Projection device, active state regulation apparatus, polarization control device, and circadian rhythm control device

Abstract

To provide a projection device, an active state regulation apparatus, a polarization control device, and a circadian rhythm control device, which are capable of emitting light having a random polarization state.SOLUTION: A projection device comprises: a light modulation element that modulates incident light on the basis of an image signal; a projection lens that projects the light output from the light modulation element; and a polarization control device that is arranged closer to an emission side than the light modulation element in an optical path of the light which is emitted from the light modulation element and projected by the projection lens, and that controls a polarization state of the light modulated by the light modulation element. The polarization control device includes: a first substrate; a second substrate arranged to face the first substrate; a first organic film layered on the first substrate and having no orientation regulating force that regulates orientations of liquid crystal molecules; a second organic film layered on the second substrate and having no orientation regulating force that regulates orientations of liquid crystal molecules; and a liquid crystal layer arranged between the first organic film and the second organic film. The liquid crystal layer contains a plurality of liquid crystal molecules, of which the major axes are arranged disorderly with respect to the first organic film and the second organic film.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a projection device, an active state adjustment device, a polarization control device, and a circadian rhythm control device.

Background Art

[0002] Conventionally, a projection device including a color synthesis unit that synthesizes red, green, and blue light of each color to emit synthesized light, a polarization conversion unit, and a projection lens has been known (see, for example, Patent Document 1). In the projection device described in Patent Document 1, the polarization conversion unit converts the polarization state of each color light emitted by the color synthesis unit into an omnidirectionally uniform unpolarized state. Specifically, the polarization conversion unit is any one of a wavelength-selective half-wave plate that shifts the phase by π with respect to a predetermined wavelength, a uniaxial organic material that is an organic material having one optical axis (optical axis), and a uniaxial crystal that is a crystal having one optical axis. By disposing the polarization conversion unit between the color synthesis unit and the projection lens, the polarization of the wavelength within each color light of the synthesized light emitted from the color synthesis unit is converted into mutually different polarizations for each wavelength, and an omnidirectionally uniform unpolarized state without bias is obtained.

[0003] The projection lens projects light in an unpolarized state by the polarization conversion unit. Therefore, the projection light projected from the projection device toward the screen is in an omnidirectionally uniform unpolarized state. An observer wears active shutter glasses. The active shutter glasses alternately block the field of view in synchronization with the switching of the images of the left-eye image and the right-eye image alternately displayed by the projection device, so that the left-eye image enters the left eye of the observer and the right-eye image enters the right eye of the observer. Thereby, the 3D glasses create a parallax and enable stereoscopic vision. In such a projection device, it is possible to eliminate color unevenness of a 3D image in a state where the 3D glasses are not tilted, and to eliminate color unevenness and brightness drop of the 3D image in a state where the 3D glasses are tilted, thereby improving the image quality of the 3D image.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2013 - 113984 Summary of the Invention Problems to be Solved by the Invention

[0005] However, in the projection device described in Patent Document 1, in the polarization conversion unit composed of the retardation plate or the like, since the incident light is converted into polarized light that is different for each wavelength to reduce the degree of polarization and is converted into unpolarized light, there is a problem that the degree of unpolarization is not sufficient. For this reason, a configuration that can emit light in a more random polarization state has been demanded. Means for Solving the Problems

[0006] The projection device according to the first aspect of the present disclosure includes a light modulation element that modulates incident light based on an image signal, a projection lens that projects the light emitted from the light modulation element, and a polarization control device that is disposed on the emission side of the light modulation element in the optical path of the light emitted from the light modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the light modulation element. The polarization control device includes a first substrate, a second substrate disposed opposite to the first substrate, a first organic film laminated on the first substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, a second organic film laminated on the second substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, and a liquid crystal layer disposed between the first organic film and the second organic film. The liquid crystal layer includes a plurality of liquid crystal molecules disposed in a state where the major axis direction is disordered with respect to the first organic film and the second organic film.

[0007] The projection device according to the second aspect of the present disclosure includes a light modulation element that modulates incident light based on an image signal, a projection lens that projects the light emitted from the light modulation element, and a polarization control device that is disposed on the emission side of the light modulation element rather than the light modulation element in the optical path of the light emitted from the light modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the light modulation element. The polarization control device includes a first substrate having a light incident surface on which light is incident, a second substrate disposed opposite to the first substrate, a first electrode disposed on a surface of the first substrate opposite to the light incident surface, a first vertical alignment film laminated on the first electrode and having no alignment restricting force for restricting the alignment direction of liquid crystal molecules when a voltage is applied, a second electrode disposed on a surface of the second substrate on the first substrate side, a second vertical alignment film laminated on the second electrode and having no alignment restricting force for restricting the alignment direction of liquid crystal molecules when a voltage is applied, and a liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and including a plurality of liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode.

[0008] The active state adjustment device according to the third aspect of the present disclosure includes the projection device according to the first or second aspect, and a control device that irradiates the projection device with linearly polarized light and unpolarized light separately to change the active state of a photoreceptor.

[0009] The polarization control device according to the fourth aspect of the present disclosure includes a first substrate, a second substrate disposed opposite to the first substrate, a first organic film laminated on the first substrate and having no alignment restricting force for restricting the alignment direction of liquid crystal molecules, a second organic film laminated on the second substrate and having no alignment restricting force for restricting the alignment direction of liquid crystal molecules, and a liquid crystal layer disposed between the first organic film and the second organic film and including liquid crystal molecules that are disposed in a state where the major axis direction is disordered with respect to the first organic film and the second organic film.

[0010] The polarization control device according to the fifth aspect of the present disclosure includes a first substrate, a second substrate disposed opposite to the first substrate, a first electrode provided on the surface of the first substrate on the second substrate side, a first vertical alignment film laminated on the first electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied, a second electrode provided on the surface of the second substrate on the first substrate side, a second vertical alignment film laminated on the second electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied, and a liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and including liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode.

[0011] The circadian rhythm control device according to the sixth aspect of the present disclosure includes a light source, a polarization control device according to the fourth or fifth aspect described above, which is disposed in the optical path of the light emitted from the light source and controls the polarization state of the incident light, and a control device that controls the polarization control device to emit one of linearly polarized light and unpolarized light from the polarization control device according to the time zone.

Brief Description of the Drawings

[0012]

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[0013] [First Embodiment] Hereinafter, the first embodiment of the present disclosure will be described with reference to the drawings. [Schematic Configuration of Projector] FIG. 1 is a schematic diagram showing the configuration of a projector 1A according to the present embodiment. As shown in FIG. 1, the projector 1A according to the present embodiment is a projection device that modulates the light emitted from the light source 31 to form image light PL corresponding to image information, and enlarges and projects the formed image light PL onto a projection surface PS such as a screen. The projector 1A includes an exterior housing 2, an image projection unit 3A housed in the exterior housing 2, and a control unit 7. In addition, although not shown, the projector 1A includes a cooling device that cools the object to be cooled and a power supply device that supplies power to the electronic components constituting the projector 1A. The control unit 7 controls the image projection unit 3A. For example, the control unit 7 controls the light source 31 and the light modulation element 35 that constitute the image projection unit 3A, and applies a voltage to the polarization control device 5A that constitutes the image projection unit 3A to control the operation of the polarization control device 5A.

[0014] [Configuration of Image Projection Unit] The image projection unit 3A forms and projects image light PL. The image projection unit 3A includes a light source 31, a color separation device 32, an image forming device 33, a projection lens 37, and a polarization control device 5A. In the following description, the direction in which the light source 31 emits illumination light WL is defined as the +Z direction, and the directions orthogonal to the +Z direction are defined as the +X direction and the +Y direction. The direction opposite to the +Z direction is defined as the -Z direction, the direction opposite to the +X direction is defined as the -X direction, and the direction opposite to the +Y direction is defined as the -Y direction. The axis along the +Z direction is defined as the Z axis, the axis along the +X direction is defined as the X axis, and the axis along the +Y direction is defined as the Y axis.

[0015] [Configuration of the light source] The light source 31 emits illumination light WL in the +Z direction. As a configuration of the light source 31, an example of a configuration including a solid-state light-emitting element and a wavelength conversion element that converts the wavelength of the light emitted from the solid-state light-emitting element can be given. Alternatively, as a configuration of the light source 31, an example of a configuration including a discharge light-emitting lamp such as an ultra-high pressure mercury lamp can be given.

[0016] [Configuration of the color separation device] The color separation device 32 separates the illumination light WL incident from the light source 31 into three color lights: blue light LB, green light LG, and red light LR. The color separation device 32 includes dichroic mirrors 321, 322, total reflection mirrors 323, 324, 325, and relay lenses 326, 327. The dichroic mirror 321 transmits the blue light LB among the illumination light WL incident from the light source 31 and reflects the green light LG and the red light LR in the +X direction. The dichroic mirror 322 reflects the green light LG among the green light LG and the red light LR separated by the dichroic mirror 321 in the +Z direction and transmits the red light LR in the +X direction. The green light LG reflected by the dichroic mirror 322 is incident on the green light modulation element 35G included in the image forming device 33.

[0017] The total reflection mirror 323 reflects the blue light LB transmitted through the dichroic mirror 321 in the +X direction. The blue light LB reflected by the total reflection mirror 323 is incident on the blue light modulation element 35B included in the image forming device 33. The total reflection mirror 324 reflects the red light LR that has passed through the dichroic mirror 322 in the +Z direction. The total reflection mirror 325 reflects the red light LR reflected by the total reflection mirror 324 in the -X direction. The red light LR reflected by the total reflection mirror 325 enters the red light modulation element 35R provided in the image forming apparatus 33.

[0018] The relay lens 326 is disposed between the dichroic mirror 322 and the total reflection mirror 324 in the optical path of the red light LR, and the relay lens 327 is disposed between the total reflection mirror 324 and the total reflection mirror 325 in the optical path of the red light LR. The relay lenses 326 and 327 compensate for the optical loss of the red light LR due to the optical path of the red light LR being longer than the optical paths of the blue light LB and the green light LG.

[0019] [Configuration of Image Forming Apparatus] The image forming apparatus 33 individually modulates the incident blue light LB, green light LG, and red light LR, synthesizes the modulated color lights LB, LG, and LR, and forms image light PL that is projected by the projection lens 37. The image forming apparatus 33 includes a field lens 34, a light modulation element 35, and a light combining element 36.

[0020] [Configuration of Field Lens] The field lens 34 collimates the incident light. The image forming apparatus 33 includes three field lenses 34. The three field lenses 34 include a field lens 34B provided in the optical path of the blue light LB, a field lens 34G provided in the optical path of the green light LG, and a field lens 34R provided in the optical path of the red light LR. The color lights LB, LG, and LR that have passed through the respective field lenses 34R, 34G, and 34B enter the light modulation element 35 provided according to the color light.

[0021] [Configuration of Light Modulation Element] The light modulation element 35 modulates the respective color lights emitted from the light source 31 according to the image information, and emits the modulated respective color lights to the light combining element 36. The light modulation element 35 includes a blue light modulation element 35B that modulates blue light LB, a green light modulation element 35G that modulates green light LG separated by the color separation device 32, and a red light modulation element 35R that modulates red light LR.

[0022] Each light modulation element 35 has a light modulation module 351, an incident side polarizing plate 352, and an emission side polarizing plate 353. Specifically, the blue light modulation element 35B has a blue light modulation module 351B that modulates blue light LB, an incident side polarizing plate 352 disposed on the light incident side with respect to the blue light modulation module 351B, and an emission side polarizing plate 353 disposed on the light emission side with respect to the blue light modulation module 351B. The blue light modulation element 35B emits the modulated blue light in the +X direction. The green light modulation element 35G has a green light modulation module 351G that modulates green light LG, an incident side polarizing plate 352, and an emission side polarizing plate 353. The green light modulation element 35G emits the modulated green light in the +Z direction. The red light modulation element 35R has a red light modulation module 351R that modulates red light LR, an incident side polarizing plate 352, and an emission side polarizing plate 353. The red light modulation element 35R emits the modulated red light in the -X direction. In this embodiment, the light modulation module 351 is constituted by a liquid crystal panel, and each light modulation element 35 is a liquid crystal light valve having a light modulation module 351, an incident side polarizing plate 352, and an emission side polarizing plate 353. Further, the emission side polarizing plate 353 of each light modulation element 35 is a polarizing element located on the light incident side of the polarization control device 5A with respect to the polarization control device 5A described later.

[0023] [Configuration of Light Combining Element] The photosynthetic element 36 synthesizes the blue light incident from the blue light modulation element 35B, the green light incident from the green light modulation element 35G, and the red light incident from the red light modulation element 35R to form image light PL, and emits the formed image light PL toward the polarization control device 5A. That is, the photosynthetic element 36 emits the image light PL to the projection lens 37 via the polarization control device 5A. In the present embodiment, the photosynthetic element 36 is configured by a cross-dichroic prism having a substantially rectangular parallelepiped shape. However, the present invention is not limited to this, and the photosynthetic element 36 may be configured by a plurality of dichroic mirrors.

[0024] [Configuration of Projection Lens] The projection lens 37 projects the image light PL incident from the photosynthetic element 36 of the image forming apparatus 33 via the polarization control device 5A onto the projection surface PS. Although not shown, examples of the projection lens 37 include a combination lens having a plurality of lenses and a lens barrel that holds the plurality of lenses.

[0025] [Configuration of Polarization Control Device] FIG. 2 is a cross-sectional view schematically showing the configuration of the polarization control device 5A. In FIG. 2, each of the plurality of liquid crystal molecules 571 is shown to be oriented in the same manner along the left-right direction in FIG. 2. However, in reality, each of the plurality of liquid crystal molecules 571 is randomly oriented in a plane orthogonal to the first substrate 51A or the second substrate 52A. For example, each of the plurality of liquid crystal molecules 571 is orthogonal to the light incident surface 511 of the first substrate 51A and is randomly oriented in a plane including the depth direction toward the paper surface of FIG. 2. The polarization control device 5A controls the polarization state of the image light PL incident from the image forming apparatus 33 and emits unpolarized image light PL. In the present embodiment, the polarization control device 5A is disposed between the photosynthetic element 36 and the projection lens 37 of the image forming apparatus 33 in the optical path of the image light PL emitted from the image forming apparatus 33. However, the present invention is not limited to this, and the polarization control device 5A may be disposed on the light emission side with respect to the projection lens 37 in the optical path of the image light PL. That is, the polarization control device 5A is disposed on the emission side of the light modulation element 35 in the optical path of the image light PL emitted from the light modulation element 35 and projected by the projection lens 37. As shown in FIG. 2, the polarization control device 5A includes a first substrate 51A, a second substrate 52A, a first conductive layer 53, a second conductive layer 54, a first organic film 55, a second organic film 56, and a liquid crystal layer 57. In the following description, linearly polarized light is referred to as linearly polarized light, unpolarized light is referred to as unpolarized light, and circularly polarized light is referred to as circularly polarized light. Among linearly polarized lights, s-polarized light is referred to as s-polarized light, and p-polarized light is referred to as p-polarized light.

[0026] [Configuration of First Substrate and Second Substrate] Each of the first substrate 51A and the second substrate 52A is a translucent substrate, which is a glass substrate in the present embodiment. The first substrate 51A and the second substrate 52A are disposed to face each other in the traveling direction of the image light PL incident on the polarization control device 5A. The first substrate 51A has a light incident surface 511 and a light emission surface 512. The light incident surface 511 is the surface on which the image light PL is incident on the first substrate 51A. The light incident surface 511 is the surface on the first substrate 51A opposite to the light emission surface 512 facing the second substrate 52. The light emission surface 512 is the surface on which the image light PL is emitted from the first substrate 51A and is the surface facing the second substrate 52A. The first conductive layer 53 is formed on the light emission surface 512.

[0027] The second substrate 52A is disposed to face the first substrate 51A. The second substrate 52A has a light incident surface 521 and a light emission surface 522. The light incident surface 521 is the surface of the second substrate 52A that faces the first substrate 51A, and is the surface on which the image light PL is incident in the second substrate 52A. The second conductive layer 54 is formed on the light incident surface 521. The light emission surface 522 is the surface of the second substrate 52A that emits the image light PL. The light emission surface 522 is the surface on the second substrate 52A that is opposite to the light incident surface 521.

[0028] [Configuration of the first conductive layer and the second conductive layer] Each of the first conductive layer 53 and the second conductive layer 54 is an ITO electrode layer. The first conductive layer 53 is formed on the light emission surface 512 of the first substrate 51A. The first conductive layer 53 is laminated between the first substrate 51A and the first organic film 55. The first conductive layer 53 constitutes a first electrode that is electrically connected to the control unit 7. The second conductive layer 54 is formed on the light incident surface 521 of the second substrate 52A. The second conductive layer 54 is laminated between the second substrate 52A and the second organic film 56. The second conductive layer 54 constitutes a second electrode that is electrically connected to the control unit 7. Therefore, the control unit 7 can also apply a voltage to the liquid crystal layer 57 by applying a voltage to the first conductive layer 53 and the second conductive layer 54, and using the first electrode constituted by the first conductive layer 53 and the second electrode constituted by the second conductive layer 54. On the other hand, the first conductive layer 53 and the second conductive layer 54 do not have to be connected to the control unit 7. Thus, unlike a general liquid crystal panel having a pixel electrode and a common electrode that define a pixel, the first conductive layer 53 and the second conductive layer 54 do not define a pixel defined by a transistor or the like that a pixel electrode has in a general liquid crystal panel.

[0029] [Configuration of the first organic film and the second organic film] The first organic film 55 is formed on the first conductive layer 53 laminated on the light emission surface 512 of the first substrate 51A. That is, the first organic film 55 is laminated on the first substrate 51A. The second organic film 56 is formed on the second conductive layer 54 laminated on the light incident surface 521 of the second substrate 52A. That is, the second organic film 56 is laminated on the second substrate 52A. Each of the first organic film 55 and the second organic film 56 that contacts the liquid crystal layer 57 is a polyimide film that has not been subjected to a rubbing process. Therefore, there is no alignment regulating force for regulating the alignment direction of liquid crystal molecules in each of the first organic film 55 and the second organic film 56. That is, there is no alignment regulating force for aligning the liquid crystal molecules in one direction and making the directions of the liquid crystal molecules uniform in the first organic film 55 and the second organic film 56.

[0030] [Configuration of liquid crystal layer] FIG. 3 is a schematic diagram showing an example of the alignment state of liquid crystal molecules in the liquid crystal layer 57. The liquid crystal layer 57 is encapsulated between the first substrate 51A and the second substrate 52A. More specifically, the liquid crystal layer 57 is disposed between the first organic film 55 laminated on the first substrate 51A and the second organic film 56 laminated on the light incident surface 521 of the second substrate 52A. The liquid crystal layer 57 has a plurality of liquid crystal molecules 571. As described above, there is no such alignment regulating force in each of the first organic film 55 and the second organic film 56 that sandwich the liquid crystal layer 57. Therefore, the alignment directions of the plurality of liquid crystal molecules 571 constituting the liquid crystal layer 57 are random as shown in FIG. 3. For example, each of the plurality of liquid crystal molecules 571 is randomly aligned in a plane perpendicular to the first substrate 51A or the second substrate 52A as described above. In addition, the liquid crystal cell CL in which the liquid crystal molecules 571 exist in the liquid crystal layer 57 becomes a microscopic identical alignment state region generated because the alignment treatment is not performed on each of the first organic film 55 and the second organic film 56. Therefore, the shape of the liquid crystal cell CL surrounded by the dotted line shown in FIG. 3 is not necessarily rectangular, and the sizes of the liquid crystal cells CL are also different from each other. Such liquid crystal molecules 571 are negative nematic liquid crystal molecules. That is, the refractive index in the major axis direction of the liquid crystal molecule 571 is smaller than the refractive index in the direction perpendicular to the major axis of the liquid crystal molecule 571. In other words, the refractive index in the minor axis direction with respect to the major axis of the liquid crystal molecule 571 is larger than the refractive index in the major axis direction of the liquid crystal molecule 571.

[0031] [Operation of the polarization control device] As described above, the plurality of liquid crystal molecules 571 constituting the liquid crystal layer 57 of the polarization control device 5A are arranged such that the major axis directions face random directions. That is, each liquid crystal molecule 571 is arranged in a state where the major axis direction of the liquid crystal molecule 571 is oriented disorderly. For this reason, the light transmitted through the liquid crystal layer 57 is imparted with a disordered phase difference. As a result, the linearly polarized image light PL that is emitted from each output-side polarizing plate 353 and enters the polarization control device 5A from the photosynthetic element 36 becomes unpolarized light with a low degree of polarization and randomness by passing through the polarization control device 5A. Therefore, the image light PL projected from the projector 1A becomes more random unpolarized light.

[0032] In this way, the polarization control device 5A can emit unpolarized light without applying a voltage to the liquid crystal layer 57 via the first conductive layer 53 and the second conductive layer 54. For this reason, unlike a general liquid crystal panel, it is not necessary to configure one of the first conductive layer 53 and the second conductive layer 54 as a pixel electrode and the other conductive layer as a common electrode. That is, it is not necessary to configure a pixel electrode with one of the first conductive layer 53 and the second conductive layer 54. For this reason, in the present embodiment, each of the first electrode formed by the first conductive layer 53 and the second electrode formed by the second conductive layer 54 is a common electrode. This simplifies the configuration of the polarization control device 5A.

[0033] FIG. 4 is a schematic diagram showing the polarization state of the emitted light for each liquid crystal cell CL in a certain alignment state of the liquid crystal molecules 571. In FIG. 4, for the sake of convenience, the shape of the liquid crystal cell CL is rectangular, but as shown in FIG. 3, the actual shapes of the plurality of liquid crystal cells CL are different from each other. Also, the sizes of the liquid crystal cells CL are different from each other among the plurality of liquid crystal cells CL. In addition, in FIG. 4, the liquid crystal cell CLA with an arrow indicates the liquid crystal cell CL that emits s-polarized light, which is linearly polarized light, and the liquid crystal cell CLB with an arrow indicates the liquid crystal cell CL that emits p-polarized light, which is linearly polarized light. The liquid crystal cell CLC with an ellipse indicates the liquid crystal cell CL that emits elliptically polarized light. Note that the size of the ellipse attached to the liquid crystal cell CLC indicates that the polarization axes of the emitted elliptically polarized light are different. Thus, for example, as shown in FIG. 4, among the plurality of liquid crystal cells CL, the liquid crystal cell CLA can emit s-polarized light, the liquid crystal cell CLB can emit p-polarized light, and the liquid crystal cell CLC can emit elliptically polarized light with different polarization axes. In this way, the polarization control device 5A can emit unpolarized light.

[0034] FIG. 5 is a schematic diagram showing the polarization state of the emitted light for each liquid crystal cell CL in another alignment state of the liquid crystal molecules 571. That is, FIG. 5 is a schematic diagram showing the polarization state of the emitted light for each liquid crystal cell CL in an alignment state different from that in FIG. 4. By changing the voltage applied by the control unit 7 to the liquid crystal cell CL, the alignment state of the liquid crystal molecules 571 constituting the liquid crystal layer 57 can be changed. Therefore, for example, as shown in FIG. 5, the positions and sizes of the liquid crystal cell CLA that emits s-polarized light, the liquid crystal cell CLB that emits p-polarized light, and the liquid crystal cell CLC that emits elliptically polarized light can be made different. Then, by changing the voltage applied from the control unit 7 to the liquid crystal cell CL over time, it is possible to change the positions and sizes of the liquid crystal cells CLA, CLB, and CLC. Thereby, the polarization control device 5A can emit randomly polarized light both temporally and spatially.

[0035] [Effects of the First Embodiment] The projector 1A according to the present embodiment described above has the following effects. The projector 1A corresponds to a projection device. The projector 1A includes a light modulation element 35, a projection lens 37, and a polarization control device 5A. The light modulation element 35 modulates incident light based on an image signal. The projection lens 37 projects the light emitted from the optical modulation element 35. The polarization control device 5A is disposed on the emission side of the optical modulation element 35 in the optical path of the image light PL that is emitted from the optical modulation element 35 and projected by the projection lens 37, and controls the polarization state of the image light PL modulated by the optical modulation element 35.

[0036] The polarization control device 5A includes a first substrate 51A, a second substrate 52A, a first organic film 55, a second organic film 56, and a liquid crystal layer 57. The second substrate 52A is disposed to face the first substrate 51A. The first organic film 55 is laminated on the first substrate 51A via the first conductive layer 53. The first organic film 55 has no alignment regulating force for regulating the alignment direction of liquid crystal molecules. The second organic film 56 is laminated on the second substrate 52A via the second conductive layer 54. The second organic film 56 has no alignment regulating force for regulating the alignment direction of liquid crystal molecules. The liquid crystal layer 57 is disposed between the first organic film 55 and the second organic film 56. That is, the liquid crystal layer 57 is encapsulated between the first organic film 55 and the second organic film 56. The liquid crystal layer 57 includes a plurality of liquid crystal molecules disposed in a state where the major axis directions are disordered with respect to the first organic film 55 and the second organic film 56.

[0037] According to such a configuration, the first organic film and the second organic film in the polarization control device have no alignment regulating force for regulating the alignment direction of liquid crystal molecules. For example, the first organic film and the second organic film are not subjected to a rubbing treatment. Therefore, in the liquid crystal layer disposed between the first organic film and the second organic film, the liquid crystal molecules are disposed in a state where the major axis directions of the liquid crystal molecules are disordered. When such a polarization control device allows modulated light modulated by an optical modulation element to pass through, in the process of passing through the liquid crystal layer, a random phase difference is imparted to the modulated light. Therefore, the modulated light emitted from the polarization control device becomes light with a low degree of polarization and random unpolarized light. Therefore, the light projected from the projection device can be made into light with a more random polarization state.

[0038] In projector 1A, the polarization control device 5A has a first conductive layer 53 and a second conductive layer 54. The first conductive layer 53 is disposed between the first substrate 51A and the first organic film 55. The second conductive layer 54 is disposed between the second substrate 52A and the second organic film 56. According to such a configuration, by forming the first conductive layer 53 and the second conductive layer 54, it is possible to easily arrange a plurality of liquid crystal molecules in a disordered manner. In addition, when forming the first organic film 55 and the second organic film 56, it is possible to easily ensure the uniformity of each organic film 55, 56.

[0039] Projector 1A includes a control unit 7 that applies a voltage to the liquid crystal layer 57. The first conductive layer constitutes a first electrode that is electrically connected to the control unit. The second conductive layer constitutes a second electrode that is electrically connected to the control unit. According to such a configuration, the control unit applies a voltage to the liquid crystal layer using the first electrode constituted by the first conductive layer and the second electrode constituted by the second conductive layer, thereby changing the orientation angle of each liquid crystal molecule. That is, by the control unit applying a voltage to the liquid crystal layer, the azimuth angle of each liquid crystal molecule can be changed. Therefore, the degree of polarization of the light emitted from the polarization control device can be adjusted.

[0040] In projector 1A, the liquid crystal molecules 571 are negative nematic liquid crystal molecules. According to such a configuration, when each liquid crystal molecule 571 is arranged such that the long axis direction of the liquid crystal molecule 571 is along each organic film 55, 56, it is possible to easily impart a phase difference to the light transmitted through the liquid crystal molecule 571. Therefore, it is possible to easily form random unpolarized light by the polarization control device 5A.

[0041] [Second Embodiment] Next, a second embodiment of the present disclosure will be described. The projector according to this embodiment has the same configuration as the projector 1A according to the first embodiment, but the configuration of the polarization control device is different. In the following description, parts that are the same as or substantially the same as the parts already described are denoted by the same reference numerals and the description thereof is omitted.

[0042] [Schematic Configuration of Projector] FIG. 6 is a schematic diagram showing the configuration of the polarization control device 5B included in the projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1A according to the first embodiment, except that it includes the polarization control device 5B shown in FIG. 6 instead of the polarization control device 5A. That is, the image projection unit 3A according to this embodiment includes the polarization control device 5B instead of the polarization control device 5A according to the first embodiment.

[0043] [Configuration of Polarization Control Device] Similar to the polarization control device 5A, the polarization control device 5B controls the polarization state of incident light and emits unpolarized light. As shown in FIG. 4, the polarization control device 5B has the same configuration and functions as the polarization control device 5A, except that it includes a first substrate 51B and a second substrate 52B instead of the first substrate 51, the second substrate 52, the first conductive layer 53, and the second conductive layer 54. That is, the polarization control device 5B includes a first substrate 51B, a second substrate 52B, a first organic film 55, a second organic film 56, and a liquid crystal layer 57.

[0044] [Configuration of First Substrate and Second Substrate] The first substrate 51B is a light-transmissive substrate similar to the first substrate 51A. The first substrate 51B has a light incident surface 511 and a light exit surface 512B. The light exit surface 512B is the surface of the first substrate 51B opposite to the light incident surface 511, and emits the light that has passed through the first substrate 51B. That is, the light exit surface 512B is the surface on the side of the first organic film 55. The second substrate 52B is a light-transmissive substrate similar to the second substrate 52A. The second substrate 52B has a light incident surface 521B and a light exit surface 522. The light incident surface 521B is the surface of the second substrate 52B that faces the first substrate 51B and is the surface on which light is incident from the liquid crystal layer 47. The light emitting surface 512B of the first substrate 51B and the light incident surface 521B of the second substrate 52B are each subjected to a surface activation treatment. That is, the light emitting surface 512B is the first surface activation treatment surface, and the light incident surface 521B is the second surface activation treatment surface. The surface activation treatment includes, for example, O2 plasma treatment.

[0045] In the present embodiment, the first organic film 55 is laminated on the light emitting surface 512B of the first substrate 51B, and the second organic film 56 is laminated on the light incident surface 521B of the second substrate 52B. As described above, each of the inorganic films 55B and 56B, and each of the organic films 55 and 56 can be formed of a polyimide film. In the present embodiment as well, the rubbing treatment is not performed on each of the organic films 55 and 56. That is, each of the organic films 55 does not have an alignment regulating force for regulating the alignment direction of liquid crystal molecules.

[0046] [Effect of the Second Embodiment] The projector according to the present embodiment described above has the same effects as the projector 1A according to the first embodiment, and also has the following effects. In the projector as a projection device according to the present embodiment, the light emitting surface 512B of the first substrate 51B is the first surface activation treatment surface, and the first organic film 55 is provided on the first surface activation treatment surface. The light emitting surface 512B is the surface of the first substrate 51B on the side of the first organic film 55. The light incident surface 521B on the second substrate 52B is the second surface activation treatment surface, and the second organic film 56 is provided on the second surface activation treatment surface. The light incident surface 521B is the surface of the second substrate 52B on the side of the second organic film 56. According to such a configuration, it is possible to easily arrange a plurality of liquid crystal molecules 571 in a disordered manner without providing the first conductive layer 53 on the first substrate 51B and without providing the second conductive layer 54 on the second substrate 52B.

[0047] [Third Embodiment] Next, a third embodiment of the present disclosure will be described. The projector according to this embodiment has the same configuration as the projector 1A according to the first embodiment, but the configuration of the polarization control device is different. In the following description, parts that are the same as or substantially the same as the parts already described are denoted by the same reference numerals and the description thereof is omitted.

[0048] [Schematic Configuration of Projector] FIG. 7 is a schematic diagram showing the configuration of the polarization control device 5C included in the projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector 1A according to the first embodiment, except that it includes the polarization control device 5C shown in FIG. 7 instead of the polarization control device 5A. That is, the image projection unit 3A according to this embodiment includes the polarization control device 5C instead of the polarization control device 5A. Note that the polarization control device 5C is disposed between the photosynthetic element 36 and the projection lens 37 in the optical path of the image light PL, but may be disposed on the light emission side of the projection lens 37 with respect to the projection lens 37.

[0049] [Configuration of Polarization Control Device] Similar to the above-described polarization control devices 5A and 5B, the polarization control device 5C controls the polarization state of the incident image light PL and emits non-polarized image light PL. The polarization control device 5C has the same configuration and functions as the polarization control device 5A according to the first embodiment, except that it includes a first vertically aligned film 58 and a second vertically aligned film 59 instead of the first organic film 55 and the second organic film 56. That is, the polarization control device 5C includes a first substrate 51A, a second substrate 52A, a first conductive layer 53, a second conductive layer 54, a liquid crystal layer 57, a first vertically aligned film 58, and a second vertically aligned film 59. Note that in this embodiment, the first conductive layer 53 and the second conductive layer 54 are electrically connected to the control unit 7.

[0050] [Configuration of First Vertically Aligned Film and Second Vertically Aligned Film] The first vertical alignment film 58 is laminated on the first conductive layer 53 formed on the light emitting surface 512 of the first substrate 51A and is in contact with the liquid crystal layer 57. That is, the first vertical alignment film 58 is laminated on the light emitting surface 512 of the first substrate 51A. The second vertical alignment film 59 is laminated on the second conductive layer 54 formed on the light incident surface 521 of the second substrate 52A and is in contact with the liquid crystal layer 57. That is, the second vertical alignment film 59 is laminated on the light incident surface 521 of the second substrate 52A. Each of the vertical alignment films 58, 59 is an inorganic vertical thin film made of an inorganic material such as SiO2. Specifically, the first vertical alignment film 58 can be formed by depositing the inorganic material on the first conductive layer 53 using a film forming method such as CVD (Chemical Vapor Deposition), PVD (Physical Vapor Deposition), and ion beam sputtering method. The first vertical alignment film 58 has a columnar structure, and it is desirable that the growth direction during the film formation of the first vertical alignment film 58 is a direction perpendicular to the first substrate 51A. The same applies to the second vertical alignment film 59 laminated on the second substrate 52A.

[0051] Each of the vertical alignment films 58, 59 does not have an alignment regulating force in a specific direction for the liquid crystal molecules 571 to which a voltage is applied by the first conductive layer 53 and the second conductive layer 54. Specifically, each of the vertical alignment films 58, 59 does not have an alignment regulating force for regulating the alignment direction of the liquid crystal molecules 571 when a voltage is applied to the liquid crystal layer 57. That is, each of the vertical alignment films 58, 59 does not have an alignment regulating force for regulating the alignment direction of the liquid crystal molecules 571 when a voltage is applied. For this reason, in a state where a voltage is applied to the liquid crystal layer 57, the plurality of liquid crystal molecules 571 are arranged so that the long axis directions face random directions. Also in this embodiment, the plurality of liquid crystal molecules 571 include, for example, one or several types of nematic liquid crystal molecules and are liquid crystal molecules having dielectric anisotropy.

[0052] [Operation of the polarization control device] In a state where no voltage is applied to the liquid crystal layer 57, a plurality of liquid crystal molecules 571 constituting the liquid crystal layer 57 are oriented by the first vertical alignment film 58 and the second vertical alignment film 59 such that the major axis direction is perpendicular or substantially perpendicular to each of the substrates 51A and 52A. In such an alignment state of the liquid crystal molecules 571, when the linearly polarized image light PL is incident on the polarization control device 5C, the image light PL is emitted from the polarization control device 5C with substantially no change in the polarization state. That is, the image light PL, which is linearly polarized light incident on the polarization control device 5C, is emitted from the polarization control device 5C as linearly polarized light.

[0053] FIG. 8 is a schematic diagram showing the configuration of the polarization control device 5C and is a schematic diagram showing the alignment state of the liquid crystal molecules 571 in a state where a voltage is applied to the liquid crystal layer 57. On the other hand, when a voltage is applied to the liquid crystal layer 57 by the first conductive layer 53 and the second conductive layer 54, a plurality of liquid crystal molecules 571 constituting the liquid crystal layer 57 are oriented so that the major axis direction faces a random direction. For this reason, a phase difference corresponding to the alignment angle of the liquid crystal molecules 571 is imparted to the light passing through the liquid crystal molecules 571. That is, a phase difference is imparted to the light passing through the liquid crystal layer 57 in a disorderly manner. As a result, the image light PL emitted from the polarization control device 5C becomes image light PL in a randomly polarized state with a low degree of polarization. In this way, by controlling the voltage application state to the liquid crystal layer 57 by the control unit 7 connected to the first conductive layer 53 and the second conductive layer 54, the polarization state of the image light PL emitted from the polarization control device 5C is controlled. Then, when the control unit 7 does not apply a voltage to the liquid crystal layer 57, linearly polarized image light PL can be emitted from the polarization control device 5C, and when the control unit 7 applies a voltage to the liquid crystal layer 57, unpolarized image light PL can be emitted from the polarization control device 5C. Thereby, the projector according to the present embodiment can project linearly polarized image light PL or unpolarized image light PL.

[0054] [Effects of the Third Embodiment] The projector according to the present embodiment described above has the following effects. The projector according to this embodiment corresponds to a projection device. The projector includes a light modulation element 35, a projection lens 37, and a polarization control device 5A. The light modulation element 35 modulates incident light based on an image signal. The projection lens 37 projects the light emitted from the light modulation element 35. The polarization control device 5C is disposed on the emission side of the light modulation element 35 in the optical path of the image light PL emitted from the light modulation element 35 and projected by the projection lens 37, and controls the polarization state of the image light PL modulated by the light modulation element 35.

[0055] The polarization control device 5C includes a first substrate 51A, a second substrate 52A, a first conductive layer 53, a second conductive layer 54, a first vertical alignment film 58, a second vertical alignment film 59, and a liquid crystal layer 57. The first substrate 51A has a light incident surface 511 on which the image light PL is incident. The second substrate 52A is disposed opposite to the first substrate 51A. The first conductive layer 53 constitutes a first electrode. The first conductive layer 53 is disposed on the light emission surface 512 of the first substrate 51A, which is opposite to the light incident surface 511. The first vertical alignment film 58 is laminated on the first conductive layer 53. The first vertical alignment film 58 has no alignment regulating force for regulating the alignment direction of the liquid crystal molecules 571 when a voltage is applied. The second conductive layer 54 constitutes a second electrode. The second conductive layer 54 is disposed on the light incident surface 521 of the second substrate 52A. The light incident surface 521 is the surface of the second substrate 52A on the side of the first substrate 51A. The second vertical alignment film 59 is laminated on the second conductive layer 54. The second vertical alignment film 59 has no alignment regulating force for regulating the alignment direction of the liquid crystal molecules 571 when a voltage is applied. The liquid crystal layer 57 is disposed between the first vertical alignment film 58 and the second vertical alignment film 59. The liquid crystal layer 57 includes a plurality of liquid crystal molecules 571 that are randomly aligned by applying voltages to the first electrode constituted by the first conductive layer 53 and the second electrode constituted by the second conductive layer 54, respectively.

[0056] According to such a configuration, similar to the projector 1A according to the first embodiment, the projected image light PL can be light in a random unpolarized state. That is, in a state where no voltage is applied to the liquid crystal layer 57, the liquid crystal molecules 571 are oriented perpendicular to the respective vertical alignment films 58 and 59 by the respective vertical alignment films 58 and 59. On the other hand, when a voltage is applied to the liquid crystal layer 57, each of the plurality of liquid crystal molecules 571 falls in a random direction with respect to a virtual plane parallel to the respective vertical alignment films 58 and 59. When the image light PL modulated by the optical modulation element 35 passes through such a polarization control device 5C, a phase difference is randomly imparted to the image light PL in the process of passing through the liquid crystal layer 57. For this reason, the image light PL emitted from the polarization control device 5C is light in a randomly polarized state with a low degree of polarization. Therefore, the light projected from the projector can be light in a more random polarization state.

[0057] [Fourth Embodiment] Next, a fourth embodiment of the present disclosure will be described. The projector according to the present embodiment is different from the projector 1A in that, in addition to the configuration of the projector 1A according to the first embodiment, it includes an incident-side retardation element provided on the light incident side of the polarization control device and an emission-side retardation element provided on the light emission side of the polarization control device. In the following description, parts that are the same as or substantially the same as the parts already described will be denoted by the same reference numerals and the description thereof will be omitted.

[0058] [Schematic Configuration of Projector and Image Projection Unit] FIG. 9 is a schematic diagram showing a part of the configuration of an image projection unit 3D included in the projector according to the present embodiment. The projector according to the present embodiment has the same configuration and functions as the projector according to the third embodiment, except that it includes an image projection unit 3D whose partial configuration is shown in FIG. 7 instead of the image projection unit 3A. The 3D image projection unit is configured and functions in the same manner as the image projection unit 3A according to the third embodiment, except that it includes a polarization control device 5D instead of the polarization control device 5A. That is, the 3D image projection unit includes a light source 31, a color separation device 32, an image forming device 33, a projection lens 37, and a polarization control device 5D.

[0059] [Configuration of Polarization Control Device] The polarization control device 5D is configured and functions in the same manner as the polarization control device 5C according to the third embodiment, except that it further includes an incident-side retardation element 60 and an exit-side retardation element 61. The polarization control device 5D includes a device main body 5D1 having the same configuration as the polarization control device 5C, an incident-side retardation element 60, and an exit-side retardation element 61. Note that the polarization control device 5D is disposed between the optical combiner 36 and the projection lens 37 in the optical path of the image light PL, but may be disposed on the light exit side of the projection lens 37 with respect to the projection lens 37.

[0060] [Configuration of Incident-Side Retardation Element] The incident-side retardation element 60 is provided between the exit-side polarizing plate 353 of each light modulation element 35 and the device main body 5D1 in the optical path of the image light PL. That is, the incident-side retardation element 60 is disposed on the light incident side of the polarization control device 5D with respect to the device main body 5D1. The incident-side retardation element 60 imparts a phase difference to the linearly polarized image light PL that is emitted from each exit-side polarizing plate 353 and incident on the optical combiner 36. In this embodiment, the incident-side retardation element 60 is a λ / 4 retardation plate, and the incident-side retardation element 60 converts the incident linearly polarized image light PL into circularly polarized image light PL and emits it.

[0061] Here, when linearly polarized light is incident on the apparatus main body 5D1 having the same configuration as the polarization control device 5C, the light emitted through the apparatus main body 5D1 tends to be unpolarized light biased toward one of the linearly polarized s-polarized light and p-polarized light. Specifically, in the apparatus main body 5D1, there may be a region where liquid crystal molecules are aligned in the same direction as the vibration direction of the incident linearly polarized light. When the linearly polarized light passes through such a region, the transmitted light is emitted in the same polarization state without being depolarized. That is, linearly polarized light in the same polarization state is emitted from the region where the liquid crystal molecules are aligned in the same direction as the vibration direction of the incident linearly polarized light without changing the polarization state. In this case, the unpolarized light emitted from the apparatus main body 5D1 tends to be light in which the light amount of one of the linearly polarized s-polarized light and p-polarized light is larger than the light amount of the other linearly polarized light.

[0062] On the other hand, in the present embodiment, the incident-side retardation element 60 is provided between each emission-side polarizing plate 353 and the apparatus main body 5D1, and the incident-side retardation element 60 converts the image light PL of linearly polarized light into circularly polarized image light PL by imparting a retardation to the incident image light PL of linearly polarized light. With such an incident-side retardation element 60, the light incident on the apparatus main body 5D1 is converted into circularly polarized light regardless of the region of the apparatus main body 5D1 where the light is incident. Therefore, the apparatus main body 5D1 can impart a retardation corresponding to the alignment state of the liquid crystal molecules 571 to the incident circularly polarized image light PL, and can emit a more random unpolarized image light PL.

[0063] [Configuration of the emission-side retardation element] The emission-side retardation element 61 is disposed on the light emission side of the polarization control device 5D with respect to the apparatus main body 5D1. In the present embodiment, the emission-side retardation element 61 is disposed between the apparatus main body 5D1 and the projection lens 37 in the optical path of the image light PL. The emission-side retardation element 61 imparts a retardation to the image light PL incident from the apparatus main body 5D1. The exit-side retardation element 61 can be configured by, for example, a λ / 4 retardation plate. In this case, when no voltage is applied to the liquid crystal layer 57 of the apparatus main body 5D1 and circularly polarized image light PL is incident from the apparatus main body 5D1, the exit-side retardation element 61 converts the circularly polarized image light PL into linearly polarized image light PL, so that linearly polarized image light PL is emitted from the exit-side retardation element 61. When each of the incident-side retardation element 60 and the exit-side retardation element 61 is configured by, for example, a λ / 4 retardation plate, the retardation axes of the respective retardation elements 60 and 61 are orthogonal to each other, and the fast axes of the respective retardation elements 60 and 61 are arranged to be orthogonal to each other. On the other hand, when a voltage is applied to the liquid crystal layer 57 of the apparatus main body 5D1 and unpolarized image light PL is incident from the apparatus main body 5D1, the exit-side retardation element 61 imparts a retardation to the unpolarized image light PL, so that unpolarized image light PL is emitted from the exit-side retardation element 61.

[0064] Also, the exit-side retardation element 61 can be configured by a λ / 8 retardation plate. In this case, when no voltage is applied to the liquid crystal layer 57 of the apparatus main body 5D1 and circularly polarized image light PL is incident from the apparatus main body 5D1, elliptically polarized image light PL is emitted from the exit-side retardation element 61. On the other hand, when a voltage is applied to the liquid crystal layer 57 of the apparatus main body 5D1 and unpolarized image light PL is incident from the apparatus main body 5D1, unpolarized image light PL is emitted from the exit-side retardation element 61.

[0065] [Effects of the Fourth Embodiment] The projector according to the present embodiment described above has the same effects as the projector according to the third embodiment, and also has the following effects. In the projector as the projection apparatus according to the present embodiment, the polarization control device 5D is disposed on the side opposite to the second substrate 52A with respect to the first substrate 51A, and has the incident-side retardation element 60 that causes a retardation in the incident light. Here, when the incident-side retardation element 60 is not provided and the light incident on the polarization control device is linearly polarized light, if the linearly polarized light is converted into unpolarized light by the polarization control device, although it is unpolarized light, it becomes unpolarized light biased toward p-polarized light or s-polarized light among the linearly polarized light. On the other hand, by making the light transmitted through the incident-side retardation element 60 incident on the first substrate 51A of the device main body 5D1, light in a more random unpolarized state can be emitted from the polarization control device 5D. Therefore, light in a polarization state with less bias in all directions can be emitted.

[0066] In the projector according to the present embodiment, the incident-side retardation element 60 is a λ / 4 retardation plate. According to such a configuration, when linearly polarized light is incident on the incident-side retardation element 60, which is a λ / 4 retardation plate, the linearly polarized light is converted into circularly polarized light by passing through the incident-side retardation element 60 and is incident on the first substrate 51A. When such circularly polarized light is incident on the liquid crystal layer 57, the light emitted from the polarization control device 5D can be made into light in a more random unpolarized state.

[0067] In the projector according to the present embodiment, the polarization control device 5D is disposed on the side opposite to the first substrate 51A with respect to the second substrate 52A and has an emission-side retardation element 61 that generates a retardation in the incident light. According to such a configuration, the polarization state of the light emitted from the polarization control device 5D can be controlled by the emission-side retardation element 61. For example, when the light incident on the polarization control device 5D is linearly polarized light and each of the incident-side retardation element 60 and the emission-side retardation element 61 is a λ / 4 retardation plate, linearly polarized light can be emitted from the polarization control device 5D in a state where no voltage is applied to the liquid crystal layer 57, and unpolarized light can be emitted from the polarization control device 5D in a state where a voltage is applied to the liquid crystal layer 57. Note that when the light incident on the polarization control device 5D is linearly polarized light and each of the incident-side retardation element 60 and the exit-side retardation element 61 is a λ / 8 retardation plate, elliptically polarized light can be emitted from the polarization control device 5D in a state where no voltage is applied to the liquid crystal layer 57, and unpolarized light can be emitted from the polarization control device 5D in a state where a voltage is applied to the liquid crystal layer 57.

[0068] [Fifth Embodiment] Next, a fifth embodiment of the present disclosure will be described. The projector according to this embodiment is different in that it includes an incident-side variable retardation element and an exit-side variable retardation element instead of the incident-side retardation element 60 and the exit-side retardation element 61 included in the projector according to the fourth embodiment. In the following description, parts that are the same as or substantially the same as the parts already described will be denoted by the same reference numerals and the description thereof will be omitted.

[0069] [Schematic Configuration of Projector and Image Projection Unit] FIG. 10 is a schematic diagram showing a part of the configuration of the image projection unit 3E included in the projector according to this embodiment. The projector according to this embodiment has the same configuration and functions as the projector according to the first embodiment, except that it includes an image projection unit 3E whose partial configuration is shown in FIG. 10 instead of the image projection unit 3A. The image projection unit 3E has the same configuration and functions as the image projection unit 3A according to the first embodiment, except that it includes a polarization control device 5E instead of the polarization control device 5A. That is, the image projection unit 3E includes a light source 31, a color separation device 32, an image forming device 33, a projection lens 37, and a polarization control device 5D.

[0070] [Configuration of Polarization Control Device] The polarization control device 5E has the same configuration and functions as the polarization control device 5D according to the fourth embodiment, except that the incident-side variable retardation element 62 and the exit-side variable retardation element 63 are provided instead of the incident-side retardation element 60 and the exit-side retardation element 61. That is, the polarization control device 5E includes a device main body 5D1 having the same configuration as the polarization control device 5C, the incident-side variable retardation element 62, and the exit-side variable retardation element 63. Note that the polarization control device 5E is disposed between the optical synthesis element 36 and the projection lens 37 in the optical path of the image light PL, but may be disposed on the light exit side of the projection lens 37 with respect to the projection lens 37.

[0071] [Configuration of Incident-Side Variable Retardation Element and Exit-Side Variable Retardation Element] The incident-side variable retardation element 62 corresponds to the incident-side retardation element and is disposed on the light incident side of the polarization control device 5E with respect to the device main body 5D1. That is, the incident-side variable retardation element 62 is disposed between each exit-side polarizing plate 353 and the device main body 5D1 in the optical path of the image light PL. In the present embodiment, the incident-side variable retardation element 62 is disposed between the optical synthesis element 36 and the device main body 5D1 in the optical path of the image light PL. The exit-side variable retardation element 63 corresponds to the exit-side retardation element and is disposed on the light exit side of the polarization control device 5E with respect to the device main body 5D1. In the present embodiment, the exit-side variable retardation element 63 is disposed between the device main body 5D1 and the projection lens 37 in the optical path of the image light PL. In this way, the incident-side variable retardation element 62 and the exit-side variable retardation element 63 sandwich the device main body 5D1 in the optical path of the image light PL.

[0072] Although detailed illustration is omitted, each of the incident-side variable retardation element 62 and the exit-side variable retardation element 63 is constituted by a liquid crystal panel. For example, each variable retardation element 62, 63 is constituted by a liquid crystal panel having a polyimide film that is subjected to rubbing treatment and has the above-described alignment regulating force. Each variable retardation element 40 changes the retardation imparted to the passing light according to the level of the applied voltage. For example, when linearly polarized light is incident on the incident-side variable retardation element 62, the incident linearly polarized light is converted into circularly polarized light and incident on the apparatus main body 5D1. Therefore, the incident-side variable retardation element 62 converts the polarization state of the image light PL incident from each emission-side polarizing plate 353 through the light combining element 36 from linearly polarized light to circularly polarized light. Note that the incident-side variable retardation element 62 can also pass the incident light without changing the polarization state. Similarly, the emission-side variable retardation element 63 can also pass the incident light without changing the polarization state, and can also change the polarization state and pass the incident light. As described above, each of the variable retardation elements 62 and 63 can switch between a state in which the polarization state of the incident light is changed substantially uniformly and a state in which it is not changed.

[0073] [Effects of the Fifth Embodiment] The projector according to the present embodiment described above has the same effects as the projector according to the fourth embodiment, and also has the following effects. In the projector as the projection device according to the present embodiment, the polarization control device 5E includes an incident-side variable retardation element 62 and an emission-side variable retardation element 63. According to such a configuration, the variation in the polarization state of the light emitted from the polarization control device 5E, that is, the image light PL projected from the projector, can be increased. Therefore, the convenience of the polarization control device 5E and the projector can be enhanced.

[0074] [Sixth Embodiment] Next, a sixth embodiment of the present disclosure will be described. [Configuration of the Activity State Adjustment Device] FIG. 11 is a schematic diagram showing the configuration of the activity state adjustment device AR according to the present embodiment. The activity state adjustment device AR according to the present embodiment is a behavior control device that irradiates a living body with linearly polarized image light or non-polarized image light to control the behavior of the living body. As shown in FIG. 11, the activity state adjustment device AR is arranged and used, for example, in an indoor space SP. The active state adjustment device AR includes a projector 1F and a control device 8F.

[0075] [Configuration of the Projector] The projector 1F has the same configuration as the projector according to the fourth or fifth embodiment. That is, the projector 1F includes an image projection unit 3D having a polarization control device 5D or an image projection unit 3E having a polarization control device 5E. In the example of FIG. 11, the projector 1F is provided on the ceiling that partitions the space SP. That is, the projector 1F is arranged so as to be usable as an illumination projector that projects image light PL downward to illuminate the space SP. However, the present invention is not limited to this, and the projector 1F may project the image light PL along the horizontal direction or may project the image light PL upward.

[0076] [Configuration of the Control Device] The control device 8F controls the operation of the projector 1F to project linearly polarized image light and unpolarized image light onto the projector 1F individually. For example, when causing a predetermined action in a living body, the control device 8F irradiates the projector 1F with one of linearly polarized light and unpolarized light at the location where the living body is located or in the vicinity of the location where the living body is located. Also, for example, when not causing a predetermined action in a living body, the control device 8F irradiates the projector 1F with the other of linearly polarized light and unpolarized light at the location where the living body is located or in the vicinity of the location where the living body is located. Alternatively, when not causing a predetermined action in a living body, the control device 8F stops the irradiation of the projector 1F with the one light. In the example of FIG. 11, the control device 8F is arranged separately from the projector 1F. However, the present invention is not limited to this, and the control device 8F may be provided integrally with the projector 1F that is a projection device. That is, the control device 8F may be incorporated in the control unit 7 of the projector 1F.

[0077] Here, among organisms, there are organisms that can detect polarized light. Many of such organisms can selectively detect the polarization component. When such an organism is irradiated with light of a specific polarization state, it has been reported that the organism becomes more likely to find food, or aggregates or disperses with respect to the irradiation position. In addition, the blue light of the sky contains a polarization component corresponding to the angle with sunlight, and there are also species among birds and insects that can determine the position and azimuth of the sun based on the direction of the detected polarized light. These behaviors are caused by photoreceptors present in the eyes of organisms being stimulated by light and the active state of the photoreceptors changing. On the other hand, since the control device 8F controls the operation of the projector 1F, it is possible to stimulate the photoreceptors of the living body and adjust the active state of the photoreceptors, so that the behavior of the organism can be controlled to a certain extent.

[0078] [Effects of the Sixth Embodiment] The active state adjustment device AR according to the present embodiment described above has the same effects as the projector 1A according to the first embodiment, and also has the following effects. The active state adjustment device AR includes a projector 1F as a projection device and a control device 8F. The control device 8F individually irradiates the projector 1F with linearly polarized light and unpolarized light to change the active state of the photoreceptors. According to such a configuration, for example, when the control device 8F individually irradiates the projector 1F with linearly polarized light and unpolarized light, the photoreceptors of the organism located at the irradiation position of the light and in the vicinity of the irradiation position can be stimulated to change the active state of the photoreceptors. Therefore, the behavior and growth of the organism can be controlled.

[0079] [Seventh Embodiment] Next, a seventh embodiment of the present disclosure will be described. [Configuration of Circadian Rhythm Control Device] FIG. 12 is a schematic diagram showing the configuration of a circadian rhythm control device RC according to the present embodiment. The circadian rhythm control device RC according to this embodiment is a device that emits light with a polarization state corresponding to the time zone of a day to control the circadian rhythm of a living body. The circadian rhythm control device RC is arranged and used in, for example, an indoor space SP, similar to the activity state adjustment device AR according to the sixth embodiment. As shown in FIG. 12, the circadian rhythm control device RC includes a light source 91, a polarization control device 92, a projection lens 37, and a control device 93.

[0080] [Configuration of the light source] The light source 91 emits light that enters the polarization control device 92. The light source 91 has a light source unit 911 and a polarizing plate 912. The light source unit 911 has, for example, a light source lamp or a plurality of light emitting elements and emits light. The polarizing plate 912 is arranged in the optical path of the light emitted from the light source unit 911, and transmits one of the s-polarized light and the p-polarized light while blocking the other linearly polarized light. Therefore, the light emitted from the light source 91 through the polarizing plate 912 is a kind of linearly polarized light. If the light source unit 911 can emit one of the s-polarized light and the p-polarized light, the polarizing plate 912 can be omitted.

[0081] [Configuration of the polarization control device and the projection lens] The polarization control device 92 has the same configuration as the polarization control device 5D according to the fourth embodiment. The light emitted from the light source 91 enters the polarization control device 92. The polarization control device 92 emits either linearly polarized light or unpolarized light under the control of the control device 93. Note that the polarization control device 92 may have the same configuration as the polarization control device 5E. The projection lens 37 projects the light emitted from the polarization control device 92.

[0082] [Configuration of the control device] The control device 93 controls the operations of the light source 91 and the polarization control device 92 to cause one of the linearly polarized light and the unpolarized light to be emitted from the polarization control device 92 according to the time zone. The control device 93 has a clock unit 931 and a control unit 932. The clock unit 931 measures the current time.

[0083] The control unit 932 controls the operations of the light source 91 and the polarization control device 92 according to the time measured by the clock unit 931. For example, the control unit 932 causes linearly polarized light to be emitted to the polarization control device 92 in the morning and evening time zones, and causes unpolarized light to be emitted to the polarization control device 92 in the daytime time zone. Specifically, the control unit 932 causes linearly polarized light to be emitted from the polarization control device 92 in the time zones from 6:00 to 12:00 and from 17:00 to 18:00, and causes unpolarized light to be emitted from the polarization control device 92 in the time zone from 12:00 to 17:00. Thereby, it becomes possible to irradiate the space SP with light having a polarization state substantially the same as the polarization state of sunlight received outdoors. Therefore, it is possible to easily adjust the circadian rhythm of organisms in the space SP. Note that the time zone for emitting linearly polarized light and the time zone for emitting unpolarized light may be adjusted according to the time in a region different from the region where the circadian rhythm control device RC is disposed. By performing such adjustment of the circadian rhythm, for example, the occurrence of jet lag can be suppressed. In addition, at least one of the time zone for emitting linearly polarized light and the time zone for emitting unpolarized light may be shortened so that the circadian rhythm of the organism is shortened.

[0084] [Effects of the Seventh Embodiment] The circadian rhythm control device RC according to the present embodiment described above has the following effects. The circadian rhythm control device RC includes a light source 91, a polarization control device 92, and a control device 93. The polarization control device 92 has the same configuration as the polarization control device 5D according to the fourth embodiment or the polarization control device 5E according to the fifth embodiment. The polarization control device 92 is disposed in the optical path of the light emitted from the light source 91 and controls the polarization state of the incident light. The control device 93 controls the polarization control device 92 to cause one of linearly polarized light and unpolarized light to be emitted from the polarization control device according to the time zone. According to such a configuration, by causing the control device 93 to emit linearly polarized light to the polarization control device 92, for example, in the morning and in the evening, and to emit unpolarized light to the polarization control device 92 during the daytime, light in a polarization state close to sunlight can be irradiated onto the living organisms according to the time zone. Therefore, it is possible to make it easier for the living organisms to perceive the time zone, and it is possible to affect the circadian rhythm of the living organisms.

[0085] [Modifications of the Embodiment] The present disclosure is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope that can achieve the object of the present disclosure are included in the present disclosure. In the above-described first to sixth embodiments, the projector as the projection device is provided with the image projection units 3A, 3D, 3E in which the light source 31, the color separation device 32, the image forming device 33, and the projection lens 37 are arranged in the layout shown in FIG. 2. However, the optical components included in the image projection unit provided in the projector and the layout of the optical components are not limited to the above, and can be appropriately changed.

[0086] In the above-described seventh embodiment, the polarization control device 92 included in the circadian rhythm control device RC is assumed to have the same configuration as the polarization control device 5D according to the fourth embodiment or the polarization control device 5E according to the fifth embodiment. However, the present invention is not limited to this, and the polarization control device 92 may have the same configuration as the polarization control device 5A according to the first embodiment, the polarization control device 5B according to the second embodiment, or the polarization control device 5C according to the third embodiment.

[0087] In the above-described embodiments, the projector is assumed to include three light modulation elements 35R, 35G, and 35B. However, the present disclosure is not limited to this, and the present disclosure can also be applied to projectors including two or less, or four or more light modulation elements.

[0088] In each of the above embodiments, the optical modulation module 351 included in the optical modulation element 35 was assumed to be a transmissive liquid crystal panel having a different light incident surface and light exit surface. However, the present invention is not limited to this, and the optical modulation module 351 may be a reflective liquid crystal panel having the same light incident surface and light exit surface. Further, any optical modulation element that can modulate an incident light beam to form an image according to image information may be employed, such as a device using a micromirror, for example, a device using a DMD (Digital Micromirror Device) or the like, and an optical modulation element other than liquid crystal may be adopted. In this case, in the optical path of the image light PL, a polarizing element that transmits one of the s-polarized light and p-polarized light, which are linearly polarized lights, and blocks the other polarized light may be provided between the optical modulation element other than liquid crystal and the polarization control devices 5A, 5B, 5C, 5D, 5E.

[0089] In each of the above first to sixth embodiments, an example in which the polarization control devices 5A, 5B, 5C, 5D, 5E are applied to a projector as a projection device has been given. However, the present invention is not limited to this, and the polarization control device of the present disclosure may be applied to an electronic device other than a projector, for example, an illumination device, as shown in the seventh embodiment.

[0090] [Summary of the Present Disclosure] The summary of the present disclosure is appended below. [Appendix 1] An optical modulation element that modulates incident light based on an image signal, A projection lens that projects the light emitted from the optical modulation element, A polarization control device that is disposed on the emission side of the optical modulation element in the optical path of the light emitted from the optical modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the optical modulation element, The polarization control device includes: A first substrate, A second substrate disposed opposite to the first substrate, A first organic film laminated on the first substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, A second organic film laminated on the second substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, It has a liquid crystal layer disposed between the first organic film and the second organic film, The liquid crystal layer includes a plurality of liquid crystal molecules disposed in a state where the major axis directions are randomly oriented with respect to the first organic film and the second organic film. A projection device characterized by the above.

[0091] According to such a configuration, in the polarization control device, the first organic film and the second organic film do not have an alignment regulating force for regulating the alignment direction of the liquid crystal molecules. For example, the first organic film and the second organic film are not subjected to a rubbing treatment. Therefore, in the liquid crystal layer disposed between the first organic film and the second organic film, the liquid crystal molecules are arranged in a state where the major axis directions of the liquid crystal molecules are randomly oriented. When modulated light modulated by an optical modulation element passes through such a polarization control device, random phase differences are imparted to the modulated light in the process of passing through the liquid crystal layer. Therefore, the modulated light emitted from the polarization control device becomes light with a low degree of polarization and random unpolarized light. Therefore, the light projected from the projection device can be made into light in a more random polarization state.

[0092] [Appendix 2] In the projection device according to Appendix 1, The polarization control device, It has a first conductive layer disposed between the first substrate and the first organic film, And a second conductive layer disposed between the second substrate and the second organic film. A projection device characterized by the above. According to such a configuration, by forming the first conductive layer and the second conductive layer, it is possible to easily arrange a plurality of liquid crystal molecules in a disordered manner. In addition, when forming the first organic film and the second organic film, it is possible to easily ensure the uniformity of each organic film.

[0093] [Appendix 3] In the projection device according to Appendix 2, It includes a control unit for applying a voltage to the liquid crystal layer, The first conductive layer constitutes a first electrode electrically connected to the control unit, The second conductive layer constitutes a second electrode that is electrically connected to the control unit. A projection device characterized by this. According to such a configuration, the control unit can change the alignment angle of each liquid crystal molecule by applying a voltage to the liquid crystal layer using the first electrode constituted by the first conductive layer and the second electrode constituted by the second conductive layer. That is, by the control unit applying a voltage to the liquid crystal layer, the tilting direction of each liquid crystal molecule can be changed. Therefore, the degree of polarization of the light emitted from the polarization control device can be adjusted.

[0094] [Appendix 4] In the projection device according to Appendix 1, The surface of the first substrate on the side of the first organic film is a first surface activation treatment surface, The first organic film is provided on the first surface activation treatment surface, The surface of the second substrate on the side of the second organic film is a second surface activation treatment surface, The second organic film is provided on the second surface activation treatment surface. A projection device characterized by this. According to such a configuration, when the first conductive layer is not provided on the first substrate and the second conductive layer is not provided on the second substrate, it is possible to easily arrange a plurality of liquid crystal molecules in a disorderly manner.

[0095] [Appendix 5] In the projection device according to any one of Appendices 1 to 4, The liquid crystal molecules are negative nematic liquid crystal molecules. A projection device characterized by this. According to such a configuration, when each liquid crystal molecule is arranged such that the long axis direction of the liquid crystal molecule is along each organic film, it is possible to easily impart a phase difference to the modulated light transmitted through the liquid crystal molecule. Therefore, it is possible to easily form random unpolarized light by the polarization control device.

[0096] [Appendix 6] An optical modulation element that modulates incident light based on an image signal, A projection lens that projects the light emitted from the light modulation element; A polarization control device that is disposed on the emission side of the light modulation element with respect to the light modulation element in the optical path of the light emitted from the light modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the light modulation element, and includes: The polarization control device includes: A first substrate having a light incident surface on which light is incident; A second substrate disposed opposite to the first substrate; A first electrode disposed on a surface of the first substrate opposite to the light incident surface; A first vertical alignment film laminated on the first electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; A second electrode disposed on a surface of the second substrate on the first substrate side; A second vertical alignment film laminated on the second electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; A liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and including a plurality of liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode; A projection device characterized by the above.

[0097] According to such a configuration, similarly to the projection device according to the above-mentioned appended claim 1, the projected light can be made into random unpolarized light. That is, in a state where no voltage is applied to the liquid crystal layer, the liquid crystal molecules are aligned perpendicular to each vertical alignment film by each vertical alignment film. On the other hand, when a voltage is applied to the liquid crystal layer, each of the plurality of liquid crystal molecules falls in a random direction with respect to a virtual plane parallel to each vertical alignment film. By passing the modulated light modulated by the light modulation element through such a polarization control device, an optical path difference is randomly imparted to the modulated light in the process of passing through the liquid crystal layer. For this reason, the modulated light emitted from the polarization control device becomes light in a randomly polarized state with a low degree of polarization. Therefore, the light projected from the projection device can be made into light in a more random polarization state.

[0098] [Appendix 7] In the projection device described in Appendix 6, the polarization control device is disposed on the side opposite to the second substrate with respect to the first substrate and has an incident-side retardation element that causes a phase difference in the incident light. A projection device characterized by this. Here, when there is no incident-side retardation element and the light incident on the polarization control device is linearly polarized light, if the linearly polarized light is converted to unpolarized light by the polarization control device, although it is unpolarized light, it becomes unpolarized light that is polarized in p-polarization or s-polarization of linearly polarized light. On the other hand, by making the light that has passed through the incident-side retardation element incident on the first substrate, light in a more random unpolarized state can be emitted from the polarization control device. Therefore, light in a polarization state with less bias in all directions can be emitted.

[0099] [Appendix 8] In the projection device described in Appendix 7, the incident-side retardation element is a λ / 4 retardation plate. A projection device characterized by this. According to such a configuration, when linearly polarized light is incident on the incident-side retardation element that is a λ / 4 retardation plate, the linearly polarized light is converted to circularly polarized light by passing through the incident-side retardation element and is incident on the first substrate. When such circularly polarized light is incident on the liquid crystal layer, the light emitted from the polarization control device can be made into light in a more random unpolarized state.

[0100] [Appendix 9] In the projection device described in Appendix 7 or Appendix 8, the polarization control device is disposed on the side opposite to the first substrate with respect to the second substrate and has an emission-side retardation element that causes a phase difference in the incident light. A projection device characterized by this. According to such a configuration, the polarization state of the light emitted from the polarization control device can be controlled by the emission-side retardation element. For example, when the light incident on the polarization control device is linearly polarized light, each of the incident-side retardation element and the emission-side retardation element is a λ / 4 retardation plate, the slow axes of the respective retardation elements are orthogonal to each other, and the fast axes of the respective retardation elements are orthogonal to each other, linearly polarized light can be emitted from the polarization control device in a state where no voltage is applied to the liquid crystal layer, and unpolarized light can be emitted from the polarization control device in a state where a voltage is applied to the liquid crystal layer. Also, for example, when the light incident on the polarization control device is linearly polarized light and each of the incident-side retardation element and the emission-side retardation element is a λ / 8 retardation plate, elliptically polarized light can be emitted from the polarization control device in a state where no voltage is applied to the liquid crystal layer, and unpolarized light can be emitted from the polarization control device in a state where a voltage is applied to the liquid crystal layer.

[0101] [Appendix 10] The projection device according to any one of Appendices 1 to 9, and a control device that individually irradiates the projection device with linearly polarized light and unpolarized light to change the active state of a photoreceptor. An active state adjustment device characterized by this. Here, among living organisms, there are organisms that can detect polarized light. When light in a specific polarization state is incident on such an organism, it has been reported that the organism can better find food or gather or disperse with respect to the irradiation position. In addition, the blue light in the sky contains a polarization component corresponding to the angle with sunlight, and there are also species among birds and insects that can determine the position and azimuth of the sun based on the direction of the detected polarized light. These behaviors are caused by photoreceptors present in the eyes of organisms being stimulated by light and the active state of the photoreceptors changing. Therefore, according to the above configuration, for example, by the control device individually irradiating the projection device with linearly polarized light and unpolarized light regardless of the time zone, the photoreceptors of organisms located at the irradiation position of the light and in the vicinity of the irradiation position can be stimulated, and the active state of the photoreceptors can be changed. Therefore, the behavior and growth of organisms can be controlled.

[0102] [Appendix 11] The first substrate, A second substrate disposed to face the first substrate, a first organic film laminated on the first substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, a second organic film laminated on the second substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, and a liquid crystal layer disposed between the first organic film and the second organic film and including liquid crystal molecules disposed in a state where the major axis directions are randomly oriented with respect to the first organic film and the second organic film. A polarization control device characterized by the above. According to such a configuration, the same effects as those of the projection device according to the above-mentioned appended claim 1 can be achieved. That is, in the polarization control device, the first organic film and the second organic film have no alignment regulating force for regulating the alignment direction of liquid crystal molecules. For example, the first organic film and the second organic film are not subjected to a rubbing treatment. Therefore, in the liquid crystal layer disposed between the first organic film and the second organic film, the liquid crystal molecules are disposed in a state where the major axis directions of the liquid crystal molecules are randomly oriented. When light is incident on such a polarization control device, a random phase difference is imparted to the light passing through the liquid crystal layer. Therefore, the light emitted from the polarization control device can be made into non-polarized light with a low degree of polarization and randomness.

[0103] [Appended claim 12] In the polarization control device according to appended claim 11, a first conductive layer laminated between the first substrate and the first organic film, and a second conductive layer laminated between the second substrate and the second organic film. A polarization control device characterized by the above. According to such a configuration, similar to the projection device according to the above-mentioned appended claim 2, it is possible to easily arrange a plurality of liquid crystal molecules in a disordered manner.

[0104] [Appended claim 13] In the polarization control device according to appended claim 12, the first conductive layer constitutes a first electrode, the second conductive layer constitutes a second electrode, A polarization control device characterized by the following. According to such a configuration, similar to the projection device according to the above-mentioned supplementary note 3, by applying a voltage to the liquid crystal layer using the first electrode formed of the first conductive layer and the second electrode formed of the second conductive layer, the alignment angle of each liquid crystal molecule can be changed. That is, by applying a voltage to the liquid crystal layer, the tilting direction of each liquid crystal molecule can be changed. Therefore, the degree of polarization of the light emitted from the polarization control device can be adjusted.

[0105] [Supplementary Note 14] In the polarization control device described in Supplementary Note 11, The surface of the first substrate on the side of the first organic film is a first surface activation treatment surface, The first organic film is provided on the first surface activation treatment surface, The surface of the second substrate on the side of the second organic film is a second surface activation treatment surface, The second organic film is provided on the second surface activation treatment surface. A polarization control device characterized by the following. According to such a configuration, similar to the projection device according to the above-mentioned supplementary note 4, when the first conductive layer is not provided on the first substrate and the second conductive layer is not provided on the second substrate, it is possible to easily arrange a plurality of liquid crystal molecules in a disordered manner.

[0106] [Supplementary Note 15] In the polarization control device described in any one of Supplementary Notes 11 to 14, The liquid crystal molecules are negative nematic liquid crystal molecules. A polarization control device characterized by the following. According to such a configuration, similar to the projection device according to Supplementary Note 5, when each liquid crystal molecule is arranged such that the long axis direction of the liquid crystal molecule is along each organic film, it is possible to easily impart a phase difference to the modulated light transmitted through the liquid crystal molecules. Therefore, it is possible to easily form random unpolarized light by the polarization control device.

[0107] [Supplementary Note 16] The first substrate, A second substrate disposed to face the first substrate, A first electrode provided on the surface of the first substrate on the side of the second substrate, A first vertical alignment film laminated on the first electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied, A second electrode provided on the surface of the second substrate on the side of the first substrate, A second vertical alignment film laminated on the second electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied, A liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and containing liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode, A polarization control device characterized by the above.

[0108] According to such a configuration, similarly to the polarization control device according to the above-mentioned appended note 11, the emitted light can be made into randomly polarized light in an unpolarized state. That is, in a state where no voltage is applied to the liquid crystal layer, the liquid crystal molecules are aligned perpendicular to each vertical alignment film by each vertical alignment film. On the other hand, when a voltage is applied to the liquid crystal layer, each of the plurality of liquid crystal molecules falls in a random direction with respect to a virtual plane parallel to each vertical alignment film. An optical path difference is randomly imparted to the light passing through the liquid crystal layer of such a polarization control device. Therefore, the light emitted from the polarization control device can be made into randomly polarized light with a low degree of polarization.

[0109] [Appended note 17] In the polarization control device according to appended note 16, An incident-side retardation element disposed on the side opposite to the second substrate with respect to the first substrate and causing an optical path difference in incident light, A polarization control device characterized by the above. According to such a configuration, similarly to the projection device according to the above-mentioned appended note 7, light in a more randomly polarized state can be emitted from the polarization control device. Therefore, light in a polarized state with less polarization in all directions can be emitted.

[0110] [Appended note 18] In the polarization control device described in Supplementary Note 17, the incident-side retardation element is a λ / 4 retardation plate, and the polarization control device is characterized by this. According to such a configuration, similarly to the projection device according to Supplementary Note 8 above, by making linearly polarized light incident on the incident-side retardation element, which is a λ / 4 retardation plate, and making circularly polarized light incident on the liquid crystal layer, the light emitted from the polarization control device can be made into light in a more random unpolarized state.

[0111] [Supplementary Note 19] In the polarization control device described in Supplementary Note 17 or Supplementary Note 18, it has an emission-side retardation element that is arranged on the side opposite to the first substrate with respect to the second substrate and causes a retardation in the incident light, and the polarization control device is characterized by this. According to such a configuration, similarly to the projection device according to Supplementary Note 9 above, the polarization state of the light emitted from the polarization control device can be controlled by the emission-side retardation element.

[0112] [Supplementary Note 20] a light source, a polarization control device described in any one of Supplementary Notes 11 to 19, which is arranged in the optical path of the light emitted from the light source and controls the polarization state of the incident light, and a control device that controls the polarization control device to cause one of linearly polarized light and unpolarized light to be emitted from the polarization control device according to the time zone, and the circadian rhythm control device is characterized by this. According to such a configuration, for example, by irradiating linearly polarized light in the morning and evening and irradiating unpolarized light during the day, light in a polarization state close to sunlight can be irradiated according to the time zone. Therefore, it is possible to make it easier for organisms to perceive the time zone and to affect the circadian rhythm of organisms, so the circadian rhythm of organisms can be controlled.

Explanation of Reference Numerals

[0113] 1A, 1F… Projector (Projection device), 35… Optical modulation element, 351… Optical modulation module, 352… Incident-side polarizing plate, 353… Exit-side polarizing plate, 35B… Blue optical modulation element, 351B… Blue optical modulation module, 35G… Green optical modulation element, 351G… Green optical modulation module, 35R… Red optical modulation element, 351R… Red optical modulation module, 37… Projection lens, 5A, 5B, 5C, 5D, 5E… Polarization control device, 51A, 51B… First substrate, 511… Light incident surface, 512, 512B… Light exit surface, 52A, 52B… Second substrate, 521, 521B… Light incident surface, 522… Light exit surface, 53… First conductive layer (first electrode), 54… Second conductive layer (second electrode), 55… First organic film, 56… Second organic film, 57… Liquid crystal layer, 571… Liquid crystal molecules, 58… First vertical alignment film, 59… Second vertical alignment film, 60… Incident-side retardation element, 61… Exit-side retardation element, 62… Incident-side variable retardation element (incident-side retardation element), 63… Exit-side variable retardation element (exit-side retardation element), 7… Control unit, 8F… Control device, 91… Light source, 92… Polarization control device, 93… Control device, AR… Active state adjustment device, RC… Circadian rhythm control device.

Claims

1. An optical modulation element that modulates incident light based on an image signal, A projection lens that projects the light emitted from the optical modulation element, A polarization control device that is disposed on the emission side of the optical modulation element in the optical path of the light emitted from the optical modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the optical modulation element, The polarization control device includes: A first substrate, A second substrate disposed opposite to the first substrate, A first organic film laminated on the first substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, A second organic film laminated on the second substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules, A liquid crystal layer disposed between the first organic film and the second organic film, The liquid crystal layer includes a plurality of liquid crystal molecules disposed in a state where the major axis directions are disordered with respect to the first organic film and the second organic film, A projection device characterized by the above.

2. In the projection device according to Claim 1, The polarization control device includes: A first conductive layer disposed between the first substrate and the first organic film, A second conductive layer disposed between the second substrate and the second organic film, A projection device characterized by the above.

3. In the projection device according to Claim 2, A control unit that applies a voltage to the liquid crystal layer is provided, The first conductive layer constitutes a first electrode electrically connected to the control unit, The second conductive layer constitutes a second electrode electrically connected to the control unit, A projection device characterized by the above.

4. In the projection device according to Claim 1, The surface of the first substrate on the side of the first organic film is a first surface activation treatment surface, The first organic film is provided on the first surface activation treatment surface, The surface of the second substrate on the side of the second organic film is a second surface activation treatment surface, The second organic film is provided on the second surface activation treatment surface, A projection device characterized by the above.

5. In the projection device according to any one of Claims 1 to 4, The liquid crystal molecules are negative nematic liquid crystal molecules, A projection device characterized by the above.

6. An optical modulation element that modulates incident light based on an image signal, A projection lens that projects the light emitted from the optical modulation element, A polarization control device that is disposed on the emission side of the light modulation element with respect to the light modulation element in the optical path of the light emitted from the light modulation element and projected by the projection lens, and controls the polarization state of the light modulated by the light modulation element; The polarization control device is A first substrate having a light incident surface on which light is incident; A second substrate disposed opposite to the first substrate; A first electrode disposed on the surface of the first substrate opposite to the light incident surface; A first vertical alignment film laminated on the first electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; A second electrode disposed on the surface of the second substrate on the side of the first substrate; A second vertical alignment film laminated on the second electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; A liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and including a plurality of liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode; A projection device characterized by this.

7. In the projection device according to claim 6, The polarization control device is disposed on the side opposite to the second substrate with respect to the first substrate, and has an incident-side retardation element that causes a phase difference in the incident light. A projection device characterized by this.

8. In the projection device according to claim 7, The incident-side retardation element is a λ / 4 retardation plate. A projection device characterized by this.

9. In the projection device according to claim 7, The polarization control device is disposed on the side opposite to the first substrate with respect to the second substrate, and has an emission-side retardation element that causes a phase difference in the incident light. A projection device characterized by this.

10. A projection device according to any one of claims 1 to 4 and claims 6 to 9, And a control device that irradiates the projection device with linearly polarized light and unpolarized light individually to change the active state of a photoreceptor. An active state adjustment device characterized by this.

11. A first substrate; A second substrate disposed opposite to the first substrate; A first organic film laminated on the first substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules; A second organic film laminated on the second substrate and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules; A liquid crystal layer disposed between the first organic film and the second organic film and including liquid crystal molecules that are disposed in a state where the major axis directions are disordered with respect to the first organic film and the second organic film; A polarization control device characterized by the following.

12. In the polarization control device according to claim 11, a first conductive layer laminated between the first substrate and the first organic film; and a second conductive layer laminated between the second substrate and the second organic film. A polarization control device characterized by the following.

13. In the polarization control device according to claim 12, the first conductive layer constitutes a first electrode; the second conductive layer constitutes a second electrode. A polarization control device characterized by the following.

14. In the polarization control device according to claim 11, the surface of the first substrate on the side of the first organic film is a first surface activation treatment surface; the first organic film is provided on the first surface activation treatment surface; the surface of the second substrate on the side of the second organic film is a second surface activation treatment surface; the second organic film is provided on the second surface activation treatment surface. A polarization control device characterized by the following.

15. In the polarization control device according to any one of claims 11 to 14, the liquid crystal molecules are negative nematic liquid crystal molecules. A polarization control device characterized by the following.

16. A first substrate; a second substrate disposed opposite to the first substrate; a first electrode provided on the surface of the first substrate on the side of the second substrate; a first vertical alignment film laminated on the first electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; a second electrode provided on the surface of the second substrate on the side of the first substrate; a second vertical alignment film laminated on the second electrode and having no alignment regulating force for regulating the alignment direction of liquid crystal molecules when a voltage is applied; and a liquid crystal layer disposed between the first vertical alignment film and the second vertical alignment film and containing liquid crystal molecules that are randomly aligned by applying a voltage to each of the first electrode and the second electrode. A polarization control device characterized by the following.

17. In the polarization control device according to claim 16, an incident-side retardation element that is disposed on the side opposite to the second substrate with respect to the first substrate and generates a retardation in incident light. A polarization control device characterized by the following.

18. In the polarization control device according to claim 17, the incident-side retardation element is a λ / 4 retardation plate. A polarization control device characterized by the following.

19. In the polarization control device according to claim 17 or claim 18, An emission-side retardation element that is disposed on the side opposite to the first substrate with respect to the second substrate and that causes a phase difference in incident light. A polarization control device characterized by the above. **Claim 20** A light source, A polarization control device according to any one of claims 11 to 14 and claims 16 to 18, which is disposed in an optical path of light emitted from the light source and controls a polarization state of incident light, A control device that controls the polarization control device to emit one of linearly polarized light and unpolarized light from the polarization control device according to a time zone. A circadian rhythm control device characterized by the above.

Images