projector

Abstract

This projector offers superior light utilization efficiency and eliminates color breakup. [Solution] The projector of the present invention comprises an image generation unit having a first image generation region for generating first image light in a first wavelength band and a second image generation region for generating second image light in a second wavelength band; an integrator optical system for superimposing and imaging the first image light and the second image light emitted from the image generation unit to generate an intermediate image; and a projection optical device for projecting the intermediate image onto the projection surface. The back focus position of the projection optical device coincides with the position of the intermediate image. The first image generation region and the second image generation region are arranged in the same plane along a second direction perpendicular to the first direction, which is the emission direction of the first image light and the second image light.

Description

Technical Field

[0001] The present invention relates to a projector.

Background Art

[0002] Conventionally, a projector capable of projecting a color image using only one light modulation element has been known. Patent Document 1 below discloses a projector including a light source such as a high-pressure mercury lamp, a liquid crystal panel that modulates light from the light source, a color filter that is disposed corresponding to each pixel of the liquid crystal panel and selectively transmits any one of blue light, green light, and red light included in the white light from the light source, and a projection lens.

[0003] Patent Document 2 below discloses a field sequential color type projector including a light source having a light emitting element that emits blue light, a light emitting element that emits green light, and a light emitting element that emits red light, a liquid crystal panel that modulates light from the light source, and a projection lens.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the above two projectors have different color image display methods using a single liquid crystal panel and have the following problems respectively.

[0006] In the case of the projector described in Patent Document 1, at each pixel of the liquid crystal panel, light in a specific wavelength range from the white light emitted from the light source is transmitted through the color filter, while light outside that specific wavelength range is absorbed by the color filter and does not contribute to the display. Therefore, there is a problem in that the utilization efficiency of the light emitted from the light source is low, making it difficult to obtain a bright image. Furthermore, if the brightness of the light source is increased unnecessarily in order to obtain a bright image, there is a risk of deterioration of the color filter.

[0007] In contrast, the projector described in Patent Document 2 displays color images without using a color filter by using a field sequential color method. However, this projector may suffer from a color breakup phenomenon due to the principle of the field sequential method, which could degrade the display quality. [Means for solving the problem]

[0008] To solve the above problems, a projector according to one aspect of the present invention includes an image generation unit having a first image generation region for generating first image light in a first wavelength band and a second image generation region for generating second image light in a second wavelength band different from the first wavelength band; an integrator optical system for superimposing and imaging the first image light and the second image light emitted from the image generation unit to generate an intermediate image; and a projection optical device for projecting the intermediate image onto a projection surface. The back focus position of the projection optical device coincides with the position of the intermediate image. The first image generation region and the second image generation region are arranged in the same plane along a second direction perpendicular to a first direction which is the emission direction of the first image light and the second image light. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the projector according to the first embodiment. [Figure 2] This is a front view of the optical modulation element. [Figure 3]This figure shows another example of a light source device configuration. [Figure 4] This is a schematic diagram of the projector according to the second embodiment. [Figure 5] This figure shows the optical modulation element and the second lens array in the projector of the third embodiment. [Figure 6] This figure shows the optical modulation element and second lens array of the comparative example. [Figure 7] This diagram shows the optical path of leaked light to adjacent lenses. [Figure 8] This is a schematic diagram illustrating the problems with projected images. [Figure 9] This figure shows the optical modulation element and second lens array of the first example of countermeasures. [Figure 10] This figure shows the optical modulation element and second lens array of the second example of countermeasures. [Figure 11] This figure shows the optical modulation element, second lens array, and first lens array of the third example of countermeasures. [Figure 12] This figure shows the image generation unit, second lens array, and first lens array of the fourth countermeasure example. [Figure 13] This is a schematic diagram of the projector according to the fourth embodiment. [Figure 14] This is a schematic diagram of the projector according to the fifth embodiment. [Modes for carrying out the invention]

[0010] [First Embodiment] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Please note that the drawings used in the following explanation may be enlarged for convenience to clearly show the characteristics of each part, and therefore, for example, the dimensional ratios of each component may differ from the actual ones.

[0011] Figure 1 is a schematic diagram of the projector 10 according to the first embodiment. As shown in FIG. 1, the projector 10 of the present embodiment is a projection type image display device that displays a color image on a screen SCR. The projector 10 includes an image generation unit 11, a second lens array 12, an integrator optical system 13 including a first lens array 21, and a projection optical device 14. The image generation unit 11 includes a light source device 15 and a light modulation element 16.

[0012] In the following description, an XYZ orthogonal coordinate system is used. The axis corresponding to the front-rear direction of the projector 10 and along the light emission direction from the light source device 15 is defined as the X-axis, the side where the light travels is the +X side, and the opposite side is the -X side. The axis corresponding to the vertical direction of the projector 10 is defined as the Y-axis, the upper side of the projector 10 is the +Y side, and the lower side is the -Y side. The axis corresponding to the left-right direction of the projector 10 is defined as the Z-axis, the front side of the paper surface is the +Z side, and the back side is the -Z side. The X-axis direction of the present embodiment corresponds to the first direction in the claims. The Y-axis direction of the present embodiment corresponds to the second direction in the claims. Further, an axis passing through the center of the light modulation element 16 and parallel to the optical axis of the projection lens constituting the projection optical device 14 is defined as the system optical axis AX1.

[0013] The light source device 15 includes a red light emitting element 17R, a green light emitting element 17G, a blue light emitting element 17B, and collimator lenses 18R, 18G, 18B. The three light emitting elements are arranged in the order of the red light emitting element 17R, the green light emitting element 17G, and the blue light emitting element 17B from the +Y side to the -Y side along the Y-axis direction. The red light emitting element 17R emits red light R1 in the red wavelength band. The red wavelength band is, for example, a wavelength band of 650 to 770 nm. The green light emitting element 17G emits green light G1 in the green wavelength band. The green wavelength band is, for example, a wavelength band of 490 to 550 nm. The blue light emitting element 17B emits blue light B1 in the blue wavelength band. The blue wavelength band is, for example, a wavelength band of 430 to 490 nm. Each of the red light emitting element 17R, the green light emitting element 17G, and the blue light emitting element 17B is composed of a laser diode (LD). The red light R1 of the present embodiment corresponds to the first light in the first wavelength band of the claims. The green light G1 of the present embodiment corresponds to the second light in the second wavelength band of the claims. The blue light B1 of the present embodiment corresponds to the third light in the third wavelength band of the claims.

[0014] When a laser diode is used for the light emitting element constituting the light source device 15, the projector 10 can project an image with excellent color reproducibility. Further, when a laser diode is used, a diffusion element such as a transmissive diffusion plate for diverging the laser light to equalize the illuminance distribution may be provided on the light emission side of the light source device 15. Note that, instead of the laser diode, a light emitting diode (LED) may be used.

[0015] Collimator lenses 18R, 18G, and 18B are provided corresponding to the red light-emitting element 17R, the green light-emitting element 17G, and the blue light-emitting element 17B, respectively. Collimator lens 18R, positioned opposite the red light-emitting element 17R, parallelizes the red light R1 emitted from the red light-emitting element 17R at a predetermined divergence angle. Collimator lens 18G, positioned opposite the green light-emitting element 17G, parallelizes the green light G1 emitted from the green light-emitting element 17G at a predetermined divergence angle. Collimator lens 18B, positioned opposite the blue light-emitting element 17B, parallelizes the blue light B1 emitted from the blue light-emitting element 17B at a predetermined divergence angle. Each collimator lens 18R, 18G, and 18B is made of a convex lens. In this embodiment, one collimator lens is used for each light-emitting element, but for example, a configuration using multiple collimator lenses to shape each color of light into a rectangular beam may also be used.

[0016] The optical modulation element 16 is located on the light emission side (+X side) of the light source device 15. The optical modulation element 16 modulates each color of light R1, G1, and B1 emitted from the light source device 15 according to image information. The optical modulation element 16 is composed of, for example, a transmissive liquid crystal panel. The liquid crystal panel can be a general type, and detailed illustration is omitted, but it has components such as an element substrate, a liquid crystal layer, a counter substrate, an incident side dustproof glass, and an exit side dustproof glass. The optical modulation element 16 has a plurality of pixels arranged in a matrix in the vertical direction (Y axis direction) and the horizontal direction (Z axis direction).

[0017] Although not shown in the diagram, an incident polarizer is provided between the collimator lenses 18R, 18G, and 18B and the optical modulation element 16. The incident polarizer transmits light having a predetermined polarization direction. In this embodiment, when each light-emitting element 17R, 17G, and 17B is composed of a laser diode, linearly polarized light of each color R1, G1, and B1 is emitted from each light-emitting element 17R, 17G, and 17B. Therefore, if the linear polarization state is sufficiently maintained when the light of each color R1, G1, and B1 is incident on the optical modulation element 16, the incident polarizer may not be necessary.

[0018] Although not shown in the diagram, an exit-side polarizer is provided between the second lens array 12 and the first lens array 21, which will be described later. The exit-side polarizer transmits light having a polarization direction perpendicular to the polarization direction of the incident-side polarizer. If there are space constraints, such as insufficient space to accommodate the polarizer, the exit-side polarizer may be placed on the light exit side of the first lens array 21. In that case, it is desirable to adopt a configuration that suppresses disturbance of the polarization state caused by the optical component, for example, by using quartz as the constituent material of the optical component between the optical modulation element 16 and the exit-side polarizer.

[0019] Figure 2 is a front view of the optical modulation element 16 as seen from the direction along the system optical axis AX1 (+X side). As shown in Figure 2, the optical modulation element 16 has a red image generation region 16R, a green image generation region 16G, and a blue image generation region 16B. Each of the red image generation region 16R, green image generation region 16G, and blue image generation region 16B is one of the regions obtained by dividing the optical modulation element 16 into three regions in the Y-axis direction, and has a rectangular shape. Therefore, the red image generation region 16R, green image generation region 16G, and blue image generation region 16B are arranged in the same plane along the Y-axis direction perpendicular to the emission direction of each image light.

[0020] The dimensions in the Y-axis direction, the Z-axis direction, and the area of ​​the red image generation region 16R, the green image generation region 16G, and the blue image generation region 16B are equal to each other. Furthermore, the number of pixels in the horizontal direction (Z-axis direction) of each image generation region 16R, 16G, and 16B is equal to the number of pixels in the horizontal direction of the liquid crystal panel. The number of pixels in the vertical direction (Y-axis direction) of each image generation region 16R, 16G, and 16B is 1 / 3 of the number of pixels in the vertical direction of the liquid crystal panel. In this embodiment, the red image generation region 16R corresponds to the first image generation region of the claims. In this embodiment, the green image generation region 16G corresponds to the second image generation region of the claims. In this embodiment, the blue image generation region 16B corresponds to the third image generation region of the claims.

[0021] Between the red image generation region 16R and the green image generation region 16G, and between the green image generation region 16G and the blue image generation region 16B, a light-shielding region 16E that does not contribute to image generation is provided. The light-shielding region 16E is provided with a light-shielding film made of a metal such as chromium. The vertical dimension (Y-axis direction) of the light-shielding region 16E is sufficiently smaller than the vertical dimension (Y-axis direction) of each image generation region 16R, 16G, and 16B.

[0022] As shown in Figure 1, the red image generation region 16R is positioned opposite the red light-emitting element 17R. The green image generation region 16G is positioned opposite the green light-emitting element 17G. The blue image generation region 16B is positioned opposite the blue light-emitting element 17B. The red image generation region 16R modulates the red light R1 emitted from the red light-emitting element 17R according to the red image information to generate red image light R2. The green image generation region 16G modulates the green light G1 emitted from the green light-emitting element 17G according to the green image information to generate green image light G2. The blue image generation region 16B modulates the blue light B1 emitted from the blue light-emitting element 17B according to the blue image information to generate blue image light B2. In this embodiment, the red image light R2 corresponds to the first image light in the claims. In this embodiment, the green image light G2 corresponds to the second image light in the claims. In this embodiment, the blue image light B2 corresponds to the third image light in the claims.

[0023] The second lens array 12 is positioned between the image generation unit 11 and the first lens array 21, which will be described later. The second lens array 12 includes a fourth lens 24, a fifth lens 25, and a sixth lens 26. The fourth lens 24, the fifth lens 25, and the sixth lens 26 are arranged along the Y-axis. That is, the second lens array 12 is a lens array in which three lenses are arranged in a row along the Y-axis. The fourth lens 24 guides the red image light R2 emitted from the red image generation region 16R to the first lens 31, which will be described later. The fifth lens 25 guides the green image light G2 emitted from the green image generation region 16G to the second lens 32, which will be described later. The sixth lens 26 guides the blue image light B2 emitted from the blue image generation region 16B to the third lens 33, which will be described later. Each of the fourth lens 24, the fifth lens 25, and the sixth lens 26 is made of a convex lens.

[0024] In this embodiment, the second lens array 12 is positioned in contact with the light-emitting surface of the optical modulation element 16. The second lens array 12 may be positioned away from the light-emitting surface of the optical modulation element 16. The colored light R1, G1, and B1 from each light-emitting element 17R, 17G, and 17B are parallelized by the collimator lenses 18R, 18G, and 18B before being incident on the optical modulation element. However, at the point of emission from the optical modulation element 16, the light may become divergent due to diffraction and other effects within the optical modulation element 16. In contrast, with the configuration of this embodiment, since the second lens array 12 is provided on the light-emitting side of the optical modulation element 16, the divergent image light R2, G2, and B2 of each color are picked up by the second lens array 12 and reliably transmitted to the subsequent first lens array 21. This improves the utilization efficiency of each image light R2, G2, and B2.

[0025] The integrator optical system 13 includes a first lens array 21 and a superimposing lens 22. The integrator optical system 13 superimposes the red image light R2, green image light G2, and blue image light B2 emitted from the image generation unit 11, and forms an image to generate an intermediate image Z.

[0026] The first lens array 21 is located on the light-emitting side of the second lens array 12. That is, the first lens array 21 is located on the light-emitting side of the image generation unit 11. The first lens array 21 has a first lens 31, a second lens 32, and a third lens 33. The first lens 31, the second lens 32, and the third lens 33 are arranged along the Y-axis. In other words, the first lens array 21, like the second lens array 12, is a lens array in which three lenses are arranged in a row along the Y-axis.

[0027] The first lens 31 is positioned opposite the fourth lens 24. The second lens 32 is positioned opposite the fifth lens 25. The third lens 33 is positioned opposite the sixth lens 26. The first lens 31 forms an image of the red image light R2 emitted from the fourth lens 24. The second lens 32 forms an image of the green image light G2 emitted from the fifth lens 25. The third lens 33 forms an image of the blue image light B2 emitted from the sixth lens 26. Each of the first lens 31, the second lens 32, and the third lens 33 is made of a convex lens.

[0028] The superposition lens 22 is positioned on the light emission side of the first lens array 21. The superposition lens 22 superimposes the red image light R2 emitted from the first lens 31, the green image light G2 emitted from the second lens 32, and the blue image light B2 emitted from the third lens 33 at the light incidence side of the projection optical device 14.

[0029] In this way, the first lens array 21 and the superimposing lens 22 superimpose and enlarge the images of the red image generation region 16R, the green image generation region 16G, and the blue image generation region 16B, and generate an intermediate image Z on the light incident side of the projection optical device 14. When the distance from the object plane of the optical modulation element 16 to the main lens plane of the first lens array 21 is A, and the distance from the main lens plane of the first lens array 21 to the intermediate image Z is B, the magnification ratio of the intermediate image Z relative to the images of each image generation region 16R, 16G, and 16B is B / A. The integrator optical system 13 may be composed of a lens group combining multiple lenses that perform the same functions as described above. With this configuration, chromatic aberration can be suppressed and imaging performance can be improved by increasing the number of lenses.

[0030] The projection optical device 14 is positioned on the light output side of the superimposed lens 22. The back focus position of the projection optical device 14 coincides with the position of the intermediate image Z. The projection optical device 14 is composed of multiple projection lenses. The projection optical device 14 magnifies and projects the intermediate image Z generated by the integrator optical system 13 onto the screen SCR. As a result, a full-color image is projected onto the screen SCR.

[0031] [Effects of the First Embodiment] The projector 10 of this embodiment includes an image generation unit 11 that includes an optical modulation element 16 having a red image generation region 16R for generating red image light R2, a green image generation region 16G for generating green image light G2, and a blue image generation region 16B for generating blue image light B2; an integrator optical system 13 that superimposes and images the red image light R2, green image light G2, and blue image light B2 emitted from the image generation unit 11 to generate an intermediate image Z; and a projection optical device 14 that magnifies and projects the intermediate image Z onto a screen SCR. The back focus position of the projection optical device 14 coincides with the position of the intermediate image Z. The red image generation region 16R, the green image generation region 16G, and the blue image generation region 16B are arranged in the same plane along the Y-axis direction perpendicular to the emission direction of each image light R2, G2, and B2.

[0032] In the projector 10 of this embodiment, three light-emitting elements 17R, 17G, and 17B emit three colors of light R1, G1, and B1. Three different image generation regions 16R, 16G, and 16B on a single optical modulation element 16 generate three colors of image light R2, G2, and B2. The integrator optical system 13 then superimposes the three colors of image light R2, G2, and B2 to form an image. The generated intermediate image Z is then magnified and projected by the projection optical device 14 to display a full-color image. This configuration requires only one optical modulation element 16 and eliminates the need for color separation and color synthesis optical systems, resulting in miniaturization of the projector 10, reduction in the number of parts, simplification of the assembly process, and cost reduction. Furthermore, since the field sequential color method is not used, the color breakup problem does not occur in principle. In addition, the optical modulation element 16 does not need to have a color filter, and since there is no light absorption by the color filter, a projector 10 with excellent light utilization efficiency can be realized.

[0033] [Differentiation] Figure 3 shows another example of the configuration of the light source device 30. As shown in Figure 3, the light source device 30 of this modified example comprises a red light-emitting element 17R, a green light-emitting element 17G, a blue light-emitting element 17B, tapered rods 35R, 35G, 35B, and collimator lenses 18R, 18G, 18B. The tapered rods 35R, 35G, 35B are provided in correspondence with the red light-emitting element 17R, the green light-emitting element 17G, and the blue light-emitting element 17B, respectively. The tapered rods 35R, 35G, 35B are made of a translucent material such as glass in the shape of a pyramidal pyramidal cylinder that widens from the incident side to the exit side. Alternatively, instead of tapered rods, an internal reflection mirror with a pyramidal pyramidal cylinder whose inner surface is a reflective surface may be used.

[0034] Collimator lenses 18R, 18G, and 18B are provided on the light-emitting sides of the tapered rods 35R, 35G, and 35B. This shapes the light of each color emitted from each light-emitting element 17R, 17G, and 17B into a rectangular shape and equalizes the illuminance. Furthermore, a reflective polarizer may be provided on the light-emitting side of the tapered rods 35R, 35G, and 35B. With this configuration, the polarization direction can be aligned while retrospectively reflecting each color of light, thereby increasing the utilization efficiency of each color of light.

[0035] [Second Embodiment] A second embodiment of the present invention will be described below with reference to Figure 4. Since the basic configuration of the projector in the second embodiment is the same as in the first embodiment, a description of the basic configuration of the projector will be omitted. Figure 4 is a schematic diagram of the projector 40 according to the second embodiment. In Figure 4, components common to the drawings used in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0036] As shown in Figure 4, the projector 40 of this embodiment includes an image generation unit 11, a second lens array 12, an integrator optical system 13 including a first lens array 21, a field lens 41, and a projection optical device 14.

[0037] The field lens 41 is positioned between the superimposed lens 22 and the intermediate image Z. The field lens 41 refracts at least some of the red image light R2, green image light G2, and blue image light B2 emitted from the superimposed lens 22 in a direction in which the principal rays of the image light approach the optical axis of the superimposed lens 22, i.e., the system optical axis AX1. Therefore, the rays incident on the upper and lower ends of the intermediate image Z are oriented in a direction parallel to the system optical axis AX1 compared to the rays in Figure 4 of the first embodiment. The other configurations of the projector 40 are the same as those of the projector in the first embodiment.

[0038] [Effects of the second embodiment] In this embodiment as well, the same effects as in the first embodiment can be obtained, such as miniaturization of the projector 40, reduction of the number of parts and cost reduction by using only one optical modulation element 16, and a projector 40 with excellent light utilization efficiency because no color breakup occurs and no light absorption occurs by the color filter.

[0039] In this embodiment, since the field lens 41 is provided on the light emission side of the superimposed lens 22, the telecentricity is improved, and each image light R2, G2, and B2 emitted from the light modulation element 16 is incident on the projection lens of the projection optical device 14 from a direction that is closer to perpendicular. As a result, vignetting of each image light R2, G2, and B2 at the projection lens is suppressed, and the uniformity of the color and illuminance of the image projected onto the screen SCR can be improved.

[0040] [Third Embodiment] A third embodiment of the present invention will be described below with reference to Figures 5 to 8. Since the basic configuration of the projector in the third embodiment is the same as in the first embodiment, a description of the basic configuration of the projector will be omitted. Figure 5 shows the optical modulation element 45 and the second lens array 12 in the projector of the third embodiment. In Figure 5, components common to the drawings used in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0041] As shown in Figure 5, the projector of this embodiment comprises an optical modulation element 45 and a second lens array 12 that constitute an image generation unit. Other components are the same as in the first embodiment and are therefore not shown or described.

[0042] The optical modulation element 45 includes, in order from the light incident side, an incident side dustproof glass 46 and a liquid crystal panel 47. The liquid crystal panel 47 includes an element substrate 48, a liquid crystal layer 49, and a counter substrate 50. The second lens array 12 is provided in contact with the light emission surface of the counter substrate 50 that constitutes the liquid crystal panel 47.

[0043] [Effects of the third embodiment] In this embodiment as well, the same effects as in the first embodiment can be obtained, such as miniaturization of the projector, reduction of the number of parts and cost by using only one optical modulation element 45, no color breakup occurs, and a projector with excellent light utilization efficiency can be obtained by eliminating light absorption by the color filter.

[0044] The following describes the effects specific to the projector of this embodiment. Figure 6 shows a typical optical modulation element 52 and second lens array 12 as a comparative example. In Figure 6, the same reference numerals are used for components identical to those in Figure 5. As shown in Figure 6, a typical optical modulation element 52 has an emission-side dustproof glass 51 on the light emission side of the opposing substrate 50. Therefore, when a second lens array 12 is combined with a typical optical modulation element 52, the second lens array 12 is positioned on the light emission side of the emission-side dustproof glass 51.

[0045] Here, we will explain the problems of the projector according to the first embodiment. As described in the first embodiment, the image light of each color emitted from each image generation region of the optical modulation element basically enters a predetermined lens of the second lens array and a predetermined lens of the first lens array that are opposite the image generation region. Specifically, as shown in Figure 1, the red image light R2 enters sequentially into the fourth lens 24 and the first lens 31. The green image light G2 enters sequentially into the fifth lens 25 and the second lens 32. The blue image light B2 enters sequentially into the sixth lens 26 and the third lens 33.

[0046] However, as shown in Figure 7, the individual colored light R1, G1, and B1 incident on the optical modulation element 16 as parallel light diffracts within the optical modulation element 16, resulting in the emission of divergent image light from the lenses 24, 25, and 26 of the second lens array 12. As a result, a portion of the image light R3, G3, and B3 emitted from each image generation region 16R, 16G, and 16B of the optical modulation element 16 passes through the second lens array 12 and then incident on the lens adjacent to the lens facing the image generation region of the first lens array 21. Specifically, a portion of the green image light G3 is incident on the first lens 31 into which the red image light R2 is incident, a portion of the red image light R3 and a portion of the blue image light B3 are incident on the second lens 32 into which the green image light G2 is incident, and a portion of the green image light G3 is incident on the third lens 33 into which the blue image light B2 is incident. Hereinafter, R3, G3, and B3, which are portions of the image light incident from areas other than the image generation region corresponding to a given lens, will be referred to as leak light.

[0047] Thus, when stray light R3, G3, and B3 are incident on predetermined lenses 31, 32, and 33 of the first lens array 21, for example, on the intermediate image plane, images due to the stray light R3, G3, and B3 are generated above and below the intermediate image Z. Therefore, for the intermediate image in the red image generation region 16R, an image due to green stray light G3 is generated above the red intermediate image. For the intermediate image in the green image generation region 16G, an image due to blue stray light B3 is generated above the green intermediate image, and an image due to red stray light R3 is generated below the green intermediate image. For the intermediate image in the blue image generation region 16B, an image due to green stray light G3 is generated below the blue intermediate image. When such images are superimposed by the superposition lens 22, as shown in Figure 8, a cyan image ZC is displayed above the intermediate image Z, and a yellow image ZY is displayed below the intermediate image Z. These types of images ZC and ZY are magnified and displayed on the screen SCR by the projection optical device 14, which may degrade the display quality.

[0048] To address this issue, in the projector of this embodiment, as described above, the second lens array 12 is provided in contact with the light emission surface of the opposing substrate 50, and has a configuration in which the emission-side dustproof glass 51 is removed from the configuration of the comparative example shown in Figure 6. Therefore, the second lens array 12 of this embodiment is located closer to the liquid crystal layer 49, i.e., the image forming surface, by the thickness of the emission-side dustproof glass 51, compared to the second lens array 12 of the first embodiment. Consequently, in this embodiment, the proportion of leaked light R3, G3, B3 emitted from the light modulation element 45 that enters the second lens array 12 is less than in the first embodiment. As a result, the proportion of leaked light R3, G3, B3 that enters the first lens array 21 is also reduced. This reduces the phenomenon in which unintended colored images are displayed above or below the projected image.

[0049] The following describes other countermeasures for the phenomenon described above where unintended colored images appear above and below the projected image due to light leakage.

[0050] [Example of countermeasure 1] Figure 9 shows the optical modulation element 45 and the second lens array 53 of the first countermeasure example. In Figure 9, components common to both Figure 5 and the third embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0051] As shown in Figure 9, the fourth lens 54, fifth lens 55, and sixth lens 56 constituting the second lens array 53 are not in contact with each other as in the example in Figure 5, but are spaced apart from each other. As a result, the leaked light G3, R3, and B3 emitted from the optical modulation element 45 passes through the gaps between each lens 54, 55, and 56, and does not enter each lens 54, 55, and 56. In other words, the fourth lens 54, fifth lens 55, and sixth lens 56 are positioned to avoid the region through which the leaked light G3, R3, and B3 pass. Note that a light-shielding film may be provided in the gaps between each lens 54, 55, and 56 to block the leaked light G3, R3, and B3. In this example, an emission-side dustproof glass 51 is provided on the light emission side of the opposing substrate 50.

[0052] With this configuration, similar to the third embodiment, the proportion of leaked light G3, R3, and B3 emitted from the optical modulation element 45 that enters the second lens array 53 is reduced, resulting in a reduced proportion of leaked light G3, R3, and B3 that enters the first lens array 21. This reduces the phenomenon of unintended colored images appearing above or below the projected image.

[0053] [Example of countermeasure 2] Figure 10 shows the optical modulation element 45 and the second lens array 57 of the second countermeasure example. In Figure 10, components common to both Figure 5 and the third embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0054] As shown in Figure 10, the fourth lens 58, fifth lens 59, and sixth lens 60 constituting the second lens array 57 are made of Fresnel lenses, rather than general convex lenses like those in the example in Figure 5. In this example, an ejection-side dustproof glass 51 is provided, but ideally, it is desirable that the Fresnel lens be directly provided on the light-emitting side of the opposing substrate 50. Also, if the lens surface of the Fresnel lens and the liquid crystal layer 49 are too close together, the pattern of the Fresnel lens will be projected onto the screen SCR, so it is desirable that the lens surface of the Fresnel lens face the light-emitting side.

[0055] With this configuration, by replacing the conventional convex lens with a Fresnel lens, the position of the lens surface of the second lens array 57 becomes closer to the liquid crystal layer 49, i.e., the image forming surface. As a result, the proportion of stray light G3, R3, and B3 emitted from the optical modulation element 45 that enters the second lens array 57 is reduced, and consequently, the proportion of stray light G3, R3, and B3 that enters the first lens array 21 is also reduced. This reduces the phenomenon of unintended colored images appearing above or below the projected image.

[0056] [Example of countermeasure 3] Figure 11 shows the optical modulation element 16, the second lens array 12, and the first lens array 21 of the third countermeasure example. In Figure 11, components common to both Figure 1 and the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0057] As shown in Figure 11, a dichroic mirror 62R that transmits red light and reflects green and blue light is provided on each of the fourth lens 24 and the first lens 31 facing the red image generation region 16R. A dichroic mirror 62G that transmits green light and reflects red and blue light is provided on each of the fifth lens 25 and the second lens 32 facing the green image generation region 16G. A dichroic mirror 62B that transmits blue light and reflects red and green light is provided on each of the sixth lens 26 and the third lens 33 facing the blue image generation region 16B. In other words, the lenses facing each image generation region 16R, 16G, and 16B are provided with dichroic mirrors 62R, 62G, and 62B that transmit image light of the color emitted from the image generation region and reflect image light of other colors. Furthermore, it is preferable that each dichroic mirror 62R, 62G, and 62B be provided on the first lens array 21 side, but not necessarily on the second lens array 12 side.

[0058] With this configuration, dichroic mirrors 62R, 62G, and 62B are provided on each lens of the second lens array 12 and the first lens array 21. Therefore, even if stray light emitted from the optical modulation element 16 travels toward an adjacent lens, it is reflected at least by each lens surface of the first lens array 21, and its incidence into the first lens array 21 is suppressed. This reduces the phenomenon of unintended colored images appearing above or below the projected image.

[0059] [Example of countermeasure #4] Figure 12 shows the image generation unit 64, the second lens array 12, and the first lens array 21 of the fourth countermeasure example.

[0060] As shown in Figure 12, in this example, the arrangement of the three light-emitting elements constituting the light source device is reversed compared to the first embodiment. That is, the three light-emitting elements are arranged in the order of blue light-emitting element 17B, green light-emitting element 17G, and red light-emitting element 17R, along the Y-axis from the +Y side to the -Y side. On the light-emitting side of the blue light-emitting element 17B, the collimator lens 18B and the deflection prism 66B are arranged in this order. On the light-emitting side of the red light-emitting element 17R, the collimator lens 18R and the deflection prism 66R are arranged in this order. On the other hand, on the light-emitting side of the green light-emitting element 17G, the condensing lens 67G is arranged.

[0061] The blue light B1 emitted from the blue light-emitting element 17B is parallelized by the collimator lens 18B, then its direction of travel is bent by the declination prism 66B, and it travels obliquely in a direction that intersects the system optical axis AX1. As a result, the blue light B1 is incident obliquely on the blue image generation region 16B of the optical modulation element 16, moving away from the system optical axis AX1. Similarly, the red light R1 emitted from the red light-emitting element 17R is parallelized by the collimator lens 18R, then its direction of travel is bent by the declination prism 66R, and it travels obliquely in a direction that intersects the system optical axis AX1. As a result, the red light R1 is incident obliquely on the red image generation region 16R of the optical modulation element 16, moving away from the system optical axis AX1. On the other hand, the green light G1 emitted from the green light-emitting element 17G is slightly focused by the condensing lens 67G and is incident perpendicularly on the green image generation region 16G of the optical modulation element 16. In other words, each of the red light-emitting element 17R, green light-emitting element 17G, and blue light-emitting element 17B is configured such that the principal rays of the red light R1, green light G1, and blue light B1 respectively illuminate the optical modulation element 16 at angles that are separated from each other from the system optical axis AX1.

[0062] With this configuration, each color of light R1, G1, and B1 is incident on the respective image generation regions 16R, 16G, and 16B of the optical modulator 16 in directions away from each other, thus reducing the amount of light leakage emitted from the optical modulator 16. This reduces the phenomenon of unintended colored images appearing above or below the projected image.

[0063] [Fourth Embodiment] A fourth embodiment of the present invention will be described below with reference to Figure 13. Since the basic configuration of the projector in the fourth embodiment is the same as in the first embodiment, a description of the basic configuration of the projector will be omitted. Figure 13 is a schematic diagram of the projector 70 according to the fourth embodiment. In Figure 13, components common to the drawings used in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0064] As shown in Figure 13, the projector 70 of this embodiment includes an image generation unit 11, a second lens array 12, an integrator optical system 13 including a first lens array 21, a projection optical device 14, and a pixel shift element 71.

[0065] The pixel shift element 71 is positioned between the image generation unit 11 and the integrator optical system 13, specifically between the second lens array 12 and the first lens array 21. The pixel shift element 71 includes a glass plate that transmits each image light R2, G2, B2 emitted from the optical modulation element 16, and an actuator that oscillates the glass plate at high speed. The pixel shift element 71 may also be positioned between the intermediate image Z and the projection optical device 14 (at the position indicated by reference numeral 71A). The glass plate may also function as an output polarizer. That is, an output polarizer may be used as the glass plate of the pixel shift element. The pixel shift element 71 may be provided at both of the above-mentioned positions. In that case, by shifting each pixel shift element 71, 71A in one axis direction and making the shift directions orthogonal to each other, a pixel shift element capable of two-axis pixel shift can be realized. The other configurations of the projector 70 are the same as those of the projector in the first embodiment.

[0066] [Effects of the fourth embodiment] In this embodiment as well, the same effects as in the first embodiment can be obtained, such as miniaturization of the projector 70, reduction of the number of parts and cost reduction by using only one optical modulation element 16, and a projector 70 with excellent light utilization efficiency because no color breakup occurs and no light absorption occurs by the color filter.

[0067] In the projector of the first embodiment, one liquid crystal panel is divided into three to form each image generation area, so the number of pixels per image generation area is 1 / 3 of the number of pixels that the liquid crystal panel has. As a result, the resolution of the projected image is lower than the resolution that the liquid crystal panel originally has. In contrast, according to this embodiment, since the projector 70 is equipped with a pixel shift element 71, the number of pixels in the projected image can be artificially increased by performing pixel shifts in two directions, for example, the horizontal and vertical directions, and the resolution that the liquid crystal panel originally has can be maintained. As a result, with the projector 70 of this embodiment, a high-resolution projected image can be obtained.

[0068] [Fifth Embodiment] A fifth embodiment of the present invention will be described below with reference to Figure 14. Since the basic configuration of the projector in the fifth embodiment is the same as in the first embodiment, a description of the basic configuration of the projector will be omitted. Figure 14 is a schematic diagram of the projector 80 according to the fifth embodiment. In Figure 14, components common to the drawings used in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0069] As shown in Figure 14, the projector 80 of this embodiment includes an image generation unit 81, a second lens array 12, an integrator optical system 13 including a first lens array 21, and a projection optical device 14.

[0070] While the image generation unit of the first embodiment included a light source device and a light modulation element, the image generation unit 81 of this embodiment does not include a light source device and instead includes a self-emissive display element 82. As the self-emissive display element 82, a micro-LED display in which multiple LEDs are arranged in an array, an organic electroluminescent (EL) display, a laser display, etc., can be used. The self-emissive display element 82 has a red image generation area 82R, a green image generation area 82G, and a blue image generation area 82B, similar to the liquid crystal panel of the first embodiment shown in Figure 2. The other configurations of the projector 80 are the same as those of the projector in the first embodiment.

[0071] [Effects of the Fifth Embodiment] In this embodiment as well, the same effects as in the first embodiment can be obtained, such as miniaturization of the projector 80, reduction of the number of parts and cost reduction by using only one self-emissive display element 82, and a projector 80 with excellent light utilization efficiency because no color breakup occurs and no light absorption occurs by the color filter.

[0072] According to this embodiment, since a light source device is not required, it is possible to further miniaturize the projector 80 and reduce the number of parts.

[0073] It should be noted that the technical scope of the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. Furthermore, one aspect of the present invention can be a configuration that appropriately combines the characteristic features of each of the embodiments described above.

[0074] The projector in the above embodiment includes a second lens array, but it does not necessarily have to include a second lens array if the parallelism of each image beam emitted from the optical modulation element or self-emissive display element is sufficiently high. If the parallelism of each image beam is sufficiently high, each image beam can be reliably incident on the lens of the first lens array corresponding to that image beam, even in a configuration without a second lens array.

[0075] Furthermore, the specific details regarding the shape, number, arrangement, and materials of each component of the projector are not limited to the above embodiment and can be modified as appropriate. In the above embodiment, the light modulation element is composed of one liquid crystal panel, but instead, a configuration in which three liquid crystal panels are arranged in one direction within the same plane may be used. Similarly, the self-emissive display element may be configured in which three self-emissive display elements are arranged in one direction within the same plane.

[0076] [Summary of this disclosure] A summary of this disclosure is provided below.

[0077] (Note 1) An image generation unit having a first image generation region for generating first image light in a first wavelength band, and a second image generation region for generating second image light in a second wavelength band different from the first wavelength band, An integrator optical system that superimposes the first image light and the second image light emitted from the image generation unit, forms an image, and generates an intermediate image; A projection optical device that projects the aforementioned intermediate image onto the projection surface, Equipped with, The back focus position of the projection optical device coincides with the position of the intermediate image. A projector in which the first image generation region and the second image generation region are arranged in the same plane along a second direction perpendicular to the first direction which is the direction of emission of the first image light and the second image light.

[0078] According to the configuration described in Appendix 1, the projector can be made smaller, the number of parts can be reduced, costs can be reduced, color breakup can not occur, and a projector with superior light utilization efficiency can be obtained because light absorption by the color filter is not caused.

[0079] (Note 2) The image generation unit further includes a third image generation region that generates a third image light in a third wavelength band different from the first and second wavelength bands, The integrator optical system superimposes the first image light, the second image light, and the third image light emitted from the image generation unit, and forms an image to generate the intermediate image. The projector described in Appendix 1, wherein the first image generation region, the second image generation region, and the third image generation region are arranged in the same plane along the second direction.

[0080] According to the configuration described in Appendix 2, a projector capable of projecting full-color images can be realized.

[0081] (Note 3) The integrator optical system comprises a first lens array located on the light output side of the image generation unit, and a superimposed lens located on the light output side of the first lens array. The first lens array includes a first lens for imaging the first image light, a second lens for imaging the second image light, and a third lens for imaging the third image light. The first lens, the second lens, and the third lens are arranged along the second direction, The projector as described in Appendix 2, wherein the superimposing lens superimposes the first image light, the second image light, and the third image light emitted from the first lens array.

[0082] According to the configuration described in Appendix 3, the first lens array and the superimposing lens are used to image and superimpose each image light, thereby generating an intermediate image at a predetermined position in front of the projection optical device.

[0083] (Note 4) A dichroic mirror is provided on the light incident surface of the first lens, which transmits light in the first wavelength band and reflects light in wavelength bands other than the first wavelength band. A dichroic mirror is provided on the light incident surface of the second lens, which transmits light in the second wavelength band and reflects light in other wavelength bands. The projector according to Appendix 3, wherein a dichroic mirror that transmits light in the third wavelength band and reflects light in other wavelength bands is provided on the light incident surface of the third lens.

[0084] According to the configuration described in Appendix 4, stray light emitted from the image generation unit is reflected by dichroic mirrors provided on each lens of the first lens array, preventing it from entering the first lens array. This reduces the phenomenon of unintended colored images appearing around the projected image.

[0085] (Note 5) The system further comprises a second lens array disposed between the image generation unit and the first lens array, The second lens array includes a fourth lens that guides the first image light emitted from the first image generation region to the first lens, a fifth lens that guides the second image light emitted from the second image generation region to the second lens, and a sixth lens that guides the third image light emitted from the third image generation region to the third lens. The projector according to Appendix 3 or Appendix 4, wherein the fourth lens, the fifth lens, and the sixth lens are arranged along the second direction.

[0086] According to the configuration described in Appendix 5, each image light emitted from the image generation unit is picked up by each lens in the second lens array and reliably transmitted to the subsequent first lens array. This improves the utilization efficiency of each color of light.

[0087] (Note 6) The projector as described in Appendix 5, wherein each of the fourth lens, the fifth lens, and the sixth lens is a Fresnel lens.

[0088] According to the configuration described in Appendix 6, as each lens in the second lens array becomes thinner, the proportion of stray light emitted from the image generation unit that enters the second lens array decreases, and the proportion of stray light that enters the first lens array also decreases. This reduces the phenomenon of unintended colored images appearing around the projected image.

[0089] (Note 7) The system further comprises a field lens positioned between the superimposed lens and the intermediate image, The projector according to any one of the appendices 3 to 6, wherein the field lens refracts at least a portion of the first image light, the second image light, and the third image light emitted from the superimposed lens in a direction in which the principal rays of the image light approach the optical axis of the superimposed lens.

[0090] According to the configuration described in Appendix 7, each image light emitted from the image generation unit is incident on the projection optical device from a direction that is closer to perpendicular. This suppresses vignetting of each image light in the projection optical device and improves the uniformity of color and illuminance of the projected image.

[0091] (Note 8) The image generation unit comprises a light source device and a light modulation element, The light source device includes a first light-emitting element that emits first light in the first wavelength band, a second light-emitting element that emits second light in the second wavelength band, and a third light-emitting element that emits third light in the third wavelength band. The projector according to any one of the appendices 2 to 7, wherein the optical modulation element comprises: a first image generation region that modulates the first light emitted from the first light-emitting element to generate the first image light; a second image generation region that modulates the second light emitted from the second light-emitting element to generate the second image light; and a third image generation region that modulates the third light emitted from the third light-emitting element to generate the third image light.

[0092] According to the configuration described in Appendix 8, an image generation unit can be constructed using a light source device and an optical modulation element.

[0093] (Note 9) The projector according to Appendix 8, wherein each of the first light-emitting element, the second light-emitting element, and the third light-emitting element is arranged such that the principal rays of the first light, the second light, and the third light illuminate the light modulation element at an angle away from the principal optical axis passing through the center of the light modulation element.

[0094] According to the configuration described in Appendix 9, the amount of light leakage emitted from the optical modulation element can be reduced, thereby mitigating the phenomenon of unintended colored images appearing around the projected image.

[0095] (Note 10) The image generation unit includes a self-illuminating display element, The projector according to any one of the appendices 2 to 7, wherein the self-emissive display element comprises a first image generation region for generating the first image light, a second image generation region for generating the second image light, and a third image generation region for generating the third image light.

[0096] According to the configuration described in Appendix 10, a light source device is not required, which allows for miniaturization of the projector and a reduction in the number of parts.

[0097] (Note 11) The projector according to any one of the appendices 8 to 10, further comprising a pixel shift element disposed between the image generation unit and the integrator optical system, and between the intermediate image and the projection optical device.

[0098] According to the configuration described in Appendix 11, the inherent reduction in resolution of the optical modulation element or self-emissive display element can be suppressed, thereby enabling the acquisition of high-resolution projected images. [Explanation of Symbols]

[0099] 10, 40, 70, 80…Projector, 11, 64, 81…Image generation unit, 12, 53, 57…Second lens array, 13…Integrator optical system, 14…Projection optical device, 15, 30, 65…Light source device, 16, 45…Light modulation element, 16R…Red image generation area (first image generation area), 16G…Green image generation area (second image generation area), 16B…Blue image generation area (third image generation area), 21…First lens array, 22…Superimposed lens, 24, 54, 58…Fourth lens Z, 25, 55, 59... Fifth lens, 26, 56, 60... Sixth lens, 31... First lens, 32... Second lens, 33... Third lens, 41... Field lens, 62R, 62G, 62B... Dichroic mirror, 71, 71A... Pixel shift element, 82... Self-emissive display element, R1... Red light (first light), G1... Green light (second light), B1... Blue light (third light), R2... Red image light (first image light), G2... Green image light (second image light), B2... Blue image light (third image light), Z... Intermediate image.

Claims

1. An image generation unit having a first image generation region for generating first image light in a first wavelength band, and a second image generation region for generating second image light in a second wavelength band different from the first wavelength band, An integrator optical system that superimposes the first image light and the second image light emitted from the image generation unit, forms an image, and generates an intermediate image; A projection optical device that projects the aforementioned intermediate image onto the projection surface, Equipped with, The back focus position of the projection optical device coincides with the position of the intermediate image. A projector in which the first image generation region and the second image generation region are arranged in the same plane along a second direction perpendicular to the first direction which is the direction of emission of the first image light and the second image light.

2. The image generation unit further includes a third image generation region that generates a third image light in a third wavelength band different from the first and second wavelength bands, The integrator optical system superimposes the first image light, the second image light, and the third image light emitted from the image generation unit, and forms an image to generate the intermediate image. The projector according to claim 1, wherein the first image generation region, the second image generation region, and the third image generation region are arranged in the same plane along the second direction.

3. The integrator optical system comprises a first lens array disposed on the light output side of the image generation unit, and a superimposed lens disposed on the light output side of the first lens array. The first lens array includes a first lens for imaging the first image light, a second lens for imaging the second image light, and a third lens for imaging the third image light. The first lens, the second lens, and the third lens are arranged along the second direction, The projector according to claim 2, wherein the superimposing lens superimposes the first image light, the second image light, and the third image light emitted from the first lens array.

4. A dichroic mirror is provided on the light incident surface of the first lens, which transmits light in the first wavelength band and reflects light in other wavelength bands. A dichroic mirror is provided on the light incident surface of the second lens, which transmits light in the second wavelength band and reflects light in other wavelength bands. The projector according to claim 3, wherein a dichroic mirror that transmits light in the third wavelength band and reflects light in other wavelength bands is provided on the light incident surface of the third lens.

5. The system further comprises a second lens array disposed between the image generation unit and the first lens array, The second lens array includes a fourth lens that guides the first image light emitted from the first image generation region to the first lens, a fifth lens that guides the second image light emitted from the second image generation region to the second lens, and a sixth lens that guides the third image light emitted from the third image generation region to the third lens. The projector according to claim 3 or claim 4, wherein the fourth lens, the fifth lens, and the sixth lens are arranged along the second direction.

6. The projector according to claim 5, wherein each of the fourth lens, the fifth lens, and the sixth lens is composed of a Fresnel lens.

7. The system further comprises a field lens positioned between the superimposed lens and the intermediate image, The projector according to claim 3, wherein the field lens refracts at least a portion of the first image light, the second image light, and the third image light emitted from the superimposed lens in a direction such that the principal rays of the image light approach the optical axis of the superimposed lens.

8. The image generation unit comprises a light source device and a light modulation element, The light source device includes a first light-emitting element that emits first light in the first wavelength band, a second light-emitting element that emits second light in the second wavelength band, and a third light-emitting element that emits third light in the third wavelength band. The projector according to claim 2, wherein the optical modulation element comprises: a first image generation region that modulates the first light emitted from the first light-emitting element to generate the first image light; a second image generation region that modulates the second light emitted from the second light-emitting element to generate the second image light; and a third image generation region that modulates the third light emitted from the third light-emitting element to generate the third image light.

9. The projector according to claim 8, wherein each of the first light-emitting element, the second light-emitting element, and the third light-emitting element is arranged such that the principal rays of the first light, the second light, and the third light illuminate the light modulation element at an angle away from the principal optical axis passing through the center of the light modulation element.

10. The image generation unit includes a self-illuminating display element, The projector according to claim 2, wherein the self-emissive display element comprises a first image generation region for generating the first image light, a second image generation region for generating the second image light, and a third image generation region for generating the third image light.

11. The projector according to claim 8 or 10, further comprising a pixel shift element disposed between the image generation unit and the integrator optical system, and between the intermediate image and the projection optical device, at least one of the two.

Images