Projector

Abstract

To provide a projector capable of increasing light utilization efficiency.SOLUTION: A projector comprises: a light source device for emitting first light, second light, and third light; one liquid crystal panel that has a rectangular image formation area and generates first modulation light, second modulation light, and third modulation light; an illumination optical system for allowing first light, second light, and third light to enter mutually different positions in the image formation area; a first synthetic optical system for synthesizing each modulation light emitted from the liquid crystal panel; and a projection optical device for projecting light synthesized by the first synthetic optical system. In the first synthetic optical system, an air conversion optical path length of each modulation light from the liquid crystal panel to the projection optical device is equal mutually, or an optical path length from an image of the first modulation light emitted from the liquid crystal panel to the projection optical device, an optical path length from an image of the third modulation light emitted from the liquid crystal panel to the projection optical device, and an optical path length from the liquid crystal panel of the second modulation light emitted from the liquid crystal panel to the projection optical device are equal mutually.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Projectors that use a single liquid crystal panel as a light modulation element, so-called single-panel projectors, have been known for some time. Patent Document 1 listed below discloses a projector that includes a light source device, a liquid crystal panel with a color filter, and a projection lens, and that realizes color display using a single liquid crystal panel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-121930 Summary of the Invention [Problem to be solved by the invention]

[0004] The above projector has a problem in that light utilization efficiency is reduced because specific wavelengths of the light emitted from the light source device are absorbed by the color filter provided on the liquid crystal panel. [Means for solving the problem]

[0005] In order to solve the above problems, according to one aspect of the present invention, there is provided a light source device that emits first light in a first wavelength band, second light in a second wavelength band different from the first wavelength band, and third light in a third wavelength band different from the first wavelength band and the second wavelength band; one liquid crystal panel having a rectangular image forming area and modulating the first light, the second light, and the third light to generate first modulated light, second modulated light, and third modulated light, respectively; an illumination optical system that causes the first light, the second light, and the third light emitted from the light source device to be incident at different positions in the image forming area of ​​the one liquid crystal panel; a first combining optical system that combines the first modulated light, the second modulated light, and the third modulated light emitted from the one liquid crystal panel; and a light source that combines the light emitted by the first combining optical system. and a projection optical device that projects the composite modulated light emitted from the one liquid crystal panel, wherein in the first composite optical system, the air-equivalent optical path length of the first light, the air-equivalent optical path length of the second light, and the air-equivalent optical path length of the third light, which are emitted from the one liquid crystal panel and reach the projection optical device, are equal to one another; or in the first composite optical system, a first optical path length from an image formed by focusing the first modulated light emitted from the one liquid crystal panel to the projection optical device, a second optical path length from an image formed by focusing the third modulated light emitted from the one liquid crystal panel to the projection optical device, and a third optical path length of the second modulated light emitted from the one liquid crystal panel to the projection optical device are equal to one another. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing a schematic configuration of a liquid crystal panel. [Figure 3] FIG. 2 is a plan view showing the main configuration of an image forming area of ​​a liquid crystal panel. [Figure 4] FIG. 2 is a block diagram showing a schematic configuration of a control unit. [Figure 5] 10 is a flowchart illustrating a method for controlling the liquid crystal panel by the control unit. [Figure 6] FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a second embodiment. [Figure 7] FIG. 10 is a diagram showing a schematic configuration of a projector according to a third embodiment. [Figure 8] FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a fourth embodiment. [Figure 9] FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a fifth embodiment. [Figure 10] FIG. 13 is a diagram showing a configuration according to a modified example of the fifth embodiment. [Figure 11] FIG. 13 is a diagram illustrating a schematic configuration of a projector according to a sixth embodiment. [Figure 12] FIG. 13 is a diagram showing a schematic configuration of a projector according to a seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may show characteristic portions enlarged for convenience in order to make the characteristics easier to understand, and the dimensional ratios of the respective components may not necessarily be the same as those in reality.

[0008] (First embodiment) FIG. 1 is a diagram showing a schematic configuration of a projector according to this embodiment. 1, the projector 1 of this embodiment is an image display device that includes a single liquid crystal panel as a light modulation device, and is a so-called single-panel projector. The projector 1 includes a light source device 2, a single liquid crystal panel 3, an illumination optical system 4, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0009] Hereinafter, the positional relationship of each component may be explained using the XYZ coordinate system shown in the drawings. In each drawing, the X axis is the axis along the width direction of the screen SCR. The Y axis is the axis perpendicular to the X axis and is the axis along the up-down direction of the screen SCR. The Z axis is the axis perpendicular to the X axis and Y axis and is the axis along the projection direction of modulated light I from the projector 1 onto the screen SCR. Also, one side in the X direction is the -X side, and the side opposite the -X side in the X direction is the +X side. One side in the Y direction is the -Y side, and the side opposite the -Y side in the Y direction is the +Y side. One side in the Z direction is the -Z side, and the side opposite the -Z side in the Z direction is the +Y side.

[0010] The light source device 2 emits red light (first light) LR, green light (second light) LG, and blue light (third light) LB. The light source device 2 has a first light source 21 that emits red light LR, a second light source 22 that emits green light LG, and a third light source 23 that emits blue light LB. In this embodiment, the first light source 21, the second light source 22, and the third light source 23 are each configured as a light-emitting element made up of a light-emitting diode (LED).

[0011] The red light LR emitted by the first light source 21 is light having a first wavelength band, for example, a red wavelength band of 600 nm to 680 nm. The green light LG emitted by the second light source 22 is light having a second wavelength band different from the first wavelength band, for example, a green wavelength band of 520 nm to 620 nm. The blue light LB emitted by the third light source 23 is light having a third wavelength band different from the first and second wavelength bands, for example, a blue wavelength band of 400 nm to 500 nm.

[0012] Each liquid crystal panel 3 is, for example, a transmissive liquid crystal panel. Polarizing plates (not shown) are arranged on the incident side and the exit side of the liquid crystal panel 3. The polarizing plates only allow linearly polarized light in a specific direction to pass through.

[0013] The red light LR, green light LG, and blue light LB emitted from the light source device 2 are incident on different positions in the image forming area 30 of the liquid crystal panel 3 by the illumination optical system 4. Specifically, the red light LR, green light LG, and blue light LB are incident on a first illumination area 30R, a second illumination area 30G, and a third illumination area 30B, respectively, of the image forming area 30, which will be described later.

[0014] The illumination optical system 4 has a first light guide element 41, a second light guide element 42, and a third light guide element 43. The first light guide element 41 faces the light emission side of the first light source 21 and is disposed on the optical path of the red light LR emitted from the first light source 21. The first light guide element 41 uniforms the illuminance of the red light LR that illuminates the first illumination region 30R of the image formation region 30. The first light guide element 41 has a first light incident surface 41a onto which the red light LR emitted from the first light source 21 is incident, a first light emission surface 41b from which the red light LR exits, and a side surface 41c that reflects the incident red light LR toward the first light emission surface 41b.

[0015] The second light guide element 42 faces the light emission side of the second light source 22 and is disposed on the optical path of the green light LG emitted from the second light source 22. The second light guide element 42 homogenizes the illuminance of the green light LG that illuminates the second illumination region 30G of the image formation region 30. The second light guide element 42 has a second light incident surface 42a onto which the green light LG emitted from the second light source 22 is incident, a second light exit surface 42b from which the green light LG exits, and a side surface 42c that reflects the incident green light LG toward the second light exit surface 42b.

[0016] The third light guide element 43 faces the light emission side of the third light source 23 and is disposed on the optical path of the red light LR emitted from the third light source 23. The third light guide element 43 uniforms the illuminance of the blue light LB that illuminates the third illumination region 30B of the image formation region 30. The third light guide element 43 has a third light incident surface 43a onto which the blue light LB emitted from the third light source 23 is incident, a third light emission surface 43b from which the blue light LB exits, and a side surface 43c that reflects the incident blue light LB toward the third light emission surface 43b.

[0017] The first light guide element 41, the second light guide element 42, and the third light guide element 43 are each formed of a tapered rod. Each of the light guide elements 41, 42, and 43 has a truncated quadrangular pyramid shape, and the cross-sectional area perpendicular to the optical axis of each element expands along the light propagation direction.

[0018] In the first light guide element 41, the area of ​​the first light exit surface 41b is larger than the area of ​​the first light incident surface 41a. An axis passing through the centers of the first light exit surface 41b and the first light incident surface 41a and parallel to the X axis is defined as an optical axis J1 of the first light guide element 41. The optical axis J1 of the first light guide element 41 coincides with the optical axis AX1 of the first light source 21.

[0019] In the second light guide element 42, the area of ​​the second light exit surface 42b is larger than the area of ​​the second light incident surface 42a. An axis that passes through the centers of the second light exit surface 42b and the second light incident surface 42a and is parallel to the X axis is defined as an optical axis J2 of the second light guide element 42. The optical axis J2 of the second light guide element 42 coincides with the optical axis AX2 of the second light source 22. The optical axis AX2 coincides with the illumination optical axis of the projector 1.

[0020] In the third light guide element 43, the area of ​​the third light exit surface 43b is larger than the area of ​​the third light incident surface 43a. An axis that passes through the centers of the third light exit surface 43b and the third light incident surface 43a and is parallel to the X axis is defined as an optical axis J3 of the third light guide element 43. The optical axis J3 of the third light guide element 43 coincides with the optical axis AX3 of the third light source 23.

[0021] The liquid crystal panel 3 modulates the red light LR, green light LG, and blue light LB based on input image data input from an image forming device such as a computer (not shown) to generate a red image IR, a green image IG, and a blue image IB. The liquid crystal panel 3 emits each color light constituting the red image IR, the green image IG, and the blue image IB toward the +X side in the X direction.

[0022] Fig. 2 is a diagram showing a schematic configuration of the liquid crystal panel 3. In Fig. 2, the shorter side direction of the rectangular liquid crystal panel 3 is the X direction, and the longer side direction is the Y direction. As shown in FIG. 2, the liquid crystal panel 3 includes an image forming area 30 and a drive circuit 35 provided on a substrate 40. The image forming area 30 is a rectangular area in which a plurality of pixels 30P are arranged in a matrix. The image forming area 30 is provided with a plurality of data lines 33 extending in the X direction and a plurality of scanning lines 32 extending in the Y direction intersecting with the X direction. Each pixel 30P is provided corresponding to an intersection of the plurality of scanning lines 32 and the plurality of data lines 33. Therefore, the plurality of pixels 30P are arranged in a matrix in both the X direction and the Y direction. A pixel 30P corresponds to the smallest unit of the display area that turns on or off in response to image data for one pixel.

[0023] The drive circuit 35 is an L-shaped region that surrounds the peripheral region of the image forming region 30. The drive circuit 35 is a circuit that drives each pixel 30P in the image forming region 30. The drive circuit 35 includes a scanning line drive circuit 36, a data line drive circuit 37, and a power supply circuit and a control circuit (not shown). The control unit 10 controls the driving of the liquid crystal panel 3 via the drive circuit 35.

[0024] The scanning line driving circuit 36 ​​is provided on the +Y side, which is one end side in the extension direction of the multiple scanning lines 32. Note that the scanning line driving circuit 36 ​​may be arranged one on each side of the image forming area 30 in the Y direction.

[0025] The data line driving circuit 37 supplies image data input from the control unit 10 as a gradation potential (data signal) corresponding to the gradation designated for each pixel 30P in parallel to the plurality of data lines 33 for each writing period (horizontal scanning period). Note that the data line driving circuit 37 may supply signals to all data lines 33 simultaneously during the horizontal scanning period, or may supply signals in multiple batches.

[0026] The scanning line driving circuit 36 ​​sequentially selects each of the plurality of scanning lines 32 for each writing period by supplying a scanning signal to each of the plurality of scanning lines 32. As a result, the selection transistor of the pixel 30P corresponding to the scanning line 32 selected by the scanning line driving circuit 36 ​​is turned on. Then, a gradation potential is supplied to the gate of the driving transistor of each pixel 30P via the data line 33 and the selection transistor, and a voltage according to the gradation potential is supplied to the pixel electrode, causing any pixel 30P corresponding to the image data to be emitted from the image forming area 30 as part of modulated light.

[0027] Hereinafter, in this specification, the manner in which the scanning line driving circuit 36 ​​sequentially selects the multiple scanning lines 32 is referred to as "vertical scanning." The direction in which the scanning lines 32 are sequentially scanned in one direction in the Y direction by the vertical scanning of the scanning line driving circuit 36 ​​is referred to as the "vertical scanning direction."

[0028] FIG. 3 is a plan view showing the main configuration of the image forming area 30 of the liquid crystal panel 3. As shown in FIG. 3, the image forming area 30 has a first illumination area 30R illuminated with red light LR, a second illumination area 30G illuminated with green light LG, and a third illumination area 30B illuminated with blue light LB. In the image forming area 30, the first illumination area 30R, the second illumination area 30G, and the third illumination area 30B are arranged in this order from the -Y side to the +Y side of the image forming area 30. The order in which the first illumination area 30R, the second illumination area 30G, and the third illumination area 30B are arranged within the image forming area 30 is not particularly limited.

[0029] The liquid crystal panel 3 of this embodiment is a panel compatible with 4K image signals, and the image forming area 30 has 3840 × 2160 pixels 30P. That is, the number of pixels in the Y direction of the image forming area 30 is 3840, and the number of pixels in the X direction of the image forming area 30 is 2160.

[0030] In the liquid crystal panel 3 of this embodiment, the long side direction of each of the illumination areas 30R, 30G, and 30B coincides with the short side direction of the image forming area 30, and the short side direction of each of the illumination areas 30R, 30G, and 30B coincides with the long side direction of the image forming area 30. Each of the illumination areas 30R, 30G, and 30B is an area capable of displaying high-definition images, and each has 1920 × 1080 pixels 30P. That is, the number of pixels in the Y direction of each of the illumination areas 30R, 30G, and 30B is 1080, and the number of pixels in the X direction of each of the illumination areas 30R, 30G, and 30B is 1920.

[0031] The first illumination area 30R is an area that generates a red image IR by modulating red light LR incident from the illumination optical system 4. The second illumination area 30G is an area that generates a green image IG by modulating green light LG incident from the illumination optical system 4. The third illumination area 30B is an area that generates a blue image IB by modulating blue light LB incident from the illumination optical system 4. The liquid crystal panel 3 of this embodiment does not have color filters in each of the illumination areas 30R, 30G, and 30B, and therefore efficiently utilizes the colored light LR, LG, and LB incident from the illumination optical system 4 without absorbing them, thereby generating bright images.

[0032] The image forming region 30 includes a grid-shaped parting region 31 surrounding each of the illumination regions 30R, 30G, and 30B. The pixels 30P that make up the parting region 31 always display black. Therefore, the parting region 31 is an area that does not contribute to image display. In the long side direction of the image forming region 30, the parting region 31 located between the first illumination region 30R and the second illumination region 30G has a width that includes at least one pixel 30P, and the parting region 31 located between the second illumination region 30G and the third illumination region 30B has a width that includes at least one pixel 30P.

[0033] Therefore, in the image forming area 30, the first illumination area 30R and the second illumination area 30G are spaced apart by at least one pixel, and the second illumination area 30G and the third illumination area 30B are spaced apart by at least one pixel.

[0034] Driving of the liquid crystal panel 3 is controlled by the control unit 10. A method of controlling the liquid crystal panel 3 by the control unit 10 will be described below. FIG. 4 is a block diagram showing a schematic configuration of the control unit 10. FIG. 5 is a flowchart showing a method of controlling the liquid crystal panel 3 by the control unit 10.

[0035] As shown in Fig. 4, the control unit 10 includes a data separation unit 11, an image processing unit 12, and a data synthesis unit 13. The control unit 10 is electrically connected to an image forming apparatus such as a computer (not shown), and starts the control flow of the liquid crystal panel 3 when image data is input from the image forming apparatus. The control unit 10 is configured with a processor such as a CPU (Central Processing Unit). Note that some or all of the functions of the control unit 10 may be configured with circuits such as a DSP (Digital Signal Processor), ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), and FPGA (Field Programmable Gate Array).

[0036] The control unit 10 receives input image data corresponding to a full-color image at the data separation unit 11. The data separation unit 11 executes step S1 shown in FIG. 5. In step S1, the data separation unit 11 separates the input image data D into image data for each color of RGB. Specifically, the data separation unit C1 separates the input image data D into red image data (first color image data) Dr, green image data (second color image data) Dg, and blue image data (third color image data) Db. The red image data Dr, green image data Dg, and blue image data Db each correspond to a high-definition image and each contain information on 1920 x 1080 pixels. Note that the red image data Dr, green image data Dg, and blue image data Db are data relating to the same image, differing only in color.

[0037] Next, the control unit 10 causes the image processing unit 12 to perform the first image processing of step S2 shown in Fig. 5 on the red image data Dr, green image data Dg, and blue image data Db. In step S2, the image processing unit 12 performs image processing on each of the red image data Dr, green image data Dg, and blue image data Db to correct at least one of gradation, image size, and sharpness. By performing the first image processing, the control unit 10 can correct the red image data Dr, green image data Dg, and blue image data Db, for example, to an image size corresponding to the size of each illumination area 30R, 30G, 30B, or correct them to image data suitable for the image display mode of the projector 1.

[0038] As described above, the long side direction of each of the illumination areas 30R, 30G, 30B coincides with the short side direction of the image forming area 30, and the short side direction of each of the illumination areas 30R, 30G, 30B coincides with the long side direction of the image forming area 30.

[0039] If the red image data Dr is input to the first illumination region 30R with the long side direction of the red image data Dr aligned with the short side direction of the first illumination region 30R, the red image IR corresponding to the red image data Dr will extend beyond the first illumination region 30R. As a result, the entire red image IR based on the red image data Dr cannot be displayed within the first illumination region 30R. The same can be said for the green image data Dg and blue image data Db.

[0040] In response to this, the control unit 10 causes the image processing unit 12 to perform a rotation process on the red image data Dr, green image data Dg, and blue image data Db in step S3 shown in Fig. 5. Specifically, in step S3, the image processing unit 12 rotates the orientation of each of the red image data Dr, green image data Dg, and blue image data Db relative to the image forming area 30 by 90 degrees.

[0041] As a result, the long side direction of the red image IR corresponding to the red image data Dr coincides with the short side direction of the first illumination region 30R. Similarly, the long side direction of the green image IG corresponding to the green image data Dg coincides with the short side direction of the second illumination region 30G, and the long side direction of the blue image IB corresponding to the blue image data Db coincides with the short side direction of the third illumination region 30B.

[0042] Next, the control unit 10 causes the image processing unit 12 to perform the second image processing of step S4 shown in Fig. 5 on the red image data Dr, green image data Dg, and blue image data Db after the rotation processing. In step S4, the image processing unit 12 performs image processing on each of the red image data Dr, green image data Dg, and blue image data Db to correct at least one of color unevenness and streak unevenness. By performing the second image processing, the control unit 10 can correct the red image data Dr, green image data Dg, and blue image data Db to image data that suppresses color unevenness and streaks, thereby further improving the image quality of each color displayed in each of the illumination areas 30R, 30G, and 30B.

[0043] As a comparative example, consider a case where the second image processing is performed together with the first image processing before the rotation processing that rotates the orientations of the red image data Dr, green image data Dg, and blue image data Db. If the first image processing and the second image processing are performed together before the rotation processing in this way, color unevenness and streak unevenness in the images displayed in each of the illumination areas 30R, 30G, and 30B cannot be sufficiently corrected, and color unevenness and streak unevenness occur after the rotation processing, resulting in the need to correct the color unevenness and streak unevenness again.

[0044] In this embodiment, the control unit 10 performs the second image processing after rotating the red image data Dr, green image data Dg, and blue image data Db, so that color unevenness and streak unevenness in the displayed image can be efficiently corrected with a single second image processing.

[0045] Next, the control unit 10 performs image synthesis processing in step S5 shown in FIG. 5, in which the data synthesis unit 13 synthesizes the red image data Dr, green image data Dg, and blue image data Db. Specifically, in step S5, the data synthesis unit 13 synthesizes the red image data Dr, green image data Dg, and blue image data Db to generate one piece of synthetic image data AD. The synthetic image data AD includes not only the red image data Dr, green image data Dg, and blue image data Db, but also image data of black display corresponding to the parting region 31. The data synthesis unit 13 generates synthetic image data AD for each frame of the display image in the image forming region 30 of the liquid crystal panel 3.

[0046] 5 based on the composite image data AD generated by the data synthesis unit 13. In step S6, the control unit 10 inputs the rotated red image data Dr, green image data Dg, and blue image data Db aligned along the long side of the image forming area 30.

[0047] In step S6, the control unit 10 displays one composite image A in the image forming area 30 of the liquid crystal panel 3 based on one piece of composite image data AD. As shown in Fig. 3 , the composite image A includes a red image RR corresponding to the red image data Dr, a green image GG corresponding to the green image data Dg, and a blue image BB corresponding to the blue image data Db, which are arranged in this order along the long side direction of the image forming area 30, as well as a black image K displayed in the parting area 31.

[0048] In the composite image A, the black image formed by the parting region 31 provided between the red image RR and the green image GG includes at least one pixel 30P. Also, in the composite image A, the black image formed by the parting region 31 provided between the green image GG and the blue image BB includes at least one pixel 30P. Therefore, in the composite image A, the red image RR and the green image GG are separated by at least one pixel, and the green image GG and the blue image BB are separated by at least one pixel. In this way, in the composite image A, the red image RR, the green image GG, and the blue image BB are separated from each other, so that the light constituting the red image RR, the green image GG, and the blue image BB can be efficiently incident on the desired positions of the first combining optical system 5, which will be described later.

[0049] More specifically, in step S6, the data line driving circuit 37 inputs each image data constituting the composite image data AD to the corresponding data lines 33 in the image forming area 30. For example, the data line driving circuit 37 inputs red image data Dr to the data lines 33 provided in the first illumination area 30R, green image data Dg to the data lines 33 provided in the second illumination area 30G, blue image data Db to the data lines 33 provided in the third illumination area 30B, and black display image data to the data lines 33 corresponding to the parting area 31.

[0050] The scanning line driving circuit 36 ​​sequentially selects each of the multiple scanning lines 32 from the +X side to the -X side of the image forming area 30 and supplies a scanning signal to each of them. While the entire composite image A is shown in the image forming area 30 in Fig. 3 for ease of viewing, the actual composite image A is displayed sequentially along the X direction, which is the short side direction of the image forming area 30, for each pixel row 30PL along the Y direction, which is the long side direction of the image forming area 30. Therefore, each pixel row 30PL of the image forming area 30 displays a part of the red image RR, a part of the green image GG, a part of the blue image BB, and a part of the black image in the parting area 31.

[0051] However, with conventional single-panel projectors, each RGB color light is incident on the image formation area of ​​a single LCD panel in time sequential manner, which can lead to the risk of color breakup, in which each color light appears separated over time on the image. In contrast, according to the liquid crystal panel 3 of this embodiment, the composite image A that is displayed sequentially during vertical scanning includes part of the red image RR, part of the green image GG, and part of the blue image BB, thereby suppressing degradation of image quality due to the color breakup phenomenon.

[0052] In this way, the liquid crystal panel 3 modulates the colored light LR, LG, and LB input to each lighting area 30R, 30G, and 30B based on the image data Dr, Dg, and Db input to each lighting area 30R, 30G, and 30B, thereby generating a composite image A in the image forming area 30, which consists of three identical color images: a red image RR, a green image GG, and a blue image BB.

[0053] The red image RR, green image GG, and blue image BB emitted from each of the illumination areas 30R, 30G, and 30B of the liquid crystal panel 3 are incident on the first combining optical system 5. Thereafter, the red image RR, green image GG, and blue image BB are emitted from each of the illumination areas 30R, 30G, and 30B as red modulated light (first modulated light) RR1, green modulated light (second modulated light) GG1, and blue modulated light (third modulated light) BB1.

[0054] The first combining optical system 5 combines the red modulated light RR1, the green modulated light GG1, and the blue modulated light BB1 emitted from the illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3. The first combining optical system 5 has a first prism 51, a second prism 52, a first bending prism 53, a second bending prism 54, and a light combining prism 55.

[0055] The first prism 51 is disposed on the light exit side of the first illumination region 30R of the liquid crystal panel 3. The first prism 51 transmits the red modulated light RR1 exiting from the first illumination region 30R of the liquid crystal panel 3 and causes the light to enter the first bending prism 53. The first prism 51 has a rectangular parallelepiped shape and is made of a light-transmitting member such as glass or plastic.

[0056] The second prism 52 is disposed on the light exit side of the third illumination region 30B of the liquid crystal panel 3. The second prism 52 transmits the blue modulated light BB1 exiting from the third illumination region 30B of the liquid crystal panel 3 and causes the blue modulated light BB1 to enter the second bending prism 54. The second prism 52 has a rectangular parallelepiped shape and is made of a light-transmitting member such as glass or plastic.

[0057] The first bending prism 53 is disposed on the light exit side of the first prism 51. The first bending prism 53 bends the red modulated light RR1 that has passed through the first prism 51. The first bending prism 53 has a right-angled triangular prism shape and is made of a light-transmitting material such as glass or plastic. The first bending prism 53 bends the optical path of the red modulated light RR1 by 90 degrees, emits it to the -Y side, and makes it incident on the light combining prism 55.

[0058] The second bending prism 54 is disposed on the light exit side of the second prism 52. The second bending prism 54 bends the blue modulated light BB1 that has passed through the second prism 52. The second bending prism 54 has a right-angled triangular prism shape and is made of a light-transmitting material such as glass or plastic. The second bending prism 54 bends the optical path of the blue modulated light BB1 by 90 degrees, emits it to the +Y side, and makes it incident on the light combining prism 55.

[0059] The light combining prism 55 is disposed on the light exit side of the second illumination region 30G of the liquid crystal panel 3. The light combining prism 55 is disposed at a predetermined gap from the liquid crystal panel 3. The light combining prism 55 is disposed so as to be sandwiched between the first bending prism 53 and the second bending prism 54 along the Y direction.

[0060] The light combining prism 55 reflects red modulated light RR1 incident from the +Y side toward the -Y side by 90 degrees and emits it to the +X side, reflects blue modulated light BB1 incident from the -Y side toward the +Y side by 90 degrees and emits it to the +X side, and transmits green modulated light GG1 incident from the -X side toward the +X side and emits it to the +X side. The light combining prism 55 generates full-color modulated light (combined modulated light) I by combining the red modulated light RR1 emitted from the first bending prism 53, the green modulated light GG1 emitted from the liquid crystal panel 3, and the blue modulated light BB1 emitted from the second bending prism 54. A cross dichroic prism, for example, is used as the light combining prism 55 of this embodiment.

[0061] In this way, the first combining optical system 5 combines the red modulated light RR1, the green modulated light GG1, and the blue modulated light BB1 emitted from the liquid crystal panel 3, and emits the modulated light I toward the projection optical device 6.

[0062] The projection optical device 6 is composed of multiple projection lenses. The projection optical device 6 enlarges and projects the full-color modulated light I synthesized by the first synthesizing optical system 5 onto the screen SCR, thereby displaying a color image on the screen SCR.

[0063] Here, the optical path length of the green modulated light GG1 passing through the air portion after being emitted from the liquid crystal panel 3 until it is incident on the light combining prism 55 is set to GSa.

[0064] In the red modulated light RR1 emitted from the liquid crystal panel 3 until it enters the light-combining prism 55, the optical path length passing through the air portion is defined as RSa, the optical path length in the optical axis direction of the first bending prism 53 is defined as RS1, the refractive index of the first bending prism 53 is defined as Rn1, the optical path length in the optical axis direction of the light-combining prism 55 is defined as RS2, and the refractive index of the light-combining prism 55 is defined as Rn2.

[0065] In the blue modulated light BB1 emitted from the liquid crystal panel 3 and incident on the light-combining prism 55, the optical path length passing through the air portion is BSa, the optical path length in the optical axis direction of the second bending prism 54 is BS1, the refractive index of the second bending prism 54 is Bn1, the optical path length in the optical axis direction of the light-combining prism 55 is BS2, and the refractive index of the light-combining prism 55 is Bn2.

[0066] In this embodiment, the air-equivalent optical path length of the green modulated light GG1 from the liquid crystal panel 3 to the light combining prism 55 is defined as GSa. The air-equivalent optical path length of the red modulated light RR1 from the liquid crystal panel 3 to the light combining prism 55 is defined as RSa+(RS1 / Rn1)+(RS2 / Rn2). The air-equivalent optical path length of the blue modulated light BB1 from the liquid crystal panel 3 to the light combining prism 55 is defined as BSa+(BS1 / Bn1)+(BS2 / Bn2). In the light combining prism 55, the optical path lengths of the red modulated light RR1, the green modulated light GG1, and the blue modulated light BB1 are equal to one another.

[0067] Therefore, in the first combining optical system 5 of this embodiment, the air-equivalent optical path length RS of the red modulated light RR1, the air-equivalent optical path length GS of the green modulated light GG1, and the air-equivalent optical path length BS of the blue modulated light BB1 are all equal, all of which are emitted from the liquid crystal panel 3 and reach the projection optical device 6. In other words, the distances from the first illumination area 30R, the second illumination area 30G, and the third illumination area 30B of the liquid crystal panel 3 to the projection optical device 6 for each of the color modulated lights RR1, GG1, and BB1 are optically transmitted. In this specification, the air-equivalent optical path lengths being equal to each other does not necessarily mean that the air-equivalent optical path lengths are completely the same, but also means that the air-equivalent optical path lengths are approximately equal to each other.

[0068] As described above, the projector 1 of this embodiment comprises a light source device 2 that emits red light LR in the red wavelength band, green light LG in a green wavelength band different from the red wavelength band, and blue light LB in a blue wavelength band different from the red wavelength band and the green wavelength band; one liquid crystal panel 3 that has a rectangular image forming area 30 and modulates the red light LR, green light LG, and blue light LB; an illumination optical system 4 that causes the red light LR, green light LG, and blue light LB emitted from the light source device 2 to be incident at different positions in the image forming area 30 of the one liquid crystal panel 3; a first combining optical system 5 that combines the red modulated light RR1, green modulated light GG1, and blue modulated light BB1 emitted from the one liquid crystal panel 3; and a projection optical device 6 that projects the modulated light I combined by the first combining optical system 5. In the first combining optical system 5, the air-equivalent optical path length RS of the red modulated light RR1, the air-equivalent optical path length GS of the green modulated light GG1, and the air-equivalent optical path length BS of the blue modulated light BB1 that are emitted from one liquid crystal panel 3 and reach the projection optical device 6 are all equal to one another.

[0069] According to the projector 1 of this embodiment, red light LR, green light LG, and blue light LB incident on the image forming area 30 of one liquid crystal panel 3 are modulated, so that red modulated light RR1, green modulated light GG1, and blue modulated light BB1 can be generated without using color filters. Therefore, by efficiently using the light emitted from the light source device 2, bright full-color modulated light I can be enlarged and projected onto the screen SCR. The projector 1 of this embodiment can provide a single-panel projector that can improve the light utilization efficiency of the light source device 2. Because the projector 1 of this embodiment employs the single-panel system, an alignment process for multiple liquid crystal panels is not required. In conventional three-panel projectors, different types of LCD panels were sometimes used depending on their position relative to the cross dichroic prism. This required the preparation of two types of LCD panels, which could lead to increased costs. In the present embodiment, only one type of LCD panel 3 is required, so this problem does not occur.

[0070] Furthermore, in the projector 1 of this embodiment, the air-equivalent optical path lengths of the color modulated light RR1, GG1, and BB1 that are emitted from the liquid crystal panel 3 and reach the projection optical device 6 are equal to one another, and therefore it is possible to properly focus the red modulated light RR1, green modulated light GG1, and blue modulated light BB1 that are emitted from the illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3. Therefore, the projector 1 of this embodiment can project a high-quality color image with little blur onto the screen SCR.

[0071] (Second embodiment) A second embodiment of the present invention will be described below with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and only the configuration of the first composite optical system differs from that of the first embodiment, so a description of the common parts will be omitted.

[0072] FIG. 6 is a diagram showing a schematic configuration of the projector of this embodiment. As shown in FIG. 6, the projector 102 of this embodiment includes a light source device 2, one liquid crystal panel 3, an illumination optical system 4, a first combining optical system 15, a projection optical device 6, and a control unit 10.

[0073] The first combining optical system 15 of this embodiment has a first deflection element 150, a second deflection element 151, a first imaging element 152, a second imaging element 153, a pair of phase difference elements 154, and a light combining prism 55.

[0074] The first deflector 150 is an element that bends the optical path of the red modulated light RR1 emitted from the liquid crystal panel 3. The first deflector 150 of this embodiment is a polarization separation element that reflects S-polarized light of the incident light and transmits P-polarized light of the incident light. In this embodiment, the red modulated light RR1 passes through a polarizer provided on the exit side of the liquid crystal panel 3 and is incident on the first deflector 150 as S-polarized light. Therefore, the first deflector 150 reflects the red modulated light RR1 to the +Y side.

[0075] The red modulated light RR1 is incident on one of a pair of phase difference elements 154. The phase difference element 154 is composed of a quarter-wave plate (λ / 4 plate). The red modulated light RR1, which is S-polarized light, is converted into red modulated light RRc1, which is, for example, right-handed circularly polarized light, by passing through the phase difference element 154. The circularly polarized red modulated light RRc1 emerging from the phase difference element 154 is incident on the first imaging element 152.

[0076] The first imaging element 152 is composed of a curved mirror that is convex toward the +Y side and reflects the red modulated light RRc1 incident from the first deflection element 150. For example, the red modulated light RRc1, which is clockwise circularly polarized light, is reflected by the first imaging element 152 and becomes the red modulated light RRc2, which is counterclockwise circularly polarized light. The red modulated light RRc2 passes through the phase difference element 154 again and is converted into P-polarized red modulated light RR2. The P-polarized red modulated light RR2 passes through the first deflection element 150. The red modulated light RR2 that has passed through the first deflection element 150 is focused by the first imaging element 152 to form an image RZ that is equal to the image on the liquid crystal panel 3 near the light combining prism 55. In other words, the first imaging element 152 has the same function as a relay lens. The modulated red light RR2 forms an image RZ and then enters the light combining prism 55.

[0077] The second deflector 151 is an element that bends the optical path of the blue modulated light BB1 emitted from the liquid crystal panel 3. The second deflector 151 of this embodiment is a polarization separation element that reflects S-polarized light of the incident light and transmits P-polarized light of the incident light. In this embodiment, the blue modulated light BB1 passes through a polarizer provided on the exit side of the liquid crystal panel 3 and is incident on the second deflector 151 as S-polarized light. Therefore, the second deflector 151 reflects the blue modulated light BB1 to the -Y side.

[0078] The blue modulated light BB1 is incident on the other of the pair of phase difference elements 154. The blue modulated light BB1, which is S-polarized light, is converted into blue modulated light BBc1, which is, for example, right-handed circularly polarized light, by passing through the phase difference element 154. The circularly polarized blue modulated light BBc1 emerging from the phase difference element 154 is incident on the second imaging element 153.

[0079] The second imaging element 153 is composed of a curved mirror convex toward the -Y side and reflects the blue modulated light BBc1 incident from the second deflector element 151. For example, the blue modulated light BBc1, which is clockwise circularly polarized light, is reflected by the second imaging element 153 and becomes the blue modulated light BBc2, which is counterclockwise circularly polarized light. The blue modulated light BBc2 passes through the phase difference element 154 again and is converted into the P-polarized blue modulated light BB2. The P-polarized blue modulated light BB2 passes through the second deflector element 151. The blue modulated light BB2 that has passed through the second deflector element 151 is focused by the second imaging element 153 to form an image BZ at the same magnification as the image on the liquid crystal panel 3 near the light combining prism 55. In other words, the second imaging element 153 has the same function as a relay lens. The blue modulated light BB2 forms an image BZ and then enters the light combining prism 55.

[0080] Light combining prism 55 is disposed along the Y direction so as to be sandwiched between first deflection element 150 and second deflection element 151. Light combining prism 55 combines red modulated light RR2, blue modulated light BB2, and green modulated light GG1 emitted from liquid crystal panel 3 to generate full-color modulated light (combined modulated light) I2. Modulated light I2 is enlarged and projected onto screen SCR by projection optical device 6.

[0081] In the first combining optical system 15 of this embodiment, the optical path length from the image RZ formed by focusing the red modulated light RR1 emitted from the liquid crystal panel 3 to the projection optical device 6 is defined as the first optical path length RS2, the optical path length from the image BZ formed by focusing the blue modulated light BB1 emitted from the liquid crystal panel 3 to the projection optical device is defined as the second optical path length BS2, and the optical path length from the liquid crystal panel 3 to the projection optical device 6 of the green modulated light GG1 emitted from the liquid crystal panel 3 is defined as the third optical path length GS2.

[0082] The exit surface of the liquid crystal panel 3 from which the red modulated light RR1 emerges and the surface on which the image RZ is formed are optically conjugate positions. Also, the exit surface of the liquid crystal panel 3 from which the blue modulated light BB1 emerges and the surface on which the image BZ is formed are optically conjugate positions. In the first combining optical system 15 of this embodiment, the first optical path length RS2, the second optical path length BS2, and the third optical path length GS2 are all equal to one another. Note that the first optical path length RS2, the second optical path length BS2, and the third optical path length GS2 being equal does not necessarily mean that the optical path lengths are completely equal to one another, but also means that the air-equivalent optical path lengths are almost equal to one another. Therefore, the distance from each illumination area 30R, 30G, 30B of the image forming area 30 of the liquid crystal panel 3 to the projection optical device 6 is optically transparent, so that the projection optical device 6 can properly focus the red modulated light RR2, the green modulated light GG2, and the blue modulated light BB2.

[0083] As described above, projector 102 of the present embodiment includes light source device 2, one liquid crystal panel 3, illumination optical system 4, first combining optical system 15 that combines red modulated light RR2, green modulated light GG2, and blue modulated light BB2 emitted from one liquid crystal panel 3, and projection optical device 6 that projects modulated light I2 combined by first combining optical system 15. In first combining optical system 15, a first optical path length RS2 from image RZ formed by focusing red modulated light RR2 emitted from one liquid crystal panel 3 to projection optical device 6, a second optical path length BS2 from image BZ formed by focusing blue modulated light BB2 emitted from one liquid crystal panel 3 to projection optical device 6, and a third optical path length GS2 of green modulated light GG2 emitted from one liquid crystal panel 3 from one liquid crystal panel 3 to projection optical device 6 are all equal.

[0084] According to the projector 102 of this embodiment, similar to the projector 1 of the first embodiment, it is possible to provide a single-panel projector that can improve the light utilization efficiency of the light source device 2. Furthermore, since the optical path lengths of the color modulated light RR2, GG2, and BB2 that are emitted from the liquid crystal panel 3 and reach the projection optical device 6 are equal to each other, it is possible to project a high-quality color image with little blur onto the screen SCR, similar to the projector 1 of the first embodiment.

[0085] (Third embodiment) A third embodiment of the present invention will be described below with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and only the configuration of the illumination optical system differs from that of the first embodiment, so a description of the common parts will be omitted.

[0086] FIG. 7 is a diagram showing a schematic configuration of the projector of this embodiment. As shown in FIG. 7, the projector 103 of this embodiment includes a light source device 2, one liquid crystal panel 3, an illumination optical system 16, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0087] The illumination optical system 16 of this embodiment includes a first light guide element 41, a second light guide element 42, a third light guide element 43, and a plurality of reflective polarizing elements 16a. The plurality of reflective polarizing elements 16a are provided for each of the light guide elements 41, 42, and 43.

[0088] The first light guide element 41 has one reflective polarizing element 16a arranged at a position facing the first light exit surface 41b. The second light guide element 42 has one reflective polarizing element 16a arranged at a position facing the second light exit surface 42b. The third light guide element 43 has one reflective polarizing element 16a arranged at a position facing the third light exit surface 43b.

[0089] Each reflective polarizing element 16a transmits P-polarized light, which is a first polarized light that passes through an incident-side polarizing plate arranged in front of the liquid crystal panel 3, and reflects S-polarized light, which is a second polarized light different from the first polarized light, toward the corresponding light guide element 41, 42, 43. In this embodiment, each reflective polarizing element 16a is formed of, for example, a WGP (Wire Grid Polarizer).

[0090] For example, at least a portion of the S-polarized red light LR that is reflected by the reflective polarizing element 16a and enters the first light guide element 41 propagates through the first light guide element 41, returns to the first light source 21, and is emitted again from the first light source 21. At this time, the polarization of some of the S-polarized red light LR is disturbed and becomes P-polarized light. Then, the red light LR that propagates through the first light guide element 41 and is emitted from the first light exit surface 41b is transmitted through the reflective polarizing element 16a. The same can be said about the behavior of light in the second light guide element 42 and the third light guide element 43.

[0091] As described above, the illumination optical system 16 of this embodiment includes the reflective polarizing element 16a located on the light exit side of each of the light guide elements 41, 42, and 43, so that the polarization directions of the colored light LR, LG, and LB incident on the liquid crystal panel 3 can be aligned to P-polarized light. Since the polarization directions of the colored light LR, LG, and LB are aligned, loss due to the incident-side polarizing plate of the liquid crystal panel 3 can be reduced, and light utilization efficiency can be improved. Furthermore, because linearly polarized light can be incident on the liquid crystal panel 3, the incident-side polarizing plate of the liquid crystal panel 3 can be omitted. Therefore, according to the projector 103 of this embodiment, by providing the illumination optical system 16, it is possible to further improve the light utilization efficiency.

[0092] In this embodiment, the reflective polarizing element 16a is arranged in each of the first light-guiding element 41, the second light-guiding element 42, and the third light-guiding element 43, but the reflective polarizing element 16a may be arranged on the light exit surface side of at least one of the first light-guiding element 41, the second light-guiding element 42, and the third light-guiding element 43.

[0093] Furthermore, for example, a quarter-wave plate may be placed between the reflective polarizing element 16a and each of the light sources 21, 22, and 23 to more easily align the polarization directions of the colored lights LR, LG, and LB, thereby further improving the light utilization efficiency.

[0094] (Fourth embodiment) A fourth embodiment of the present invention will be described below with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and only the configuration of the illumination optical system differs from that of the first embodiment, so a description of the common parts will be omitted.

[0095] FIG. 8 is a diagram showing a schematic configuration of the projector of this embodiment. As shown in FIG. 8, the projector 104 of this embodiment includes a light source device 2, one liquid crystal panel 3, an illumination optical system 114, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0096] The illumination optical system 114 of this embodiment includes a first light guide element 41, a second light guide element 42, a third light guide element 43, and a plurality of relay optical systems 27. The plurality of relay optical systems 27 are provided for each of the light guide elements 41, 42, and 43.

[0097] The first light guide element 41 has one reflective polarizing element 16a arranged at a position facing the first light exit surface 41b. The second light guide element 42 has one reflective polarizing element 16a arranged at a position facing the second light exit surface 42b. The third light guide element 43 has one reflective polarizing element 16a arranged at a position facing the third light exit surface 43b.

[0098] Each relay optical system 27 is composed of a first lens 27a, a second lens 27b, and a third lens 27c. The type and number of lenses constituting the relay optical system 27 are not particularly limited. The relay optical system 27 forms images of the color light LR, LG, and LB emitted from the corresponding light guide elements 41, 42, and 43 onto the illumination regions 30R, 30G, and 30B of the image forming region 30 of the liquid crystal panel 3. In this embodiment, the light exit surfaces 41b, 42b, and 43b of the light guide elements 41, 42, and 43 and the illumination regions 30R, 30G, and 30B of the image forming region 30 of the liquid crystal panel 3 are optically conjugate.

[0099] As described above, the illumination optical system 114 of this embodiment is provided with the relay optical system 27, which reduces uneven illuminance caused by the colored lights LB, LG, LB emitted from the light exit surfaces 41b, 42b, 43b of the light-guiding elements 41, 42, 43, while allowing the colored lights LB, LG, LB to efficiently enter the illumination regions 30R, 30G, 30B. Therefore, according to the projector 104 of this embodiment, by providing the illumination optical system 114, it is possible to further improve the light utilization efficiency.

[0100] In this embodiment, an example has been given in which the relay optical system 27 is arranged in each of the first light-guiding element 41, the second light-guiding element 42, and the third light-guiding element 43, but the relay optical system 27 may also be arranged on the light exit surface side of at least one of the first light-guiding element 41, the second light-guiding element 42, and the third light-guiding element 43.

[0101] (Fifth embodiment) Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the first embodiment, and only the configuration of the illumination optical system differs from that of the first embodiment, so a description of the common parts will be omitted.

[0102] FIG. 9 is a diagram showing a schematic configuration of the projector of this embodiment. As shown in FIG. 9, a projector 105 of this embodiment includes a light source device 2, one liquid crystal panel 3, an illumination optical system 115, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0103] The illumination optical system 115 of this embodiment has a plurality of collimating optical systems 24 , a lens integrator 25 , a polarization conversion unit 26 , a plurality of superimposing lenses 28 , and a plurality of field lenses 29 .

[0104] A plurality of collimating optical systems 24 are provided for each of the light sources 21, 22, and 23. Each collimating optical system 24 is composed of a pair of convex lenses 24a and 24b. Each collimating optical system 24 collimates the light emitted from the corresponding light source and guides the collimated light to the lens integrator 25.

[0105] The lens integrator 25 includes a first multi-lens array 25a and a second multi-lens array 25b. The first multi-lens array 25a includes a plurality of first small lenses for dividing the color light LR, LG, and LB into a plurality of partial beams. The lens surfaces of the first multi-lens array 25a are conjugate with the illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3. Therefore, the shape of each of the first small lenses is substantially similar (rectangular) to the shape of the illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3. This allows the partial beams emitted from the first multi-lens array 25a to efficiently enter the illumination areas 30R, 30G, and 30B, respectively.

[0106] The second multi-lens array 25b has a plurality of second small lenses corresponding to the plurality of first small lenses of the first multi-lens array 25a. The second multi-lens array 25b, together with the superimposing lens 28, forms images of the first small lenses of the first multi-lens array 25a in the illumination areas 30R, 30G, and 30R of the liquid crystal panel 3.

[0107] In this embodiment, the first multi-lens array 25a and the second multi-lens array 25b that constitute the lens integrator 25 have an integrated configuration, but the first multi-lens array 25a and the second multi-lens array 25b may also be divided into areas corresponding to each collimating optical system 24.

[0108] The polarization conversion unit 26 is composed of a plurality of polarization conversion elements 26R, 26G, and 26B. The polarization conversion elements 26R, 26G, and 26B are provided corresponding to the color lights LR, LG, and LB emitted from the second multi-lens array 25b. The red light LR emitted from the second multi-lens array 25b is incident on the polarization conversion element 26R, the green light LG emitted from the second multi-lens array 25b is incident on the polarization conversion element 26G, and the blue light LB emitted from the second multi-lens array 25b is incident on the polarization conversion element 26B.

[0109] The polarization conversion elements 26R, 26G, and 26B have the same configuration and are configured by arranging polarization separation films and retardation plates (1 / 2 retardation plates) in an array. Each polarization conversion element 26R, 26G, and 26B converts the polarization direction of the corresponding color light LR, LG, and LB into a predetermined direction and aligns them. More specifically, the polarization conversion elements 26R, 26G, and 26B are aligned with the direction of the transmission axis of the incident-side polarizer disposed on the light incident side of the liquid crystal panel 3. As a result, the polarization directions of the colored light LR, LG, and LB correspond to the transmission axis directions of the incident-side polarizer of the liquid crystal panel 3. Therefore, the colored light LR, LG, and LB are not blocked by the incident-side polarizer, and are properly guided to the illumination regions 30R, 30G, and 30B of the image forming region 30 of the liquid crystal panel 3.

[0110] Each of the color lights LR, LG, and LB that have passed through the polarization conversion unit 26 is incident on the corresponding superimposing lens 28. The superimposing lens 28 cooperates with the lens integrator 25 to homogenize the illuminance distribution in each of the illumination areas 30R, 30G, and 30R of the image forming area 30 of the liquid crystal panel 3.

[0111] The plurality of field lenses 29 are provided to form pairs with the plurality of superimposing lenses 28. Each field lens 29 is provided opposite a corresponding illumination region 30R, 30G, 30B of the image forming region 30 of the liquid crystal panel 3. Therefore, the color lights LR, LG, LB emitted from the superimposing lens 28 are efficiently incident on each illumination region 30R, 30G, 30B via the field lens 29.

[0112] As described above, the illumination optical system 115 of this embodiment is equipped with the lens integrator 25, polarization conversion unit 26, superimposing lens 28, and field lens 29, and therefore has a higher light utilization efficiency of the light source device 2 than the illumination optical system 16 having a reflective polarizing element 16a as in the third embodiment, and can uniformly illuminate the respective color lights LR, LG, and LB emitted from the light source device 2 to the respective illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3.

[0113] Therefore, according to the projector 105 of this embodiment, by providing an illumination optical system 115, it is possible to further improve light utilization efficiency while uniformly illuminating the image forming area 30 of the liquid crystal panel 3, thereby projecting bright, high-quality images.

[0114] In the projector 105 of this embodiment, laser light sources that emit linearly polarized light may be used as the light sources 21, 22, and 23 of the light source device 2. In this case, as shown in Fig. 10, the color light LR, LG, and LB emitted from the light sources 21, 22, and 23 are incident on the diffusion element 19 in a condensed state, and the color light LR, LG, and LB emitted from the diffusion element 19 in a diffused state are collimated by the collimating optical system 24 and are incident on the lens integrator 25.

[0115] With this configuration, even when laser light sources are used as the light sources 21, 22, and 23, the generation of speckle noise can be suppressed by diffusing the colored light LR, LG, and LB made of laser light. Note that the diffusion element 19 may be a fixed type, or may have a rotating structure that is rotated by a drive device such as a motor. Furthermore, by using laser light as the colored light LR, LG, and LB, a projector that can project images with a wide color reproduction range can be realized.

[0116] (Sixth embodiment) A sixth embodiment of the present invention will be described below with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the first embodiment, but the configurations of the light source device and illumination optical system are different from those of the first embodiment, so a description of the common parts will be omitted.

[0117] FIG. 11 is a diagram showing a schematic configuration of a projector according to this embodiment. As shown in FIG. 11, the projector 106 of this embodiment includes a light source device 116, one liquid crystal panel 3, an illumination optical system 117, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0118] The light source device 116 of this embodiment has a first light source 21 that emits red light LR, a second light source 22 that emits green light LG, a third light source 23 that emits blue light LB, a plurality of collimating optical systems 24 that collimate the color lights LR, LG, and LB, and a second combining optical system 60.

[0119] For example, a cross dichroic prism is used for the second combining optical system 60. The second combining optical system 60 combines the colored light LR, LG, and LB that are collimated by the collimating optical system 24 and incident from three different directions, and emits the white illumination light WL toward the illumination optical system 117 located on the +Z side.

[0120] The illumination optical system 117 of this embodiment includes a lens integrator 61, a polarization conversion element 62, a plurality of superimposing lenses 63a to 63f, a plurality of field lenses 64a to 64c, a plurality of mirrors 65a and 65b, and a light separation element 66.

[0121] The lens integrator 61 has a first multi-lens array 61a and a second multi-lens array 61b. The lens integrator 61 of this embodiment has the same configuration and function as the lens integrator 25 of the fifth embodiment, and therefore detailed description thereof will be omitted. The polarization conversion element 62 has the same configuration and function as the polarization conversion elements 26R, 26G, and 26B of the polarization conversion unit 26 of the fifth embodiment, and therefore detailed description thereof will be omitted.

[0122] The illumination light WL emitted from the polarization conversion element 62 passes through a superimposing lens 63a and enters the light separation element 66. For example, a cross dichroic prism is used as the light separation element 66. The light separation element 66 separates the illumination light WL into red light LR, green light LG, and blue light LB.

[0123] The red light LR reflected to the +Y side by the light separation element 66 is reflected to the +Z side by the mirror 65b and passes through the superimposing lens 63d and the field lens 64a to illuminate the first illumination area 30R of the image forming area 30 of the liquid crystal panel 3 with a uniform illuminance distribution.

[0124] The blue light LB reflected to the -Y side by the light separation element 66 is reflected to the +Z side by the mirror 65a and passes through the superimposing lens 63d and the field lens 64c to illuminate the third illumination area 30B of the image forming area 30 of the liquid crystal panel 3 with a uniform illuminance distribution.

[0125] The green light LG transmitted through the light separating element 66 can efficiently illuminate the second illumination area 30G of the image forming area 30 of the liquid crystal panel 3 with a uniform illuminance distribution via the superimposing lens 63e and the field lens 64b.

[0126] In the illumination optical system 117 of this embodiment, illumination light WL, which is a combination of the color lights LR, LG, and LB, is incident from the light source device 116, so the size of the lens integrator 61, which is made up of the first multi-lens array 61a and the second multi-lens array 61b, and the polarization conversion element 62 can be made smaller than in the configuration of the fifth embodiment. In particular, since the polarization conversion element 62, which is costly, can be made smaller, the cost reduction effect can be enhanced.

[0127] Therefore, according to the projector 106 of this embodiment, by providing the illumination optical system 117, it is possible to suppress an increase in the size of the device configuration and further improve the light utilization efficiency, and by uniformly illuminating the image forming area 30 of the liquid crystal panel 3, it is possible to realize a projector that projects bright, high-quality images at low cost.

[0128] (Seventh embodiment) A seventh embodiment of the present invention will be described below with reference to the drawings. The basic configuration of the projector of this embodiment is the same as that of the sixth embodiment, and only the configuration of the light source device differs from that of the sixth embodiment, so a description of the common parts will be omitted.

[0129] FIG. 12 is a diagram showing a schematic configuration of the projector of this embodiment. As shown in FIG. 12, the projector 107 of this embodiment includes a light source device 118, one liquid crystal panel 3, an illumination optical system 117, a first combining optical system 5, a projection optical device 6, and a control unit 10.

[0130] The light source device 118 of this embodiment has a light source 20, a wavelength conversion element 123, a diffuser plate 124, a light separation / combination element 125, a first phase difference element 126, a second phase difference element 127, a first focusing optical system 120, a second focusing optical system 121, and a third focusing optical system 122.

[0131] The light source 20 is configured with a laser light emitting element, and emits blue light B made of laser light in the blue wavelength band of 400 nm to 500 nm, for example, as the first light in the first wavelength band.

[0132] The first light-collecting optical system 120 is composed of, for example, multiple convex lenses and collimates the blue light B emitted from the light source 20. The blue light B collimated by the first light-collecting optical system 120 enters the first phase difference element 126. The first phase difference element 126 is disposed on the optical path of the blue light B between the light source 20 and the light separating / combining element 125. The first phase difference element 126 is, for example, a rotatable half-wave plate. The blue light B emitted from the light source 20 is linearly polarized light. By appropriately setting the rotation angle of the first phase difference element 126, the blue light B passing through the first phase difference element 126 can be converted into light containing an S-polarized component and a P-polarized component relative to the light separating / combining element 125 at a predetermined ratio. By rotating the first phase difference element 126, the ratio of the S-polarized component to the P-polarized component can be changed. That is, the first phase difference element 126 divides the blue light B from the light source 20 into an S-polarized component and a P-polarized component.

[0133] The light separating / combining element 125 is disposed at an angle of 45° with respect to the optical axis of the blue light B and the optical axis of the fluorescence YL. The light separating / combining element 125 has a polarization separation function that separates the blue light B into a light ray B1 having an S-polarized component and a light ray B2 having a P-polarized component relative to the light separating / combining element 125. The light separating / combining element 125 is formed, for example, by a plate-type polarization separation element. Furthermore, the light separating / combining element 125 has a color separating function that transmits the fluorescence YL, which has a different wavelength band from the blue light B, regardless of its polarization state. As a result, the light separating / combining element 125 functions as a combining means that combines a portion of the blue light B with the fluorescence YL, as will be described later.

[0134] Light separating / combining element 125 reflects light ray B1, which is an S-polarized component that is part of blue light B distributed by first phase difference element 126, and emits it toward wavelength conversion element 123, and transmits light ray B2, which is another part of blue light B, and emits it toward diffuser plate 124. S-polarized light ray B1 emitted from light separating / combining element 125 is incident on second condensing optical system 121. Second condensing optical system 121 is composed of, for example, multiple convex lenses, and condenses light ray B1 toward wavelength conversion element 123.

[0135] The wavelength conversion element 123 includes a phosphor that is excited by absorbing the light ray B1. The phosphor included in the wavelength conversion element 123 converts the wavelength of the light ray B2, thereby generating and emitting fluorescence (fourth light) YL having a wavelength band of, for example, 500 to 700 nm. In this embodiment, the wavelength conversion element 123 converts the wavelength of the light ray B1, which is a part of the blue light B, to generate fluorescence YL having a wavelength band different from that of the blue light B. The fluorescence YL is light in a yellow wavelength band that includes a green wavelength band (second wavelength band) and a red wavelength band (third wavelength band).

[0136] The fluorescence YL emitted from the wavelength conversion element 123 is unpolarized light. After passing through the second light collection optical system 121, the fluorescence YL is incident on the light separation / combination element 125. The fluorescence YL passes through the light separation / combination element 125 and travels toward the illumination optical system 117.

[0137] On the other hand, light ray B2, which is a P-polarized component of blue light B emitted from light separating / combining element 125, is incident on second phase difference element 127. Second phase difference element 127 is made up of a quarter-wave plate arranged in the optical path between light separating / combining element 125 and diffuser 124. Therefore, P-polarized light ray B2 emitted from light separating / combining element 125 is converted by second phase difference element 127 into, for example, right-handed circularly polarized blue light B2c1, and then incident on third condensing optical system 122. Third condensing optical system 122 is made up of, for example, a pair of convex lenses, and condenses blue light B2c1 and causes it to be incident on diffuser 124.

[0138] The diffuser 124 is disposed on the opposite side of the wavelength conversion element 123 in the light separation / combining element 125, and diffuses and reflects the blue light B2c1 emitted from the third light collection optical system 122 toward the light separation / combining element 125. It is preferable to use a diffuser 124 that performs Lambertian reflection on the blue light B2c1 without disturbing the polarization state. Note that the diffuser 124 may be configured to rotate a circular diffuse reflection plate.

[0139] Hereinafter, the light diffused and reflected by the diffuser 124 will be referred to as blue light B2c2. According to this embodiment, blue light B2c2 with a substantially uniform illuminance distribution is obtained by diffusing and reflecting blue light B2c1. For example, right-handed circularly polarized blue light B2c1 is reflected as left-handed circularly polarized blue light B2c2. The blue light B2c2 is converted into parallel light by the third focusing optical system 122 and then enters the second phase difference element 127 again.

[0140] The left-handed circularly polarized blue light B2c2 is converted into S-polarized blue light B3 by the second phase difference element 127. The S-polarized blue light B3 is reflected by the light separating / combining element 125 and reflected toward the illumination optical system 117.

[0141] The light separating / combining element 125 emits, in the same direction, the blue light B3 (another part of the first light emitted from the light source) incident from the diffuser 124 and the fluorescence YL incident from the wavelength converting element 123. Therefore, the blue light B3 and the fluorescence YL are combined by the light separating / combining element 125 to generate white illumination light (combined light) WL1.

[0142] The illumination optical system 117 separates the illumination light WL1 incident from the light source device 118 into red light LR, green light LG, and blue light LB, and illuminates each of the color lights LR, LG, and LB onto the illumination areas 30R, 30G, and 30B of the image forming area 30 of the liquid crystal panel 3 with a uniform illuminance distribution.

[0143] According to the projector 107 of this embodiment, the light source device 118 can be configured with one light source 20, which simplifies the configuration and reduces the power consumption of the light source device 118, thereby achieving energy savings. Furthermore, according to the projector 107 of this embodiment, even when using a light source device 118 that emits illumination light WL1 containing fluorescence YL, by combining it with the illumination optical system 117, it is possible to prevent the device configuration from becoming larger and further improve light utilization efficiency, and to realize a projector that projects bright, high-quality images by uniformly illuminating the image forming area 30 of the liquid crystal panel 3.

[0144] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, when displaying composite image A in image forming area 30 of liquid crystal panel 3, vertical scanning is performed along the short side direction of image forming area 30, but liquid crystal panel 3 may also be controlled to perform vertical scanning along the long side direction of image forming area 30.

[0145] In addition, the specific descriptions of the shape, number, arrangement, material, etc. of each component of the light source device and projector are not limited to the above-described embodiments and can be changed as appropriate.

[0146] A summary of this disclosure is provided below.

[0147] (Appendix 1) a light source device that emits first light in a first wavelength band, second light in a second wavelength band different from the first wavelength band, and third light in a third wavelength band different from the first wavelength band and the second wavelength band; a liquid crystal panel having a rectangular image forming area, which modulates the first light, the second light, and the third light to generate first modulated light, second modulated light, and third modulated light, respectively; an illumination optical system that causes the first light, the second light, and the third light emitted from the light source device to be incident on different positions in the image forming area of ​​the one liquid crystal panel; a first combining optical system that combines the first modulated light, the second modulated light, and the third modulated light emitted from the one liquid crystal panel; a projection optical device that projects the combined modulated light combined by the first combining optical system, In the first combining optical system, the air-equivalent optical path length of the first light, the air-equivalent optical path length of the second light, and the air-equivalent optical path length of the third light, which are emitted from the one liquid crystal panel and reach the projection optical device, are equal to one another. or In the first combining optical system, a first optical path length from an image formed by focusing the first modulated light emitted from the one liquid crystal panel to the projection optical device, a second optical path length from an image formed by focusing the third modulated light emitted from the one liquid crystal panel to the projection optical device, and a third optical path length from the one liquid crystal panel to the projection optical device of the second modulated light emitted from the one liquid crystal panel are all equal to one another. A projector characterized by:

[0148] A projector with this configuration can generate three-color modulated light without using color filters because it modulates the first, second, and third light beams incident on the image formation area of ​​a single liquid crystal panel. This eliminates the loss caused by color filters, making it possible to efficiently utilize the light emitted from the light source device and project bright, full-color modulated light. This configuration therefore provides a single-panel projector that can improve the light utilization efficiency of the light source device. Furthermore, because this projector employs a single-panel system, it eliminates the need for an alignment process for multiple liquid crystal panels. However, with conventional three-panel projectors, different types of LCD panels were required depending on their position relative to the cross dichroic prism, which required the use of two different types of LCD panels, potentially increasing costs.With this configuration, only one type of LCD panel is required, eliminating this problem. Furthermore, in a projector with this configuration, the air-equivalent optical path lengths of the modulated light beams emitted from the liquid crystal panel and reaching the projection optical device are all equal, or the first optical path length from the image of the first modulated light to the projection optical device, the second optical path length from the image of the third modulated light to the projection optical device, and the third optical path length of the second modulated light from the liquid crystal panel to the projection optical device are all equal, so that the modulated light beams emitted from the image forming area of ​​the liquid crystal panel can be well focused.As a result, a projector with this configuration can project a high-quality color image with little blur onto the projection surface.

[0149] (Appendix 2) In the image forming area of ​​the one liquid crystal panel, a first illumination area illuminated with the first light, a second illumination area illuminated with the second light, and a third illumination area illuminated with the third light are arranged along a long side direction of the image forming area. 2. The projector according to claim 1,

[0150] This configuration allows each color to be efficiently incident on each illumination area in the image forming area of ​​one liquid crystal panel, thereby generating corresponding modulated light in each illumination area.

[0151] (Appendix 3) the image forming area is made up of a plurality of pixels, the first illumination area and the second illumination area are spaced apart by at least one pixel, The second illumination area and the third illumination area are spaced apart by at least one pixel. 3. The projector according to claim 2.

[0152] With this configuration, two adjacent color images in the composite image are spaced apart by at least one pixel, so that light emitted from each color image can be efficiently incident on an optical system located after the liquid crystal panel.

[0153] (Appendix 4) The first synthesis optical system is a first prism through which the first modulated light emitted from the one liquid crystal panel passes; a second prism through which the third modulated light emitted from the one liquid crystal panel passes; a first bending prism that bends the optical path of the first modulated light that has passed through the first prism; a second bending prism that bends the optical path of the third modulated light that has passed through the second prism; a light combining prism that combines the first modulated light emitted from the first bending prism, the third modulated light emitted from the second bending prism, and the second modulated light emitted from the one liquid crystal panel. 4. The projector according to claim 1, wherein the first and second projections are arranged in a plane parallel to each other.

[0154] According to this configuration, the first combining optical system can combine the first modulated light, the second modulated light, and the third modulated light emitted from the image forming area of ​​one liquid crystal panel.

[0155] (Appendix 5) The first synthesis optical system is a first polarizing element that bends the optical path of the first modulated light emitted from the one liquid crystal panel; a second polarizing element that bends the optical path of the third modulated light emitted from the one liquid crystal panel; a first imaging element that reflects the first modulated light incident from the first polarizing element and forms an image of the first modulated light that has passed through the first polarizing element; a second imaging element that reflects the third modulated light incident from the second polarizing element and forms an image of the second modulated light that has passed through the second polarizing element; a light combining prism that combines the first modulated light emitted from the first imaging element, the third modulated light emitted from the second imaging element, and the second modulated light emitted from the one liquid crystal panel, 4. The projector according to claim 1, wherein the first and second projections are arranged in a plane parallel to each other.

[0156] According to this configuration, in the first combining optical system, it is possible to realize a configuration in which the first optical path length from the image of the first modulated light emitted from one liquid crystal panel to the projection optical device, the second optical path length from the image of the third modulated light emitted from one liquid crystal panel to the projection optical device, and the third optical path length of the second modulated light emitted from one liquid crystal panel from one liquid crystal panel to the projection optical device are all equal to each other. Therefore, it is possible to provide a projector that projects a high-quality color image with little blur onto a projection surface such as a screen.

[0157] (Appendix 6) the light source device includes a first light source that emits the first light, a second light source that emits the second light, and a third light source that emits the third light, the illumination optical system comprises: a first light guide element having a first light incident surface onto which the first light emitted from the first light source is incident and a first light exit surface from which the first light is exited, and which uniforms the illuminance of the first illumination area in the image forming area where the first light is illuminated; a second light guide element having a second light incident surface onto which the second light emitted from the second light source is incident and a second light exit surface from which the second light is exited, and which uniforms the illuminance of the second illumination area in the image forming area where the second light is illuminated; and a third light guide element having a third light incident surface onto which the third light emitted from the third light source is incident and a third light exit surface from which the third light is exited, and which uniforms the illuminance of the third illumination area in the image forming area where the third light is illuminated. 4. The projector according to claim 2 or 3.

[0158] According to this configuration, the first, second, and third light guide elements of the illumination optical system can uniformly illuminate the illumination areas of the image forming area of ​​the liquid crystal panel.

[0159] (Appendix 7) the illumination optical system includes a reflective polarizing element that is disposed at at least one of a position on the light exit side of the first light guide element, a position on the light exit side of the second light guide element, and a position on the light exit side of the third light guide element, and that transmits first polarized light and reflects second polarized light different from the first polarized light toward the corresponding light guide element; 7. The projector according to claim 6,

[0160] This configuration allows the polarization direction of light incident on the liquid crystal panel to be aligned in one direction. Since the polarization direction of each light is aligned in this way, loss due to the incident-side polarizer of the liquid crystal panel can be reduced, improving light utilization efficiency. Furthermore, since linearly polarized light can be incident on the liquid crystal panel, the incident-side polarizer of the liquid crystal panel can be omitted.

[0161] (Appendix 8) the illumination optical system includes a relay optical system that is arranged at at least one position of a light exit side of the first light guide element, a position of the light exit side of the second light guide element, and a position of the light exit side of the third light guide element, and that forms an image of the light exited from the corresponding light guide element on the image formation area. 7. The projector according to claim 6,

[0162] According to this configuration, by providing a relay optical system, it is possible to reduce uneven illuminance caused by the light emitted from the light exit surface of each light guide element, while allowing each light to efficiently enter the image formation area. Therefore, with a projector having this configuration, by providing an illumination optical system using a relay optical system, it is possible to further improve light utilization efficiency.

[0163] (Appendix 9) the light source device includes a first light source that emits the first light, a second light source that emits the second light, and a third light source that emits the third light, the illumination optical system includes a first multi-lens array onto which the first light emitted from the first light source, the second light emitted from the second light source, and the third light emitted from the third light source are incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, and a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array. 5. The projector according to claim 1, wherein the first and second projections are arranged in a plane parallel to each other.

[0164] With this configuration, the light utilization efficiency of the light source device is higher than that of an illumination optical system using a reflective polarizing element, and the light emitted from the light source device can uniformly illuminate the image formation area of ​​the liquid crystal panel.

[0165] (Appendix 10) at least one of the first light source, the second light source, and the third light source is a laser light source that emits linearly polarized light, the illumination optical system is disposed between the laser light source and the first multi-lens array and includes a diffusion element that diffuses incident light. 10. The projector according to claim 9,

[0166] With this configuration, even when using a laser light source, the occurrence of speckle noise can be suppressed by diffusing each light component of the laser light.In addition, by using laser light as each light component, a projector that can project images with a wide color reproduction range can be realized.

[0167] (Appendix 11) the light source device includes a first light source that emits the first light, a second light source that emits the second light, a third light source that emits the third light, and a second combining optical system that combines the first light emitted from the first light source, the second light emitted from the second light source, and the third light emitted from the third light source, the illumination optical system includes a first multi-lens array onto which the combined light emitted from the second combining optical system is incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array, and a light separation element that separates the light emitted from the polarization conversion element into the first light, the second light, and the third light. 5. The projector according to claim 1, wherein the first and second projections are arranged in a plane parallel to each other.

[0168] With this configuration, the light generated by combining three beams of light from the light source device enters the illumination optical system, allowing the lens integrator consisting of the first and second multi-lens arrays and the polarization conversion element to be made smaller. This allows the polarization conversion element, which is particularly costly, to be made smaller, further reducing costs. A projector with this configuration prevents the device configuration from becoming larger, further improving light utilization efficiency, and can project bright, high-quality images by uniformly illuminating the image formation area of ​​the liquid crystal panel, all at low cost.

[0169] (Appendix 12) the light source device includes a light source that emits the first light, a wavelength conversion element that converts the first light into fourth light including the second wavelength band and the third wavelength band, and a light separation / combining element that separates a portion of the first light emitted from the light source toward the wavelength conversion element and combines the fourth light emitted from the wavelength conversion element with another portion of the first light emitted from the light source, the illumination optical system includes a first multi-lens array onto which the combined light emitted from the light separating / combining element is incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array, and a light separating element that separates the light emitted from the polarization conversion element into the first light, the second light, and the third light; 5. The projector according to claim 1, wherein the first and second projections are arranged in a plane parallel to each other.

[0170] According to this configuration, the light source device can be configured with only one light source, which simplifies the configuration and reduces the power consumption of the light source device, thereby achieving energy savings. Furthermore, when using a light source device that emits light including the fourth light, which is wavelength-converted light, it is possible to prevent the device configuration from becoming too large and further improve light utilization efficiency, and to realize a projector that projects bright, high-quality images by uniformly illuminating the image formation area of ​​the liquid crystal panel. [Explanation of symbols]

[0171] 1,102,103,104,105,106,107...Projector, 2,116,118...Light source device, 3...Liquid crystal panel, 4,16,114,115,117...Illumination optical system, 5,15...First combining optical system, 6...Projection optical device, 16a...Reflective polarizing element, 19...Diffusion element, 20...Light source, 21...First light source, 22...Second light source, 23...Third light source, 25a,61a...First multi-lens array, 25b,61b...Second multi-lens array Lens array, 26B, 26G, 26R, 62...polarization conversion element, 27...relay optical system, 30...image forming region, 30B...third illumination region, 30G...second illumination region, 30P...pixel, 30R...illumination region, 30R...first illumination region, 41...first light guide element, 41a...first light incident surface, 41b...first light exit surface, 41c...side surface, 42...second light guide element, 42a...second light incident surface, 42b...second light exit surface, 42c...side surface, 43...third light guide element, 43a...third light incident surface, 43b...third light exit surface, 43c...side surface, 51...first prism, 52...second prism, 53...first bending prism, 54...second bending prism, 55...light combining prism, 60...second combining optical system, 66...light separation element, 123...wavelength conversion element, 125...light separation / combination element, 150...first polarizing element, 151...second polarizing element, 152...first imaging element, 153...second imaging element, A...composite image, BB1...blue color shift Dimming (third modulated light), BS, GS, RS...air-equivalent optical path length, BS2...second optical path length, BZ, RZ...image, GG1...green modulated light (second modulated light), GS2...third optical path length, I, I2...modulated light (composite modulated light), RR1...red modulated light (first modulated light), RS2...first optical path length, WL, WL1...illumination light, WL1...illumination light (composite light), LR...red light (first light), LG...green light (second light), LB...blue light (third light), YL...fluorescence (fourth light).

Claims

1. a light source device that emits first light in a first wavelength band, second light in a second wavelength band different from the first wavelength band, and third light in a third wavelength band different from the first wavelength band and the second wavelength band; a liquid crystal panel having a rectangular image forming area, the liquid crystal panel modulating the first light, the second light, and the third light to generate first modulated light, second modulated light, and third modulated light, respectively; an illumination optical system that causes the first light, the second light, and the third light emitted from the light source device to be incident on different positions in the image forming area of ​​the one liquid crystal panel; a first combining optical system that combines the first modulated light, the second modulated light, and the third modulated light emitted from the one liquid crystal panel; a projection optical device that projects the combined modulated light combined by the first combining optical system, In the first combining optical system, the air-equivalent optical path lengths of the first modulated light, the second modulated light, and the third modulated light, which are emitted from the one liquid crystal panel and reach the projection optical device, are equal to one another. or In the first combining optical system, a first optical path length from an image formed by focusing the first modulated light emitted from the one liquid crystal panel to the projection optical device, a second optical path length from an image formed by focusing the third modulated light emitted from the one liquid crystal panel to the projection optical device, and a third optical path length from the one liquid crystal panel to the projection optical device of the second modulated light emitted from the one liquid crystal panel are all equal to each other. A projector characterized by:

2. In the image forming area of ​​the one liquid crystal panel, a first illumination area illuminated with the first light, a second illumination area illuminated with the second light, and a third illumination area illuminated with the third light are arranged along a long side direction of the image forming area.

2. The projector according to claim 1.

3. the image forming area is made up of a plurality of pixels, the first illumination area and the second illumination area are spaced apart by at least one pixel, The second illumination area and the third illumination area are spaced apart by at least one pixel.

3. The projector according to claim 2.

4. The first synthesis optical system is a first prism through which the first modulated light emitted from the one liquid crystal panel passes; a second prism through which the third modulated light emitted from the one liquid crystal panel passes; a first bending prism that bends the optical path of the first modulated light that has passed through the first prism; a second bending prism that bends the optical path of the third modulated light that has passed through the second prism; a light combining prism that combines the first modulated light emitted from the first bending prism, the third modulated light emitted from the second bending prism, and the second modulated light emitted from the one liquid crystal panel.

4. The projector according to claim 1, wherein the light source is a light source.

5. The first synthesis optical system is a first deflection element that bends an optical path of the first modulated light emitted from the one liquid crystal panel; a second deflection element that bends an optical path of the third modulated light emitted from the one liquid crystal panel; a first imaging element that reflects the first modulated light emitted from the first deflection element and forms an image of the first modulated light; a second imaging element that reflects the third modulated light emitted from the second deflection element and forms an image of the second modulated light; a light combining prism that combines the first modulated light emitted from the first imaging element, the third modulated light emitted from the second imaging element, and the second modulated light emitted from the one liquid crystal panel.

4. The projector according to claim 1, wherein the light source is a light source.

6. the light source device includes a first light source that emits the first light, a second light source that emits the second light, and a third light source that emits the third light, the illumination optical system comprises: a first light guide element having a first light incident surface onto which the first light emitted from the first light source is incident and a first light exit surface from which the first light is exited, and which uniforms the illuminance of the first illumination area in the image forming area illuminated with the first light; a second light guide element having a second light incident surface onto which the second light emitted from the second light source is incident and a second light exit surface from which the second light is exited, and which uniforms the illuminance of the second illumination area in the image forming area illuminated with the second light; and a third light guide element having a third light incident surface onto which the third light emitted from the third light source is incident and a third light exit surface from which the third light is exited, and which uniforms the illuminance of the third illumination area in the image forming area illuminated with the third light.

4. The projector according to claim 2 or 3.

7. the illumination optical system includes a reflective polarizing element that is disposed at at least one of a position on a light exit side of the first light guide element, a position on the light exit side of the second light guide element, and a position on the light exit side of the third light guide element, and that transmits a first polarized light and reflects a second polarized light different from the first polarized light toward a corresponding light guide element; 7. The projector according to claim 6.

8. the illumination optical system includes a relay optical system that is arranged at at least one position of a light exit side of the first light guide element, a position of the light exit side of the second light guide element, and a position of the light exit side of the third light guide element, and that forms an image of the light exited from the corresponding light guide element on the image forming area.

7. The projector according to claim 6.

9. the light source device includes a first light source that emits the first light, a second light source that emits the second light, and a third light source that emits the third light, the illumination optical system includes a first multi-lens array onto which the first light emitted from the first light source, the second light emitted from the second light source, and the third light emitted from the third light source are incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, and a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array.

4. The projector according to claim 1, wherein the light source is a light source.

10. at least one of the first light source, the second light source, and the third light source is configured as a laser light source that emits linearly polarized light, the illumination optical system includes a diffusion element disposed between the laser light source and the first multi-lens array and diffusing incident light; 10. The projector according to claim 9.

11. the light source device includes a first light source that emits the first light, a second light source that emits the second light, a third light source that emits the third light, and a second combining optical system that combines the first light emitted from the first light source, the second light emitted from the second light source, and the third light emitted from the third light source, the illumination optical system includes a first multi-lens array onto which the combined light emitted from the second combining optical system is incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array, and a light separation element that separates the light emitted from the polarization conversion element into the first light, the second light, and the third light; 4. The projector according to claim 1, wherein the light source is a light source.

12. the light source device includes a light source that emits the first light, a wavelength conversion element that converts the first light into fourth light including the second wavelength band and the third wavelength band, and a light separation / synthesis element that separates a portion of the first light emitted from the light source toward the wavelength conversion element and combines the fourth light emitted from the wavelength conversion element with another portion of the first light emitted from the light source, the illumination optical system includes a first multi-lens array onto which the combined light emitted from the light separating / combining element is incident, a second multi-lens array onto which the light emitted from the first multi-lens array is incident, a polarization conversion element that aligns the polarization direction of the light emitted from the second multi-lens array, and a light separating element that separates the light emitted from the polarization conversion element into the first light, the second light, and the third light; 4. The projector according to claim 1, wherein the light source is a light source.

Images