Single-panel projector

Abstract

To prevent a reduction in the light efficiency of a light source even when the light emission area of the light source is increased to make a single-plate projector brighter.SOLUTION: A single-plate projector has: a first light source that emits first light; a second light source that emits second light different from the first light; a light composition element that combines the first light and the second light to emit composite light; a light modulation element that modulates the composite light to modulated light; and a projection lens that projects the modulated light.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A projector composed of one liquid crystal panel is described in Patent Document 1. The projector in this document is a so-called single-panel projector, and includes a light source, a focusing optical system that focuses light emitted from the light source, a liquid crystal panel that modulates the light from the focusing optical system to form an image, and a projection lens that projects the image generated by the liquid crystal panel onto a screen. The light source is a single LED light source. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] China Utility Model No. 212515320 Specification Summary of the Invention [Problem to be solved by the invention]

[0004] Here, a projector with bright projection light is required. In this case, in the single-panel projector of the above document, it is considered to use a light source with a large light-emitting area in order to brighten the projection light. However, if the light-emitting area of ​​the light source becomes too large compared to the size of the effective display area of ​​the liquid crystal panel, the light efficiency of the light source decreases (Etendue becomes large), so there is a problem that the projection light does not become bright even if the light-emitting area of ​​the light source becomes large. [Means for solving the problem]

[0005] In order to solve the above problems, the single-panel projector of the present invention is characterized by having a first light source that emits a first light, a second light source that emits a second light different from the first light, a light combining element that combines the first light and the second light and emits combined light, a light modulation element that modulates the combined light into modulated light, and a projection lens that projects the modulated light. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of a main part of a projector according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing pixels of a liquid crystal panel. [Diagram 3] FIG. 11 is a schematic diagram of a main part of a projector according to a second embodiment. [Figure 4] FIG. 11 is a schematic diagram of a main part of a projector according to a third embodiment. [Diagram 5] FIG. 11 is a schematic diagram of a main part of a projector according to a fourth embodiment. [Figure 6] 13 is a schematic diagram showing a light-emitting element of a first light source according to a fourth embodiment. FIG. [Figure 7] FIG. 13 is a schematic diagram of a main part of a projector according to a fifth embodiment. [Figure 8] 13 is a schematic diagram showing a light-emitting element of a first light source according to a fifth embodiment. FIG. [Figure 9] FIG. 13 is a schematic diagram of a main part of a projector according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projector according to an embodiment of the invention will be described with reference to the drawings.

[0008] [Embodiment 1] Fig. 1 is a schematic diagram of a main part of a projector of embodiment 1. Fig. 2 is a schematic diagram showing pixels of a liquid crystal panel. As shown in Fig. 1, the projector 1 includes a light source device 2, an image forming section 3 that generates a projection image to be projected onto a screen S, a projection lens 4 that enlarges the projection image and projects it onto the screen S, a reflection mirror 5 disposed between the image forming section 3 and the projection lens 4, and a control section 6 that controls the operation of the image forming section 3.

[0009] The light source device 2 includes a light source 10, a pickup lens 15, and a light combining element 16. The light source 10 is, for example, an ultra-high pressure mercury lamp, a solid-state light source, or the like. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, and a second light source 12 that emits a second light different from the first light. Here, as shown in FIG. 1, if three mutually orthogonal axes are the X-axis, the Y-axis, and the Z-axis, the X-axis is a first axis N along the direction in which the image forming unit 3 and the reflecting mirror 5 are arranged. On the X-axis, the direction in which the first light source 11 is located is the X1 direction, and the direction in which the reflecting mirror 5 is located is the X2 direction. The Y-axis is an axis parallel to the direction in which the second light source 12 and the light combining element 16 are arranged, and the direction in which the reflecting mirror 5 and the projection lens 4 are arranged. On the Y axis, the direction in which the second light source 12 and the projection lens 4 are located is defined as the Y1 direction, and the opposite direction is defined as the Y2 direction.

[0010] As shown in FIG. 1, the first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is yellow light LY. The wavelength band of the yellow light LY is, for example, 500 nm to 680 nm, and includes green light and red light. The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 that covers the emission surface of the first light emitting element 111. The first light emitting element 111 is a blue LED element that emits blue light. In this embodiment, the fluorescent element 115 is a yellow phosphor. The fluorescent element 115 converts the blue light emitted from the first light emitting element 111 into yellow light LY, which is the first light.

[0011] The second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is blue light LB. The wavelength band of the blue light LB is, for example, 420 nm to 500 nm. The second light source 12 includes a second light emitting element 121 that emits the blue light LB. The second light emitting element 121 is a blue LED element. In this embodiment, the light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12.

[0012] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the yellow light LY and the blue light LB, and emits white light LW as combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic mirror 17. The dichroic mirror 17 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. In this embodiment, a dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits the yellow light LY and reflects the blue light LB. As a result, the dichroic mirror 17 emits white light LW obtained by combining the yellow light LY and the blue light LB.

[0013] The image forming unit 3 includes a first Fresnel lens 21, a first polarizing plate 22, a light modulation element 23, a second polarizing plate 24, and a second Fresnel lens 25. The first light source 11, the first Fresnel lens 21, the first polarizing plate 22, the light modulation element 23, the second polarizing plate 24, the second Fresnel lens 25, and the reflecting mirror 5 are arranged along a first axis N.

[0014] The first Fresnel lens 21 collimates the light beam emitted from the light source 10. The first polarizing plate 22 is disposed on the incident side of the light modulation element 23, and transmits or reflects either the P-polarized component or the S-polarized component of the polarized components contained in the white light LW emitted from the first Fresnel lens 21. In this embodiment, the first polarizing plate 22 is a transmissive polarizing plate, and transmits the P-polarized component of the polarized components contained in the white light LW emitted from the first Fresnel lens 21.

[0015] The light modulation element 23 modulates the white light LW of the P-polarized component transmitted through the first polarizing plate 22 into modulated light LA ​​to form a projection image. The light modulation element 23 is a liquid crystal panel 230. The dimensions of the effective display area of ​​the liquid crystal panel 230 are 6.48 mm×11.52 mm (0.52 inches) to 99.6 mm×176.8 mm (8.0 inches). In this embodiment, the liquid crystal panel 230 is made of one panel and forms a full-color projection image. That is, the projector 1 of this embodiment is a full-color single-panel type projector. As shown in FIG. 2, the liquid crystal panel 230 includes a first sub-pixel 231B to which blue light is incident, a second sub-pixel 231G to which green light is incident, and a third sub-pixel 231R to which red light is incident. A microlens array having a plurality of microlenses (not shown) is arranged on the incident side of the liquid crystal panel 230. The microlenses cause the sub-pixels 231B-231R to receive colored light corresponding to the sub-pixels 231B-231R. When the colored light corresponding to the sub-pixels 231B-231R is received by the sub-pixels 231B-231R, the sub-pixels 231B-231R modulate the corresponding colored light. As a result, the liquid crystal panel 230 forms a full-color projection image, which is the modulated light LA.

[0016] The second polarizing plate 24 is disposed on the exit side of the light modulation element 23, and transmits either the P polarized component or the S polarized component of the polarized components contained in the modulated light LA ​​exiting from the light modulation element 23. In this embodiment, the second polarizing plate 24 transmits the S polarized component of the polarized components contained in the modulated light LA ​​exiting from the light modulation element 23. The second Fresnel lens 25 collects the modulated light LA ​​exiting from the second polarizing plate 24 onto the projection lens 4.

[0017] The reflection mirror 5 is disposed along the first axis N. The reflection mirror 5 reflects the modulated light LA ​​emitted from the second Fresnel lens 25 toward the projection lens 4. In this embodiment, the reflection mirror 5 bends the modulated light LA ​​by 90°. The projection lens 4 enlarges the modulated light LA ​​emitted from the second Fresnel lens 25 and projects it onto the screen S. The projection lens 4 includes a plurality of lenses. The control unit 6 operates the liquid crystal panel 230 based on an external image signal such as a video signal.

[0018] (Action and effect) The projector 1 of this embodiment is a single-panel type. The projector 1 has a first light source 11 that emits yellow light LY, a second light source 12 that emits blue light LB different from the yellow light LY, a light combining element 16 that combines the yellow light LY and the blue light LB to emit white light LW, a light modulation element 23 that modulates the white light LW into modulated light LA, and a projection lens 4 that projects the modulated light LA. According to this embodiment, the projector 1 has two light sources. As a result, the light-emitting area of ​​the light source is divided between the first light source 11 and the second light source 12, so the light-emitting areas of the first light source 11 and the second light source 12 are smaller than when there is one light source. As a result, even if the light-emitting area of ​​the light source is increased to brighten the projector 1, the light-emitting areas of the first light source 11 and the second light source 12 can be kept small, so that the light efficiency of the light source can be prevented from decreasing (Etendue becomes large), and the projection light of the projector 1 can be brightened.

[0019] The light combining element 16 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. A dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits yellow light LY, which is the first light, and reflects blue light LB, which is the second light. In other words, the light combining element 16 is a dichroic mirror 17. Misalignment of the optical axes of the yellow light LY transmitted by the dichroic mirror 17 and the blue light LB reflected by the dichroic mirror 17 is suppressed. Furthermore, the space required for arranging the dichroic mirror 17 is smaller than when the light combining element 16 is a dichroic prism.

[0020] The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 that converts the light emitted from the first light emitting element 111 into a first light. The first light is yellow light LY. The second light is blue light LB. This allows the combined light combined by the light combining element 16 to be white light LW containing red light, green light, and blue light, thereby widening the color gamut of the modulated light LA ​​projected by the projector 1.

[0021] The light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12. This suppresses color unevenness in the white light LW, which is the combined light.

[0022] The projector 1 of this embodiment has a reflection mirror 5 that reflects the modulated light LA ​​emitted from the light modulation element 23 toward the projection lens 4. The light combining element 16, the light modulation element 23, and the reflection mirror 5 are arranged along a first axis N. The second light source 12 and the projection lens 4 are arranged in the Y1 direction, which intersects with the first axis N and is on the same side. This reduces the dimension of the projector 1 in the direction along the first axis N.

[0023] The projector 1 further includes a first polarizing plate 22 arranged on the incident side of the light modulation element 23 and transmitting the combined light, and a second polarizing plate 24 arranged on the exit side of the light modulation element 23 and transmitting the modulated light LA ​​from the light modulation element 23. As shown in Fig. 2, the liquid crystal panel 230 which is the light modulation element 23 includes a first sub-pixel 231B to which blue light is incident, a second sub-pixel 231G to which green light is incident, and a third sub-pixel 231R to which red light is incident. As a result, compared to a three-panel projector which includes three liquid crystal panels, the projector 1 of this embodiment includes one liquid crystal panel 230 which forms a full-color projection image, and therefore can be made smaller.

[0024] [Embodiment 2] 3 is a schematic diagram of a main part of a projector 1A of embodiment 2. The projector 1A of embodiment 2 differs from the projector 1 of embodiment 1 in a light source device 2A. Therefore, in embodiment 2, the same configurations as those of embodiment 1 are given the same reference numerals, and descriptions thereof may be omitted.

[0025] 3, the light source device 2A includes a light source 10, a pickup lens 15, and a light combining element 16. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, and a second light source 12 that emits a second light different from the first light.

[0026] The first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is white light LW. The wavelength band of the white light LW is, for example, 420 nm to 680 nm. The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 that covers the emission surface of the first light emitting element 111. The first light emitting element 111 is a blue LED element that emits blue light. In this embodiment, the fluorescent element 115 includes a fluorescent material that emits red light and a fluorescent material that emits green light. The fluorescent element 115 converts the blue light emitted from the first light emitting element 111 into white light LW, which is the first light.

[0027] The second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is red light LR. The wavelength band of the red light LR is, for example, 600 nm to 680 nm. The second light source 12 includes a second light emitting element 121 that emits the red light LR. The second light emitting element 121 is a red LED element. In this embodiment, the light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12.

[0028] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the white light LW and the red light LR, and emits the white light LW as a combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic mirror 17. The dichroic mirror 17 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. In this embodiment, a dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits the blue light LB and the green light LG and reflects the red light LR. As a result, the dichroic mirror 17 emits white light LW obtained by combining the white light LW and the red light LR. The dielectric multilayer film 173 reflects the red light LR of the white light LW of the first light source 11 in the Y2 direction.

[0029] (Action and effect) According to this embodiment, even if the overall light-emitting area of ​​light source 10 is increased, the light-emitting areas of first light source 11 and second light source 12 can be kept small, so projector 1A can obtain the same effects as in the first embodiment.

[0030] The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 that converts the light emitted from the first light emitting element 111 into the first light. The first light is white light LW. The second light is red light LR. Here, the white light LW converted by the fluorescent element 115 is likely to have a low light intensity of the red light LR contained in the white light LW. According to this embodiment, since the second light is red light LR, the light intensity of the red light LR of the white light LW combined by the light combining element 16 becomes high. This corrects the color of the white light LW combined by the light combining element 16. In addition, since the color of the white light LW combined by the light combining element 16 is corrected, the white balance of the projection image projected by the projector 1A is improved.

[0031] [Embodiment 3] 4 is a schematic diagram of a main part of a projector 1B of embodiment 3. Projector 1B of embodiment 3 differs from projector 1 of embodiment 1 in a light source device 2B. Therefore, in embodiment 3, the same configurations as those in embodiment 1 are given the same reference numerals, and descriptions thereof may be omitted.

[0032] 4, the light source device 2B includes a light source 10, a pickup lens 15, and a light combining element 16. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, and a second light source 12 that emits a second light different from the first light.

[0033] The first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is green light LG. The wavelength band of the green light LG is, for example, 500 nm to 600 nm. The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 covering the emission surface of the first light emitting element 111. The first light emitting element 111 is a blue LED element that emits blue light. In this embodiment, the fluorescent element 115 is a green phosphor. The fluorescent element 115 converts the blue light LB emitted from the first light emitting element 111 into green light LG, which is the first light.

[0034] The second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is mixed light LC containing blue light LB and red light LR. The wavelength band of the blue light LB is, for example, 420 nm to 500 nm. The wavelength band of the red light LR is, for example, 600 nm to 680 nm. The second light source 12 includes a second light emitting element 121 that emits blue light LB and a third light emitting element 122 that emits red light LR. The second light emitting element 121 is a blue LED element. The third light emitting element 122 is a red LED element. In this embodiment, the light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12.

[0035] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the green light LG and the mixed light LC, and emits white light LW as combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic mirror 17. The dichroic mirror 17 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. In this embodiment, a dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits the green light LG and reflects the blue light LB and red light LR, which are the mixed light LC. As a result, the dichroic mirror 17 emits white light LW obtained by combining the green light LG and the mixed light LC.

[0036] (Action and effect) According to this embodiment, even if the overall light-emitting area of ​​light source 10 is increased, the light-emitting areas of first light source 11 and second light source 12 can be kept small, so projector 1B can obtain the same effects as in the first embodiment.

[0037] The first light source 11 includes a first light emitting element 111 and a fluorescent element 115 that converts the light emitted from the first light emitting element 111 into a first light. The first light is green light LG. The second light is mixed light LC containing blue light LB and red light LR. In this way, the light intensity of the green light LG contained in the white light LW combined by the light combining element 16 is increased. As a result, the light intensity of the green light LG contained in the modulated light LA ​​projected from the projector 1B is increased, and the projected image becomes a vivid image.

[0038] [Embodiment 4] Fig. 5 is a schematic diagram of a main part of a projector 1C of embodiment 4. Fig. 6 is a schematic diagram showing a light emitting element of a first light source of embodiment 4. Projector 1C of embodiment 4 differs from projector 1 of embodiment 1 in a light source device 2C. Therefore, in embodiment 4, the same configurations as those of embodiment 1 may be assigned the same reference numerals and descriptions thereof may be omitted.

[0039] 5, the light source device 2C includes a light source 10, a pickup lens 15, and a light combining element 16. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, and a second light source 12 that emits a second light different from the first light.

[0040] The first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is mixed light LC containing blue light LB and green light LG. The wavelength band of the blue light LB is, for example, 420 nm to 500 nm. The wavelength band of the green light LG is, for example, 500 nm to 600 nm.

[0041] The first light source 11 includes a first light emitting element 111 and a second light emitting element 112. The first light emitting element 111 is a blue LED element that emits blue light LB. The second light emitting element 112 is a green LED element that emits green light LG. In this embodiment, the total number of the second light emitting elements 112 is greater than the total number of the first light emitting elements 111. As shown in FIG. 6, in the first light source 11, the second light emitting element 112 is disposed in the outermost periphery of the region E in which the first light emitting elements 111 and the second light emitting elements 112 are disposed. In addition, the first light emitting element 111 is surrounded by the second light emitting elements 112.

[0042] As shown in FIG. 5, the second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is red light LR. The wavelength band of the red light LR is, for example, 600 nm to 680 nm. The second light source 12 includes a third light emitting element 126 that emits the red light LR. The third light emitting element 126 is a red LED element. In this embodiment, the light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12.

[0043] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the mixed light LC and the red light LR, and emits white light LW as combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic mirror 17. The dichroic mirror 17 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. In this embodiment, a dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits the blue light LB and the green light LG and reflects the red light LR. As a result, the dichroic mirror 17 emits white light LW obtained by combining the mixed light LC and the red light LR.

[0044] (Action and effect) According to this embodiment, even if the overall light-emitting area of ​​light source 10 is increased, the light-emitting areas of first light source 11 and second light source 12 can be kept small, so projector 1C can obtain the same effects as in the first embodiment.

[0045] The first light source 11 includes a first light emitting element 111 which is an LED element that emits blue light LB, and a second light emitting element 112 which is an LED element that emits green light LG. The second light source 12 includes a third light emitting element 126 which is an LED element that emits red light LR. As a result, compared to a case where the light emitted from the first light emitting element is converted by a fluorescent element to produce mixed light containing blue light and green light, the mixed light LC emitted from the first light source 11 of this embodiment has a narrower spectral distribution width, and therefore the color gamut of the white light LW which is a composite light obtained by combining the mixed light LC and the red light LR is wider.

[0046] Here, the light intensity of the LED element emitting red light LR is lower than the light intensity of the LED element emitting blue light LB and the LED element emitting green light LG. Therefore, according to this embodiment, since the second light source 12 includes only the third light-emitting element 126 which is an LED element emitting red light LR, the light intensity of the red light LR contained in the white light LW which is the composite light is high. As a result, the color of the white light LW composited by the light composite element 16 is corrected, and the white balance of the projection image projected by the projector 1C is improved.

[0047] The total number of the second light emitting elements 112 is greater than the total number of the first light emitting elements 111. The second light emitting elements 112 are arranged in the outermost periphery of the region E in which the first light emitting elements 111 and the second light emitting elements 112 of the first light source 11 are arranged. In this way, even if the total number of the second light emitting elements 112 is greater than the total number of the first light emitting elements 111, it is easy to uniformly distribute the first light emitting elements 111 and the second light emitting elements 112 in the region E. In addition, the light intensity of the green light LG included in the mixed light LC can be made higher than the blue light LB. As a result, the light intensity of the green light LG included in the modulated light LA ​​projected from the projector becomes higher, so that the projected image becomes a vivid image.

[0048] [Embodiment 5] Fig. 7 is a schematic diagram of a main part of a projector 1D of embodiment 5. Fig. 8 is a schematic diagram showing a light emitting element of a first light source of embodiment 5. In projector 1D of embodiment 5, a light source device 2D is different from that of projector 1 of embodiment 1. Therefore, in embodiment 5, the same components as those in embodiment 1 may be assigned the same reference numerals and descriptions thereof may be omitted.

[0049] 7, the light source device 2D includes a light source 10, a pickup lens 15, and a light combining element 16. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, and a second light source 12 that emits a second light different from the first light.

[0050] The first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is mixed light LC containing blue light LB and red light LR. The wavelength band of the blue light LB is, for example, 420 nm to 500 nm. The wavelength band of the red light LR is, for example, 600 nm to 680 nm.

[0051] The first light source 11 includes a first light emitting element 111 and a second light emitting element 112. The first light emitting element 111 is a blue LED element that emits blue light LB. The second light emitting element 112 is a red LED element that emits red light LR. In this embodiment, the total number of the second light emitting elements 112 is greater than the total number of the first light emitting elements 111. As shown in FIG. 8, the second light emitting element 112 is disposed in the outermost periphery of the region E in which the first light emitting elements 111 and the second light emitting elements 112 are disposed. In addition, the first light emitting element 111 is surrounded by the second light emitting elements 112.

[0052] As shown in Fig. 7, the second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is green light LG. The wavelength band of the green light LG is, for example, 500 nm to 600 nm. The second light source 12 includes a third light emitting element 126 that is a green LED element that emits the green light LG. In this embodiment, the light emitting area of ​​the first light source 11 is the same as the light emitting area of ​​the second light source 12.

[0053] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the mixed light LC and the green light LG, and emits white light LW as combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic mirror 17. The dichroic mirror 17 has a plate-shaped base 170 including a first surface 171 and a second surface 172 facing the opposite side to the first surface 171. In this embodiment, a dielectric multilayer film 173 is provided on the first surface 171. The dielectric multilayer film 173 transmits the blue light LB and the red light LR and reflects the green light LG. As a result, the dichroic mirror 17 emits white light LW obtained by combining the mixed light LC and the green light LG.

[0054] (Action and effect) According to this embodiment, even if the overall light-emitting area of ​​light source 10 is increased, the light-emitting areas of first light source 11 and second light source 12 can be kept small, so projector 1D can obtain the same effects as in the first embodiment.

[0055] The first light source 11 includes a first light emitting element 111 which is an LED element that emits blue light LB, and a second light emitting element 112 which is an LED element that emits red light LR. The second light source 12 includes a third light emitting element 126 which is an LED element that emits green light LG. In this way, it is possible to increase the light intensity of the green light LG contained in the white light LW combined by the light combining element 16. This increases the light intensity of the green light LG contained in the modulated light LA ​​projected from the projector, resulting in a vivid projection image.

[0056] The total number of the second light-emitting elements 112 is greater than the total number of the first light-emitting elements 111. The second light-emitting elements 112 are arranged in the outermost periphery of the region E in which the first light source 11 and the second light-emitting elements 112 are arranged. In this way, even if the total number of the second light-emitting elements 112 is greater than the total number of the first light-emitting elements 111, it is easy to distribute the first light-emitting elements 111 and the second light-emitting elements 112 evenly in the region E.

[0057] Here, the light intensity of the LED element emitting red light LR is lower than the light intensity of the LED element emitting blue light LB. Therefore, according to this embodiment, in the second light source 12, the total number of the second light emitting elements 112 emitting red light LR is greater than the total number of the first light emitting elements 111 emitting blue light LB, so that the light hardness of the blue light LB and the light intensity of the red light LR in the mixed light LC are approximately equal.

[0058] [Embodiment 6] 9 is a schematic diagram of a main part of a projector 1E of embodiment 6. Projector 1E of embodiment 6 differs from projector 1 of embodiment 1 in a light source device 2E. Therefore, in embodiment 6, the same configurations as those in embodiment 1 are given the same reference numerals, and descriptions thereof may be omitted.

[0059] The light source device 2E includes a light source 10, a pickup lens 15, and a light combining element 16. In this embodiment, the light source 10 is an LED. The light source 10 includes a first light source 11 that emits a first light, a second light source 12 that emits a second light different from the first light, and a third light source 13 that emits a third light different from the first light and the second light.

[0060] 9, the first light source 11 is located in the X1 direction of the light combining element 16. In this embodiment, the first light emitted by the first light source 11 is green light LG. The wavelength band of the green light LG is, for example, 500 nm to 600 nm. The first light source 11 includes a first light emitting element 116 that emits the green light LG. The first light emitting element 116 is a green LED element.

[0061] The second light source 12 is located in the Y1 direction of the light combining element 16. In this embodiment, the second light emitted by the second light source 12 is blue light LB. The wavelength band of the blue light LB is, for example, 420 nm to 500 nm. The second light source 12 includes a second light emitting element 121 that emits the blue light LB. The second light emitting element 121 is a blue LED element.

[0062] The third light source 13 is located in the Y2 direction of the light combining element 16. In this embodiment, the third light emitted by the third light source 13 is red light LR. The wavelength band of the red light LR is, for example, 600 nm to 680 nm. The third light source 13 includes a third light emitting element 136 that emits the red light LR. The third light emitting element 136 is a red LED element.

[0063] In this embodiment, the dimensions of the light emitting surface of the first light source 11 are 0.25 mm×0.25 mm to 10 mm×10 mm. The dimensions of the light emitting surface of the second light source 12 are 0.25 mm×0.25 mm to 10 mm×10 mm. The dimensions of the light emitting surface of the third light source 13 are 0.5 mm×0.5 mm to 20 mm×20 mm.

[0064] The pickup lens 15 converts the light from the light source 10 into substantially parallel light and emits it toward the light combining element 16. The light combining element 16 combines the blue light LB, the green light LG, and the red light LR, and emits white light LW as combined light in the X1 direction. In this embodiment, the light combining element 16 is a dichroic prism 19. The dichroic prism 19 has a rectangular parallelepiped shape consisting of four triangular prisms. The dichroic prism 19 has a first surface 191 facing the first light source 11 and on which the green light LG is incident, a second surface 192 facing the second light source 12 and on which the blue light LB is incident, a third surface 193 facing the third light source 13 and on which the red light LR is incident, and a fourth surface 194 that emits white light LW obtained by combining the blue light LB, the green light LG, and the red light LR.

[0065] The dichroic prism 19 includes a first dichroic film 195 and a second dichroic film 196. The first dichroic film 195 and the second dichroic film 196 are dielectric multilayer films. The first dichroic film 195 transmits the green light LG and the red light LR and reflects the blue light LB. The second dichroic film 196 transmits the blue light LB and the green light LG and reflects the red light LR. As a result, the dichroic prism 19 emits white light LW, which is a composite light obtained by combining the blue light LB, the green light LG, and the red light LR, from the fourth surface 194.

[0066] (Action and effect) According to this embodiment, even if the overall light-emitting area of ​​light source 10 is increased, the light-emitting areas of first light source 11, second light source 12, and third light source 13 can be kept small, so projector 1E can obtain the same effects as in embodiment 1.

[0067] The projector 1E of this embodiment further includes a third light source 13 that emits a third light different from the first light and the second light. The first light source 11 emits green light LG as the first light. The second light source 12 emits blue light LB as the second light. The third light source 13 emits red light LR as the third light. The light combining element 16 includes a first surface 191 that faces the first light source 11 and on which the green light LG is incident, a second surface 192 that faces the second light source 12 and on which the blue light LB is incident, a third surface 193 that faces the third light source 13 and on which the red light LR is incident, and a fourth surface 194 that emits white light LW obtained by combining the blue light LB, the green light LG, and the red light LR. This allows the light emission amounts of the first light source 11, the second light source 12, and the third light source 13 to be adjusted, respectively, and therefore allows the white balance of the projection image projected by the projector 1E to be easily adjusted.

[0068] In the projector 1E of this embodiment, the effective display area of ​​the light modulation element 23 has dimensions of 6.48 mm×11.52 mm to 99.6 mm×176.8 mm. The light emitting surface of the first light source 11 has dimensions of 0.25 mm×0.25 mm to 10 mm×10 mm. The light emitting surface of the second light source 12 has dimensions of 0.25 mm×0.25 mm to 10 mm×10 mm. The light emitting surface of the third light source 13 has dimensions of 0.5 mm×0.5 mm to 20 mm×20 mm. This makes it possible to prevent the light modulation element 23 from becoming large, while preventing the light efficiency of the first light source 11, the second light source 12, and the third light source 13 from decreasing.

[0069] [Other embodiments] In the first to fifth embodiments, the light-emitting area of ​​the first light source 11 is the same as that of the second light source 12. In other embodiments, the light-emitting area of ​​the first light source 11 may be larger than that of the second light source 12. In this case, the light-emitting efficiency of the first light based on the first light source 11 may be lower than that of the second light based on the second light source 12. This prevents the light-emitting area of ​​the second light source 12 from becoming larger, and increases the overall light-emitting area of ​​the light source 10, so that the projection light of the projector becomes brighter. In addition, the light-emitting efficiency of the second light source having a smaller light-emitting area becomes higher, so that the white balance of the projection image projected by the projector is improved. Here, the light-emitting efficiency is calculated by dividing the amount of light (W) generated by the light source by the power (W) input to the light source to emit light.

[0070] In the above embodiment, the light modulation element 23 is a transmissive liquid crystal panel, but in other embodiments, the light modulation element 23 may be a reflective liquid crystal panel, a DMD (digital mirror device), etc. The light modulation element 23 does not have to form a full-color projected image.

[0071] In the above embodiment, the first polarizing plate 22 is a transmissive polarizing plate, but it may be a reflective polarizing plate.

[0072] In the above embodiment, the projector has the reflecting mirror 5. However, in other embodiments, the projector does not have to have the reflecting mirror 5. Furthermore, the projector may have a plurality of reflecting mirrors 5.

[0073] In embodiments 1 to 5, the first light source 11 is positioned in the X1 direction of the light combining element 16, and the second light source 12 is positioned in the Y1 direction of the light combining element 16. However, in other embodiments, the first light source 11 may be positioned in the Y1 direction of the light combining element 16, and the second light source 12 may be positioned in the X1 direction of the light combining element 16.

[0074] [Summary of this disclosure] The following is a summary of this disclosure.

[0075] (Appendix 1) a first light source that emits a first light; A second light source that emits a second light different from the first light; a light combining element that combines the first light and the second light and outputs a combined light; a light modulation element that modulates the combined light into modulated light; a projection lens that projects the modulated light; A single-panel projector comprising:

[0076] As a result, the light-emitting area of ​​the light source is divided between the first light source and the second light source, so the light-emitting area of ​​the first light source and the second light source is smaller than when there is one light source. As a result, even if the light-emitting area of ​​the light source is increased to brighten the single-panel projector, the light-emitting area of ​​the first light source and the second light source can be kept small, so that a decrease in the light efficiency of the light source (an increase in Etendue) can be suppressed.

[0077] (Appendix 2) The light combining element includes a plate-shaped base including a first surface and a second surface facing an opposite side to the first surface; At least one of the first surface and the second surface is provided with a dielectric multilayer film; The single-panel projector described in Appendix 1, characterized in that the dielectric multilayer film transmits the first light and reflects the second light, or reflects the first light and transmits the second light.

[0078] Since the light combining element is plate-shaped, the space required for arranging the light combining element is smaller than when the light combining element is a dichroic prism.

[0079] (Appendix 3) the first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is a yellow light; 3. The single-panel projector according to claim 1 or 2, wherein the second light is blue light.

[0080] This allows the combined light generated by the light combining element to be white light containing red, green and blue light, thereby widening the color gamut of the modulated light projected by the single-panel projector.

[0081] (Appendix 4) the first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is white light; 3. The single-panel projector according to claim 1, wherein the second light is red light.

[0082] This allows the color of the white light combined by the light combining element to be corrected. Also, since the color of the white light combined by the light combining element is corrected, the white balance of the image projected by the single-panel projector is improved.

[0083] (Appendix 5) the first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is green light; 3. The single-panel projector according to claim 1 or 2, wherein the second light is a mixed light containing blue light and red light.

[0084] This increases the light intensity of the green light contained in the modulated light LA ​​projected from the single-panel projector, making the projected image vivid.

[0085] (Appendix 6) 6. The single-panel projector according to claim 1, wherein a light-emitting area of ​​the first light source is the same as a light-emitting area of ​​the second light source.

[0086] This reduces color unevenness in the white light, which is the synthesized light.

[0087] (Appendix 7) The light emitting area of ​​the first light source is larger than the light emitting area of ​​the second light source, A single-panel projector as described in any one of appendix 1 to 5, characterized in that the luminous efficiency of the first light based on the first light source is lower than the luminous efficiency of the second light based on the second light source.

[0088] This increases the luminous efficiency of the second light source, which has a smaller luminous area, and improves the white balance of the image projected by the single-panel projector.

[0089] (Appendix 8) The first light source includes a first light emitting element that is an LED element that emits blue light and a second light emitting element that is an LED element that emits green light, 3. The single-panel projector described in claim 2, wherein the second light source includes a third light-emitting element that is an LED element that emits red light.

[0090] As a result, compared to when the light emitted from the first light-emitting element is converted by a fluorescent element to produce mixed light containing blue and green light, the mixed light emitted from the first light source has a narrower spectral distribution width, and therefore the color gamut of the white light, which is a composite light obtained by combining the mixed light and red light, is wider.

[0091] (Appendix 9) The first light source includes a first light emitting element that is an LED element that emits blue light and a second light emitting element that is an LED element that emits red light, 3. The single-panel projector described in claim 2, wherein the second light source includes a third light-emitting element that is an LED element that emits green light.

[0092] As a result, the light intensity of the green light contained in the white light combined by the light combining element increases, so that the light intensity of the green light contained in the modulated light projected from the single-panel projector increases, resulting in a vivid projected image.

[0093] (Appendix 10) the total number of the second light emitting elements is greater than the total number of the first light emitting elements; The single-panel projector described in Appendix 8 or 9, characterized in that the second light-emitting element is always arranged at the outermost periphery of the area in which the first light-emitting element and the second light-emitting element of the first light source are arranged.

[0094] This makes it easy to distribute the first light-emitting elements and the second light-emitting elements uniformly in the region E even when the total number of the second light-emitting elements is greater than the total number of the first light-emitting elements.

[0095] (Appendix 11) a third light source that emits a third light different from the first light and the second light, the first light source emits green light as the first light, the second light source emits blue light as the second light, the third light source emits red light as the third light, The single-panel projector described in Appendix 1, characterized in that the light combining element comprises a first surface facing the first light source and on which the first light is incident, a second surface facing the second light source and on which the second light is incident, a third surface facing the third light source and on which the third light is incident, and a fourth surface that emits the combined light obtained by combining the first light, the second light, and the third light.

[0096] This makes it possible to adjust the light emission amounts of the first light source, the second light source, and the third light source, respectively, and therefore makes it possible to easily adjust the white balance of an image projected by a single-panel projector.

[0097] (Appendix 12) The dimensions of the effective display area of ​​the light modulation element are 6.48 mm × 11.52 mm to 99.6 mm × 176.8 mm, The dimensions of the light emitting surface of the first light source are 0.25 mm × 0.25 mm to 10 mm × 10 mm; The dimensions of the light emitting surface of the second light source are 0.25 mm × 0.25 mm to 10 mm × 10 mm; 12. The single-panel projector according to claim 11, wherein the light-emitting surface of the third light source has a size of 0.5 mm×0.5 mm to 20 mm×20 mm.

[0098] This makes it possible to suppress an increase in size of the light modulation element, while suppressing a decrease in the light efficiency of the first light source, the second light source, and the third light source.

[0099] (Appendix 13) a reflection mirror that reflects the modulated light emitted from the light modulation element toward the projection lens, the first light source, the light combining element, the light modulation element, and the reflecting mirror are arranged along a first axis; The single-panel projector described in any one of appendixes 1 to 12, characterized in that the second light source and the projection lens are arranged on the same side, intersecting the first axis.

[0100] This reduces the size of the single-panel projector along the first axis.

[0101] (Appendix 14) a first polarizing plate arranged on the incident side of the light modulation element and transmitting or reflecting the combined light; and a second polarizing plate arranged on the exit side of the light modulation element and transmitting the modulated light from the light modulation element, The single-panel projector described in any one of appendixes 1 to 13, characterized in that the light modulation element has a first sub-pixel to which blue light is incident, a second sub-pixel to which green light is incident, and a third sub-pixel to which red light is incident.

[0102] As a result, compared to a three-panel projector equipped with three light modulation elements, a single-panel projector has one light modulation element that forms a full-color projected image, making it more compact. [Explanation of symbols]

[0103] 1·1A·1B...·1C·1D·1E...projector, 2·2A·2B·2C·2D·2E...light source device, 3...image forming section, 4...projection lens, 5...reflection mirror, 6...control section, 10...light source, 11...first light source, 12...second light source, 13...third light source, 15...pickup lens, 16...light combining element, 17...dichroic mirror, 19...dichroic prism, 21...first Fresnel lens, 22...first polarizing plate, 23...light modulation element, 23...second polarizing plate, 25...second Fresnel lens, 111...first light-emitting element, 112...second light-emitting element, 115...fluorescent element, 116...first light-emitting element, 121...second light-emitting element, 122...third light-emitting element, 126...third light-emitting element, 136...third light-emitting element, 170...base, 171...first surface, 172...second surface, 173...dielectric multilayer film, 191...first surface, 192...second surface, 193...third surface, 194...fourth surface, 195...first dichroic film, 196...second dichroic film, 230...liquid crystal panel, 231B...first sub-pixel, 231G...second sub-pixel, 231R...third sub-pixel, E...area, LA...modulated light, LB...blue light, LC...mixed light, LG...green light, LR...red light, LW...white light, LY...yellow light, N...first axis, S...screen.

Claims

1. A first light source that emits a first light; A second light source that emits a second light different from the first light; a light combining element that combines the first light and the second light and outputs a combined light; a light modulation element that modulates the combined light into modulated light; a projection lens that projects the modulated light; A single-panel projector comprising:

2. The light combining element includes a plate-shaped base including a first surface and a second surface facing an opposite side to the first surface; a dielectric multilayer film is provided on at least one of the first surface and the second surface; 2. The single-panel projector according to claim 1, wherein the dielectric multilayer film transmits the first light and reflects the second light, or reflects the first light and transmits the second light.

3. The first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is a yellow light; 3. The single-panel projector according to claim 1, wherein the second light is blue light.

4. The first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is white light; 3. The single-panel projector according to claim 1, wherein the second light is red light.

5. The first light source includes a first light emitting element and a fluorescent element that converts light emitted from the first light emitting element into the first light, the first light is green light; 3. The single-panel projector according to claim 1, wherein the second light is a mixed light containing blue light and red light.

6. 2. The single-panel projector according to claim 1, wherein a light-emitting area of ​​the first light source is the same as a light-emitting area of ​​the second light source.

7. The light emitting area of ​​the first light source is larger than the light emitting area of ​​the second light source, 2. The single-panel projector according to claim 1, wherein a luminous efficiency of the first light based on the first light source is lower than a luminous efficiency of the second light based on the second light source.

8. the first light source includes a first light emitting element that is an LED element that emits blue light and a second light emitting element that is an LED element that emits green light; 3. The single-panel projector according to claim 2, wherein the second light source includes a third light-emitting element that is an LED element that emits red light.

9. The first light source includes a first light-emitting element that is an LED element that emits blue light and a second light-emitting element that is an LED element that emits red light, 3. The single-panel projector according to claim 2, wherein the second light source includes a third light-emitting element that is an LED element that emits green light.

10. The total number of the second light-emitting elements is greater than the total number of the first light-emitting elements, 10. The single-panel projector according to claim 8, wherein the second light-emitting element is always disposed at the outermost periphery of an area in which the first light-emitting element and the second light-emitting element of the first light source are disposed.

11. a third light source that emits a third light different from the first light and the second light, the first light source emits green light as the first light, the second light source emits blue light as the second light, the third light source emits red light as the third light, 2. The single-panel projector according to claim 1, wherein the light combining element comprises: a first surface facing the first light source and on which the first light is incident; a second surface facing the second light source and on which the second light is incident; a third surface facing the third light source and on which the third light is incident; and a fourth surface that emits the combined light obtained by combining the first light, the second light, and the third light.

12. The dimensions of the effective display area of ​​the light modulation element are 6.48 mm x 11.52 mm to 99.6 mm x 176.8 mm, The dimensions of the light emitting surface of the first light source are 0.25 mm x 0.25 mm to 10 mm x 10 mm; The dimensions of the light emitting surface of the second light source are 0.25 mm x 0.25 mm to 10 mm x 10 mm; 12. The single-panel projector according to claim 11, wherein the light-emitting surface of the third light source has a size of 0.5 mm×0.5 mm to 20 mm×20 mm.

13. a reflection mirror that reflects the modulated light emitted from the light modulation element toward the projection lens, the first light source, the light combining element, the light modulation element, and the reflecting mirror are arranged along a first axis; 2. The single-panel projector according to claim 1, wherein the second light source and the projection lens are arranged on the same side intersecting the first axis.

14. a first polarizing plate arranged on the incident side of the light modulation element and transmitting or reflecting the combined light; and a second polarizing plate arranged on the exit side of the light modulation element and transmitting the modulated light from the light modulation element, 2. The single-panel projector according to claim 1, wherein the light modulation element comprises a first sub-pixel to which blue light is incident, a second sub-pixel to which green light is incident, and a third sub-pixel to which red light is incident.

Images