Projector

Abstract

To suppress the occurrence of color breakup in a projector.SOLUTION: A projector according to an aspect of the invention includes a light source device configured to periodically emit illumination light including first light and second light, a light modulation device configured to modulate the illumination light emitted from the light source device according to image information, and a projection optical system configured to project image light emitted from the light modulation device. An irradiation period of the second light emitted from the light source device and irradiated on the second liquid crystal element and an image formation period of the second liquid crystal element are synchronized with each other, an image formation period of the first liquid crystal element and an image formation period of the second liquid crystal element are shifted from each other, and a wavelength of the first light entering the first liquid crystal element and a wavelength of the second light entering the second liquid crystal element are different from each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a projector. [Background technology]

[0002] As a projector, which is an image display device, a device has been proposed in which illumination light emitted from a light source device is scanned temporally on the modulation surface of an optical modulation device such as a liquid crystal panel, thereby illuminating the optical modulation device with colored light, and the image light emitted from the optical modulation device is projected onto a projection surface such as a screen using a projection optical system.

[0003] For example, Patent Document 1 discloses a projector in which a black display period is set within an image formation cycle of a vertical synchronization signal along the scanning direction that scans the illumination light of a liquid crystal panel of a light modulation device. That is, the projector disclosed in Patent Document 1 is controlled so that the output of the light emitting element of the light source device is turned off during a period corresponding to at least one or more subframes among periods corresponding to multiple subframes of the light modulation device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-221500 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional projectors, including the projector disclosed in the aforementioned Patent Document 1, for example, single-panel or two-panel configurations are easier to reduce in size, weight, and simplicity than three-panel configurations. However, in single-panel or two-panel configurations, color mixing occurs in the projected image over time. Even if the drive frequency related to the image formation period in multiple color regions of the liquid crystal panel of the light modulation device is set to a critical fusion frequency (CFF) or higher, a viewer of the projected image may see or perceive separation of multiple color image lights corresponding to each color region when viewing the projected image with rapid eye movements such as saccadic eye movements. This phenomenon of seeing or perceiving colored light is called color breakup.

[0006] In conventional projectors, when a black display period is provided in each pixel of the liquid crystal panel of the light modulation device, color breakup may occur, and therefore measures to suppress the occurrence of color breakup are desired. [Means for solving the problem]

[0007] A projector according to one aspect of the present invention includes a light source device that periodically emits illumination light including a first light and a second light, a light modulation device that modulates the illumination light emitted from the light source device in accordance with image information, and a projection optical system that projects the image light emitted from the light modulation device, wherein the light source device has a light-emitting element that emits the first light and the second light, and the light modulation device has a first liquid crystal element that forms an image by converting the incident first light into first image light in accordance with the input image information, and a projection optical system that converts the incident second light into second image light in accordance with the input image information. and a second liquid crystal element that forms an image by converting light emitted from the light source device to the first liquid crystal element, wherein an irradiation cycle of the first light emitted from the light source device to be irradiated onto the first liquid crystal element and an image formation cycle of the first liquid crystal element are synchronized with each other, an irradiation cycle of the second light emitted from the light source device to be irradiated onto the second liquid crystal element and an image formation cycle of the second liquid crystal element are synchronized with each other, the image formation cycle of the first liquid crystal element and the image formation cycle of the second liquid crystal element are shifted from each other, and the wavelength of the first light incident on the first liquid crystal element and the wavelength of the second light incident on the second liquid crystal element are different from each other. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a projector according to a first embodiment. [Figure 2] 2 is a schematic diagram for explaining the behavior of the optical scanning device of the projector in FIG. 1. FIG. [Figure 3] 2 is a schematic diagram for explaining the behavior of the optical scanning device of the projector in FIG. 1. FIG. [Figure 4] 2 is a schematic diagram for explaining the behavior of the optical scanning device of the projector in FIG. 1. FIG. [Figure 5] 2 is a time chart relating to the operation of the light source device and the liquid crystal panel of one light modulation device of the projector of FIG. 1. [Figure 6] 10 is a time chart relating to the operation of a light source device and a liquid crystal panel of one light modulation device in a divided region of a modulation surface of one light modulation device of the projector of FIG. [Figure 7]2 is a schematic diagram showing an example of the distribution of color regions on a modulation surface of one light modulation device and in a projected image in the projector of FIG. 1. FIG. [Figure 8] 2 is a time chart relating to the operation of the light source device and the liquid crystal panel of the two light modulation devices of the projector of FIG. 1. [Figure 9] 10 is another time chart relating to the operation of the light source device and the liquid crystal panel of the two light modulation devices of the projector of FIG. [Figure 10] 2 is a flowchart relating to control performed by a control unit of the projector in FIG. [Figure 11] FIG. 4 is a schematic diagram of a light source device of a projector according to a modified example of the first embodiment. [Figure 12] FIG. 10 is a schematic diagram of a projector according to a second embodiment. [Figure 13] FIG. 10 is a schematic diagram of a light source device of a projector according to a modified example of the second embodiment. [Figure 14] FIG. 10 is a schematic diagram of a projector according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] In the drawings referred to below, the scale of the dimensions of some components may be changed to make them easier to see.

[0010] [First embodiment] First, a first embodiment of the present invention will be described with reference to FIGS.

[0011] First, the basic configuration of a projector 201 according to a first embodiment of the present invention will be described. FIG. 1 is a schematic diagram of the projector 201. The projector 201 is a two-panel image display device equipped with two liquid crystal panels as light modulation devices. As shown in FIG. 1, the projector 201 includes a light source device 230, a polarization separation element 310, an optical scanning device 40, a reflecting element 271, an optical modulation device 60, a polarizing plate 281, an optical scanning device 70, a reflecting element 272, an optical modulation device 260, a polarizing plate 282, a polarization separation element 320, a projection optical system 80, a light source output control device 110, a rotation control device 120, a drive control device 130, a central processing unit 140, a user interface 150, a video processing circuit 160, and a video interface 170.

[0012] The light source device 230 includes a light-emitting element 21, a collimating lens 26, and a spatial light modulator 250. The light-emitting element 21 periodically switches between red light RL, green light GL, and blue light BL contained in white light and emits them. The red light RL, green light GL, or blue light BL emitted from the light-emitting element 21 is described and illustrated as colored light WL. The colored light WL corresponds to illumination light described in the claims below. The colored light WL emitted from the light-emitting element 21 is S-polarized or P-polarized light, for example, S-polarized light.

[0013] In the following description, the axis parallel to the optical axis AX and the principal ray of the colored light WL emitted from the light-emitting element 21 is referred to as the Z axis, with one side parallel to the Z axis being the -Z side and the other side parallel to the Z axis being the +Z side. The axis perpendicular to the Z axis is referred to as the X axis, with one side parallel to the X axis being the -X side and the other side parallel to the X axis being the +X side. The axis perpendicular to the Z axis and the X axis is referred to as the Y axis, with one side parallel to the Y axis being the -Y side and the other side parallel to the X axis being the +Y side.

[0014] The light emitting element 21 emits color light WL from the emission surface 21e toward the +Z side along the Z axis. The light emitting element 21 is, for example, a white LD in which a red laser diode (LD), a green LD, and a blue LD are integrated.

[0015] The collimating lens 26 is disposed on the optical path of the colored light WL emitted from the light-emitting element 21, and is disposed on the +Z side of the emission surface 21e of the light-emitting element 21. The central axis of the collimating lens 26 overlaps with the optical axis AX.

[0016] The collimating lens 26 converts the color light WL emitted from the light-emitting element 21 into parallel light parallel to the Z axis and emits it along the optical axis AX. The collimating lens 26 is, for example, a biconvex lens. The collimating lens 26 may also be a plano-convex lens having a flat entrance surface parallel to the XY plane including the X and Y axes and an exit surface that is convex on the +Z side. In FIG. 1, the collimating lens 26 is disposed away from the exit surface 21e of the light-emitting element 21, but if the collimating lens 26 is a plano-convex lens, the collimating lens 26 may be in contact with the exit surface 21e of the light-emitting element 21.

[0017] The spatial light modulator 250 is disposed on the optical path of the color light WL emitted from the collimating lens 26, and is disposed so as to substantially overlap with the collimating lens 26 in the X-axis and Y-axis, and on the +Z side of the collimating lens 26. The color light WL emitted from the collimating lens 26 enters the spatial light modulator 250 from the -Z side.

[0018] The polarization of the color light WL incident on the spatial light modulator 250 from the collimating lens 26 is converted into a different polarization at a predetermined polarization switching period. The S-polarized color light WL incident on the spatial light modulator 250 from the collimating lens 26 is converted into P-polarized light at a predetermined polarization switching period. That is, the spatial light modulator 250 alternately emits P-polarized color light WLP and S-polarized color light WLS in a time series at a predetermined polarization switching period. The P-polarized color light WLP corresponds to the first light described in the claims below. The S-polarized color light WLS corresponds to the second light described below.

[0019] The polarization separation element 310 is disposed on the optical path of the colored lights WLP and WLS emitted periodically in time series from the spatial light modulator 250 of the light source device 230, overlaps with the modulation surface of the spatial light modulator 250 in the X and Y axes, and is disposed on the +Z side of the spatial light modulator 250. The polarization separation element 310 corresponds to a first polarization separation element described below.

[0020] The polarization separation element 310 is, for example, a cube-type polarization beam splitter 312. The polarization beam splitter 312 has a reflective film 314 that transmits one polarized light of the color light WL and reflects the other polarized light of the color light WL. The reflective film 314 is tilted with respect to the optical axis AX so that it moves from the +Y side to the -Y side as it moves from the -X side to the +X side of the polarization beam splitter 312. The reflective film 314 transmits, for example, the color light WLP and reflects the color light WLS. The polarization separation element 310 may also be a plate-type polarization beam splitter having the reflective film 314.

[0021] The polarization separation element 310 periodically emits the colored light WLP toward the +Z side along the Z axis in accordance with the aforementioned polarization switching period. The polarization separation element 310 periodically emits the colored light WLS toward the -Y side along the Y axis in accordance with the aforementioned polarization switching period. During the period in which the colored light WLP is emitted from the polarization separation element 310 toward the +Z side along the Z axis, the colored light WLS is not emitted from the polarization separation element 310 toward the -Y side along the Y axis. Similarly, during the period in which the colored light WLS is emitted from the polarization separation element 310 toward the -Y side along the Y axis, the colored light WLP is not emitted from the polarization separation element 310 toward the +Z side along the Z axis.

[0022] The optical scanning device 40 is disposed on the optical path of the colored light WLP emitted from the polarization separation element 310, and is disposed so as to substantially overlap with the polarization separation element 310 in the X and Y axes, and is disposed on the +Z side of the polarization separation element 310. The optical scanning device 40 scans the colored light WLP emitted from the light source device 230 and separated by the polarization separation element 310 within the XY plane.

[0023] The optical scanning device 40 has a light-transmitting member 42 and a rotating device such as a motor (not shown). The light-transmitting member 42 corresponds to a transmissive optical element (described later). The light-transmitting member 42 is disposed on the optical path of the white colored light WL emitted from the light source device 230, and is disposed on the +Z side of the light source device 230. The light-transmitting member 42 is formed in a columnar shape. The central axis JX1 of the light-transmitting member 42 is parallel to the X-axis and intersects with the optical axis AX of the colored light WLP or passes near the optical axis AX of the colored light WLP.

[0024] The light-transmitting member 42 is a polygonal prism having a central axis JX1. The light-transmitting member 42 has two end faces 51, 52 that intersect the central axis JX1 and are parallel to a YZ plane that includes the Y axis and the Z axis, and a plurality of side faces 54. The end faces 51, 52 correspond to a first face, which will be described later. The end face 51 is disposed relatively on the +X side. The end face 52 is disposed on the -X side of the end face 51 and overlaps with the end face 51 when viewed along the X axis. The end faces 51, 52 have a polygonal shape centered on the central axis JX1. The multiple side faces 54 correspond to an entrance face, an exit face, and a second face, which will be described later.

[0025] The number of side surfaces 54 is the same as the number of corners and sides of end surfaces 51 and 52. Side surfaces 54 connect each of the multiple outer peripheral edge edges of end surface 51 to the outer peripheral edge edges of end surface 52 that overlap with the aforementioned outer peripheral edge edges when viewed along the X-axis.

[0026] The end faces 51 and 52 are, for example, regular quadrilaterals and have the same shape, size, and area. The light-transmitting member 42 has two end faces 51 and 52 and four side faces 54A, 54B, 54C, and 54D. The side faces 54A, 54B, 54C, and 54D have the same size and area. The size and area of ​​the side faces 54A, 54B, 54C, and 54D are appropriately larger than the irradiation area centered on the optical axis AX of the colored light WLP emitted from the polarization separation element 310, depending on the scanning region of the colored light WLP, as described below.

[0027] When viewed along the X-axis, the side surfaces 54A and 54C face each other across the central axis JX1 and are parallel to each other. The side surfaces 54B and 54D face each other across the central axis JX1 and are parallel to each other. In this specification, "the two side surfaces 54 are parallel to each other" means that the angle between the two side surfaces 54 is within a range of 0° to 5°, taking into consideration the processing accuracy of the material of the light-transmitting member 42, the tolerance for the parallelism of the colored light WLP, and the like.

[0028] The light-transmitting member 42 is disposed so as to be rotatable about a central axis JX1. The central axis JX1 corresponds to the rotation axis CX1 of the light-transmitting member 42. While rotating about the rotation axis CX1, the light-transmitting member 42 transmits colored light WLP that is incident from the -Z side along the Z axis and the optical axis AX and emits it to the +Z side.

[0029] In this specification, a state in which the light-transmitting member 42 rotates around the rotation axis CX1 may be referred to as a rotation state. In the rotation state of the light-transmitting member 42, the side surface 54 onto which the color light WLP emitted from the light source device 230 and separated by the polarization separation element 310 enters the light-transmitting member 42 is not fixed to one of the four side surfaces 54A, 54B, 54C, and 54D, but is any one or two of the four side surfaces 54A, 54B, 54C, and 54D, and changes depending on time t.

[0030] The number of side surfaces 54 in the light-transmitting member 42 is not limited to four, and is preferably 2×m, where m is a natural number greater than or equal to 2. If the number of side surfaces 54 is an even number greater than or equal to 4, all of the side surfaces 54 are parallel to the opposing side surfaces 54, which reduces the generation of stray light of the colored light WLP that passes through the light-transmitting member 42 and improves the light utilization efficiency of the projector 211.

[0031] The material of the light-transmitting member 42 is a material that is translucent to the color light WL, and is, for example, optical glass such as borosilicate crown glass BK7 or high-transparency crown glass B270, quartz, transparent resin, or the like.

[0032] The reflecting element 271 is disposed on the optical path of the colored light WLP emitted from the light-transmitting member 42 of the optical scanning device 40 and within the area scanned by the colored light WLP, and is disposed on the +Z side of the light-transmitting member 42. The reflecting element 271 is a mirror having a reflecting surface that moves from the +Y side to the -Y side as it moves from the -X side to the +X side. The reflecting surface of the reflecting element 271 specularly reflects the colored light WLP that has been emitted from the light-transmitting member 42 and is incident on it from the -Z side, and emits it to the -Y side.

[0033] The light modulation device 60 is disposed on the optical path of the colored light WLP emitted from the reflecting element 271 and within the area scanned by the colored light WLP. The light modulation device 60 overlaps with the reflecting element 271 in the X-axis and Z-axis, and is disposed on the -Y side of the reflecting element 271. The area in the XY plane onto which the colored light WLP can be irradiated as the colored light WLP is scanned by the light-transmitting member 42 of the optical scanning device 40 is converted by the reflecting element 271 into an area in the XZ plane including the X-axis and Z-axis of the light modulation device 60.

[0034] The light modulation device 60 has a modulation surface 64 parallel to the XZ plane. The position, size, area, and shape of the modulation surface 64 on the XZ plane are equivalent to the region on the XZ plane onto which the colored light WLP can be irradiated by scanning the colored light WLP with the light-transmitting member 42 as described above, and are equivalent to the range on the XZ plane where the colored light WLP is irradiated and an appropriate margin area is secured outside the irradiation area.

[0035] The light modulation device 60 modulates the color light WLP incident from the +Y side by the reflecting element 271 with an electrical signal input from the drive control device 130 according to image information of the projection target, as will be described later, and converts it into image light IL1. The image light IL1 corresponds to first image light, which will be described later.

[0036] The light modulation device 60 is, for example, a transmissive liquid crystal panel 62. The liquid crystal panel 62 corresponds to a first liquid crystal element described below. The liquid crystal panel 62 constituting the light modulation device 60 has a plurality of pixels arranged two-dimensionally along the X-axis and Z-axis in the XZ plane. The plurality of pixels of the liquid crystal panel 62 constitute a modulation surface 64.

[0037] The plurality of pixels of the liquid crystal panel 62 include an element substrate (not shown), an opposing substrate, and a liquid crystal layer 68 sandwiched between the element substrate and the opposing substrate along the Y axis. The switching elements are provided on, for example, the element substrate. The switching elements are, for example, polysilicon thin film transistors (TFTs). The driving control device 130 supplies the switching elements of each pixel with electrical signals corresponding to the brightness and light amount of red light, green light, and blue light at the relative positions of each pixel of image information on the modulation surface 64 of the light modulation device 60 in the image of the projection target projected by the projector 211.

[0038] Each pixel of the liquid crystal panel 62 modulates the vibration direction of any one of the red light, green light, and blue light included in the color light WLP in the liquid crystal layer 68 by the operation of a switching element in response to the above-mentioned electrical signal, generates red image light, green image light, and blue image light, and emits image light IL1 according to the light intensity ratio of the three colors. The light modulation device 60 emits the image light IL1 generated by the liquid crystal panel 62 to the -Y side along the optical axis AX and the Y axis.

[0039] Each pixel of the liquid crystal panel 62 has red, green, and blue color filters (not shown). Therefore, the light modulation device 60 emits full-color image light IL1 that can be generated by red image light, green image light, and blue image light. The projector 211 is capable of full-color display.

[0040] The driving method of the liquid crystal panel 62 is not particularly limited, but may be, for example, a twisted nematic (TN) method, a vertical alignment (VA) method, or an in plane switching (IPS) method.

[0041] The polarizing plate 281 is disposed on the optical path of the image light IL1 emitted from the light modulation device 60, overlaps with the light modulation device 60 in the X-axis and Z-axis, and is disposed on the −Y side of the light modulation device 60.

[0042] The polarizing plate 281 transmits specific linearly polarized light of the image light IL1 emitted from the light modulation device 60, and absorbs or reflects polarized light components other than the specific linearly polarized light. The polarizing plate 281 transmits, for example, P-polarized light of the image light IL1 and emits it to the -Y side, and absorbs or reflects polarized light other than P-polarized light of the image light IL1. If an absorption-type polarizing plate is used as the polarizing plate 281, returned light due to polarized light other than P-polarized light emitted from the polarizing plate 281 to the -Z side is reduced, the generation of stray light in the projector 211 is suppressed, and light utilization efficiency is improved.

[0043] The optical scanning device 70 is disposed on the optical path of the colored light WLS emitted from the polarization separation element 310, and substantially overlaps with the polarization separation element 310 along the X and Z axes, and is disposed on the -Y side of the polarization separation element 310 and moderately on the +Y side of the light modulation device 60 and the polarizing plate 281. The optical scanning device 70 scans the colored light WLP emitted from the light source device 230 and separated by the polarization separation element 310 within the XZ plane.

[0044] The optical scanning device 70 has a light-transmitting member 76 and a rotating device such as a motor (not shown). The light-transmitting member 76 corresponds to a transmissive optical element (described later). The light-transmitting member 76 is disposed on the optical path of the colored light WLS emitted from the polarization separation element 310, and is disposed on the -Y side of the polarization separation element 310. The light-transmitting member 76 is formed in a columnar shape. The central axis JX2 of the light-transmitting member 76 is parallel to the X-axis and intersects with the optical axis AX of the colored light WLS or passes near the optical axis AX of the colored light WLS.

[0045] The light-transmitting member 76 is a polygonal prism having a central axis JX2. The light-transmitting member 76 has two end faces 71 and 72 that intersect the central axis JX2 and are parallel to the YZ plane, and a plurality of side faces 74. The end faces 71 and 72 correspond to the first face described below. The end face 71 is relatively disposed on the +X side. The end face 72 is disposed on the -X side of the end face 51 and overlaps with the end face 51 when viewed along the X axis. The end faces 71 and 72 have a polygonal shape centered on the central axis JX2. The multiple side faces 74 correspond to the incident face, exit face, and second face described below.

[0046] The number of side surfaces 74 is the same as the number of corners and sides of end surfaces 71 and 72. Side surfaces 74 connect each of the multiple outer peripheral edge edges of end surface 71 to the outer peripheral edge edges of end surface 72 that overlap with the aforementioned outer peripheral edge edges when viewed along the X axis.

[0047] The end faces 71 and 72 are, for example, regular quadrilaterals and have the same shape, size, and area. The light-transmitting member 76 has two end faces 71 and 72 and four side faces 74A, 74B, 74C, and 74D. The side faces 74A, 74B, 74C, and 74D have the same size and area. The size and area of ​​the side faces 74A, 74B, 74C, and 74D are appropriately larger than the irradiation area centered on the optical axis AX of the colored light WLS emitted from the polarization separation element 310, depending on the scanning region of the colored light WLS, as described below.

[0048] When viewed along the X-axis, side surfaces 74A and 74C face each other across central axis JX2 and are parallel to each other. Side surfaces 74B and 74D face each other across central axis JX2 and are parallel to each other. In this specification, "two side surfaces 74 are parallel to each other" means that the angle between the two side surfaces 74 is within a range of 0° to 5°, taking into consideration the processing accuracy of the material of light-transmitting member 76, the tolerance for the parallelism of colored light WLS, and the like.

[0049] The light-transmitting member 76 is disposed so as to be rotatable about a central axis JX2. The central axis JX2 corresponds to the rotation axis CX2 of the light-transmitting member 76. While rotating about the rotation axis CX2, the light-transmitting member 76 transmits colored light WLS that is incident from the +Y side along the Y axis and the optical axis AX and emits it to the -Y side.

[0050] In this specification, a state in which the light-transmitting member 76 is rotating around the rotation axis CX2 may also be referred to as a rotating state. In the rotating state of the light-transmitting member 76, the side surface 74 onto which the color light WLS emitted from the light source device 230 and separated by the polarization separation element 310 enters the light-transmitting member 76 is not fixed to one of the four side surfaces 74A, 74B, 74C, and 74D, but is one or two of the four side surfaces 74A, 74B, 74C, and 74D, and changes depending on time t.

[0051] The number of side surfaces 74 in the light-transmitting member 76 is not limited to four, and is preferably 2×m, where m is a natural number greater than or equal to 2. If the number of side surfaces 74 is an even number greater than or equal to 4, all of the side surfaces 74 are parallel to the opposing side surfaces 74, which reduces the generation of stray light of the colored light WLS that passes through the light-transmitting member 76 and improves the light utilization efficiency of the projector 211.

[0052] The material of the translucent member 76, like the material of the translucent member 42, is a material that is translucent to the colored light WL, and is, for example, optical glass such as borosilicate crown glass BK7 or high-transparency crown glass B270, quartz, transparent resin, etc.

[0053] The reflecting element 272 is disposed on the optical path of the colored light WLS emitted from the light-transmitting member 76 of the optical scanning device 70 and within the region scanned by the colored light WLS, and is disposed on the -Y side of the light-transmitting member 76 and on the -Y side of the light modulation device 60 and the polarizing plate 281. The reflecting element 272 is a mirror having a reflecting surface that moves from the +Y side to the -Y side as it moves from the -X side to the +X side. The reflecting surface of the reflecting element 272 specularly reflects the colored light WLS emitted from the light-transmitting member 76 and incident on it from the +Y side, and emits it to the +Z side.

[0054] The light modulation device 260 is disposed on the optical path of the colored light WLS emitted from the reflecting element 272 and within the area scanned by the colored light WLS. The light modulation device 260 overlaps with the reflecting element 272 in the X and Z axes, and is disposed on the +Z side of the reflecting element 272. The area in the XZ plane that can be irradiated with the colored light WLS as a result of the colored light WLS being scanned by the light-transmitting member 76 of the optical scanning device 70 is converted by the reflecting element 272 into an area in the XY plane of the light modulation device 260.

[0055] The light modulator 260 has a modulation surface 264 parallel to the XY plane. The position, size, area, and shape of the modulation surface 264 on the XY plane are equivalent to the region on the XY plane that can be irradiated with the colored light WLS by scanning the colored light WLS with the light-transmitting member 76 as described above, and are equivalent to the range on the XY plane that the colored light WLS irradiates and that ensures an appropriate margin area outside the irradiation area.

[0056] The light modulation device 260 modulates the color light WLS incident from the -Z side by the reflecting element 272 with an electrical signal input from the drive control device 130 according to image information of the projection target, as will be described later, and converts it into image light IL2. The image light IL2 corresponds to second image light, which will be described later.

[0057] The light modulation device 260 is, for example, a transmissive liquid crystal panel 262. The liquid crystal panel 262 corresponds to a second liquid crystal element described later. The liquid crystal panel 262 constituting the light modulation device 260 has a plurality of pixels arranged two-dimensionally along the X-axis and Y-axis on the XY plane. The plurality of pixels of the liquid crystal panel 262 constitute a modulation surface 264.

[0058] The plurality of pixels of the liquid crystal panel 262 include an element substrate (not shown), an opposing substrate, and a liquid crystal layer 68 sandwiched between the element substrate and the opposing substrate along the Z axis. The switching elements are provided, for example, on the element substrate. The switching elements are, for example, TFTs. Electric signals corresponding to the brightness and light amount of each of the red light, green light, and blue light at the relative position of each pixel of the image information on the modulation surface 264 of the light modulation device 260 in the image of the projection target projected by the projector 211 are supplied to the switching elements of each pixel from the drive control device 130.

[0059] Each pixel of the liquid crystal panel 262 modulates the vibration direction of any one of the red light, green light, and blue light included in the color light WLS in the liquid crystal layer 268 by the operation of a switching element in response to the above-mentioned electrical signal, generates red image light, green image light, and blue image light, and emits image light IL2 according to the light intensity ratio of the three colors. The light modulation device 260 emits the image light IL2 generated by the liquid crystal panel 262 to the +Z side along the optical axis AX and the Z axis.

[0060] Each pixel of the liquid crystal panel 262 has red, green, and blue color filters (not shown). Therefore, the light modulation device 260 emits full-color image light IL2 that can be generated by red image light, green image light, and blue image light. The projector 211 is capable of full-color display.

[0061] Note that each pixel of the liquid crystal panel 62 of the light modulation device 60 and each pixel of the liquid crystal panel 262 of the light modulation device 260 may not have a color filter. In that case, when any color light of red light, green light, or blue light is emitted from the light emitting element 21 of the light source device 230, the light modulation devices 60, 260 emit monochromatic image light IL1, IL2 corresponding to any of the aforementioned color lights. When each pixel of the liquid crystal panels 62, 260 does not have a color filter, the projector 211 can display a monochromatic image.

[0062] The driving method of the liquid crystal panel 262 is not particularly limited, but like the driving method of the liquid crystal panel 62, it may be, for example, the TN method, the VA method, or the IPS method.

[0063] The polarizing plate 282 is disposed on the optical path of the image light IL2 emitted from the light modulation device 260, overlaps with the light modulation device 260 in the X-axis and Y-axis, and is disposed on the +Z side of the light modulation device 260.

[0064] The polarizing plate 282 transmits specific linearly polarized light of the image light IL2 emitted from the light modulation device 260, and absorbs or reflects polarized light components other than the specific linearly polarized light. The polarizing plate 282 transmits, for example, S-polarized light of the image light IL2 and emits it to the +Z side, and absorbs or reflects polarized light of the image light IL2 other than the S-polarized light. If an absorption-type polarizing plate is used as the polarizing plate 282, returned light due to polarized light other than S-polarized light emitted from the polarizing plate 282 to the -Z side is reduced, the generation of stray light in the projector 211 is suppressed, and light utilization efficiency is improved.

[0065] The polarization separation element 320 is disposed in a region where the optical path of image light IL1 periodically emitted in time series from the liquid crystal panel 62 of the light modulation device 60 and the optical path of image light IL2 periodically emitted in time series from the liquid crystal panel 262 of the light modulation device 260 overlap. The polarization separation element 320 overlaps with the liquid crystal panel 62 in the X-axis and Z-axis and is disposed on the -Y side of the liquid crystal panel 62, and overlaps with the liquid crystal panel 262 in the X-axis and Y-axis and is disposed on the +Z side of the liquid crystal panel 262. The polarization separation element 320 corresponds to a second polarization separation element described below. The polarization separation element 320 is a light combining element for superimposing the image light IL1 and IL2 on optical paths that run in the same direction.

[0066] The polarization separation element 320 is, for example, a cube-type polarization beam splitter 322. The polarization beam splitter 322 has a reflective film 324 that transmits one polarized light of the color light WL and reflects the other polarized light of the color light WL. The reflective film 324 is inclined with respect to the optical axis AX of the image light IL1 and the optical axis AX of the image light IL2 so that the reflective film 324 moves from the +Y side to the -Y side as it moves from the -X side to the +X side in the polarization beam splitter 322. The reflective film 324 transmits, for example, the color light WLP and reflects the color light WLS. The polarization separation element 320 may also be a plate-type polarization beam splitter having the reflective film 324.

[0067] The polarization separation element 320 periodically emits the color light WLP toward the -Y side along the Y axis in accordance with the polarization switching cycle described above. The polarization separation element 320 periodically emits the color light WLS toward the -Y side along the Y axis, also in accordance with the polarization switching cycle described above, in the same direction as the color light WLP, and emits the image light IL in time series. During the period in which the image light IL1 is emitted from the polarization separation element 320 toward the -Y side along the Y axis, the image light IL2 is not emitted from the polarization separation element 320 toward the -Y side along the Y axis. Similarly, during the period in which the image light IL2 is emitted from the polarization separation element 320 toward the -Y side along the Y axis, the image light IL is not emitted from the polarization separation element 320 toward the -Y side along the Y axis.

[0068] The projection optical system 80 is disposed on the optical path of the image light IL emitted from the polarization separation element 320, overlaps with the polarization separation element 320 in the X-axis and Z-axis, and is disposed on the -Y side of the polarization separation element 320. The projection optical system 80 enlarges and projects the image light IL1, IL2 generated by the light modulation devices 60, 260 onto a projection surface such as a screen. The projection optical system 80 is composed of multiple optical lenses disposed along the Y-axis. The optical lenses include, for example, a plano-convex lens, a plano-concave lens, a biconvex lens, a biconcave lens, a meniscus lens, an aspherical lens, or a free-form lens.

[0069] The above-mentioned light source device 230, polarization separation element 310, optical scanning device 40, reflecting element 271, optical modulation device 60, polarizing plate 281, optical scanning device 70, reflecting element 272, optical modulation device 260, polarizing plate 282, polarization separation element 320 and projection optical system 80 constitute the optical section 10 of the projector 211.

[0070] The light source output control device 110 is electrically connected to the light emitting element 21 of the light source device 230 by wire or wirelessly, and controls the amount of colored light WL emitted from the light emitting element 21. Specifically, the light source output control device 110 outputs an electrical signal related to a drive voltage or drive current to the light emitting element 21 for controlling the amount of colored light WL emitted from the light emitting element 21, causing the light emitting element 21 to periodically emit the colored light WL. The light source output control device 110 is, for example, an LD driver. A program of periodic drive voltage values ​​or drive current values ​​to the light emitting element 21 corresponding to elapsed time and time t is stored and saved in the driver, which is the light source output control device 110. The drive voltage values ​​or drive current values ​​to the light emitting element 21 corresponding to elapsed time and time t will be described later.

[0071] The rotation control device 120 is electrically connected via a motor to the light-transmitting member 42 of the optical scanning device 40 and the light-transmitting member 76 of the optical scanning device 70, either wired or wirelessly, and controls the rotation speed of the light-transmitting member 42 about the rotation axis CX1 and the rotation speed of the light-transmitting member 76 about the rotation axis CX2. The rotation control device 120 is configured by, for example, a motor driver.

[0072] The drive control device 130 is electrically connected to the light source output control device 110 and the rotation control device 120, and is electrically connected by wire or wirelessly to the spatial light modulator 250 of the light source device 230, the liquid crystal panel 62 of the light modulation device 60, and the liquid crystal panel 262 of the light modulation device 260. The drive control device 130 outputs electrical signals to each of the light source output control device 110 and the rotation control device 120, and controls the position, area, and timing in the XZ plane where the color light WLP emitted from the spatial light modulator 250 of the light source device 230 is scanned by the light-transmitting member 42 of the optical scanning device 40 and irradiated on the modulation surface 64 of the liquid crystal panel 62 of the light modulation device 60, and the position, area, and timing in the XY plane where the color light WL emitted from the spatial light modulator 250 is scanned by the light-transmitting member 76 of the optical scanning device 70 and irradiated on the modulation surface 264 of the liquid crystal panel 262 of the light modulation device 260. The drive control device 130 supplies electrical signals to each pixel of the liquid crystal panel 62, 262 on the modulation surface 64, 264 in accordance with the irradiation position, irradiation area and timing of the color light WL described above.

[0073] The drive control device 130 synchronizes and drives the pixels corresponding to the three primary colors of the light-emitting elements 21 of the light source device 230, the spatial light modulator 250, the light-transmitting member 42 of the optical scanning device 40, the light-transmitting member 76 of the optical scanning device 70, the liquid crystal panel 62 of the light modulation device 60, and the liquid crystal panel 262 of the light modulation device 260 based on the refresh rate of the liquid crystal panels 62 and 262. If a synchronization error occurs between the above components, the error may be corrected by feedback, for example, by detecting the amount of image light IL at regular intervals. Image information output to the liquid crystal panels 62 and 262 may be subjected to appropriate processing, such as image processing and frame interpolation. Area dimming of the colored lights WLP and WLS emitted from the spatial light modulator 250 may be performed based on the scanning position of the light-transmitting member 42 and the image information output to the video panel 62, or based on the scanning position of the light-transmitting member 76 and the image information output to the video panel 262.

[0074] The drive control device 130 is, for example, a processor. The timing for supplying a drive voltage value or a drive current value to the light-emitting element 21, the timing for supplying a polarization switching cycle to the spatial light modulator 250, the timing for supplying a drive voltage for increasing or decreasing the rotation speed of the light-transmitting member 42 and for modulating the color light appropriate for each pixel of the liquid crystal panel 62, the timing for supplying a drive voltage for increasing or decreasing the rotation speed of the light-transmitting member 76 and for modulating the color light appropriate for each pixel of the liquid crystal panel 262, and the like are stored and saved in the processor that is the drive control device 130.

[0075] The central processing unit (CPU) 140 is electrically connected to the drive control device 130 via a wired or wireless connection. The central processing unit 140 transmits video information and drive information to the drive control device 130. The central processing unit 140 receives frame information from the video processing circuit 160 and receives information such as the refresh rate of the liquid crystal panel 62 from a user interface (UI) 150. The refresh rate of the liquid crystal panel 62 is arbitrarily set by the user of the projector 201 from pre-set options, and is, for example, 60 Hz or 90 Hz.

[0076] The user interface 150 is electrically connected to the central processing unit 140 via a wired or wireless connection. The user interface 150 transmits information such as the refresh rate to the central processing unit 140. The user interface 150 is, for example, an input device or a tablet terminal device installed in the projector 201.

[0077] The video processing circuit 160 is electrically connected to the central processing unit 140 via a wired or wireless connection. The video processing circuit 160 receives video information from the video interface 170, breaks down the received video information into frame information for each color, and transmits the frame information for each color of the video or image to the central processing unit 140. The video processing circuit 160 includes, for example, a VRAM (Video Random Access Memory), which is a memory dedicated to video processing.

[0078] The video interface 170 is electrically connected to the video processing circuit 160 via a wired or wireless connection. The video interface 170 transmits image information and video information of the object to be projected by the projector 201 to the video processing circuit 160.

[0079] The light source output control device 110 , rotation control device 120 , drive control device 130 , central processing unit 140 , user interface 150 , video processing circuit 160 and video interface 170 described above constitute the control unit 100 of the projector 201 .

[0080] Next, we will explain the scanning of the color light WLP by the optical scanning device 40 of the projector 211. When viewed from the +X side, i.e., the front side of the paper surface of Fig. 1, toward the -X side, i.e., the back side of the paper surface of Fig. 1, the light-transmitting member 42 of the optical scanning device 40 rotates clockwise, for example, as indicated by the arrow, around the rotation axis CX1.

[0081] In FIG. 1, the first state, i.e., the initial state, of the rotational states of the light-transmitting member 42 of the optical scanning device 40 is shown by solid lines. In the first state, the side surface 54A of the light-transmitting member 42 is located furthest from the -Z side of the four side surfaces 54 and is parallel to the XY plane. The rotation angle ω is the counterclockwise angle from an imaginary line TX that passes through the central axis JX1 and the rotation axis CX1 and is perpendicular to the side surface 54A to an axis PX that starts from the central axis JX1 and the rotation axis CX1 and extends parallel to the Z axis and toward the -Z side. The actual colored light WLP has a predetermined beam width on the X axis, Y axis, and XY plane. In describing the scanning and behavior of the colored light WLP, we will focus on the light ray WBM on the optical axis AX of the colored light WLP.

[0082] As shown in FIG. 1 , in the first state, the rotation angle ω is 0°, and the colored light WLP entering the light-transmitting member 42 from the -Z side is not refracted at the side surface 54A because it is perpendicular to the side surface 54A. The colored light WLP travels parallel to the Z axis, is perpendicular to the side surface 54C, is not refracted at the side surface 54C, and is emitted from the side surface 54C to the +Z side along the Z axis. The light rays WBM of the colored light WLP pass through the center of the side surface 54A in the XY plane, the central axis JX1, the rotation axis CX1, and the center of the side surface 54C in the XY plane. The distance d along the Z axis between the light rays WBM emitted from the side surface 54C of the light-transmitting member 42 and the axis QX, which starts from the central axis JX1 and the rotation axis CX1 and extends parallel to the Z axis and toward the +Z side, is approximately zero.

[0083] 2 is a schematic diagram of a second state in which the light-transmitting member 42 has rotated from the first state. As shown in FIG. 2, in the second state, the rotation angle ω is greater than 0° and less than 45°. In the second state, the colored light WLP incident on the light-transmitting member 42 from the -Z side is incident on the side surface 54A at an angle of incidence equal to the narrow angle formed by the normal to the side surface 54A and the light ray WBM. Therefore, in accordance with the angle of incidence on the side surface 54A, the refractive index n of the material of the light-transmitting member 42, and Snell's law, the colored light WLP is refracted toward the -Y side of the central axis JX1 at the side surface 54A.

[0084] In the second state, as described above, the colored light WLP entering the light-transmitting member 42 is refracted at the side surface 54A, enters the side surface 54C at an angle determined by the angle of incidence of the colored light WLP on the side surface 54A, the refractive index n, and Snell's law, is refracted at the side surface 54C, and is emitted from the side surface 54C to the +Z side along the Z axis. The separation distance d in the second state is greater than the separation distance d in the first state.

[0085] Regardless of the rotation state of the light-transmitting member 42, the rotation angle ω determines one or two of the four side surfaces 54A, 54B, 54C, and 54D of the light-transmitting member 42 onto which the colored light WLP is incident and the angle of incidence at which the colored light WLP is incident on one or two side surfaces 54. The separation distance d is determined by the angle of incidence of the colored light WLP onto one or two side surfaces 54 according to the rotation angle ω, the refractive index n, and the distance on the Z axis between the side surfaces 54A and 54C and between the side surfaces 54B and 54D, i.e., the length of one side of the polygon of the end surfaces 51 and 52.

[0086] 3 is a schematic diagram of a third state in which the rotation of the light-transmitting member 42 has progressed further from the second state. As shown in FIG. 3, the rotation angle ω is 45°, and light rays WBM of the colored light WLP incident on the light-transmitting member 42 from the -Z side are incident on the angle between the side surfaces 54A and 54B. In the third state, the colored light WLP incident on the light-transmitting member 42 from the -Z side, which is on the +Y side of the angle between the side surfaces 54A and 54B, is refracted at the side surface 54A, as in the second state, and is incident on the side surface 54C at an angle determined by the angle of incidence of the colored light WLP on the side surface 54A, the refractive index n, and Snell's law. Then, the colored light WLP is refracted at the side surface 54C and is emitted from the side surface 54C to the +Z side along the Z axis.

[0087] In the third state, of the colored light WLP incident on the light-transmitting member 42 from the -Z side, the colored light WLP on the -Y side of the angle between the side surfaces 54A and 54B is refracted at the side surface 54B, enters the side surface 54D at an angle determined by the angle of incidence of the colored light WLP on the side surface 54B, the refractive index n, and Snell's law, is refracted at the side surface 54D, and is emitted from the side surface 54D to the +Z side along the Z axis. The separation distance d in the third state is greater than the separation distance d in the second state.

[0088] 4 is a schematic diagram of a fourth state in which the rotation of the light-transmitting member 42 has progressed further from the third state. As shown in FIG. 4, in the fourth state, the rotation angle ω is greater than 45° and less than 90°. In the fourth state, the colored light WLP incident on the light-transmitting member 42 from the -Z side is incident at an angle of incidence equal to the narrow angle formed between the normal to the side surface 54B and the light ray WBM. Therefore, in accordance with the angle of incidence on the side surface 54B, the refractive index n, and Snell's law, the colored light WLP is refracted toward the +Y side of the central axis JX1 at the side surface 54B.

[0089] In the fourth state, as described above, the colored light WLP entering the light-transmitting member 42 is refracted at the side surface 54B, enters the side surface 54D at an angle determined by the angle of incidence of the colored light WLP on the side surface 54B, the refractive index n, and Snell's law, is refracted at the side surface 54D, and is emitted from the side surface 54D to the +Z side along the Z axis. The separation distance d in the fourth state is smaller than the separation distance d in the third state.

[0090] Although not shown, as the rotation state of the light-transmitting member 42 progresses, in the behavior from the first state to the fourth state described above, the side surface 54A of the light-transmitting member 42 is replaced with the side surface 54B, and the side surface 54B is replaced with the side surface 54C. Thereafter, in the behavior from the first state to the fourth state described above, the side surface 54A of the light-transmitting member 42 is replaced with the side surface 54C, and the side surface 54B is replaced with the side surface 54D. Further thereafter, in the behavior from the first state to the fourth state described above, the side surface 54A of the light-transmitting member 42 is replaced with the side surface 54D, and the side surface 54B is replaced with the side surface 54A.

[0091] By circulating these behaviors, the colored light WLP emitted from the light-transmitting member 42 of the optical scanning device 40 is scanned along the Y axis. Because the beam width of the colored light WLP incident on the light-transmitting member 42 in the X axis is larger than the beam width in the Y axis and is equivalent to the size of the modulation surface 64 of the light modulation device 60 in the X axis, the colored light WLP emitted from the light-transmitting member 42 is scanned in the XY plane and is scanned on the modulation surface 64 of the light modulation device 60. In the behaviors from the first state to the fourth state described above, the maximum value of the separation distance d is set to be equivalent to half the size of the modulation surface 64 in the X axis or Z axis. Based on this, the length and size of one side of the end faces 51, 52 of the light-transmitting member 42 and the refractive index n are appropriately set so that the maximum value of the separation distance d is equivalent to half the size of the modulation surface 64 in the X axis or Z axis.

[0092] The light-transmitting member 76 of the optical scanning device 70 of the projector 211 rotates clockwise, for example, as indicated by the arrow, about a rotation axis CX2 when viewed from the +X side, i.e., from the front side of the paper surface of Fig. 1, toward the -X side, i.e., from the back side of the paper surface of Fig. 1. The scanning of the colored light WLS by the optical scanning device 70 is based on the same principle as the scanning of the colored light WLP by the optical scanning device 40 described above, and can be understood by appropriately converting the axes and planes in the description of the scanning of the colored light WLP by the optical scanning device 40 described above.

[0093] Next, the flow from emission of color light WL in the projector 211 to projection will be described. Returning to FIG. 1 , in the first stage, S-polarized red light is emitted as color light WL from the light-emitting element 21 of the light source device 230. The spatial light modulator 250 is in the off state, i.e., the polarization state of the incident color light WL is not converted. Red color light WLS is emitted from the spatial light modulator 250, enters the polarization separation element 310, and is reflected. The red color light WLS reflected by the polarization separation element 310 enters the optical scanning device 70, is scanned, and enters the light modulation device 260. The color light WLS entering the light modulation device 260 is converted into red S-polarized image light IL2 by an electrical signal corresponding to image information. The red image light IL2 is reflected by the polarization separation element 320 and is enlarged and projected onto a projection surface such as a screen by the projection optical system 80.

[0094] In the second stage, S-polarized blue light is emitted from the light-emitting element 21 of the light source device 230 as the color light WL. The spatial light modulator 250 is in an on state, i.e., a state in which the polarization state of the incident color light WL is converted. The blue color light WLP is emitted from the spatial light modulator 250, enters the polarization separation element 310, and is transmitted therethrough. The blue color light WLP that passes through the polarization separation element 310 enters the optical scanning device 40, is manipulated, and enters the light modulation device 60. The color light WLP that enters the light modulation device 60 is converted into blue image light IL1 by an electrical signal corresponding to image information. The image light IL1, which is blue P-polarized light, passes through the polarization separation element 320 and is enlarged and projected by the projection optical system 80 onto a projection surface such as a screen.

[0095] In the third stage, S-polarized green light is emitted from the light-emitting element 21 of the light source device 230 as colored light WL. The spatial light modulator 250 is in an off state. The green light WLS is emitted from the spatial light modulator 250, enters the polarization separation element 310, and is reflected. The green light WLS reflected by the polarization separation element 310 enters the optical scanning device 70, is scanned, and enters the light modulation device 260. The colored light WLS entering the light modulation device 260 is converted into image light IL2, which is green S-polarized light, by an electrical signal corresponding to image information. The green image light IL2 is reflected by the polarization separation element 320 and is enlarged and projected by the projection optical system 80 onto a projection surface such as a screen.

[0096] In the fourth stage, S-polarized red light is emitted from the light-emitting element 21 of the light source device 230 as color light WL. The spatial light modulator 250 is in an on state. The red light WLP is emitted from the spatial light modulator 250, enters the polarization separation element 310, and passes through it. The red light WLP that passes through the polarization separation element 310 enters the optical scanning device 40, is manipulated, and enters the light modulation device 60. The color light WLP that enters the light modulation device 60 is converted into red image light IL1 by an electrical signal corresponding to image information. The image light IL1, which is red P-polarized light, passes through the polarization separation element 320 and is enlarged and projected by the projection optical system 80 onto a projection surface such as a screen.

[0097] In the fifth stage, S-polarized blue light is emitted from the light-emitting element 21 of the light source device 230 as colored light WL. The spatial light modulator 250 is in an off state. The blue light WLS is emitted from the spatial light modulator 250, enters the polarization separation element 310, and is reflected. The blue light WLS reflected by the polarization separation element 310 enters the optical scanning device 70, is scanned, and enters the light modulation device 260. The colored light WLS entering the light modulation device 260 is converted into blue S-polarized image light IL2 by an electrical signal corresponding to image information. The green image light IL2 is reflected by the polarization separation element 320 and is enlarged and projected by the projection optical system 80 onto a projection surface such as a screen.

[0098] In the sixth stage, S-polarized green light is emitted from the light-emitting element 21 of the light source device 230 as colored light WL. The spatial light modulator 250 is in an on state. The green colored light WLP is emitted from the spatial light modulator 250, enters the polarization separation element 310, and passes through it. The green colored light WLP that passes through the polarization separation element 310 enters the optical scanning device 40, is manipulated, and enters the light modulation device 60. The colored light WLP that enters the light modulation device 60 is converted into green image light IL1 by an electrical signal corresponding to image information. The image light IL1, which is green P-polarized light, passes through the polarization separation element 320 and is enlarged and projected by the projection optical system 80 onto a projection surface such as a screen.

[0099] In the optical section 10 of the projector 211, the above-described flow from the first stage to the sixth stage is repeated.

[0100] Next, a description will be given of the control by the control unit 100 over the optical unit 10 of the projector 201. Fig. 5 is a time chart relating to the operations of the light emitting element 21 of the light source device 230, the spatial light modulator 250, and the liquid crystal panel 62 of the light modulation device 60.

[0101] In the following description, an input image to the liquid crystal panel 62 of the light modulation device 60 is divided into eight regions along the X axis perpendicular to the scanning direction of the color light WL. When viewed along the Y axis from the +Y side, the input image to the liquid crystal panel 62 is divided along the X axis from the -X side to the +X side into a first region X1, a second region X2, a third region X3, a fourth region X4, a fifth region X5, a sixth region X6, a seventh region X7, and an eighth region X8.

[0102] In an input image to the liquid crystal panel 62, for example, the first region X1 is assigned white and is displayed by combining red, green, and blue light. The second region X2 is assigned red and is displayed by monochromatic red light only. The third region X3 is assigned yellow and is displayed by combining red and green light. The fourth region X4 is assigned green and is displayed by monochromatic green light only. The fifth region X5 is assigned cyan and is displayed by combining green and blue light. The sixth region X6 is assigned blue and is displayed by monochromatic blue light only. The seventh region X7 is assigned magenta and is displayed by combining red and blue light. The eighth region X8 is assigned black and does not include any of the red, green, or blue light colors.

[0103] As shown in FIG. 5, in each pixel of the liquid crystal panel 62, for each of the red region R, green region G, and blue region B, there is a rise period T1 from the rise start time to the rise completion time, a fixed period T2 from the rise completion time to the fall start time, and a fall period T3 from the fall start time to the fall completion time.

[0104] The rise period T1 corresponds to a first period, which will be described later. The fixed period T2 corresponds to a second period, which will be described later. In the liquid crystal panel 62, the rise period T1 is, for example, about 1.5 ms, and the fall period T3 is, for example, about 3.0 ms.

[0105] The time chart shown in Figure 5 assumes that the colors red, green, and blue are displayed one frame at a time at a driving speed of 360 Hz. In this case, the frame rate is 180 fps, which corresponds to 60 fps for color display. One cycle is approximately 2.78 ms.

[0106] Figure 6 is a time chart in which, as in Figure 5, the horizontal axis represents time t, and the vertical axis represents the liquid crystal response rate and colored light intensity in each region when the modulation surface 64 of the liquid crystal panel 62 of the projector 211 of the first embodiment is divided along the scanning direction, i.e., the Z axis, from the +Z side to the -Z side into five regions, from the first region Y1 to the second region Y2, the third region Y3, the fourth region Y4, and the fifth region Y5.

[0107] 5 and 6, the red light of the colored light WLP emitted from the light source device 230 is irradiated onto the modulation surface 64 through a color filter during a red irradiation period TR that does not overlap with the fall period T3 of the blue region B or the rise period T1 of the green region G within a certain period T2 of the red region R. The fall start time of the red region R and the rise start time of the green region G coincide with each other.

[0108] The green light of the colored light WLP emitted from the light source device 230 is irradiated onto the modulation surface 64 through a color filter during a green irradiation period TG that does not overlap with the fall period T3 of the red region R or the rise period T1 of the blue region B within the fixed period T2 of the green region G. The blue light of the colored light WLP emitted from the light source device 230 is irradiated onto the modulation surface 64 through a color filter during a blue irradiation period TB that does not overlap with the fall period T3 of the green region G or the rise period T1 of the red region R within the fixed period T2 of the blue region B.

[0109] The timing charts relating to the operation of the light-emitting element 21 of the light source device 230, the spatial light modulator 250, and the liquid crystal panel 262 of the light modulation device 260 are similar to the timing charts relating to the operation of the light source device 230 and the liquid crystal panel 62 of the light modulation device 60 described above in FIGS. 5 and 6.

[0110] That is, in the projector 211, each color light is emitted only during the period when the liquid crystal response of each pixel of the liquid crystal panels 62, 262 is complete. Therefore, the color of the input image input from the control unit 100 is accurately reproduced over the entire area of ​​the image projected onto a projection surface such as a screen (not shown). In each of the red area R, green area G, and blue area B, color light from the light emitting element 21 is emitted over the entire period when the liquid crystal response is complete and does not overlap with the rise period or fall period of the other color areas.

[0111] To each pixel of the liquid crystal panel 62 of the optical modulation device 60, a positive drive voltage PR1 and a negative drive voltage PR2 corresponding to red light according to the frame rate, a positive drive voltage PG3 and a negative drive voltage PG4 corresponding to green light, and a positive drive voltage PB5 and a negative drive voltage PB6 corresponding to blue light are sequentially supplied.

[0112] Fig. 7 is a schematic diagram showing the distribution of each color region on modulation surface 64. As shown in Fig. 7, in the scanning illumination projector 211 controlled as shown in Fig. 5 and Fig. 6, the brightness of image light IL1 is improved compared to a conventional projector with in-plane illumination. By the above-described control, unevenness and loss of illuminance of the projected image on the projection surface are suppressed in any region of modulation surface 64 and at time t, and color mixing does not occur.

[0113] To each pixel of the liquid crystal panel 262 of the light modulation device 260, a positive drive voltage PR1 and a negative drive voltage PR2 corresponding to red light, a positive drive voltage PG3 and a negative drive voltage PG4 corresponding to green light, and a positive drive voltage PB5 and a negative drive voltage PB6 corresponding to blue light are sequentially supplied in accordance with the frame rate. The projector 211 also improves the brightness of the image light IL2 compared to conventional projectors with in-plane illumination. Through the above-described control, uneven illuminance and loss of the projected image on the projection surface are suppressed in any region of the modulation surface 264 and at time t, and color mixing does not occur.

[0114] In the scanning illumination projector 211, the relative beam width of the colored light WLP on the modulation surface 64 of the light modulation device 60 is large in the Z axis, and the red irradiation period TR, green irradiation period TG, and blue irradiation period TB are each ensured to be relatively long, as shown in FIGS. 5 to 7. When obtaining a constant brightness of the image light IL1, the light density is suppressed, and the reliability of the projector 211 is high. The large relative beam width of the colored light WLP on the Z axis increases the irradiation efficiency of the colored light WLP. Note that, when the red irradiation period TR, green irradiation period TG, and blue irradiation period TB are each ensured to be relatively long, as shown in FIGS. 5 to 7, measures are required to prevent additional colored light from appearing from the beginning as the scanning of the colored light WLP approaches the end.

[0115] In the scanning illumination projector 211, when the relative beam width of the colored light WL on the modulation surface 64 of the light modulation device 60 in the Z axis is shortened, the red irradiation period TR, the green irradiation period TG, and the blue irradiation period TB are each shortened relatively. When a constant brightness of the image light IL1 is obtained, the light density increases and the reliability of the projector 211 is low. Because the relative beam width of the colored light WLP in the Z axis is small, the irradiation efficiency of the colored light WLP is low. Increasing the driving frequency of the liquid crystal of the liquid crystal panel 62 approaches the above-mentioned trend.

[0116] In the scanning illumination projector 211, the effects of the increase / decrease in the relative beam width of the colored light WL on the Y axis at the modulation surface 264 of the light modulation device 260 are similar to the effects of the increase / decrease in the relative beam width of the colored light WL on the Z axis at the modulation surface 64 of the light modulation device 60 described above.

[0117] Figure 8 is a time chart showing the modulation amount φ related to the liquid crystal response rate in each region of the modulation surface 64, the colored light WLP, WLS irradiated onto the liquid crystal panels 62, 262, and the change in the display color in the projected image in each region of the modulation surface 64, in the liquid crystal panel 62 of the light modulation device 60 and the liquid crystal panel 262 of the light modulation device 260.

[0118] 8, in the projector 211, when colored light WLP is irradiated in synchronization with a red irradiation period TR of the red region R of the liquid crystal panel 62 of the light modulation device 60, red image light IL1 is generated and projected. The red irradiation period TR of the red region R of the liquid crystal panel 62 overlaps with the rise period T1 and a first half of the fixed period T2 of the blue region B of the liquid crystal panel 262 of the light modulation device 260. However, the colored light WLS is not irradiated during the rise period T1 and a first half of the fixed period T2 of the blue region B of the liquid crystal panel 262. Therefore, during the red irradiation period TR of the red region R of the liquid crystal panel 62, red image light IL1 is displayed in the projected image.

[0119] When the colored light WLP is irradiated in synchronization with the green irradiation period TG of the green region G of the liquid crystal panel 62 of the light modulation device 60, green image light IL1 is generated and projected. The green irradiation period TG of the green region G of the liquid crystal panel 62 overlaps with most of the fall period T3 of the blue region B of the liquid crystal panel 262 of the light modulation device 260, the rise period T1 of the red region R, and a first half of the fixed period T2. However, the colored light WLS is not irradiated during most of the fall period T3 of the blue region B of the liquid crystal panel 262, the rise period T1 of the red region R, and a first half of the fixed period T2. Therefore, during the green irradiation period TG of the green region G of the liquid crystal panel 62, green image light IL1 is displayed in the projected image.

[0120] When colored light WLP is irradiated in synchronization with the blue irradiation period TB of the blue region B of the liquid crystal panel 62 of the light modulation device 60, blue image light IL1 is generated and projected. The blue irradiation period TB of the blue region B of the liquid crystal panel 62 overlaps with most of the fall period T3 of the red region R of the liquid crystal panel 262 of the light modulation device 260, the rise period T1 of the green region G, and a first half of the fixed period T2. However, colored light WLS is not irradiated during most of the fall period T3 of the red region R of the liquid crystal panel 262, the rise period T1 of the green region G, and a first half of the fixed period T2. Therefore, during the blue irradiation period TB of the blue region B of the liquid crystal panel 62, blue image light IL1 is displayed in the projected image.

[0121] When colored light WLS is emitted in synchronization with the red irradiation period TR of the red region R of the liquid crystal panel 262 of the light modulation device 260, red image light IL2 is generated and projected. The red irradiation period TR of the red region R of the liquid crystal panel 262 overlaps with most of the fall period T3 of the green region G of the liquid crystal panel 62 of the light modulation device 60, the rise period T1 of the blue region B, and a first half of the fixed period T2. However, colored light WLP is not emitted during most of the fall period T3 of the green region G of the liquid crystal panel 62, the rise period T1 of the blue region B, and a first half of the fixed period T2. Therefore, during the red irradiation period TR of the red region R of the liquid crystal panel 262, red image light IL2 is displayed in the projected image.

[0122] A red irradiation period TR of the red region R of the liquid crystal panel 262 and a red display period of the projection image by the image light IL2 <r>occurs with a black display period (K) between the green display period [G] and blue display period [B] of the image projected by the image light IL1.

[0123] When the colored light WLS is irradiated in synchronization with the green irradiation period TG of the green region G of the liquid crystal panel 262 of the light modulation device 260, green image light IL2 is generated and projected. The green irradiation period TG of the green region G of the liquid crystal panel 262 overlaps with most of the fall period T3 of the blue region B of the liquid crystal panel 62 of the light modulation device 60, the rise period T1 of the red region R, and a first half of the fixed period T2. However, the colored light WLP is not irradiated during most of the fall period T3 of the blue region B of the liquid crystal panel 62, the rise period T1 of the red region R, and a first half of the fixed period T2. Therefore, during the green irradiation period TG of the green region G of the liquid crystal panel 262, green image light IL2 is displayed in the projected image.

[0124] A green illumination period TG of the green area G of the liquid crystal panel 262 and a green display period of the projection image by the image light IL2 <g>occurs with a black display period (K) between the blue display period [B] and the red display period [R] of the image projected by the image light IL1.

[0125] When colored light WLS is emitted in synchronization with the blue irradiation period TB of the blue region B of the liquid crystal panel 262 of the light modulation device 260, blue image light IL2 is generated and projected. The blue irradiation period TB of the blue region B of the liquid crystal panel 262 overlaps with most of the fall period T3 of the red region R of the liquid crystal panel 62 of the light modulation device 60, the rise period T1 of the green region G, and a first half of the fixed period T2. However, colored light WLP is not emitted during most of the fall period T3 of the red region R of the liquid crystal panel 62, the rise period T1 of the green region G, and a first half of the fixed period T2. Therefore, during the blue irradiation period TB of the blue region B of the liquid crystal panel 262, blue image light IL2 is displayed in the projected image.

[0126] A blue illumination period TB of the blue region B of the liquid crystal panel 262 and a blue display period of the projection image by the image light IL2 occurs with a black display period (K) between a red display period [R] and a green display period [G] of the image projected by the image light IL1.

[0127] That is, in the projector 211, the timing and period when the colored light WLP is incident on the liquid crystal panel 62 are different from the timing and period when the colored light WLS is incident on the liquid crystal panel 262. The wavelength of the colored light WLP incident on the liquid crystal panel 62 is different from the wavelength of the colored light WLS incident on the liquid crystal panel 262. Therefore, in the projector 211, when only the liquid crystal panel 62 is used like a single-panel projector, the red display period of the projected image is <r>and green display period <g>Between these periods, not only a black display period (K) but also a blue display period (B) by the liquid crystal panel 262 occurs. <g>and blue display period Between these periods, not only a black display period (K) but also a red display period (R) by the liquid crystal panel 262 occurs. and red display period <r>Between these periods, not only a black display period (K) but also a green display period (G) by the liquid crystal panel 262 occurs.

[0128] The projector 211 employs a two-plate configuration, and the two light modulation devices 60 and 260 each display black (K) and red (R) lights. <r>[R], green indicates the period <g>, [G] and blue display period , [B] occurs, and the color display period of the projected image is shorter than when only one of the light modulation devices 60, 260 is used, as in a single-panel configuration. This suppresses the occurrence of color breakup when the viewer observes the projected image with rapid eye movement, making it difficult to see or perceive the separation of the multi-color image lights IL1, IL2 at time t.

[0129] Figure 9 is a time chart showing the modulation amount φ related to the liquid crystal response rate in each region of the modulation surface 64 in the liquid crystal panel 62 of the light modulation device 60 and the liquid crystal panel 262 of the light modulation device 260, the colored light WLP, WLS irradiated onto the liquid crystal panels 62, 262, and the change in the display color in the projected image, and is different from Figure 8.

[0130] 9, the red light irradiation period TR of the liquid crystal panels 62, 262 may be extended to cover, for example, a period from a predetermined time after the rising edge of the red region R to an intersection time between the falling edge of the red region R and the rising edge of the green region G. Similarly, the green light irradiation period TG may be extended to cover a period from a predetermined time after the rising edge of the green region G to an intersection time between the falling edge of the green region G and the rising edge of the blue region B. The blue light irradiation period TB may be extended to cover a period from a predetermined time after the rising edge of the blue region B to an intersection time between the falling edge of the blue region B and the rising edge of the red region R.

[0131] 9, there is a period when the red irradiation period TR of the liquid crystal panel 62 and the blue irradiation period TB of the liquid crystal panel 262 overlap at time t, red image light IL1 and blue image light IL2 are projected, and magenta is displayed in the projected image. There is a period when the green irradiation period TG of the liquid crystal panel 62 and the blue irradiation period TB of the liquid crystal panel 262 overlap at time t, green image light IL1 and blue image light IL2 are projected, and cyan is displayed in the projected image.

[0132] There is a period when the green irradiation period TG of the liquid crystal panel 62 and the red irradiation period TR of the liquid crystal panel 262 overlap at time t, green image light IL1 and red image light IL2 are projected, and yellow is displayed in the projected image. There is a period when the blue irradiation period TB of the liquid crystal panel 62 and the red irradiation period TR of the liquid crystal panel 262 overlap at time t, blue image light IL1 and red image light IL2 are projected, and magenta is displayed in the projected image.

[0133] There is a period when the blue light irradiation period TB of the liquid crystal panel 62 and the green light irradiation period TG of the liquid crystal panel 262 overlap at time t, blue image light IL1 and green image light IL2 are projected, and cyan is displayed in the projected image. There is a period when the red light irradiation period TR of the liquid crystal panel 62 and the green light irradiation period TG of the liquid crystal panel 262 overlap at time t, red image light IL1 and green image light IL2 are projected, and yellow is displayed in the projected image.

[0134] When controlled as shown in FIG. 9, the projected image displays magenta, yellow, and cyan in addition to red, green, and blue, resulting in a full-color, six-color time-division display. The display period of each color is shorter than when controlled as shown in FIG. 8. This further suppresses color breakup and improves the brightness of the projected image. However, when controlled as shown in FIG. 9, the triangular area of ​​the chromaticity diagram that can be represented by the projected image is narrower, with each vertex closer to the center, than when controlled as shown in FIG. 8. Taking these factors into consideration, the red irradiation period TR, green irradiation period TG, and blue irradiation period TB of each of liquid crystal panels 62 and 262 are appropriately set according to the quality of the projected image that is prioritized, such as the degree of suppression of color breakup, the brightness of the projected image, or the size of the color gamut of the projected image.

[0135] Fig. 10 is a flowchart relating to the control performed by the control unit 100 as exemplified in Fig. 5 to Fig. 9. As shown in Fig. 10, in step S301, the central processing unit 140 transmits various initial values ​​to the drive control device 130 based on the video information received from the video processing circuit 160 and the refresh rate of the liquid crystal of the liquid crystal panels 62, 262 set by the user interface 150 or the like. The various initial values ​​include the video information of the projection target, the drive frequency of the light-emitting element 21, the polarization switching period of the spatial light modulator 250, the drive frequency of the liquid crystal panel 62, the operation time, the standby period, threshold values ​​for determining various malfunction differences, etc.

[0136] In step S302, the drive control device 130 transmits a synchronization signal to the light-source output control device 110 and the rotation control device 120. In step S303, electrical signals are received from the light-source output control device 110 and the rotation control device 120, and colored light WL is periodically emitted from the light-emitting element 21 of the light source device 20, colored light WLP and WLS are periodically emitted from the spatial light modulator 250, the light-transmitting member 42 of the optical scanning device 40 rotates about the rotation axis CX1, the light-transmitting member 76 of the optical scanning device 70 rotates about the rotation axis CX2, the colored light WLP is converted into image light IL1 by the liquid crystal of each pixel of the liquid crystal panel 62 of the light modulation device 60, and the colored light WLS is converted into image light IL2 by the liquid crystal of each pixel of the liquid crystal panel 262 of the light modulation device 260. At this time, errors representing deviations from the set values ​​of the light intensity and output of the colored light WL of the light-emitting element 21 and the rotation speed of the light-transmitting members 42 and 76 are constantly detected and fed back to the drive control device 130.

[0137] If the error in the output of the light-emitting element 21 from a predetermined target value exceeds a predetermined value, and if the error in the rotation speed of the light-transmitting members 42, 76 exceeds a target error range of, for example, about 0.5%, in step S304, black is displayed in each pixel of the liquid crystal panel 62 until the error falls within the target error range. Once the errors in the output of the light-emitting element 21 and the rotation speed of the light-transmitting members 42, 76 fall within the target error range, in step S306, the colored lights WLP, WLS are converted into image lights IL1, IL2 in each pixel of the liquid crystal panels 62, 262.

[0138] In step S307, when image lights IL1, IL2 are generated at each pixel of the liquid crystal panels 62, 262, the amount of missynchronization between the output period of the light-emitting element 21 and the rotational speed of the light-transmitting members 42, 76 is detected at a constant period, i.e., at constant time intervals. While it is detected that the amount of missynchronization between the output period of the light-emitting element 21 and the rotational speed of the light-transmitting members 42, 76 is less than a predetermined value, each setting condition and setting value is maintained. Note that the polarization switching period of the spatial light modulator 250 is synchronized with the output period of the light-emitting element 21.

[0139] If it is detected that the amount of misalignment between the output period of the light-emitting element 21 and the rotation speed of the light-transmitting member 42, 76 is equal to or greater than a predetermined value, the drive frequency of the liquid crystal panel 62, 262 is changed in step S308 to reduce the amount of misalignment. The timing of synchronization between the output period of the light-emitting element 21 and the rotation speed of the light-transmitting member 42, 76 is adjusted mainly by the liquid crystal panel 62, 262. The rotation angle of the light-transmitting member 42, 76 of the optical scanning device 40, 70, the rotation angle, and the timing of emission of the color light WL of the light-emitting element 21 in the light source device 230 are synchronized with the liquid crystal panel 62, 262.

[0140] As an example, when the drive frequency of liquid crystal panel 62 on the Z axis and the drive frequency of liquid crystal panel 262 on the Y axis are 1080 / 1124 lines, there is a margin of adjustment of about 97%. After the drive frequencies of liquid crystal panels 62 and 262 are changed in step S308, the process returns to step S306, and modulation and image display on liquid crystal panels 62 and 262 based on the input image are performed under the changed conditions.

[0141] The projector 211 of the first embodiment described above includes a light source device 230, light modulation devices 60 and 260, and a projection optical system 80. The light source device 230 periodically emits color light (illumination light) WL including P-polarized color light (first light) WLP and S-polarized color light (second light) WLS. The light modulation device 60 modulates the color light WL emitted from the light source device 230 according to image information to generate image light IL1. The light modulation device 260 modulates the color light WL emitted from the light source device 230 according to image information to generate image light IL2. The projection optical system 80 projects the image light IL1 and IL2 emitted from the light modulation devices 60 and 260 onto a projection surface such as a screen. The light source device 230 has a light emitting element 21 that emits the color light WLP and WLS. The light modulation devices 60 and 260 each include a liquid crystal panel (first liquid crystal element) 62 and a liquid crystal panel (second liquid crystal element) 262. The liquid crystal panel 62 forms an image by converting incident color light WLP into image light (first image light) IL1 according to input image information. The liquid crystal panel 262 forms an image by converting incident color light WLS into image light (second image light) IL2 according to input image information. In the projector 211 of the first embodiment, the irradiation cycle of the color light WLP emitted from the light source device 230 and irradiated onto the liquid crystal panel 62 is synchronized with the image formation cycle of the liquid crystal panel 62. The irradiation cycle of the color light WLS emitted from the light source device 230 and irradiated onto the liquid crystal panel 262 is synchronized with the image formation cycle of the liquid crystal panel 262. The image formation cycle of the liquid crystal panel 62 is shifted from the image formation cycle of the liquid crystal panel 262. That is, the timing and time period when an image is formed by the liquid crystal panel 62 is different from the timing and time period when an image is formed by the liquid crystal panel 262. In the projector 211 of the first embodiment, the color and wavelength of the colored light WLP incident on the liquid crystal panel 62 are different from the color and wavelength of the colored light WLS incident on the liquid crystal panel 262.

[0142] The projector 211 of the first embodiment employs a two-plate configuration, in which the image formation cycle of the liquid crystal panel 62 of the light modulation device 60 and the image formation cycle of the liquid crystal panel 262 are synchronized with each other, and the color and wavelength of the colored light WLP incident on the liquid crystal panel 62 are different from the color and wavelength of the colored light WLS incident on the liquid crystal panel 262. As a result, in the projector 201 of the first embodiment, the color display cycle and period of the projected image are shorter than when an image is formed only on each of the liquid crystal panels 62 and 262. The projector 201 of the first embodiment can suppress the occurrence of color breakup in the projected image.

[0143] The projector 211 of the first embodiment further includes optical scanning devices 40 and 70 that periodically scan the colored lights WLP and WLS emitted from the light source device 230 and emit the light to the light modulation devices 60 and 260.

[0144] 5 and 6, the projector 211 of the first embodiment is equipped with the optical scanning devices 40, 70, and therefore can irradiate colored light WLP, WLS for a certain period T2 after the completion of rise in the modulation amount of the liquid crystal layer 68, 268 of each pixel in the liquid crystal panel 62, 262 of the light modulation device 60, 260. According to the projector 211 of the first embodiment, the color of the image information input to the liquid crystal panel 62, 262 can be reproduced well over the entire area of ​​the image projected onto the projection surface, and the brightness of the projected image can be improved.

[0145] In the projector 211 of the first embodiment, the optical scanning device 40 has a light-transmitting member (transmissive optical element) 42. The light-transmitting member 42 scans the incident color light (illumination light) WLP along a first direction parallel to the Y axis, and has side surfaces (incident surfaces) 54A, 54B, 54C, and 54D onto which the color light WLP emitted from the light source device 230 is incident, and side surfaces (exit surfaces) 54C, 54D, 54A, and 54C from which the color light WLP incident from the side surfaces 54A, 54B, 54C, and 54D exits. The optical scanning device 70 has a light-transmitting member (transmissive optical element) 76. The light-transmitting member 76 scans the incident colored light (illumination light) WLS along a first direction parallel to the Z axis, and has side surfaces (incident surfaces) 74A, 74B, 74C, and 74D onto which the colored light WLS emitted from the light source device 230 is incident, and side surfaces (exit surfaces) 74C, 74D, 74A, and 74C from which the colored light WLS incident from the side surfaces 74A, 74B, 74C, and 74D exits. The light-transmitting member 42 has end surfaces (first surfaces) 51 and 52 parallel to the Y axis and the first direction, and 2×m side surfaces (second surfaces) 54 in contact with the end surfaces 51 and 52. The light-transmitting member 76 has end surfaces (first surfaces) 71 and 72 parallel to the Z axis and the first direction, and 2×m side surfaces (second surfaces) 74 in contact with the end surfaces 71 and 72.

[0146] In the projector 211 of the first embodiment, the light-transmitting member 42 has an even number of side surfaces 54, four or more, and all of the side surfaces 54 are opposed to each other across the central axis JX1 and are parallel to each other. The light-transmitting member 76 has an even number of side surfaces 74, four or more, and all of the side surfaces 74 are opposed to each other across the central axis JX2 and are parallel to each other. According to the projector 201 of the first embodiment, the colored light WLP emitted from the light source device 230 and incident on the optical scanning device 40 can be emitted in a direction parallel to the incident direction from the optical scanning device 40. The colored light WLS emitted from the light source device 230 and incident on the optical scanning device 70 can be emitted in a direction parallel to the incident direction from the optical scanning device 70.

[0147] In the projector 211 of the first embodiment, the liquid crystal panel 62 of the light modulation device 60 has a liquid crystal layer (first liquid crystal layer) 68 whose modulation amount for the colored light WLP changes in response to an input electrical signal having image information. The liquid crystal panel 262 of the light modulation device 260 has a liquid crystal layer (second liquid crystal layer) 268 whose modulation amount for the colored light WLS changes in response to an input electrical signal having image information. The modulation period TAL of the liquid crystal layers 68, 268 includes a rise period (first period) T1 and a fixed period (second period) T2. The rise period T1 is the period from the time when an electrical signal is input to the liquid crystal layers 68, 268 to the time when the phase modulation amount for the colored light WLP, WLS reaches a predetermined value. The fixed period T2 is the period during which the phase modulation amount for the colored light WLP, WLS is maintained at a predetermined value. The colored light WLP, WLS emitted from the light source device 230 is incident on the liquid crystal panels 62, 262 during the fixed period T2.

[0148] According to the projector 211 of the first embodiment, the colored lights WLP and WLS are irradiated onto the liquid crystal layers 68 and 268 of the liquid crystal panels 62 and 262 for a certain period T2, so that uneven illuminance and color mixing in the projected image can be suppressed.

[0149] In the projector 211 of the first embodiment, the time period of the rise period T1 of the liquid crystal layer 68 of the liquid crystal panel 62 is included in the fixed period T2 of the liquid crystal layer 268 of the liquid crystal panel 262. The colored light WLS is incident on the liquid crystal panel 262 during the time period when the rise period T1 of the liquid crystal layer 68 and the fixed period T2 of the liquid crystal layer 268 overlap.

[0150] In the projector 211 of the first embodiment, for example, the rise period T1 of the green region G of the liquid crystal layer 68 of the liquid crystal panel 62 overlaps with the fixed period T2 of the blue region B of the liquid crystal layer 268 of the liquid crystal panel 262 at time t, and is included in the fixed period T2 of the blue region B of the liquid crystal layer 268. According to the projector 211 of the first embodiment, it is possible to suppress uneven illuminance in the projected image, shorten the cycle of color display in the projected image, and suppress the occurrence of color breakup.

[0151] The projector 211 of the first embodiment further includes a drive control device 130 that transmits an electrical signal for driving the liquid crystal of the liquid crystal layer 68, 268 of each pixel to the liquid crystal panels 62, 262 of the light modulation devices 60, 260. The drive control device 130 transmits an electrical signal (synchronization signal) to the light source device 230 for synchronizing the output power of the color light WL from the light emitting element 21 with the light modulation devices 60, 260, based on an electrical signal related to image information output to the liquid crystal panels 62, 262.

[0152] The projector 211 of the first embodiment includes the drive control device 130, and therefore can easily synchronize the output power of the color light WL emitted from the light emitting element 21 with the drive of the light modulation devices 60, 260.

[0153] The projector 211 of the first embodiment further includes a drive control device 130 that performs scanning illumination and transmits electrical signals for driving the liquid crystal of the liquid crystal layers 68, 268 of each pixel to the liquid crystal panels 62, 262 of the light modulation devices 60, 260. The drive control device 130 transmits electrical signals (synchronization signals) for synchronizing the output power of the color light WL from the light emitting element 21 with the light modulation devices 60, 260 to the light source device 230 and the optical scanning devices 40, 70, based on electrical signals related to image information output to the liquid crystal panels 62, 262.

[0154] The projector 211 of the first embodiment includes the drive control device 130, which makes it possible to easily synchronize the output power of the color light WL emitted from the light emitting element 21 with the rotation speed of the light-transmissive members 42, 76 of the optical scanning devices 40, 70.

[0155] In the projector 211 of the first embodiment, when the error in the scanning period of the optical scanning device 40, 70 relative to the image formation period of the liquid crystal panel 62, 262 is equal to or greater than a predetermined value, and when the error in the light emission period of the light source device 230 relative to the image formation period of the liquid crystal panel 62, 262 is equal to or greater than a predetermined value, the optical modulation device 60, 260 does not emit image light IL1, IL2 and displays black.

[0156] According to the projector 211 of the first embodiment, it is possible to prevent the display of an unexpected image that is not based on the image information or video information input to the drive control device 130.

[0157] In the projector 211 of the first embodiment, when an error in the scanning period of the optical scanning devices 40, 70 with respect to the image formation period of the liquid crystal panels 62, 262 of the light modulation devices 60, 260 becomes equal to or greater than a predetermined value, the drive control device 130 changes the scanning period of the optical scanning devices 40, 70. The scanning period of the optical scanning device 40 is determined by the rotation speed of the light-transmitting members 42, 76.

[0158] According to the projector 211 of the first embodiment, the light emission cycle of the light source device 230, the scanning cycle of the optical scanning devices 40, 70, and the image formation cycle of the optical modulation devices 60, 260 can be smoothly maintained in a synchronized state, thereby suppressing deterioration of image quality over time.

[0159] In the projector 211 of the first embodiment, when the error in the scanning period of the optical scanning device 40, 70 relative to the image formation period of the liquid crystal panel 62, 262 of the optical modulation device 60, 260 becomes equal to or greater than a predetermined value, the drive control device 130 changes the image formation period of the liquid crystal panel 62, 262 of the optical modulation device 60, 260.

[0160] According to the projector 211 of the first embodiment, even when controlled as described above, it is possible to smoothly maintain a synchronized state in which the light emission period of the light source device 230, the scanning period of the optical scanning devices 40, 70, and the image formation period of the optical modulation devices 60, 260 are synchronized with each other, thereby suppressing deterioration in image quality over time.

[0161] In the projector 211 of the first embodiment, the modulation period TAL during which the three color lights (first lights) contained in the color lights WLP, WLS are modulated in the liquid crystal layers 68, 268 of the liquid crystal panels 62, 262 further includes the aforementioned rise period T1, a certain period T2, and a fall period T3 from the time when the modulation amount of the liquid crystal layers 68, 268 reaches a predetermined value to the time when it completely returns to the initial value.

[0162] The rise period T1 represents the period from the start time of the rise to the completion time of the liquid crystal layer of the liquid crystal panels 62, 262. The fall period T3 represents the period from the start time of the fall to the completion time of the fall of the liquid crystal layer of the liquid crystal panels 62, 262. In the projector 211 of the first embodiment, the colored light WLP, WLS emitted from the light source device 230 does not enter the light modulation device 60, 260 during a period that overlaps with the fall period T3 of the other color region within the fixed period T2 in each color region of the liquid crystal panels 62, 262 and with the rise period T1 of the other color region within the fixed period T2.

[0163] In the projector 211 of the first embodiment, the modulation period TAL in each pixel of the liquid crystal panel 62, 262 of the light modulation device 60, 260 includes a rise period (first period) T1, a fixed period (second period) T2, and a fall period (third period) T3. The rise period T1 is the period from when the modulation amount of the phase of the colored light in the liquid crystal layer of the liquid crystal panel 62, 262 changes from an initial value to a predetermined value and starts to rise until the predetermined value is reached. The fixed period T2 is the period during which the modulation amount of the phase of the colored light in the liquid crystal layer of the liquid crystal panel 62, 262 is maintained constant at a predetermined value. The fall period T3 is the period from when the modulation amount of the phase of the colored light in the liquid crystal layer 68, 268 of the liquid crystal panel 62, 262 changes from a predetermined value to an initial value and starts to fall until the initial value is reached.

[0164] In the projector 211 of the first embodiment, the colored lights WLP, WLS emitted from the light source device 230 and manipulated in a first direction along the Y-axis and Z-axis by the optical scanning devices 40, 70 preferably enter the liquid crystal panels 62, 262 of the optical modulation devices 60, 260 during a certain period T2 of the red region R of the pixel for the red light (first colored light) contained in the colored lights WLP, WLS, which period does not overlap with the rise period T1 or fall period T3 of the green light (second colored light) or blue light (second colored light) contained in the colored lights WLP, WLS and having a wavelength band different from that of the red light. Similarly, the colored lights WLP, WLS emitted from the light source device 230 are incident on the liquid crystal panel 62, 262 during a fixed period T2 of the green region G of the pixel for green light (first colored light), which does not overlap with the rising period T1 or falling period T3 of the blue light (second colored light) or red light (second colored light) that is included in the colored lights WLP, WLS and has a wavelength band different from that of the green light. The colored lights WLP, WLS emitted from the light source device 230 are incident on the liquid crystal panel 62, 262 during a fixed period T2 of the blue region B of the pixel for blue light (first colored light), which does not overlap with the rising period T1 or falling period T3 of the red light (second colored light) or green light (second colored light) that is included in the colored lights WLP, WLS and has a wavelength band different from that of the blue light.

[0165] That is, in the projector 211 of the first embodiment, control can be performed so that the colored lights WLP, WLS do not enter pixels among the multiple pixels of the liquid crystal panel 62, 262 during the rise period T1 or fall period T3, during which the liquid crystal molecules in the liquid crystal layer rotate with respect to red light, green light, or blue light, changing the phase modulation amount φ. In other words, one of the colored lights WLP, WLS is incident on pixels among the multiple pixels of the liquid crystal panel 62, 262 during a certain period T2 of any one of the colored lights of red light, green light, or blue light, which does not overlap with the rise period T1 or fall period T3 of the other colored light. Depending on the increase or decrease in the phase modulation amount φ added to the colored lights WLP, WLS when they pass through the liquid crystal of the liquid crystal layer of each pixel of the liquid crystal panel 62, 262, the liquid crystal layer functions like a color filter, and the light intensity I and light amount of the colored lights WLP, WLS passing through the liquid crystal layer increase or decrease. According to the projector 211 of the first embodiment controlled in this manner, the color of the input image is reproduced well, and in addition to uneven illuminance of the projected image on the projection surface, color mixing between color light intended for display and color light not intended for display can be suppressed.

[0166] In the projector 211 of the first embodiment, the polarization direction of the color light WLP and the polarization direction of the color light WLS are different from each other. The light source device 230 has a spatial light modulator 250 that periodically changes the polarization state of the color light (light) WL emitted from the light emitting element 21 to alternately emit the color light WLP and the color light WLS.

[0167] According to the projector 211 of the first embodiment, the polarization switching period in the spatial light modulator 250 can be controlled, and the P-polarized colored light WLP and the S-polarized colored light WLS emitted from the light source device 230 can be easily switched alternately in time series.

[0168] The projector 211 of the first embodiment further includes a polarization separation element (first polarization separation element) 310, a light-transmitting member 42, a light-transmitting member 76, and a polarization separation element (second polarization separation element) 320. The polarization separation element 310 separates the color light WL emitted from the light source device 230 into color light WLP and color light WLS and emits them in different directions. The light-transmitting member 42 periodically scans the color light WLP emitted from the polarization separation element 310 and emits them to the liquid crystal panel 62. The light-transmitting member 76 periodically scans the color light WLS emitted from the polarization separation element 310 and emits them to the liquid crystal panel 262. The polarization separation element 310 emits image light (first image light) IL1 emitted from the liquid crystal panel 62 and image light (second image light) emitted from the liquid crystal panel 262 in the same direction.

[0169] According to the projector 211 of the first embodiment, the colored lights WLP and WLS having different weaving directions are scanned and irradiated onto the modulation surfaces 64 and 264 of the liquid crystal panels 62 and 262 by the light-transmitting members 42 and 76, thereby ensuring the brightness of the projected image.

[0170] [Modification of the first embodiment] Next, a modification of the first embodiment of the present invention will be described with reference to Fig. 11. In the modification of the first embodiment, the projector 211 may include a light source device 220 instead of the light source device 230.

[0171] Fig. 11 is a schematic diagram of a light source device 220. As shown in Fig. 11, the light source device 220 periodically emits colored light WLP and WLS. The light source device 220 includes a light-emitting element 22 that emits blue light BL, a light-emitting element 23 that emits green light GL, a light-emitting element 24 that emits red light RL, collimating lenses 27, 28, and 29, dichroic mirrors 31 and 32, and a spatial light modulator 250.

[0172] The light emitting element 22 emits blue light BL from the emission surface 22e toward the +Z side along the Z axis. The light emitting element 22 is, for example, a blue LD. The blue light BL is, for example, S-polarized or P-polarized light.

[0173] The collimating lens 27 is disposed on the optical path of the blue light BL emitted from the light-emitting element 22, and is disposed at the same position as the emission surface 22e of the light-emitting element 22 in the X and Y axes, and is disposed on the +Z side of the emission surface 22e of the light-emitting element 22. The central axis of the collimating lens 27 overlaps with the optical axis of the blue light BL emitted from the light-emitting element 22. The collimating lens 27 converts the blue light BL emitted from the light-emitting element 22 into parallel light parallel to the Z axis and emits it along the optical axis AX.

[0174] The collimating lens 27 is, for example, a biconvex lens. The collimating lens 27 may also be a plano-convex lens having a flat entrance surface parallel to the XY plane and an exit surface convex on the +Z side. In Fig. 13, the collimating lens 27 is disposed away from the exit surface 22e of the light-emitting element 22, but if the collimating lens 27 is a plano-convex lens, the collimating lens 27 may be in contact with the exit surface 22e of the light-emitting element 22.

[0175] The light-emitting element 23 is disposed at the same position on the X-axis as the light-emitting element 22, on the -Y side of the light-emitting element 22, on the +Z side of the light-emitting element 22, and on the -Z side of the light-transmitting member 42 of the optical scanning device 40. The light-emitting element 23 emits green light GL from the emission surface 23e toward the +Y side along the Y-axis. The light-emitting element 23 is, for example, a green LD. The green light GL is, for example, S-polarized light or P-polarized light.

[0176] The collimating lens 28 is disposed on the optical path of the green light GL emitted from the light-emitting element 23, and is disposed at the same position as the emission surface 23e of the light-emitting element 23 along the X and Z axes, and is disposed between the emission surface 23e of the light-emitting element 23 and the emission surface 22e of the light-emitting element 22 along the Y axis. The central axis of the collimating lens 28 overlaps with the optical axis of the green light GL emitted from the light-emitting element 23 and intersects with the central axis of the collimating lens 27. The collimating lens 28 emits the green light GL emitted from the light-emitting element 23 to the +Y side as parallel light parallel to the Y axis.

[0177] The collimating lens 28 is, for example, a biconvex lens. The collimating lens 28 may also be a plano-convex lens having a flat entrance surface parallel to the XZ plane including the X-axis and the Z-axis and an exit surface that is convex on the +Y side. In Fig. 13, the collimating lens 28 is disposed away from the exit surface 23e of the light-emitting element 23, but if the collimating lens 28 is a plano-convex lens, the collimating lens 28 may be in contact with the exit surface 23e of the light-emitting element 23.

[0178] The light-emitting element 24 is disposed at the same position on the X-axis as the light-emitting elements 22 and 23, and is disposed on the -Y side of the light-emitting element 22, on the +Z side of the light-emitting element 23, and on the -Z side of the light-transmitting member 42 of the optical scanning device 40. The light-emitting element 24 emits red light RL from the emission surface 24e toward the +Y side along the Y-axis. The light-emitting element 24 is, for example, a red LD. The red light RL is, for example, S-polarized light or P-polarized light.

[0179] The collimating lens 29 is disposed on the optical path of the red light RL emitted from the light-emitting element 24, is disposed at the same position as the emission surface 24e of the light-emitting element 24 in the X-axis and Z-axis, and is disposed between the emission surface 24e of the light-emitting element 24 and the emission surface 22e of the light-emitting element 22 in the Y-axis. The central axis of the collimating lens 29 overlaps with the optical axis of the red light RL emitted from the light-emitting element 24 and intersects with the central axis of the collimating lens 27. The collimating lens 29 emits the red light RL emitted from the light-emitting element 24 to the +Y side as parallel light parallel to the Y-axis.

[0180] The collimating lens 28 is, for example, a biconvex lens. The collimating lens 28 may also be a plano-convex lens having a flat entrance surface parallel to the XZ plane including the X-axis and the Z-axis and an exit surface that is convex on the +Y side. In Fig. 13, the collimating lens 28 is disposed away from the exit surface 23e of the light-emitting element 23, but if the collimating lens 28 is a plano-convex lens, the collimating lens 28 may be in contact with the exit surface 23e of the light-emitting element 23.

[0181] Dichroic mirror 31 is disposed in a region where the optical path of blue light BL emitted from collimating lens 27 overlaps with the optical path of green light GL emitted from collimating lens 28. The center of dichroic mirror 31 in the XY plane substantially overlaps with the intersection point between the optical axis of blue light BL emitted from light-emitting element 22 and the optical axis of green light GL emitted from light-emitting element 23.

[0182] The dichroic mirror 31 has a reflective surface that transmits the blue light BL and reflects the green light GL. The reflective surface of the dichroic mirror 31 is inclined so that it moves from the -Y side to the +Y side as it moves from the -Z side to the +Z side when viewed along the X axis. The blue light BL emitted from the collimating lens 27 passes through the dichroic mirror 31 and is emitted toward the +Z side along the Z axis. The green light GL emitted from the collimating lens 28 is incident on the dichroic mirror 31, reflected by the reflective surface of the dichroic mirror 31 toward the +Z side along the Z axis, and emitted in the same direction as the blue light BL.

[0183] Dichroic mirror 32 is disposed in a region where the optical paths of blue light BL and green light GL emitted from dichroic mirror 31 overlap with the optical path of red light RL emitted from collimating lens 29. The center of dichroic mirror 32 in the XY plane substantially overlaps with the intersection of the optical axis of blue light BL emitted from light-emitting element 22 and the optical axis of red light RL emitted from light-emitting element 24.

[0184] The dichroic mirror 32 has a reflective surface that transmits the blue light BL and the green light GL and reflects the red light RL. The reflective surface of the dichroic mirror 32 is inclined so that it moves from the -Y side to the +Y side as it moves from the -Z side to the +Z side when viewed along the X axis. The blue light BL and the green light GL emitted from the dichroic mirror 32 pass through the dichroic mirror 32 and are emitted toward the +Z side along the Z axis. The red light RL emitted from the collimating lens 29 is incident on the dichroic mirror 32, reflected by the reflective surface of the dichroic mirror 32 toward the +Z side along the Z axis, and emitted in the same direction as the blue light BL and the green light GL.

[0185] The blue light BL, green light GL, and red light RL emitted from the dichroic mirror 32 constitute colored light WL, which is emitted from the light source device 230 to the +Z side along the optical axis AX and enters the spatial light modulator 250 as colored light WL. The behavior of the colored light WLP, WLS emitted from the light source device 220 in the projector 211 is similar to the behavior of the colored light WLP, WLS emitted from the light source device 230 in the projector 211.

[0186] In a modification of the first embodiment, the light source output control device 110 may include light source output control devices 111, 112, and 113.

[0187] The light source output control device 111 is electrically connected to the light emitting element 22 of the light source device 220 by wire or wirelessly, and controls the amount of blue light BL emitted from the light emitting element 22. Specifically, the light source output control device 111 outputs an electrical signal related to a drive voltage or drive current to the light emitting element 22 for controlling the amount of blue light BL emitted from the light emitting element 22, causing the light emitting element 22 to periodically emit the blue light BL. The light source output control device 111 is, for example, an LD driver. A program for setting a periodic drive voltage value or drive current value to the light emitting element 22 corresponding to an elapsed time and a time t is stored and saved in the driver, which is the light source output control device 111.

[0188] The light source output control device 112 is electrically connected to the light emitting element 23 of the light source device 220 by wire or wirelessly, and controls the amount of green light GL emitted from the light emitting element 23. Specifically, the light source output control device 112 outputs an electrical signal related to a drive voltage or drive current to the light emitting element 23 for controlling the amount of green light GL emitted from the light emitting element 23, causing the light emitting element 23 to periodically emit the green light GL. The light source output control device 112 is, for example, an LD driver. A program for setting periodic drive voltage values ​​or drive current values ​​to the light emitting element 23 corresponding to elapsed time and time t is stored and saved in the driver that is the light source output control device 112.

[0189] The light source output control device 113 is electrically connected to the light emitting element 24 of the light source device 220 by wire or wirelessly, and controls the amount of red light RL emitted from the light emitting element 24. Specifically, the light source output control device 113 outputs an electrical signal related to a drive voltage or drive current to the light emitting element 24 for controlling the amount of red light RL emitted from the light emitting element 24, causing the light emitting element 24 to periodically emit the red light RL. The light source output control device 113 is, for example, an LD driver. A program for setting a periodic drive voltage value or drive current value to the light emitting element 24 corresponding to an elapsed time and a time t is stored and saved in the driver, which is the light source output control device 113.

[0190] The drive control device 130 is electrically connected to the light source output control devices 111, 112, 113 and the rotation control device 120, and is also electrically connected by wire or wirelessly to the liquid crystal panel 62 of the light modulation device 60. The drive control device 130 outputs electrical signals to each of the light source output control devices 111, 112, 113 and the rotation control device 120, and controls the position, area, and timing at which the blue light BL emitted from the light emitting element 22 of the light source device 220, the green light GL emitted from the light emitting element 23, and the red light RL emitted from the light emitting element 24 are scanned as colored light WL by the light-transmitting members 42, 76 of the optical scanning devices 40, 70 and irradiated on the modulation surfaces 64, 264 of the liquid crystal panels 62, 262 of the light modulation devices 60, 260. The drive control device 130 supplies electrical signals to each pixel of the liquid crystal panels 62, 262 on the modulation surfaces 64, 264 in accordance with the irradiation position, irradiation area, and timing of the colored light WL.

[0191] The light source output control devices 111, 112, and 113, rotation control device 120, drive control device 130, central processing unit 140, user interface 150, video processing circuit 160, and video interface 170 described above constitute the control unit 100 of the projector 211.

[0192] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Fig. 12 and Fig. 13. In the following description of each embodiment, description of the contents common to the first embodiment will be omitted, and only the contents different from the first embodiment will be described. Furthermore, with regard to the configuration of the projector of each embodiment, components common to the projector 201 of the first embodiment will be assigned the same reference numerals as the corresponding components of the projector 201 of the first embodiment, and description thereof will be omitted.

[0193] Fig. 12 is a schematic diagram of a projector 212 of the second embodiment. As shown in Fig. 12, the projector 212 of the second embodiment includes a light source device 231 instead of the light source device 230 of the projector 211 of the first embodiment, and similarly includes other components other than the light source device 230. The light source device 231 includes a light emitting element 25 instead of the light emitting element 21, and does not include a spatial light modulator 250. The light emitting element 25 receives an electrical signal from the light source output control device 110, and alternately emits colored light WLP and WLS in time series from an emission surface 25e. The light source device 231 alternately emits colored light WLP and WLS, which are parallel light, in time series toward the +Z side along the Z axis.

[0194] The projector 212 of the second embodiment described above has the same configuration as the projector 211 of the first embodiment, and therefore provides the same effects as the projector 211 of the first embodiment. [Modification of the second embodiment]

[0195] A projector according to a modification of the second embodiment may include a light source device 232 instead of the light source device 231. FIG. 13 is a schematic diagram of the light source device 232 according to the modification of the second embodiment. As shown in FIG. 13, in the light source device 232, the P-polarized red light emitted from the light-emitting element 422 passes through the dichroic mirrors 431, 432, and 433 as colored light WL and is emitted toward the +Z side. The P-polarized green light emitted from the light-emitting element 423 is reflected by the dichroic mirror 431 as colored light WL, passes through the dichroic mirrors 432 and 433, and is emitted toward the +Z side. The P-polarized blue light emitted from the light-emitting element 424 is reflected by the dichroic mirror 432 as colored light WL, passes through the dichroic mirror 433, and is emitted toward the +Z side.

[0196] In light source device 232, S-polarized red light emitted from light-emitting element 442 passes through dichroic mirrors 434 and 435 as colored light WL, is reflected by dichroic mirror 433, and is emitted toward the +Z side. S-polarized green light emitted from light-emitting element 443 is reflected by dichroic mirror 434 as colored light WL, passes through dichroic mirror 435, is reflected by dichroic mirror 433, and is emitted toward the +Z side. P-polarized blue light emitted from light-emitting element 444 is reflected by dichroic mirrors 435 and 433 as colored light WL, and is emitted toward the +Z side.

[0197] [Third embodiment] Next, a third embodiment of the present invention will be described with reference to Fig. 14. Fig. 14 is a schematic diagram of a projector 213 of the third embodiment. As shown in Fig. 14, the projector 213 includes an optical unit 10 and a control unit 100. Specifically, the optical unit 10 of the projector 213 includes a light source device 233, an optical scanning device 40, a reflecting element 271, light modulation devices 60 and 260, a polarization separation element 320, and a projection optical system 80.

[0198] The projector 213 of the third embodiment includes only one optical scanning device 40. A light emitting element 451 of the light source device 233 irradiates one side surface 54 of the translucent member 42 of the optical scanning device 40 with S-polarized colored light WLS. A light emitting element 452 of the light source device 233 irradiates a side surface 54 of the translucent member 42 of the optical scanning device 40 that is different from the one side surface 54 with P-polarized colored light WLP. The projector 213 of the third embodiment uses only one optical scanning device 40, which allows for miniaturization.

[0199] The projector 213 of the second embodiment described above has the same configuration as the projector 211 of the first embodiment, and therefore provides the same effects as the projector 211 of the first embodiment. Furthermore, the light source device 233 may be configured as in a modified example shown in FIG. 13 and the like.

[0200] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as set forth in the claims. Furthermore, the components of multiple embodiments can be combined as appropriate.

[0201] For example, although not shown, the projector of this embodiment is not limited to one including the optical scanning devices 40, 70 that scan the color light WL toward the light modulation devices 60, 260, and may be a uniform surface illumination type.

[0202] Summary of this disclosure A summary of this disclosure is provided below. (Supplementary Note 1) A projection optical system includes a light source device that periodically emits illumination light including first light and second light, a light modulation device that modulates the illumination light emitted from the light source device in accordance with image information, and a projection optical system that projects the image light emitted from the light modulation device, wherein the light source device has a light emitting element that emits the first light and the second light, and the light modulation device includes a first liquid crystal element that forms an image by converting the incident first light into first image light in accordance with the input image information, and a first liquid crystal element that forms an image by converting the incident second light into second image light in accordance with the input image information. a second liquid crystal element that forms an image, wherein an irradiation period of the first light emitted from the light source device and irradiated onto the first liquid crystal element and an image formation period of the first liquid crystal element are synchronized with each other, an irradiation period of the second light emitted from the light source device and irradiated onto the second liquid crystal element and an image formation period of the second liquid crystal element are synchronized with each other, the image formation period of the first liquid crystal element and the image formation period of the second liquid crystal element are shifted from each other, and the wavelength of the first light incident on the first liquid crystal element and the wavelength of the second light incident on the second liquid crystal element are different from each other.

[0203] The configuration of Appendix 1 allows a time-division color two-plate projector to synchronize the light emission timing of the light source device, the output cycle, and the image formation cycle of each of the first and second liquid crystal elements of the light modulation device, and also to differentiate the time periods for image formation of the first and second liquid crystal elements from each other, thereby suppressing the occurrence of color breakup in the projected image.

[0204] (Supplementary Note 2) The projector according to Supplementary Note 1, further comprising an optical scanning device that periodically scans the illumination light emitted from the light source device and emits the light to the light modulation device.

[0205] The configuration of Appendix 2 synchronizes the scanning period of the optical scanning device that scans the illumination light emitted from the light source device with the light emission timing and output period of the light source device and the image formation period of each of the first and second liquid crystal elements of the optical modulation device, thereby suppressing the occurrence of uneven illuminance in the projected image.

[0206] (Appendix 3) A projector according to Appendix 2, wherein the optical scanning device scans the illumination light along a first direction and includes a transmissive optical element having an incident surface onto which the first light emitted from the light source device is incident and an exit surface from which the first light incident from the incident surface is exited, and the transmissive optical element has a first surface parallel to the first direction and 2×m second surfaces tangent to the first surface.

[0207] With the configuration of Supplementary Note 3, the first light beam scanned by the optical scanning device and emitted from the optical scanning device can be emitted parallel to the principal ray of the first light beam incident on the optical scanning device.

[0208] (Appendix 4) Any of the projectors according to appendix 1 to appendix 3, wherein the first liquid crystal element has a first liquid crystal layer in which a modulation amount for the first light changes in response to an input electrical signal having the image information, and the second liquid crystal element has a second liquid crystal layer in which a modulation amount for the second light changes in response to an input electrical signal having the image information, the modulation period of the first liquid crystal layer and the modulation period of the second liquid crystal layer include a first period from the time the electrical signal is input to the time the modulation amount reaches a predetermined value, and a second period in which the modulation amount is maintained at the predetermined value, and the illumination light emitted from the light source device is incident on the first liquid crystal element and the second liquid crystal element in the second period.

[0209] With the configuration of Appendix 4, the illumination light emitted from the light source is incident on the second period of the first liquid crystal layer of the first liquid crystal element, and the illumination light is incident on the second period of the second liquid crystal layer of the second liquid crystal element, which is offset from the second period of the first liquid crystal layer, thereby suppressing the occurrence of uneven illumination in the projected image.

[0210] (Appendix 5) Any of the projectors of Appendix 4, wherein the time period of the first period of the first liquid crystal element is included in the time period of the second period of the second liquid crystal element, and the illumination light is incident on the second liquid crystal element during a time period when the first period and the second period overlap.

[0211] With the configuration of Appendix 5, the first period for the colored light of the first liquid crystal element overlaps with a certain period for another colored light of the second liquid crystal element, and the illumination light is incident on the second liquid crystal element instead of the first liquid crystal element, thereby suppressing uneven illumination and color breakup in the projected image.

[0212] (Appendix 6) Any of the projectors according to Appendix 4, further comprising a drive control device that transmits the electrical signal to the light modulation device, and the drive control device transmits a synchronization signal based on the electrical signal to the light source device.

[0213] The configuration of Supplementary Note 6 makes it possible to easily synchronize the power, light emission period or output period of the illumination light emitted from the light source device with the image formation period of the light modulation device using the drive control device.

[0214] (Appendix 7) A projector according to Appendix 2 or Appendix 3, further comprising a drive control device that transmits the electrical signal to the light modulation device, and the drive control device transmits a synchronization signal based on the electrical signal that provides the image information to the light source device and the optical scanning device.

[0215] The configuration of Appendix 7 makes it possible to easily synchronize the power, light emission period or output period of the illumination light emitted from the light source device, the scanning period of the optical scanning device, and the image formation period of the optical modulation device using a drive control device.

[0216] (Appendix 8) A projector according to any one of Appendices 1 to 7, wherein the optical modulation device does not emit image light when an error in the scanning period of the optical scanning device relative to the image formation period of the optical modulation device is equal to or greater than a predetermined value, and an error in the light emission period of the light source device relative to the image formation period of the optical modulation device is equal to or greater than a predetermined value.

[0217] The configuration of Supplementary Note 8 makes it possible to prevent unexpected display in the projection image that is not based on the image information or video information of the projection target input to the drive control device.

[0218] (Appendix 9) A projector according to any one of appendices 1 to 7, wherein when an error in the scanning period of the optical scanning device relative to the image formation period of the optical modulation device becomes equal to or greater than a predetermined value, the drive control device changes the scanning period of the optical scanning device.

[0219] The configuration of Supplementary Note 9 makes it possible to smoothly maintain a synchronized state in which the light emission cycle of the light source device, the scanning cycle of the optical scanning device, and the image formation cycle of the optical modulation device are synchronized with each other, thereby suppressing deterioration of image quality over time.

[0220] (Appendix 10) A projector according to any one of appendices 1 to 9, wherein when an error in the scanning period of the optical scanning device relative to the image formation period of the optical modulation device becomes equal to or greater than a predetermined value, the drive control device changes the image formation period of the optical modulation device.

[0221] The configuration of Supplementary Note 10 makes it possible to smoothly maintain a synchronized state and suppress deterioration of image quality over time.

[0222] (Appendix 11) A projector according to Appendix 4, wherein the modulation period further includes a third period from the time when the modulation amount is the predetermined value to the time when the modulation amount reaches an initial value, and the first light emitted from the light source device is incident on the light modulation device during the second period for first color light contained in the first light, in a period that does not overlap with the first period or the third period for second color light having a different wavelength band from the first color light contained in the first light.

[0223] The configuration of Appendix 11 allows the color of the image contained in the image information or video information input to the light modulation device from a drive control device or the like to be reproduced well, and suppresses uneven illuminance in the projected image as well as color mixing between color light intended for display and color light not intended for display.

[0224] (Appendix 12) A projector according to any one of Appendices 1 to 3, wherein the polarization direction of the first light and the polarization direction of the second light are different from each other, and the light source device has a spatial light modulator that periodically changes the polarization state of the light emitted from the light-emitting element to alternately emit the first light and the second light.

[0225] The configuration of Supplementary Note 12 makes it possible to control the polarization switching period of the first light and the second light in the spatial light modulator, and to easily switch between the first light and the second light emitted from the light source device in time series.

[0226] (Appendix 13) The projector of Appendix 12, comprising: a first polarization separation element that separates the illumination light emitted from the light source device into the first light and the second light and emits them in different directions; a first transmission optical element that periodically scans the first light emitted from the first polarization separation element and emits it to the first liquid crystal element; a second transmission optical element that periodically scans the second light emitted from the first polarization separation element and emits it to the second liquid crystal element; and a second polarization separation element that emits the first image light emitted from the first liquid crystal element and the second image light emitted from the second liquid crystal element in the same direction.

[0227] With the configuration of Supplementary Note 13, the first light and the second light having different polarization directions are scanned and irradiated onto the modulation surfaces of the first liquid crystal element and the second liquid crystal element of the light modulation device by the first transmissive optical element and the second transmissive optical element, thereby ensuring the brightness of the projected image.

[0228] (Appendix 14) The projector of any one of Appendices 1 to 3, wherein the light source device has a first light-emitting element that periodically emits the first light and a second light-emitting element that periodically emits the second light, and further comprises an optical scanning device that periodically scans the first light and the second light that are emitted from the first light-emitting element and the second light-emitting element and are incident at different angles to each other and emits them to the optical modulation device, and a reflecting element that reflects one of the first light and the second light emitted from the optical scanning device and makes it incident on the first liquid crystal element or the second liquid crystal element corresponding to the one light.

[0229] With the configuration of Appendix 14, the first light emitted from the first light-emitting element and the second light emitted from the second light-emitting element are scanned by a single optical scanning device and irradiated onto the modulation surfaces of the first liquid crystal element and the second liquid crystal element, thereby making it possible to miniaturize the projector. [Explanation of symbols]

[0230] 230, 231, 232, 233...light source device, 21...light-emitting element (first light-emitting element), 40, 70...optical scanning device, 42, 76...light-transmitting member (transmitting optical element), 60, 260...light modulation device, 62...liquid crystal panel (first liquid crystal element), 80...projection optical system, 211, 212, 213...projector, 262...liquid crystal panel (second liquid crystal element). < / g> < / r> < / r> < / g> < / g> < / r> < / g> < / r>

Claims

1. a light source device that periodically emits illumination light including a first light and a second light; a light modulation device that modulates the illumination light emitted from the light source device in accordance with image information; a projection optical system that projects image light emitted from the light modulation device; Equipped with the light source device includes a light emitting element that emits the first light and the second light, The optical modulation device a first liquid crystal element that forms an image by converting the incident first light into first image light in accordance with the input image information; a second liquid crystal element that forms an image by converting the incident second light into second image light in accordance with the input image information; and an irradiation cycle of the first light emitted from the light source device and irradiated onto the first liquid crystal element and an image formation cycle of the first liquid crystal element are synchronized with each other; an irradiation cycle of the second light emitted from the light source device and irradiated onto the second liquid crystal element and an image formation cycle of the second liquid crystal element are synchronized with each other; an image formation period of the first liquid crystal element and an image formation period of the second liquid crystal element are shifted from each other; a wavelength of the first light incident on the first liquid crystal element and a wavelength of the second light incident on the second liquid crystal element are different from each other; projector.

2. further comprising an optical scanning device that periodically scans the illumination light emitted from the light source device and emits the light to the light modulation device; The projector according to claim 1 .

3. the optical scanning device scans the illumination light along a first direction, and includes a transmissive optical element having an incident surface onto which the first light emitted from the light source device is incident and an exit surface from which the first light incident from the incident surface exits; The transmissive optical element is a first surface parallel to the first direction; 2×m second surfaces tangent to the first surface; having The projector according to claim 2 . Here, m is a natural number of 2 or more.

4. the first liquid crystal element has a first liquid crystal layer whose modulation amount for the first light changes in response to an input electrical signal having the image information; the second liquid crystal element has a second liquid crystal layer that changes a modulation amount for the second light in response to an input electrical signal having the image information, a modulation period of the first liquid crystal layer and a modulation period of the second liquid crystal layer include a first period from a time when an electrical signal is input to a time when a modulation amount reaches a predetermined value, and a second period during which the modulation amount is maintained at the predetermined value; the illumination light emitted from the light source device is incident on the first liquid crystal element and the second liquid crystal element during the second period; The projector according to claim 1 .

5. a time period of the first period of the first liquid crystal element is included in a time period of the second period of the second liquid crystal element, the illumination light is incident on the second liquid crystal element during a time period in which the first period and the second period overlap; The projector according to claim 4 .

6. a drive control device that transmits the electrical signal to the optical modulation device; the drive control device transmits a synchronization signal based on the electrical signal to the light source device; The projector according to claim 4 .

7. a drive control device that transmits an electrical signal providing the image information to the light modulation device; the drive control device transmits a synchronization signal based on the electrical signal to the light source device and the optical scanning device; The projector according to claim 2 or 3.

8. when an error in the scanning period of the optical scanning device with respect to the image formation period of the optical modulation device is equal to or greater than a predetermined value and an error in the light emission period of the light source device with respect to the image formation period of the optical modulation device is equal to or greater than a predetermined value, the optical modulation device does not emit image light; The projector according to claim 2 or 3.

9. when an error in the scanning period of the optical scanning device with respect to the image formation period of the optical modulation device becomes equal to or greater than a predetermined value, the drive control device changes the scanning period of the optical scanning device; The projector according to claim 7 .

10. when an error in the scanning period of the optical scanning device with respect to the image formation period of the optical modulation device becomes equal to or greater than a predetermined value, the drive control device changes the image formation period of the optical modulation device; The projector according to claim 7 .

11. the modulation period further includes a third period from a time when the modulation amount reaches the predetermined value to a time when the modulation amount reaches an initial value, the first light emitted from the light source device is incident on the light modulation device during a period that does not overlap with the first period or the third period for second color light having a wavelength band different from that of the first color light included in the first light, during the second period for first color light included in the first light; The projector according to claim 4 .

12. the polarization direction of the first light and the polarization direction of the second light are different from each other, the light source device has a spatial light modulator that periodically changes the polarization state of light emitted from the light emitting element to alternately emit the first light and the second light, The projector according to claim 1 .

13. a first polarization separation element that separates the illumination light emitted from the light source device into the first light and the second light and emits the first light and the second light in directions different from each other; a first transmission optical element that periodically scans the first light emitted from the first polarization separation element and emits the first light to the first liquid crystal element; a second transmission optical element that periodically scans the second light emitted from the first polarization separation element and emits the second light to the second liquid crystal element; a second polarization separation element that outputs the first image light emitted from the first liquid crystal element and the second image light emitted from the second liquid crystal element in the same direction; Equipped with The projector according to claim 12.

14. The light source device is a first light emitting element that periodically emits the first light; a second light-emitting element that periodically emits the second light; and an optical scanning device that periodically scans the first light and the second light, which are emitted from the first light-emitting element and the second light-emitting element and are incident at angles different from each other, and outputs the scanned light to the optical modulation device; a reflecting element that reflects one of the first light and the second light emitted from the optical scanning device and causes the one light to be incident on the first liquid crystal element or the second liquid crystal element corresponding to the one light; Further provided with The projector according to claim 1 .

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