparatus; and an emission from the illumination apparatus A first light modulation device for modulating the light, and an optical path disposed between the lighting device and the first light modulation device, in a plane orthogonal to the central axis of the light emitted from the lighting device A light control device for adjusting the illuminance for each area, the light control device comprising: a second light modulation device for modulating light emitted from the lighting device; and modulated light modulated by the second light modulation device A reflection type relay device for forming an image on the first light modulation device, the modulated light incident from the second light modulation device is guided to the relay device, and the modulated light reflected by the relay device is Polarized light emitted to the first light modulation device side And a release device, wherein arranged between the polarizing beam splitter and the relay device, and having a phase difference plate to be substantially circularly polarized light light incident from the polarization separating device.

According to the above aspect, in the light modulation device, the modulated light modulated by the second light modulation device is incident on the polarization separation device, passes through the polarization separation device, and is incident on the reflective relay device. . This modulated light is incident on a reflective relay device and after being reflected by the relay device,
In the process of being emitted from the relay device and entering the polarization separation device again, the light is incident on the reflection type relay device as substantially circular polarization and is reflected to reverse the rotational direction of the circular polarization, thereby converting the polarization direction. Ru. Therefore, the modulated light incident from the second light modulation device and the modulated light reflected by the relay device can be reliably separated by the polarization separation device due to the difference in polarization direction. Thus, the modulated light by the second light modulation device can be reliably guided to the relay device, and the modulated light reflected by the relay device and imaged on the first light modulation device is the first light modulation device. It can be emitted reliably to the side.
In such a light control device, the modulated light reciprocates between the polarization separation device and the relay device by reflection, and then is emitted from the polarization separation device to the first light modulation device side. Each configuration of the device can be arranged compactly. Therefore, the light control device can be miniaturized, and in turn, the projector can be miniaturized.

In the above aspect, the second light modulation device is preferably a transmissive liquid crystal panel.
According to the above aspect, since the second light modulation device is a transmission type liquid crystal panel, when the second light modulation device is disposed on the optical path of the light going straight toward the polarization separation device, The second light modulation device can be arranged without arranging an optical member such as a mirror or a prism on the road. Therefore, as compared with the case where the optical member is disposed, the light control device can be miniaturized, and the projector can also be miniaturized.

In the one aspect, the first light modulation device preferably includes a reflective light modulator.
According to the above aspect, the light modulated by the light modulation device and incident on the first light modulation device including the reflection type light modulator is modulated and reflected by the first light modulation device, and the light modulation is performed. It enters into the polarization separation device of the optical device. Here, the light emitted from the first light modulation device is changed in polarization direction from that at the time of incidence, and thus is incident on the polarization separation device and then emitted in a direction different from the relay device by the polarization separation device. .
In such a configuration, in order to cause the light modulated by the first light modulation device to enter the polarization separation device again, the polarization separation device is used as an optical member for guiding the light emitted from the first light modulation device. It can be used, and the configuration can be simplified. Further, the members constituting the light control device and the first light modulation device can be disposed around the polarization separation device, and the projector can be miniaturized.

In the above aspect, the first light modulation device is disposed between the plurality of reflection-type liquid crystal panels as the reflection-type light modulator, the plurality of reflection-type liquid crystal panels, and the light control device. The light emitted from the light control device is color separated and made to enter each of the plurality of reflective liquid crystal panels, and the light emitted from each of the plurality of reflective liquid crystal panels is color synthesized It is preferable to provide a prism to be incident on the polarization separation device.
As the prism, various dichroic prisms such as a cross dichroic prism, a Phillips prism, a gapless prism and the like can be exemplified, and a plurality of dichroic mirrors can be used.
In such a configuration, since the light modulated by the light control device is separated by the prism from a plurality of color lights, only one second light modulation device of the light control device is required. Therefore, the configuration of the projector can be simplified as compared with the case where the second light modulation device is provided for each color light to be separated.
The projector can be miniaturized.
Moreover, according to such a configuration, the first light modulation device can modulate the color light for each of the color lights included in the modulation light by including the prism and the plurality of reflection type liquid crystal panels.
The color reproducibility of the projected image can be improved.
In addition, by adopting a reflection type liquid crystal panel, each color light separated by the prism can be modulated and the light path incident on the prism can be shortened again, so that the projector can be miniaturized.
Furthermore, since the prism combines the respective color lights modulated by the respective reflection type liquid crystal panels, it is not necessary to separately provide a device for combining the respective color lights. Therefore, the projector can be miniaturized also in this respect.

In the above aspect, the polarization separation device includes a polarization separation layer, and the polarization separation layer has a first polarization separation layer and a second polarization separation layer in which the transmission axis and the reflection axis of polarization are the same and are arranged to face each other. A polarization absorbing layer disposed between the polarization separation layer, the first polarization separation layer, and the second polarization separation layer, which absorbs polarization in the reflection axis direction of the first polarization separation layer and the second polarization separation layer; It is characterized by having.
According to such a configuration, even if part of the polarized light reflected by the polarization separation layer is transmitted without being totally reflected by the polarization separation layer, the polarization absorption layer It can absorb the polarization of parts. According to this, it is possible to suppress that the part of the polarized light passes through the polarizing plate, is incident on the projection optical device, and is projected by the projection optical device. Therefore, it is possible to suppress the degradation of the contrast as well as suppressing the disturbance of the projection image.

According to the above aspect, the second light modulation device emits light in a first direction to be incident on the polarization separation device, and the first light modulation device is configured to transmit the light to the polarization separation device. The relay device is disposed on the second direction side substantially orthogonal to one direction, and the relay device is disposed on the opposite side to the second direction with respect to the polarization separation device, and the projection optical device is provided to the polarization separation device It is preferable to be disposed on the first direction side.

According to the above aspect, the modulated light emitted from the second light modulation device is reflected by the polarization separation layer toward the reflective relay device. Then, the reflected modulated light is reflected by the reflection mirror of the relay device and is incident again on the polarization separation device in the process of being incident on the reflection type relay device as substantially circularly polarized light, and is reflected to be reflected. The polarization direction is converted to be able to pass through the polarization separation device. The modulated light is imaged on the first light modulation device by the relay device and is modulated by the first light modulation device. Modulated light emitted from the first light modulation device is reflected by the polarization separation device toward the projection optical device, and is projected by the projection optical device through the polarizing plate.
In such a configuration, the amount of transmitted light is adjusted by the two light modulation devices arranged in series along the optical path of the light emitted from the lighting device, so the contrast of the projected image projected by the projection optical device is improved. It can be done. In addition, in the configuration in which the illumination device is disposed on the opposite side to the projection optical device of the polarization separation device, the light adjustment device can be adopted.

According to the above aspect, the second light modulation device emits light in a first direction to be incident on the polarization separation device, and the relay device is configured to transmit the light to the first direction side with respect to the polarization separation device. And the first light modulation device is disposed on a second direction side substantially orthogonal to the first direction with respect to the polarization separation device, and the projection optical device is configured to set the first light modulation device relative to the polarization separation device. It is preferable to arrange | position on the opposite side to 2 directions.

According to the above aspect, the modulated light emitted from the second light modulation device passes through the polarization separation layer toward the relay device. Then, the modulated light is reflected by the reflection mirror of the relay device and enters the polarization separation device again in the process of entering the polarization separation device again, and enters the reflective relay device as substantially circular polarization, and is reflected to reverse the rotational direction of the circular polarization. By this, the polarization direction is converted. Then, the light is reflected toward the second light modulation device by the polarization separation device. The modulated light is imaged on the first light modulation device by the relay device and is modulated by the first light modulation device. The modulated light emitted from the first light modulation device passes through the polarization separation device toward the projection optical device side,
The light is projected by the projection optical device through the polarizing plate.
In such a configuration, the amount of transmitted light is adjusted by the two light modulation devices arranged in series along the optical path of the light emitted from the lighting device, so the contrast of the projected image projected by the projection optical device is improved. It can be done. Moreover, the said light control apparatus can be employ | adopted in the structure which an illuminating device is arrange | positioned to the side of the said polarization splitter with respect to the side by which the projection optical apparatus of the polarization splitter is arrange | positioned.

FIG. 1 is a schematic view showing a configuration of a projector according to a first embodiment of the present invention. The schematic diagram which shows schematic structure of the optical unit in the said 1st Embodiment. FIG. 2 is a schematic view showing a polarization separation device in the first embodiment. FIG. 2 is a schematic view showing a polarization separation device in the first embodiment. The schematic diagram which shows the comparative example of a polarization splitter. FIG. 7 is a schematic view showing the configuration of a projector according to a second embodiment of the present invention. FIG. 10 is a schematic view showing the configuration of a projector according to a third embodiment of the present invention. The schematic diagram which shows schematic structure of the optical unit which concerns on the said 3rd Embodiment. FIG. 11 is a schematic view showing the configuration of a projector according to a fourth embodiment of the present invention.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described based on the drawings.
[Schematic configuration of the projector]
FIG. 1 is a schematic view showing the configuration of a projector 1 according to the present embodiment.
The projector 1 according to the present embodiment modulates light emitted from the illumination device 41 provided therein to form an image according to image information, and the image is displayed on a projection surface (not shown) such as a screen. It is an image display device which carries out expansion projection. As shown in FIG. 1, the projector 1 includes an exterior housing 2 having a substantially rectangular shape in plan view, which constitutes an exterior of the projector 1, and an apparatus main body 3 housed in the exterior housing 2.

[Configuration of main unit]
The apparatus main body 3 includes an optical unit 4 as an image forming apparatus for forming a projection image, and a projection optical apparatus 5. In addition, although not shown, the device body 3 is a cooling device for cooling the cooling target of the projector 1, and a power supply device for supplying power to each component of the projector 1,
And a control device that controls the operation of the projector 1.

[Configuration of Projection Optical Device]
The projection optical device 5 enlarges and projects the projection image formed by the optical unit 4 onto the projection surface. The projection optical device 5 is configured as a combined lens including a plurality of lenses (not shown) and a lens barrel that houses the plurality of lenses therein.
In the following description, when the projector 1 is disposed so that the bottom surface portion of the exterior housing 2 faces the installation surface, the projection direction of the image by the projection optical device 5 is the Z direction, and is orthogonal to the Z direction. And, a direction from the bottom to the top (a direction from the lower side to the upper side in the vertical direction) is taken as the Y direction, orthogonal to the Y and Z directions, and viewed along the Z direction The direction from left to right along is the X direction.

[Configuration of optical unit]
FIG. 2 is a schematic view showing the optical unit 4.
The optical unit 4 includes an illumination device 41, a light modulation light modulation device 42 as a second light modulation device, a polarization separation device 43, a relay device 44, a λ / 4 plate 45 as a phase difference plate, 1 A light modulation device 46 for image as a light modulation device, a polarization plate 47, and an optical component casing 48 (see FIG. 1) for housing the respective optical components 41 to 47. The light modulation device LA1 is configured by including the light modulation light modulation device 42, the polarization separation device 43, the relay device 44, and the λ / 4 plate 45.
Among these, although the optical component casing 48 is not shown in detail, a component storage member for storing various optical components, and a lid-like member for closing an opening for component storage formed in the component storage member. And. An illumination optical axis Ax is set inside the optical component casing 48, and the optical components 41 to 47 are disposed at predetermined positions with respect to the illumination optical axis Ax.

The illumination device 41 includes a light source device and a homogenizing device which is an integrator optical system, though not shown, and emits illumination light having a uniform illuminance distribution in a plane orthogonal to the central axis. Note that
The illumination device 41 emits linearly polarized light having one type of polarization direction as the illumination light. In the present embodiment, the illumination device 41 emits p-polarized light to the polarization separation device 43.

The light source device emits fluorescence (including green light and red light) from a solid state light source and a part of excitation light that is blue light incident from the solid state light source, and transmits other part of the excitation light. And a fluorescent material to be used. In addition to this, the light source device may be configured to include solid light sources that respectively emit red, green and blue color lights, or may be configured to include discharge light source lamps such as ultra-high pressure mercury lamps.

The homogenizing device includes, for example, a first lens array, a second lens array, and a polarization conversion element.
And a superposition lens.
Among these, the first lens array divides the incident light beam into a plurality of partial light beams, and
The lens array superimposes each of the plurality of partial light beams incident from the first lens array on the dimming light modulation device 42 described later together with the superimposing lens.
The polarization conversion element has a function of aligning and emitting the polarization direction of the incident light. In the present embodiment, the polarization conversion element converts the light from the light source device into p-polarization.

The light control device LA1 transmits the light emitted from the light control light modulation device 42 in the first direction D1 (parallel to the Z direction) to the light through the polarization separation device 43, the relay device 44, and the λ / 4 plate 45. First direction D
The light is emitted in the second direction D 2 (parallel to the X direction) orthogonal to 1 and made incident on the light modulator for image 46.
The light modulation light modulation device 42 modulates p-polarized light emitted from the illumination device, and emits modulated light which is s-polarized light in the first direction D1. Further, the light modulation light modulation device 42 modulates the illumination light emitted from the illumination device 41, and the illumination intensity in the plane orthogonal to the central axis of the luminous flux of the illumination light is adjusted for each pixel or area of the image. Modulated light (modulated light by the light modulation light modulation device 42) is emitted as
As shown in FIG. 2, the light modulation light modulation device 42 for controlling light transmits an incident side polarization plate 42 that transmits p-polarized light.
1, a light modulation light modulator 422 which is a transmission type liquid crystal panel, and an exit side polarization plate 423 which transmits s-polarized light. The incident side polarization plate 421, the light modulation light modulator 422, and the emission side polarization plate 423 are disposed along the Z direction.

In the light modulation light modulation device 42, the light modulation light modulator 422 is controlled for each pixel according to the control signal, and the illuminance is modulated in a plane orthogonal to the central axis of the luminous flux.
The light modulation light modulator 422 may be different from the image light modulation device 462, which is a liquid crystal panel for image formation provided in the image light modulation device 46 described later, in the image formation area and the resolution. For example, the light modulation light modulator 422 for illuminance adjustment may use a liquid crystal panel having a resolution lower than that of the image light modulator 462 used for forming an image.

The polarization separation device 43 is a polarization beam splitter having a polarization separation layer 43A inclined with respect to the first direction D1, reflecting s-polarization incident on the polarization separation layer 43A, and transmitting p-polarization. The polarization separation layer 43A is inclined 45 ° with respect to the X axis and the Z axis so as to be orthogonal to the ZX plane and to go in the direction opposite to the Z direction as it goes in the X direction. This polarization separation layer 43A
The s-polarized light that has entered the first direction D1 is reflected in the direction opposite to the X direction and in the direction opposite to the second direction D2. The detailed configuration of this polarization separation device 43 will be described later.

The relay device 44 is a reflection type imaging optical system for forming the illuminance modulated light emitted from the light modulation light modulation device 42 at a predetermined imaging position, and includes a lens 441 and a reflection mirror 442.
The lens 441 and the reflection mirror 442 are disposed on the optical path of the illuminance-modulated light which is reflected by the polarization separation layer 43A and travels in the direction opposite to the second direction D2.
By the relay device 44 configured as described above, the illuminance-modulated light passes through the lens 441 in the direction opposite to the second direction D2, is reflected by the reflection mirror 442, and passes through the lens 441 in the second direction D2. The light beam is substantially formed on an image light modulator 462 described later.

Although illustration is omitted, a minute unevenness is formed in the reflection mirror 442, and the image of the illuminance-modulated light (light control light) formed in the vicinity of the image light modulator 462 due to the unevenness The image of the modulated light by the modulator 422 is scattered. Thereby, the illumination range of the modulated light by each pixel of the light modulation light modulator 422 is expanded, and the light modulation is performed in a range including the corresponding pixel in the image light modulator 462 and the black matrix surrounding the pixel. Modulated light from each pixel of the for-use light modulator 422 is made incident, and the black matrix becomes inconspicuous in the projected image, and generation of image disturbance such as moire is suppressed.

The λ / 4 plate 45 is a retardation plate disposed on the optical path of light traveling along the second direction D2.
This illuminance-modulated light passes through the λ / 4 plate 45 and becomes approximately circularly polarized light clockwise or counterclockwise,
The light is reflected by the mirror 442 of the relay device 44 to become substantially circularly polarized light that rotates in the opposite direction. Thereafter, the light passes through the λ / 4 plate 45 again. Thus, the illuminance-modulated light is output from the polarization separation device 43.
The light is emitted as polarized light, is incident on the polarization separation device 43 as p-polarized light, and passes through the polarization separation layer 43 A of the polarization separation device 43.

As shown in FIG. 2, the image light modulation device 46 modulates the illuminance modulation light (p polarization) emitted from the polarization separation device 43 in the second direction D2 according to the image signal, and modulates it as s polarization. The light is emitted as image modulation light in the direction opposite to the second direction D2. As shown in FIG. 1, the light modulator for image 46 for the second direction D2 side of the polarization splitter 43 (in the X direction, the polarization splitter 43
And a dichroic prism 461 as a color separation device, and three image light modulators 462.

The dichroic prism 461 has four faces 4 intersecting the XZ plane as shown in FIG.
The illuminance-modulated light incident from the first surface 4611 opposite to the X direction among the 611-414 is separated into each color light, and the separated color light is a corresponding surface other than the first surface 4611 (red light The light guide 462 guides the green light to the third surface 4613, and the blue light to the imaging light modulator 462 disposed along the fourth surface 4614).
In addition, the dichroic prism 461 combines the red light incident from the second surface 4612, the green light incident from the third surface 4613, and the blue light incident from the fourth surface 4614, and combines the light It emits from the first surface 4611.

Examples of the dichroic prism 461 include cross dichroic prisms, and various dichroic prisms such as Phillips prisms and gapless prisms. Also, instead of the dichroic prism 461, a plurality of dichroic mirrors may be arranged.

The image light modulator 462 corresponds to the reflection type light modulation device of the present invention, and as shown in FIG.
It is a reflective liquid crystal panel provided for each of the separated color lights. The image light modulator 462 modulates the incident color light (p-polarized light) according to the image signal input from the control device, and emits color light (s-polarized image modulation light) corresponding to the color image of each color. Do. In the illustrated example, the image light modulator for red light 462 (R) is formed along the second surface 4612, and the image light modulator for green light 462 (G
) Is the third surface 4613, and the image light modulator for blue light 462 (B) is the fourth surface 4614).
Are arranged along the Further, each of the image light modulators 462 is a relay device 44.
It is arranged at the imaging position of the illumination intensity modulated light by

The respective image modulated lights (s-polarized light) modulated by the respective image light modulators 462 are combined by the dichroic prism 461 to form image light. The image light (s-polarized light) is emitted from the first surface 4611 in the direction opposite to the second direction D2.
The image light modulator 462 being disposed at the above-described imaging position is disposed at a position where it is allowed from the imaging position of the illuminance modulated light, that is, at a position where the illuminance modulated light is substantially imaged. It also includes the case of placement.

The polarizing plate 47 transmits s-polarized light and blocks p-polarized light. The polarization plate 47 is a polarization separation device 4
It is disposed between the polarization separation device 43 and the projection optical device 5 on the first direction D1 side of 3 (the side opposite to the light modulation light modulation device 42 with respect to the polarization separation layer 43A). The polarizing plate 47 is
It blocks p-polarization from the polarization separation device 43 toward the projection optical device 5 and transmits s-polarization which is image modulation light. As a result, it is possible to suppress the decrease in the contrast of the projected image due to the transmission of the p-polarized light other than the image modulated light.

[Optical path in the optical unit]
In the optical unit 4, as shown in FIG. 2, the light modulation light modulation device 42 includes an illumination device 41.
The illumination light emitted in the first direction D1 is modulated to emit the s-polarized light in the first direction D1. The emitted illuminance modulated light proceeds in the first direction D1 and is incident on the polarization separation device 43,
The light is reflected toward the relay device 44 in the polarization separation layer 43A, and travels in the opposite direction to the second direction D2. The reflected illuminance modulated light is converted into p-polarized light through the relay device 44 and the λ / 4 plate 45, and is incident on the polarization separation device 43 in the second direction D2. The illuminance-modulated light that has been incident on the polarization separation device 43 is converted into p-polarization, so it passes through the polarization separation layer 43A, and the image light modulation device 46
It is incident on The illuminance-modulated light incident on the image light modulation device 46 is emitted in the opposite direction to the second direction D2 as image modulation light that is s-polarized light, and is incident on the polarization separation device 43 again, in the polarization separation layer 43A. It is reflected to the projection optical device 5 side. The reflected image modulated light is
The light travels in the direction D1, passes through the polarizing plate 47, and is incident on the projection optical device 5, as shown in FIG.

[Configuration of polarization separation apparatus]
3 and 4 schematically show the configuration of the polarization separation device 43. As shown in FIG.
The polarization separation device 43 includes a first polarization separation portion 431 having a first polarization separation layer 431A, and a second polarization separation portion 431A.
A second polarization separation unit 432 having a polarization separation layer 432A and a polarization absorption layer 433 are provided.
The first polarization separation section 431 is a right-angle prism (prism of right triangle prism), and the first polarization separation layer 431A constituting the polarization separation layer 43A is formed on the slope.

The second polarization separation unit 432 is disposed to face the first polarization separation unit 431, and is configured in the same manner as the first polarization separation unit 431. That is, the second polarization separation unit 432 includes the first polarization separation layer 431.
The second polarization separation layer 432A has the same transmission / reflection characteristics as A and the polarization. The first polarization separation layer 431A and the second polarization separation layer 432A have the same transmission axis and reflection axis of polarized light, and are disposed to face each other. In the present embodiment, the first polarization separation layer 431A and the second polarization separation layer 432A transmit p polarization and reflect s polarization.
The polarization absorbing layer 433 is an optical element which is disposed between the first polarization separation layer 431A and the second polarization separation layer 432A, absorbs s-polarization, and transmits p-polarization. The polarization separation layer 43A is
Is configured to include a first polarization separation layer 431A, a second polarization separation layer 432A, and a polarization absorption layer 433.

FIG. 5 is a view schematically showing a polarization separation device 6 not provided with the polarization absorption layer 433. As shown in FIG.
Here, the polarization separation device 6 in which the polarization absorption layer 433 is not formed is referred to as “polarization separation device 4”.
The case of adopting in place of 3 will be described.
The polarization separation device 6 includes a first polarization separation part 431 and a second polarization separation part 432, and the first polarization separation layer 431A and the second polarization separation layer 432A are joined. When the polarization separation device 6 configured in this way is used in place of the polarization separation device 43 of the present embodiment, s-polarized light traveling in the Z direction from the light modulation light modulation device 42 is the first polarization separation layer 431A. The said s without being totally reflected
When a part of the polarized light is transmitted toward the projection optical device 5, the projection optical device 5 is disturbed in the projection image or the contrast is lowered.
On the other hand, in the polarization separation device 43 of the present embodiment, part of s-polarized light is the first polarization separation layer 4.
Even if it transmits without being totally reflected by 31 A, the transmitted s-polarized light is absorbed by the polarization absorbing layer 433 as shown in FIG. Therefore, it is possible to suppress the disturbance of the projection image and the decrease in contrast due to the transmission of the s-polarized light.

[Effect of First Embodiment]
According to the projector 1 according to the present embodiment described above, the following effects can be obtained.
The illuminance-modulated light emitted from the light modulation light modulation device 42 is reflected toward the reflective relay device 44 by the polarization separation layer 43A. Then, the reflected illuminance modulated light is reflected by the reflection mirror 442 of the relay device 44 and is again incident on the polarization separation device 43,
Pass the λ / 4 plate twice. Thereby, the polarization direction of the illuminance-modulated light is converted from s-polarization to p-polarization, and can pass through the polarization separation device 43.
Therefore, the polarization separation device 43 can reliably separate the illuminance-modulated light incident from the light modulation light modulation device 42 and the light reflected by the relay device 44 according to the difference in polarization direction. Thus, it is possible to reliably guide the illuminance modulation light by the light modulation light modulation device 42 to the relay device 44, and further, the illuminance modulation light reflected by the relay device 44 and imaged on the image light modulator 462 The light can be reliably emitted to the image light modulator 462 (image light modulator 46).
Then, in such a light adjustment device LA1, after the illuminance modulated light reciprocates between the polarization separation device 46 and the relay device 45 by reflection, the light modulator for image 4 from the polarization separation device 45 is used.
Since the light is emitted to the side 62 (the image light modulation device 46), each component of the light adjustment device LA1 can be compactly arranged. Therefore, the light control device LA1 can be miniaturized, and hence the projector 1 can be miniaturized.
Further, the light modulation light modulation device 42 (light modulation light modulator 422) and the image light modulation device 46, which are two light modulation devices arranged in series along the optical path of the light emitted from the illumination device 41. Since the transmitted light amount is adjusted by the (image light modulator 462), the contrast of the projected image projected by the projection optical device 5 can be improved.

The polarization separation device 43 includes a polarization absorption layer 433 that absorbs s-polarized light. Therefore, even when a part of the s-polarized light reflected by the polarization separation layer 43A is transmitted without being totally reflected by the polarization separation layer 43A, the polarization absorption layer 433 can transmit the s-polarized light. It can absorb part. According to this, it is possible to suppress that part of the s-polarized light is incident on the projection optical device 5 and is projected by the projection optical device. Therefore, it is possible to suppress the degradation of the contrast as well as suppressing the disturbance of the projection image.

Here, in the present embodiment, the optical axis of the illumination light of the light modulation light modulation device 42 and the optical axis of the projection optical device 5 coincide with each other. Therefore, the illuminance-modulated light (p-polarized light) from the light modulation light modulation device 42 is
Although there is a possibility that the contrast of the above-mentioned projection image may be lowered by transmitting the polarization separation layer 43A, in such a case, by providing the polarizing plate 47 which absorbs p polarized light, the contrast is effectively lowered. It can be suppressed.

The image light modulation device 46 divides the illuminance-modulated light into a plurality of color lights by the dichroic prism 461 and causes the light to enter the image light modulator 462. The image light modulator 462 modulates each color light to form image light, and causes the light to enter the dichroic prism 461 again. The dichroic prism 461 combines the image lights corresponding to the respective colors to form image modulated light (s-polarized light).
Thereby, since the said color light can be modulated for every color light contained in illumination intensity modulation light, the color reproducibility of a projection image can be improved.
In addition, the adoption of the reflective image light modulator 462 modulates each color light separated by the dichroic prism 461 and shortens the light path incident on the color separation device again, so that a projector can be used. It can be miniaturized.
Furthermore, since the dichroic prism 461 combines the respective color lights modulated by the image light modulator 462 corresponding to each color, it is not necessary to separately provide a device for combining the respective color lights. Therefore, the projector 1 can be simplified and miniaturized also in this respect.

In the above-described configuration, since the plurality of color lights are separated from the illuminance modulation light by the dichroic prism 461, only one light modulation light modulation device 42 is required. Therefore, in addition to the configuration of the projector 1 being simplified as compared to the case where the light modulation light modulation device 42 is provided for each color light to be separated, the projector 1 can be miniaturized.

The projector 1 includes a transmissive light modulation light modulator 422. As a result, the light modulation light modulation device 42 can be disposed on the light path of light traveling straight toward the polarization separation device 43 without disposing an optical member such as a mirror or a prism, and the configuration of the projector 1 can be simplified. In addition, miniaturization can be achieved.

Second Embodiment
Next, a second embodiment of the present invention will be described.
The projector according to the present embodiment has the same configuration as the projector 1 described above. Here, in the projector 1, the light modulation light modulation device 42 is a transmission type light modulation light modulator 4.
The incident direction of the illumination light from the illumination device 41 and the emission direction of the illuminance-modulated light emitted from the light modulation light modulation device 42 coincide with each other. On the other hand, in the projector according to the present embodiment, the light modulation light modulation device includes the reflection type light modulation light modulator, and the incident direction of the illumination light and the light modulation light device from the light modulation light modulation device It is configured to be orthogonal to the emission direction. In the following description, descriptions of parts that are the same as or substantially the same as the parts described above will be omitted.

FIG. 6 is a diagram showing a schematic configuration of the projector 1A.
As shown in FIG. 6, the projector 1A has the same configuration and function as the projector 1 except that the projector 1A has an apparatus body 3A instead of the apparatus body 3, and the apparatus body 3A replaces the optical unit 4 The configuration is the same as that of the device main body 3 except that the optical unit 4A is included.
The optical unit 4A includes an illumination device 41A, a light control device LA2, an image light modulation device 46, and a polarizing plate 47. Among these, the light control device LA2 includes the light control light modulation device 42A, the polarization separation device 43, the relay device 44, and the λ / 4 plate 45. The illumination device 41A emits illumination light in the X direction. The illumination device 41A is configured in the same manner as the illumination device 41 of the first embodiment except the emission direction of the illumination light.

The light modulation light modulation device 42A modulates the illumination light emitted from the illumination device 41A, modulates the illuminance in a plane orthogonal to the central axis of the luminous flux of the illumination light, and modulates the illuminance modulated light which is s-polarization It emits in one direction D1. The light modulation light modulation device 42A transmits the p-polarized light by the incident side polarization plate 42.
1A, a light modulation light modulator 422A that is a reflective liquid crystal panel, an output side polarizing plate 423A that transmits s-polarized light, and a polarization separation device 424.

The incident side polarizing plate 421A is disposed on the opposite side to the X direction of the polarization separation device 424.
The dimming light modulator 422A is disposed on the X direction side of the polarization separation device 424.
The exit side polarization plate 423A is disposed on the Z direction side of the polarization separation device 424.
The polarization separation device 424 has a polarization separation layer 424A that reflects s-polarized light and transmits p-polarized light. The illumination light that is p-polarized light that has entered in the X direction with respect to the polarization separation layer 424A passes through the polarization separation layer 424A. Further, it is emitted from the light modulation optical modulator 422A, and the polarization separation layer 424
The illuminance-modulated light, which is s-polarized light that is incident to the direction opposite to the X direction with respect to A, is reflected in the first direction D1 parallel to the Z direction.

[Effect of Second Embodiment]
According to the projector 1A according to the embodiment described above, the same effects as those of the projector 1 can be obtained, and in addition, the following effects can be obtained.
The light modulation light modulation device 42A in the projector 1A includes a polarization separation device 424,
The illumination light (p-polarization) emitted from the illumination device 41 in the X direction is modulated, and the illumination modulation light (s-polarization) is emitted in a first direction D1 orthogonal to the X direction. In such a configuration, as compared with the case where the illumination light from the illumination device 41 is emitted in the Z direction, a part of the illumination light is transmitted as it is, and the projection image is disturbed by entering the projection optical device 5 or It is possible to suppress the decrease in contrast.

Third Embodiment
Next, a second embodiment of the present invention will be described.
The projector according to the present embodiment has the same configuration as the projector 1 described above. Here, in the projector 1, the light modulation light modulation device 42, the projection optical device 5, and the polarization separation device 43 are disposed so as to sandwich them, and the relay device 44 and the image light modulation device 46 sandwich the polarization separation device 43. It was arranged as. On the other hand, in the projector according to the present embodiment, the light modulation device for light modulation 46 and the projection optical device 5 are polarized so that the light modulation light modulation device and the relay device 44 sandwich the polarization separation device. It is arranged to sandwich the separation device. In the following description, descriptions of parts that are the same as or substantially the same as the parts described above will be omitted.

FIG. 7 is a diagram showing a schematic configuration of the projector 1B.
As shown in FIG. 7, the projector 1 </ b> B includes an apparatus main body 3 </ b> B housed in the exterior housing 2. The device body 3 B includes an optical unit 4 B and a projection optical device 5.
The optical unit 4B includes an illumination device 41B, a light control device LA3, an image light modulation device 46, a polarizing plate 47, and an optical component casing 48. Among these, the light adjustment device LA3 includes a light adjustment light modulation device 42B, a polarization separation device 43, a relay device 44, and a λ / 4 plate 45.

FIG. 8 is a schematic view showing the optical unit 4B.
The illumination device 41B is disposed on the X direction side of the polarization separation device 43, and s in the direction opposite to the X direction.
It emits polarized illumination light. The illumination device 41B is configured in the same manner as the illumination device 41 of the first embodiment except that the illumination light is s-polarized light and the emission direction of the illumination light is different.

The light adjustment device LA3 transmits the light emitted from the light adjustment light modulation device 42B in the first direction D3 (parallel to the X direction) through the polarization separation device 43, the relay device 44, and the λ / 4 plate 45. The light is emitted in the second direction D4 (parallel to the Z direction) orthogonal to the first direction D3 and is incident on the image light modulation device 46.
The light modulation light modulation device 42B modulates the illumination light emitted from the illumination device 41B, adjusts the illuminance in the plane orthogonal to the central axis of the illumination light, and modulates the illuminance modulated light that is p-polarized light in the first direction D3. Emit at. The light modulation light modulation device 42B includes an incident side polarization plate 421B that transmits s polarized light, a light modulation light modulator 422 that is a transmissive liquid crystal panel, and an emission side polarization plate 4 that transmits p polarized light.
And 23B.

The relay device 44 and the λ / 4 plate 45 control the polarization separation device 43 with the light modulation light modulation device 42.
It is arranged on the opposite side to B.
The image light modulation device 46 is disposed on the opposite side of the polarization separation device 43 in the Z direction. The image light modulation device 46 passes through the relay device 44 and the λ / 4 plate 45, and is incident on the polarization separation layer 43A in the direction opposite to the first direction D3. The second direction D4 (the direction opposite to the Z direction The illuminance-modulated light reflected by. Then, the image light modulation device 46 modulates the incident illuminance modulation light, and emits the image modulation light in the direction opposite to the second direction D4.
The projection optical device 5 is disposed on the opposite side of the polarization separation device 43 from the light modulation device 46 for image (see FIG. 7).

[Effect of Third Embodiment]
According to the projector 1B according to the present embodiment described above, in addition to the same effects as those of the projector 1, the following effects can be achieved. For example, the light control device LA3 can adjust the illuminance of light incident on the image light modulator 462 for each region in a plane orthogonal to the central axis of the light, so that the contrast of the projected image can be improved.

Fourth Embodiment
Next, a fourth embodiment of the present invention will be described.
The projector according to this embodiment has the same configuration as that of the projector 1B of the third embodiment. Here, in the projector 1B, the light modulation light modulation device 42B includes the transmission type light modulation light modulator 422, and the incident direction of the illumination light from the light modulation light modulation device 42B and the light modulation The emission directions of the illuminance-modulated light emitted from the light modulation device 42B are the same. On the other hand, in the projector according to the present embodiment, the light control device includes the reflection type light control light modulator, and the incident direction of the illumination light and the emission direction of the light from the light control light modulator are Configured to be orthogonal. In the following description, descriptions of parts that are the same as or substantially the same as the parts described above will be omitted.

FIG. 9 is a diagram showing a schematic configuration of the projector 1C.
As shown in FIG. 9, a projector 1 </ b> C according to the third embodiment includes an apparatus main body 3 </ b> C housed in the exterior housing 2. The device body 3C includes an optical unit 4C and a projection optical device 5. Among them, the optical unit 4C includes an illumination device 41C, a light control device LA4, an image light modulation device 46, and a polarizing plate 47. Among these, the light control device LA4 includes the light control light modulation device 42C, the polarization separation device 43, the relay device 44, and the λ / 4 plate 45. In the present embodiment, the illumination device 41C emits illumination light of s-polarization in the Z direction.

The light adjustment device LA4 orthogonally crosses the light emitted from the light modulation light modulation device 42C in the first direction D3 to the first direction D3 via the polarization separation device 43, the relay device 44, and the λ / 4 plate 45. The light is emitted in the second direction D4 to be incident on the light modulation device 46 for image.
The light modulation light modulation device 42C modulates the illuminance in the plane orthogonal to the central axis of the luminous flux of the illumination light emitted from the lighting device 41C, and emits the illuminance modulation light of p polarization in the first direction D3. The dimming light modulation device 42C is disposed on the opposite side of the polarization separation layer 43A to the relay device 44.
The light modulation light modulation device 42C includes an incident-side polarization plate 421C that transmits s-polarized light, a light modulation light modulator 422 that is a reflective liquid crystal panel, and an emission-side polarization plate 423C that transmits p-polarization.
And a polarization separation device 425 having a polarization separation layer 425A.

The incident side polarizing plate 421C is disposed on the opposite side to the Z direction of the polarization separation device 425.
The dimming light modulator 422 is disposed on the X direction side of the polarization separation device 425.
The exit side polarizing plate 423 C is disposed on the opposite side to the X direction of the polarization separation device 425.
The polarization separation device 425 has a polarization separation layer 425A that reflects s-polarized light and transmits p-polarized light. The illumination light that is s-polarized light that has entered the polarization separation layer 425A in the Z direction has a first direction D3.
Is reflected in the opposite direction. Further, the light is emitted from the light modulation light modulator 422, and the polarization separation layer 42 is
The illuminance-modulated light that is p-polarized light that is incident in the first direction D3 with respect to 5A is a polarization separation layer 425A.
Through.

[Effect of Fourth Embodiment]
According to the projector 1B according to the embodiment described above, the projector 1B is
In addition to the same effects as the above, the following effects can be achieved.
The light modulation light modulation device 42C includes a polarization separation device 425, and modulates illumination light (s-polarization) emitted from the illumination device 41C in the Z direction, and reverses illuminance modulation light (p-polarization) to the X direction. Emit in the direction. With such a configuration, it is possible to suppress the disturbance of the projection image and the decrease in contrast due to the transmission of part of the s-polarized light that is not the illuminance modulation light among the illumination light from the illumination device 41C without being shielded.

[Modification of the embodiment]
The present invention is not limited to the above-described embodiments, and modifications, improvements, and the like in the range in which the object of the present invention can be achieved are included in the present invention.
In each of the above embodiments, a cube-shaped polarization separation splitter is employed, but the present invention is not limited to this. For example, a plate-like polarization separation splitter may be used in which an optical film that reflects s-polarized light and transmits p-polarized light is formed on both sides of a plate-like optical member.

In each of the above-described embodiments, in the polarization separation device 43, the polarization absorption layer is disposed between the pair of polarization separation layers, but the present invention is not limited to this. For example, a cube-shaped polarization separation splitter including a pair of right angle prisms and a polarization separation layer disposed between the right angle prisms may be used.

In each of the above embodiments, the polarization separation device 43 exemplifies a configuration having a polarization separation layer that reflects s-polarized light and transmits p-polarized light, but the present invention is not limited to this. That is, it transmits s-polarized light,
A polarization splitter that reflects p-polarization may be employed.

In each of the above embodiments, a reflective liquid crystal panel in which the light incident surface and the light emission surface are the same is adopted as the light modulator for image, but a transmissive liquid crystal panel in which the light incident surface and the light emitting surface are different. May be used. For example, the second light modulation device includes an incident side polarization plate, a transmission type liquid crystal panel, and an emission side polarization plate, and the image modulation is performed on the projection optical device 5 disposed on the light emission side of the second modulation device. A configuration in which light is incident may be employed.

In each of the above-described embodiments, the projector includes three liquid crystal panels as the image light modulators, but the present invention is not limited to this. That is, the present invention is applicable to a projector using two or less or four or more liquid crystal panels.
In each of the above embodiments, the arrangement position of each optical component in the optical unit 4 can be changed as appropriate, and for example, a configuration having a substantially L shape in plan view or a configuration having a substantially U shape in plan view May be

In each of the above-described embodiments, an image light modulation device 46 including a plurality of image light modulators 462 is provided for one light adjustment device, and a configuration in which the light modulation device is shared by these image light modulators 462 is provided. Although employed, the present invention is not limited thereto. For example, the light control devices may be arranged individually for each of the plurality of image light modulators. In this case, the dichroic prism 461 is disposed on the output side of the image modulated light in the light adjustment device without arranging the dichroic prism 461 between the polarization separation device 43 and the image light modulator 462. Then, it is possible to exemplify a configuration in which the projection image formed by the color synthesis by the dichroic prism 461 is projected by the projection optical device.

In each of the above-described embodiments, the configuration in which the liquid crystal panel is adopted as the light modulator has been exemplified. However, as long as it is a light modulator capable of modulating the incident light flux according to the control signal (image information) May be adopted. For example, the present invention can be applied to a projector using an optical modulator other than liquid crystal, such as a device using a micro mirror. Even in the case of using such a light modulation device, a polarizing plate may be appropriately disposed to appropriately set the polarization direction of the modulated light.

1, 1A, 1B, 1C: projector, 5: projection optical device, 41, 41A, 41B,
41C: illumination device, 42, 42A, 42B, 42C: light modulation device for light control (second light modulation device) 43: polarization separation device 43A: polarization separation layer 44: relay device 45: λ / 4 plate , 4
6: Light modulation device for image (first light modulation device, reflection type light modulation device), 47: polarizing plate, 422,
422A: light modulator for dimming control, 431A: first polarization separation layer, 432A: second polarization separation layer, 4
33 Polarization absorbing layer 441 Lens 442 Reflecting mirror 461 Dichroic prism (prism) 462 Image light modulator (reflection type light modulator, liquid crystal panel) D1,
D3: first direction, D2, D4: second direction, LA1, LA2, LA3, LA4: light control device.

Claims (6)

An image forming apparatus for forming an image;
A projection optical device for projecting the formed image;
The image forming apparatus is
A lighting device,
A first light modulation device that modulates light emitted from the lighting device;
A light control device, disposed on the light path between the lighting device and the first light modulation device, for adjusting the illuminance in a plane orthogonal to the central axis of the light emitted from the lighting device for each area; Equipped
The light control device
A second light modulation device that modulates light emitted from the lighting device;
A reflective relay device for forming the modulated light modulated by the second light modulation device on the first light modulation device;
A polarization separation device that guides the modulated light incident from the second light modulation device to the relay device and emits the modulated light reflected by the relay device to the first light modulation device side;
Wherein disposed between the polarizing beam splitter and the relay device, have a, a phase difference plate to be substantially circularly polarized light light incident from the polarization separating device,
The polarization separation device comprises a polarization separation layer,
The polarization separation layer is
A first polarization separation layer and a second polarization separation layer in which the transmission axis and the reflection axis of the polarized light are the same and are arranged to face each other;
Characterized in that have a first is arranged between the polarization separation layer and the second polarization separation layer, polarized absorption layer for absorbing polarized light of the reflected axis direction of the first polarization separating layer and the second polarization separating layer To be a projector. The projector according to claim 1, wherein
A projector characterized in that the second light modulation device is a transmissive liquid crystal panel. The projector according to claim 1 or 2, wherein
The projector according to claim 1, wherein the first light modulation device includes a reflective light modulator. The projector according to claim 3, wherein
The first light modulation device is
A plurality of reflective liquid crystal panels as the reflective light modulators;
It is disposed between the plurality of reflective liquid crystal panels and the light control device, and the light emitted from the light control device is color separated to be incident on each of the plurality of reflective liquid crystal panels; And a prism configured to color combine light emitted from each of the reflection type liquid crystal panels and to make the light enter the polarization separation device. The projector according to any one of claims 1 to 4 , wherein
The second light modulation device emits light in a first direction to be incident on the polarization separation device.
The first light modulation device is disposed on a second direction side substantially orthogonal to the first direction with respect to the polarization separation device.
The relay device is disposed on the side opposite to the second direction with respect to the polarization separation device.
The projector according to claim 1, wherein the projection optical device is disposed on the first direction side with respect to the polarization separation device. The projector according to any one of claims 1 to 4 , wherein
The second light modulation device emits light in a first direction to be incident on the polarization separation device.
The relay device is disposed on the first direction side with respect to the polarization separation device.
The first light modulation device is disposed on a second direction side substantially orthogonal to the first direction with respect to the polarization separation device.
The projector according to claim 1, wherein the projection optical device is disposed on the opposite side to the second direction with respect to the polarization separation device.

Images