Illumination device and projector

Abstract

Provided are an illumination device and a projector. Even if the area of a light-emitting surface is increased, the light efficiency of a light source can be prevented from being reduced. The lighting device includes: a light source device having a light emitting surface for emitting first light; a first light guide element provided with a first reflection surface and a first emission end portion; and a second light guide element including a second incident end portion, a second exit end portion, and a second reflective surface. The first reflecting surface is inclined toward the optical axis in the direction in which the first light travels. When the area of the light-emitting surface is S1, the area of the first emission surface at the first emission end is S2, the area of the second incidence surface at the second incidence end is S3, and the area of the second emission surface at the second emission end is S4, the following conditional expression is satisfied: S4gt; s1gt; s3 > = S2.

Description

Technical Field

[0001] This utility model relates to lighting devices and projectors. Background Technology

[0002] Patent Document 1 describes an illumination device for a projector. This illumination device includes: a light-emitting body that emits diffuse light; and a light-guiding element that reflects the diffuse light from the light-emitting body on its inner surface. The light-guiding element includes: an incident end to which diffuse light is incident; a reflecting surface that reflects the diffuse light incident from the incident end; and an exiting end that emits the diffuse light reflected by the reflecting surface. The reflecting surface is radially outward relative to the center of the light-guiding element, following the direction of the emitted light. The incident end is larger than the exiting surface of the light-emitting body. The exiting end is larger than the incident end. The light-guiding element efficiently captures the diffuse light from the light-emitting body and efficiently narrows the radiation angle to emit bright, highly directional illumination light.

[0003] Existing technical documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2004-94115

[0005] Here, to make the illumination light emitted from the light guide element brighter, a light-emitting element with a large exit surface is considered. However, if the exit surface of the light-emitting element is increased, the incident end of the light guide element also needs to be increased, thus the tilt of the reflecting surface becomes gentler, and the directivity of the illumination light emitted from the exit end decreases. Therefore, even if the exit surface of the light-emitting element is increased, the luminous efficiency of the light-emitting element will decrease (the eccentricity increases). Utility Model Content

[0006] To address the aforementioned issues, the lighting device of this utility model is characterized by comprising: a light source device having a light-emitting surface emitting a first light; a first light guide element having a first reflective surface and a first emitting end, wherein the first reflective surface reflects the first light emitted from the light-emitting surface on its inner surface, and the first emitting end emits the first light reflected by the first reflective surface; and a second light guide element having a second incident end, a second emitting end, and a second reflective surface, wherein the first light emitted from the first emitting end is incident on the second incident end, and the first light emitted from the second incident end emits light from the second incident end. The first light emitted is reflected by the second reflecting surface on its inner surface. The first light incident from the second incident end is reflected by the second reflecting surface on its inner surface. The light source device, the first light guide element, and the second light guide element are arranged in the order of the optical axis of the first light guide element. The first reflecting surface is tilted towards the optical axis in the direction of the first light's travel. When the area of ​​the emitting surface is set to S1, the area of ​​the first emitting surface of the first emitting end is set to S2, the area of ​​the second incident surface of the second incident end is set to S3, and the area of ​​the second emitting surface of the second emitting end is set to S4, the following condition is satisfied.

[0007] S4>S1>S3≥S2

[0008] The projector of this invention is characterized by comprising: the aforementioned illumination device; a light modulation element that modulates the first light emitted from the illumination device to form a projected image; and a projection lens that projects the projected image as a magnified image. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the main parts of the projector in Embodiment 1.

[0010] Figure 2 This is a 3D view of the first light guide element.

[0011] Figure 3 This is a 3D view of the second light guide element.

[0012] Figure 4 This is a schematic diagram of the main parts of the projector in Embodiment 2.

[0013] Figure 5 This is a schematic diagram of the main parts of the projector in Embodiment 3.

[0014] Figure 6 This is a schematic diagram of the main parts of the projector in Embodiment 4.

[0015] Figure 7 This is a schematic diagram of the main parts of the projector in Embodiment 5.

[0016] Figure 8 This is a schematic diagram of the main parts of the projector in Embodiment 6.

[0017] Label Explanation

[0018] 1, 1A, 1B, 1C, 1D, 1E: Projector; 2: Illumination device; 2A: First illumination device; 2B: Second illumination device; 2C: Third illumination device; 3: Image forming unit; 3A: First image forming unit; 3B: Second image forming unit; 3C: Third image forming unit; 4: Projection lens; 5: Control unit; 10, 10C, 10D, 10G, 10R, 10B: Light source device; 21, 21A, 21B, 21C: First light guide element; 22: First incident end; 23: First exit end; 24: First reflecting surface; 25, 25A, 25B: Second light guide element; 26: Second incident end; 27: Second exit end End; 28: Second reflecting surface; 31, 31G, 31R, 31B: Light modulation element; 32: Second polarizing plate; 33: Second Fresnel lens; 35: First polarizing plate; 36: First Fresnel lens; 100: Emitting surface; 111: Light source; 112: Phosphor layer; 113: Substrate; 114: Exit surface; 115: Diffuser plate; 116: Phosphor layer; 117: Exit surface; 220: First incident surface; 230: First exit surface; 240: Curved surface; 260: Second incident surface; 270: Second exit surface; 310: Liquid crystal panel; L: First light; N: Optical axis of the first light guide element; M: Optical axis of the second light guide element; S: Screen. Detailed Implementation

[0019] Implementation Method 1

[0020] Figure 1 This is a schematic diagram of the main components of the projector according to Embodiment 1. (As shown...) Figure 1 As shown, the projector 1 includes: an illumination device 2; an image forming unit 3 that generates a projected image projected onto a screen S; a projection lens 4 that magnifies the projected image and projects it onto the screen S; and a control unit 5 that controls the operation of the image forming unit 3.

[0021] The lighting device 2 includes a light source device 10, a first light guide element 21, and a second light guide element 25. The light source device 10, the first light guide element 21, and the second light guide element 25 are arranged in the order of the optical axis N of the first light guide element 21.

[0022] The light source device 10 has a light-emitting surface 100 that emits a first light L. The light source device 10 includes a light source 111, a phosphor layer 112 that converts the light emitted from the light source 111 into the first light L, and a substrate 113 on which the light source 111 is arranged. The light-emitting surface 100 is the emission surface 114 of the phosphor layer 112. The area of ​​the light-emitting surface 100 is 0.3 mm². 2~20mm 2 .

[0023] Light source 111 is an LED element. The LED element, for example, emits blue light. A phosphor layer 112 covers the light source 111 at the substrate 113. The phosphor layer 112, for example, converts the blue light emitted by the light source 111 into a first light L, which is white light. In this case, the phosphor layer 112 is composed of a phosphor that emits red light and a phosphor that emits green light. Furthermore, the color of the light emitted by the light source 111 is not limited to blue light. Additionally, the first light L converted by the phosphor layer 112 is not limited to white light.

[0024] The first light guide element 21 reflects the first light L incident from the light source device 10 on its inner surface and emits it. The second light guide element 25 reflects the first light L incident from the first light guide element 21 on its inner surface and emits it. Here, the illumination device 2 includes: a reflective first polarizer 35 disposed between the first light guide element 21 and the second light guide element 25; and a first Fresnel lens 36 disposed on the emission side of the second light guide element 25. The first Fresnel lens 36 parallelizes the first light L emitted from the second light guide element 25.

[0025] The first polarizing plate 35 reflects one of the P-polarized and S-polarized components of the first light L emitted from the first light guide element 21, allowing the other to pass through. In this configuration, the first polarizing plate 35 reflects the S-polarized component of the first light L emitted from the first light guide element 21, allowing the P-polarized component to pass through. The reflected S-polarized component of the first light L passes through the phosphor layer 112, is reflected on the surface of the substrate 113, and then exits from the phosphor layer 112 again. Furthermore, when exiting from the phosphor layer 112, the S-polarized component of the first light L becomes unpolarized light containing the P-polarized component. The S-polarized component in the unpolarized first light L is reflected at the first polarizing plate 35, while the P-polarized component passes through.

[0026] The image forming unit 3 includes a light modulation element 31, a second polarizing plate 32, and a second Fresnel lens 33. The light modulation element 31 modulates the first light L from the first Fresnel lens 36 into modulated light to form a projected image. The light modulation element 31 is a liquid crystal panel 310. The effective display area of ​​the liquid crystal panel 310 is 0.3 inches to 7.0 inches in size. In this embodiment, the liquid crystal panel 310 is composed of a single panel and has pixels corresponding to each color of light. Thus, the liquid crystal panel 310 modulates the first light L, which is white light, according to the color light corresponding to each pixel, to form a full-color image light.

[0027] The second polarizer 32 is disposed on the emission side of the optical modulation element 31, allowing one of the P-polarization component and the S-polarization component of the polarization composition contained in the modulated light emitted from the optical modulation element 31 to pass through. In this configuration, the second polarizer 32 allows the S-polarization component of the polarization composition contained in the modulated light emitted from the optical modulation element 31 to pass through. The second Fresnel lens 33 focuses the modulated light emitted from the second polarizer 32 onto the projection lens 4.

[0028] The projection lens 4 has multiple lenses. The control unit 5 operates the liquid crystal panel 310 based on external image signals such as video signals.

[0029] First light guide element

[0030] Figure 2 This is a perspective view of the first light guide element 21. The first light guide element 21 is made of metal. The first light guide element 21 is formed by processing plate components made of stainless steel, aluminum, copper, etc. Figure 1 and Figure 2 As shown, the first light guide element 21 includes: a first incident end 22, to which the first light L is incident; a first reflective surface 24, which reflects the first light L on its inner surface; and a first exiting end 23, which exits the first light L reflected by the first reflective surface 24. The first light guide element 21 has a hollow structure and is a cylindrical reflector with openings at the first incident end 22 and the first exiting end 23, respectively.

[0031] A first incident surface 220 is formed at the first incident end 22. A first exit surface 230 is formed at the first exit end 23. Both the first incident surface 220 and the first exit surface 230 are circular. When viewed from the direction along the optical axis N, the first incident surface 220 overlaps with the light-emitting surface 100 of the light source device 10, and the size of the first incident surface 220 is greater than or equal to the size of the light-emitting surface 100. The area of ​​the first exit surface 230 is 0.15 mm². 2 ~10mm 2 .

[0032] The first reflecting surface 24 is inclined toward the optical axis N from the first incident end 22 toward the first exit end 23. That is, the first reflecting surface 24 is inclined toward the optical axis N along the direction of travel of the first light L. Therefore, the beam width of the first light L decreases and is focused along the direction of travel of the first light L.

[0033] The first reflective surface 24 is the inner surface of the first light guide element 21. The first reflective surface 24 is a curved surface 240 that bends radially outward relative to the optical axis N of the first light guide element 21. The curved surface 240 has a rotationally symmetric shape with the optical axis N as the center of rotation. In addition, the first reflective surface 24 can be mirror-finished. Alternatively, a reflective film can be coated on the first reflective surface 24.

[0034] Second light guide element

[0035] Figure 3 This is a perspective view of the second light guide element 25. The second light guide element 25 is made of metal. It is formed by processing sheet components made of stainless steel, aluminum, copper, etc. Figure 1 and Figure 3 As shown, the second light guide element 25 includes: a second incident end 26, to which the first light L emitted from the first exit end 23 is incident; a second exit end 27, which emits the first light L incident from the second incident end 26; and a second reflective surface 28, which reflects the first light L incident from the second incident end 26 on its inner surface. The second light guide element 25 has a hollow structure and is a cylindrical reflector with openings at both the second incident end 26 and the second exit end 27. The optical axis M of the second light guide element 25 is aligned with the optical axis N of the first light guide element 21.

[0036] A second incident surface 260 is formed at the second incident end 26. A second exit surface 270 is formed at the second exit end 27. Both the second incident surface 260 and the second exit surface 270 are rectangular. The area of ​​the second incident surface 260 is 0.15 mm. 2 ~10mm 2 The area of ​​the second exit surface 270 is 57.1424 mm. 2 ~14630.04mm 2 .

[0037] The second reflecting surface 28 is the inner surface of the second light guide element 25. The second reflecting surface 28 is a plane that is radially outward relative to the optical axis M, extending from the second incident end 26 to the second exit end 27. Therefore, the beam width of the first light L increases with the direction of travel of the first light L. Furthermore, the second reflecting surface 28 can be mirror-finished. Additionally, a reflective film can be coated on the second reflecting surface 28.

[0038] Here, when the area of ​​the light-emitting surface 100 is set to S1, the area of ​​the first emission surface 230 of the first emission end 23 is set to S2, the area of ​​the second emission surface 260 of the second incident end 26 is set to S3, and the area of ​​the second emission surface 270 of the second emission end 27 is set to S4, the following conditional expression is satisfied.

[0039] S4>S1>S3≥S2

[0040] Effects

[0041] The projector 1 of this method includes: a light source device 10 having a light-emitting surface 100 for emitting a first light L; a first light guide element 21 having a first reflective surface 24 and a first emission end 23, wherein the first reflective surface 24 reflects the first light emitted from the light-emitting surface 100 on its inner surface, and the first emission end 23 emits the first light L reflected by the first reflective surface 24; and a second light guide element 25 having a second incident end 26, a second emission end 27, and a second reflective surface 28, wherein the first light L emitted from the first emission end 23 is incident on the second incident end 26, the second emission end 27 emits the first light L incident from the second incident end 26, and the second reflective surface 28 reflects the first light L incident from the second incident end 26 on its inner surface. The light source device 10, the first light guide element 21, and the second light guide element 25 are arranged in the order of the optical axis N of the first light guide element 21. The first reflecting surface 24 is tilted toward the optical axis N in the direction of the first light L. When the area of ​​the emitting surface 100 is set as S1, the area of ​​the first emitting surface 230 of the first emitting end 23 is set as S2, the area of ​​the second emitting surface 260 of the second emitting end 26 is set as S3, and the area of ​​the second emitting surface 270 of the second emitting end 27 is set as S4, the following conditional expression is satisfied.

[0042] S4>S1>S3≥S2

[0043] According to this method, the first light guide element 21 can emit a first light L with a reduced beam width due to the first reflective surface 24 from the first emitting surface 230. Therefore, even if the area of ​​the emitting surface 100 is larger than the area of ​​the second incident surface 260, the second light guide element 25 can still capture the first light L from the first light guide element 21 without increasing the area of ​​the second incident surface 260. As a result, even if the area of ​​the emitting surface 100 is increased, the decrease in light efficiency (increased optical extension) of the light source device 10 can be suppressed. In addition, the area of ​​the second incident surface 260 is equal to or larger than the area of ​​the first emitting surface 230, so the second light guide element 25 can effectively capture the first light L from the first light guide element 21. Furthermore, the area of ​​the second emitting surface 270 is larger than the area of ​​the emitting surface 100, thus suppressing the enlargement of the lighting device 2.

[0044] The first reflective surface 24 has a curved surface 240 that bends radially outward relative to the optical axis N of the first light guide element 21. As a result, the first light guide element 21 can use the curved surface 240 to make the first light L emitted from the first emission surface 230 uniform, and can reduce the radiation angle of the first light L emitted from the first light guide element 21, thereby suppressing the reduction of the light efficiency of the light source device 10.

[0045] The light source device 10 includes: a light source 111 that emits light; and a phosphor layer 112 that converts the light emitted from the light source 111 into a first light L. The light-emitting surface 100 is the emitting surface of the phosphor layer 112. Thus, the wavelength of the first light L can be converted using the phosphor layer 112.

[0046] The lighting device 2 includes a reflective first polarizer 35 disposed between the first emission end 23 and the second incident end 26. This allows for a reduction in the size of the first polarizer 35 compared to disposing it on the emission side of the second light guide element 25. Furthermore, since the first polarizer 35 is reflective, the polarized component of the first light L, reflected by the first polarizer 35, after passing through the phosphor layer 112, is reflected again from the surface of the substrate 113 of the light source 111 and reaches the first polarizer 35. Here, the first light L reaching the first polarizer 35 again becomes unpolarized light during its journey to the first polarizer 35. Therefore, even when the first polarizer 35 is disposed between the first emission end 23 and the second incident end 26, the utilization efficiency of the first light L can be improved.

[0047] The second emission surface 270 is rectangular. As a result, the beam of the first light L emitted from the second emission surface 270 can be rectangular, thus enabling efficient illumination of the liquid crystal panel 310 used by the projector 1 when the illumination device 2 illuminates it.

[0048] The first light guide element 21 and the second light guide element 25 are made of metal. This allows for the internal structure to be a reflective surface. Furthermore, the first light guide element 21 and the second light guide element 25 are easy to manufacture. Additionally, the component strength of the first light guide element 21 and the second light guide element 25 can be improved.

[0049] The first light guide element 21 has a hollow structure. This reduces the weight of the first light guide element 21. In addition, since the interior of the first light guide element 21 is a cavity, air can circulate inside the first light guide element 21, which improves the heat dissipation effect.

[0050] The second light guide element 25 has a hollow structure. This reduces the weight of the second light guide element 25. In addition, since the interior of the second light guide element 25 is a cavity, air can circulate inside the second light guide element 25, which improves the heat dissipation effect.

[0051] The lighting device 2 includes a first Fresnel lens 36, which parallelizes the first light L emitted from the second light guide element 25. This allows a light beam larger than the emitting surface 100 to become parallel light.

[0052] The projector 1 of this method includes: an illumination device 2; a light modulation element 31 that modulates a first light L emitted from the illumination device 2 to form a projected image; and a projection lens 4 that projects the projected image as a magnified image. Therefore, for the first light L emitted from the illumination device 2, since the enlargement of the optical extension is suppressed, light loss in the light modulation element 31 and the projection lens 4 can be reduced. As a result, a bright projector 1 can be achieved.

[0053] The area of ​​the light-emitting surface 100 is 0.3 mm. 2 ~20mm 2 The area of ​​the first exit surface 230 is 0.15 mm. 2 ~10mm 2 The area of ​​the second incident surface 260 is 0.15 mm. 2 ~10mm 2 The area of ​​the second exit surface 270 is 57.1424 mm. 2 ~14630.04mm 2 This ensures the brightness of projector 1 and prevents projector 1 from becoming too large.

[0054] The effective display area of ​​the light modulation element 31 is 0.3 inches to 7.0 inches in size. This helps to suppress the enlargement of the light modulation element 31 and suppress the reduction of the light efficiency of the light source device 10.

[0055] Implementation Method 2

[0056] Figure 4 This is a schematic diagram of the main parts of the projector 1A according to Embodiment 2. The first light guide element 21A and the second light guide element 25A of the projector 1A in Embodiment 2 are different from those of the projector 1 in Embodiment 1. Therefore, in Embodiment 2, the same reference numerals are sometimes used for structures that are the same as those in Embodiment 1, and the description is omitted.

[0057] like Figure 4 As shown, the lighting device 2 includes a light source device 10, a first light guide element 21A, and a second light guide element 25A. The light source device 10, the first light guide element 21A, and the second light guide element 25A are arranged in the order of the optical axis N of the first light guide element 21A.

[0058] The lighting device 2 includes: a reflective first polarizing plate 35 disposed between the first light guide element 21A and the second light guide element 25A; and a first Fresnel lens 36 disposed on the emission side of the second light guide element 25A.

[0059] The first light guide element 21A is made of resin or glass. For example... Figure 4As shown, the first light guide element 21A includes: a first incident end 22, to which the first light L is incident; a first reflecting surface 24, which reflects the first light L on its inner surface; and a first exiting end 23, which exits the first light L reflected by the first reflecting surface 24. The first light guide element 21A is a solid structure and is an internally reflecting optical rod.

[0060] A first incident surface 220 is formed at the first incident end 22. A first exit surface 230 is formed at the first exit end 23. Both the first incident surface 220 and the first exit surface 230 are circular. When viewed from the direction along the optical axis N, the first incident surface 220 overlaps with the light-emitting surface 100 of the light source device 10, and the size of the first incident surface 220 is greater than or equal to the size of the light-emitting surface 100. The area of ​​the first exit surface 230 is 0.15 mm². 2 ~10mm 2 .

[0061] The first reflective surface 24 is formed by providing a reflective coating on the outer surface of the first light guide element 21A. The first reflective surface 24 is inclined towards the optical axis N from the first incident end 22 to the first exit end 23. That is, the first reflective surface 24 is inclined towards the optical axis N along the direction of travel of the first light L. Therefore, the beam width of the first light L decreases and is focused along the direction of travel of the first light L. The first reflective surface 24 is a curved surface 240 that is bent radially outward relative to the optical axis N of the first light guide element 21. The curved surface 240 has a rotationally symmetric shape with the optical axis N as the center of rotation.

[0062] The second light guide element 25A is made of resin or glass. For example... Figure 4 As shown, the second light guide element 25A includes: a second incident end 26, to which the first light L emitted from the first exit end 23 is incident; a second exit end 27, which emits the first light L incident from the second incident end 26; and a second reflecting surface 28, which reflects the first light L incident from the second incident end 26 on its inner surface. The second light guide element 25A is a solid structure and is an inner-surface reflective optical rod. The optical axis M of the second light guide element 25A is aligned with the optical axis N of the first light guide element 21A.

[0063] A second incident surface 260 is formed at the second incident end 26. A second exit surface 270 is formed at the second exit end 27. Both the second incident surface 260 and the second exit surface 270 are rectangular. The area of ​​the second incident surface 260 is 0.15 mm. 2 ~10mm 2 The area of ​​the second exit surface 270 is 57.1424 mm. 2 ~14630.04mm 2 .

[0064] The second reflective surface 28 is formed by providing a reflective coating on the outer surface of the second light guide element 25A. In this configuration, the second reflective surface 28 is a plane that is radially outward relative to the optical axis M, extending from the second incident end 26 to the second exit end 27. Therefore, the beam width of the first light L increases with the direction of travel of the first light L.

[0065] Here, when the area of ​​the light-emitting surface 100 is set to S1, the area of ​​the first emission surface 230 of the first emission end 23 is set to S2, the area of ​​the second emission surface 260 of the second incident end 26 is set to S3, and the area of ​​the second emission surface 270 of the second emission end 27 is set to S4, the following conditional expression is satisfied.

[0066] S4>S1>S3≥S2

[0067] Effects

[0068] The first light guide element 21A is a solid structure. The second light guide element 25A is a solid structure. This improves the component strength of the first light guide element 21A and the second light guide element 25A. With the same structure as Embodiment 1, Embodiment 2 achieves the same effects as Embodiment 1.

[0069] Implementation Method 3

[0070] Figure 5 This is a schematic diagram of the main parts of the projector 1B according to Embodiment 3. The first light guide element 21B and the second light guide element 25B of the projector 1B in Embodiment 3 are different from those of the projector 1 in Embodiment 1. Therefore, in Embodiment 3, the same reference numerals are sometimes used for structures that are the same as those in Embodiment 1, and descriptions are omitted.

[0071] like Figure 5 As shown, the lighting device 2 includes a light source device 10, a first light guide element 21B, and a second light guide element 25B. The light source device 10, the first light guide element 21B, and the second light guide element 25B are arranged in the order of optical axis N of the first light guide element 21B. In this embodiment, the first light guide element 21B and the second light guide element 25B are formed as a single unit.

[0072] The lighting device 2 includes: a reflective first polarizing plate 35 disposed on the emission side of the second light guide element 25B; and a first Fresnel lens 36 disposed on the emission side of the first polarizing plate 35.

[0073] The first polarizing plate 35 reflects one of the P-polarized and S-polarized components of the first light L emitted from the second light guide element 25B, while allowing the other to pass through. In this configuration, the first polarizing plate 35 reflects the S-polarized component of the first light L emitted from the second light guide element 25B, while allowing the P-polarized component to pass through.

[0074] The first light guide element 21B and the second light guide element 25B are made of metal. They are formed by machining sheet metal components made of stainless steel, aluminum, copper, etc. Figure 5 As shown, the first light guide element 21B includes: a first incident end 22, to which the first light L is incident; a first reflecting surface 24, which reflects the first light L on its inner surface; and a first exiting end 23, which exits the first light L reflected by the first reflecting surface 24. The first light guide element 21B has a hollow structure and is a cylindrical reflector with openings at the first incident end 22 and the first exiting end 23, respectively.

[0075] A first incident surface 220 is formed at the first incident end 22. A first exit surface 230 is formed at the first exit end 23. The first incident surface 220 is circular. When viewed from the direction along the optical axis N, the first incident surface 220 overlaps with the light-emitting surface 100 of the light source device 10, and the size of the first incident surface 220 is greater than or equal to the size of the light-emitting surface 100. The area of ​​the first exit surface 230 is 0.15 mm². 2 ~10mm 2 .

[0076] The first reflecting surface 24 is inclined towards the optical axis N from the first incident end 22 to the first exit end 23. That is, the first reflecting surface 24 is inclined towards the optical axis N along the direction of travel of the first light L. Therefore, the beam width of the first light L decreases and is focused along the direction of travel of the first light L. The first reflecting surface 24 is a curved surface 240 that is bent radially outward relative to the optical axis N of the first light guide element 21. The curved surface 240 has a rotationally symmetric shape with the optical axis N as the center of rotation.

[0077] like Figure 5 As shown, the second light guide element 25B includes: a second incident end 26, to which a first light L emitted from a first exit end 23 is incident; a second exit end 27, which emits the first light L incident from the second incident end 26; and a second reflective surface 28, which reflects the first light L incident from the second incident end 26 on its inner surface. The second light guide element 25B has a hollow structure and is a cylindrical reflector with openings at both the second incident end 26 and the second exit end 27. The optical axis M of the second light guide element 25B is aligned with the optical axis N of the first light guide element 21B.

[0078] A second incident surface 260 is formed at the second incident end 26. A second exit surface 270 is formed at the second exit end 27. The second exit surface 270 is rectangular. The second incident surface 260 has the same shape as the first exit surface 230. The first exit surface 230 and the second incident surface 260 can be circular, rectangular, elliptical, polygonal, etc. The area of ​​the second incident surface 260 is 0.15 mm². 2 ~10mm 2 The area of ​​the second exit surface 270 is 57.1424 mm. 2 ~14630.04mm 2 .

[0079] The second reflecting surface 28 is a plane that is radially outward relative to the optical axis M, extending from the second incident end 26 to the second exit end 27. Therefore, the beam width of the first light L increases with the direction of travel of the first light L. The second reflecting surface 28 is formed by mirror finishing the interior of the second light guide element 25. Alternatively, the second reflecting surface 28 can also be formed by coating the interior of the second light guide element 25 with a reflective film.

[0080] Here, when the area of ​​the light-emitting surface 100 is set to S1, the area of ​​the first emission surface 230 of the first emission end 23 is set to S2, the area of ​​the second emission surface 260 of the second incident end 26 is set to S3, and the area of ​​the second emission surface 270 of the second emission end 27 is set to S4, the following conditional expression is satisfied.

[0081] S4>S1>S3≥S2

[0082] Effects

[0083] In this embodiment, the first light guide element 21B and the second light guide element 25B are formed as a single unit. This allows the first light guide element 21B and the second light guide element 25B to be configured as a single component, thus reducing component costs. Furthermore, the second light guide element 25B can capture all the first light L from the first light guide element 21B; therefore, compared to the case where the first light guide element 21B and the second light guide element 25B are separate components, light loss can be reduced, and the first light L emitted from the second light guide element 25B can be made brighter. With the same structure as Embodiment 1, Embodiment 3 achieves the same effects as Embodiment 1.

[0084] Implementation Method 4

[0085] Figure 6This is a schematic diagram of the main parts of the projector 1C in Embodiment 4. The light source device 10C and the first light guide element 21C of the projector 1C in Embodiment 4 are different from those of the projector 1 in Embodiment 1. Therefore, in Embodiment 4, the same reference numerals are sometimes used for structures that are the same as those in Embodiment 1, and descriptions are omitted.

[0086] like Figure 6 As shown, the lighting device 2 includes a light source device 10C, a first light guide element 21C, and a second light guide element 25. The light source device 10C, the first light guide element 21C, and the second light guide element 25 are arranged in the order of the optical axis N of the first light guide element 21C.

[0087] The light source device 10C has a light-emitting surface 100 that emits a first light L. The light source device 10C includes a light source 111, a phosphor layer 112 that converts the light emitted from the light source 111 into the first light L, and a substrate 113 on which the light source 111 is arranged. The light source 111 is an LED element. The phosphor layer 112 is disposed inside a first light guide element 21C. The light-emitting surface 100 is the emission surface 114 of the phosphor layer 112. The area of ​​the light-emitting surface 100 is 0.3 mm². 2 ~20mm 2 .

[0088] The first light guide element 21C has a fluorescent layer 112 disposed inside it, and is otherwise identical in structure to the first light guide element 21 of Embodiment 1. In this embodiment, the entire internal space of the first light guide element 21C is filled with the fluorescent layer 112. The light-emitting surface 100 includes a portion that is in contact with the first reflective surface 24. Alternatively, only a portion of the internal space of the first light guide element 21C may be filled with the fluorescent layer 112.

[0089] Here, when the area of ​​the light-emitting surface 100 is set to S1, the area of ​​the first emission surface 230 of the first emission end 23 is set to S2, the area of ​​the second emission surface 260 of the second incident end 26 is set to S3, and the area of ​​the second emission surface 270 of the second emission end 27 is set to S4, the following conditional expression is satisfied.

[0090] S4>S1>S3≥S2

[0091] Effects

[0092] Even when a fluorescent layer 112 is arranged in the internal space of the first light guide element 21C, Embodiment 4 can achieve the same effect as Embodiment 1.

[0093] Implementation Method 5

[0094] Figure 7This is a schematic diagram of the main parts of the projector 1D in Embodiment 5. The light source device 10D of the projector 1D in Embodiment 5 is different from that of the projector 1 in Embodiment 1. Therefore, in Embodiment 5, the same reference numerals are sometimes used for structures that are the same as those in Embodiment 1, and descriptions are omitted.

[0095] like Figure 7 As shown, the lighting device 2 includes a light source device 10D, a first light guide element 21, and a second light guide element 25. The light source device 10D, the first light guide element 21, and the second light guide element 25 are arranged in the order of the optical axis N of the first light guide element 21.

[0096] The light source device 10D has a light-emitting surface 100 that emits a first light L. The light source device 10D includes: a light source 111; a diffuser 115 that diffuses the light emitted from the light source 111; and a phosphor layer 116 that converts the light diffused by the diffuser 115 into the first light L. The light source 111 is a semiconductor laser. For example, the semiconductor laser emits blue light. The phosphor layer 116 is disposed on the emission side of the diffuser 115. The light-emitting surface 100 is the emission surface 117 of the phosphor layer 116. The area of ​​the light-emitting surface 100 is 0.3 mm. 2 ~20mm 2 The fluorescent layer 116, for example, converts the blue light diffused by the diffuser plate 115 into a first light L, which is white light. In this case, the fluorescent layer 116 is composed of a phosphor that emits red light and a phosphor that emits green light. Furthermore, the color of the light emitted from the light source 111 is not limited to blue light. In addition, the first light L converted by the fluorescent layer 116 is not limited to white light.

[0097] Here, when the area of ​​the light-emitting surface 100 is set to S1, the area of ​​the first emission surface 230 of the first emission end 23 is set to S2, the area of ​​the second emission surface 260 of the second incident end 26 is set to S3, and the area of ​​the second emission surface 270 of the second emission end 27 is set to S4, the following conditional expression is satisfied.

[0098] S4>S1>S3≥S2

[0099] Effects

[0100] In this embodiment, the light source device 10 includes a diffuser plate 115 between the light source 111 and the phosphor layer 116 to diffuse the light emitted from the light source 111. The light source 111 is a semiconductor laser. This increases the intensity of the light from the light source 111, thereby improving the conversion efficiency at the phosphor layer 116 for the first light L. Furthermore, the diffuser plate 115 increases the diffusion angle of the light incident on the phosphor layer 116, thus suppressing leakage that occurs when the first light L is emitted from the phosphor layer 116. With the same structure as Embodiment 1, Embodiment 5 achieves the same effects as Embodiment 1.

[0101] Implementation Method 6

[0102] Figure 8 This is a schematic diagram of the main components of the projector 1E according to embodiment 6. Figure 8 As shown, the projector 1E directs light from three light sources through light guide elements to three light modulation elements, and combines the three image lights for projection. The projector 1E includes three illumination devices 2, three image forming units 3, a light combining element 9, a projection lens 4, and a control unit that controls the operation of the image forming units 3.

[0103] The lighting device 2 includes a first lighting device 2A, a second lighting device 2B, and a third lighting device 2C. The first lighting device 2A, the second lighting device 2B, and the third lighting device 2C each include a light source device 10, a first light guide element 21, and a second light guide element 25. The first light guide element 21 and the second light guide element 25 are the same as those in the projector 1 of Embodiment 1.

[0104] The first lighting device 2A emits a first light from its light source device 10G. The second lighting device 2B emits a second light, different from the first light, from its light source device 10R. The third lighting device 2C emits a third light, different from both the first and second light, from its light source device 10B. The first light is green. The second light is red. The third light is blue. The basic structure of each light source device 10 is the same as that of the light source device 10 in Embodiment 1.

[0105] Each light source 111 is an LED element. Each phosphor layer 112 converts the light emitted from the light source 111 according to the color of the light emitted from each light source device 10.

[0106] The image forming unit 3 includes a first image forming unit 3A, a second image forming unit 3B, and a third image forming unit 3C. The first image forming unit 3A, the second image forming unit 3B, and the third image forming unit 3C each include a light modulation element 31, a second polarizing plate 32, and a second Fresnel lens 33. The second polarizing plate 32 and the second Fresnel lens 33 are the same as those in the projector 1 of Embodiment 1.

[0107] The light modulation element 31G of the first image forming unit 3A modulates green light into modulated light to form a projected image. The light modulation element 31R of the second image forming unit 3B modulates red light into modulated light to form a projected image. The light modulation element 31B of the third image forming unit 3C modulates blue light into modulated light to form a projected image. Each light modulation element 31 is a liquid crystal panel 310.

[0108] Three modulated lights are incident on the light combining element 9 from different directions. The projector 1E magnifies the full-color projected image emitted from the light combining element 9 and projects it onto the screen S.

[0109] Effects

[0110] As in this method, in a projector using three LCD panels 310, embodiment 6 can also achieve the same effect as embodiment 1.

[0111] Variations

[0112] The projector in the modified embodiment of embodiment 1 may also use the first light guide element 21A of embodiment 2 instead of the first light guide element 21 of embodiment 1. In addition, the projector in the modified embodiment of embodiment 1 may use the second light guide element 25A of embodiment 2 instead of the second light guide element 25 of embodiment 1.

[0113] The projector in a modified embodiment of 1 may also include a transparent cover component that blocks the opening of the first emission end 23.

[0114] In the projector 1 of Embodiment 1, the first light guide element 21 is made of metal, but in the projector of a variation of Embodiment 1, the first light guide element 21 may also be made of resin or glass. In this case, the first reflective surface 24 is formed by coating the interior of the first light guide element 21 with a reflective film.

[0115] In the projector 1 of Embodiment 1, the second light guide element 25 is made of metal, but in the projector of a modified embodiment of Embodiment 1, the second light guide element 25 may also be made of resin or glass. In this case, a second reflective surface 28 is formed by coating the interior of the second light guide element 25 with a reflective film.

[0116] In the projector 1 of Embodiment 1, the first polarizing plate 35 is disposed between the first light guide element 21 and the second light guide element 25. However, in the projector of the modified embodiment 1, the first polarizing plate 35 may also be disposed on the emission side of the second light guide element 25. Similarly, in the projector of the modified embodiment 2, the first polarizing plate 35 may also be disposed on the emission side of the second light guide element 25A.

[0117] In the above manner, the first reflective surface 24 is a curved surface 240 that bends radially outward relative to the optical axis N of the first light guide element 21, but the first reflective surface 24 can also be a surface that extends radially outward in a straight line relative to the optical axis N.

[0118] In the above method, the first incident surface 220 and the first exit surface 230 are circular, but the first incident surface 220 and the first exit surface 230 can also be rectangular, elliptical, or polygonal.

[0119] In the above method, the second exit surface 270 is rectangular, but the second exit surface 270 can also be circular, elliptical, or polygonal.

[0120] This is a summary of the disclosure.

[0121] The following is a summary published in this note.

[0122] Postscript 1

[0123] A lighting device, characterized in that it comprises:

[0124] A light source device having a light-emitting surface that emits the first light;

[0125] A first light guiding element has a first reflective surface and a first emitting end, wherein the first reflective surface reflects the first light emitted from the light emitting surface on its inner surface, and the first emitting end emits the first light reflected by the first reflective surface; and

[0126] The second light guide element has a second incident end, a second exit end, and a second reflective surface. The first light emitted from the first exit end is incident on the second incident end, and the second exit end emits the first light incident from the second incident end. The second reflective surface reflects the first light incident from the second incident end on its inner surface.

[0127] The light source device, the first light guide element, and the second light guide element are arranged along the optical axis of the first light guide element in the following order:

[0128] The first reflecting surface is tilted toward the optical axis in the direction of the first light's travel.

[0129] When the area of ​​the emitting surface is set to S1, the area of ​​the first emitting surface of the first emitting end is set to S2, the area of ​​the second incident surface of the second incident end is set to S3, and the area of ​​the second emitting surface of the second emitting end is set to S4, the following condition is satisfied:

[0130] S4>S1>S3≥S2.

[0131] Therefore, the first light guide element can emit first light with a reduced beam width due to the first reflecting surface from the first emitting surface. Thus, even if the area of ​​the emitting surface is larger than the area of ​​the second incident surface, the second light guide element can still capture the first light from the first light guide element without increasing the area of ​​the second incident surface. Consequently, even with an increased emitting surface area, the decrease in luminous efficiency (increased optical extension) of the light source device can be suppressed. Furthermore, since the area of ​​the second incident surface is equal to or larger than the area of ​​the first emitting surface, the second light guide element can effectively capture the first light from the first light guide element. Moreover, the area of ​​the second emitting surface is larger than the area of ​​the emitting surface, thus suppressing the enlargement of the lighting device.

[0132] Appendix 2

[0133] The lighting device according to Appendix 1 is characterized in that,

[0134] The first reflective surface has a curved surface that is radially outward relative to the optical axis of the first light guide element.

[0135] Therefore, the first light guide element can make the first light emitted from the first emission surface uniform by using the curved surface, and can reduce the radiation angle of the first light emitted from the first light guide element, thus suppressing the reduction of the light efficiency of the light source device.

[0136] Appendix 3

[0137] The lighting device according to Appendix 1 or 2 is characterized in that,

[0138] The light source device includes: a light source that emits light; and a fluorescent layer that converts the light emitted by the light source into the first light.

[0139] The light-emitting surface is the emission surface of the fluorescent layer.

[0140] Therefore, the wavelength of the first light can be converted using the fluorescent layer.

[0141] Appendix 4

[0142] The lighting device according to Appendix 3 is characterized in that,

[0143] The light source device has a diffuser plate between the light source and the fluorescent layer to diffuse the light emitted from the light source.

[0144] The light source is a semiconductor laser.

[0145] This increases the intensity of light from the light source, thereby improving the conversion efficiency of the phosphor layer to the first light. Furthermore, the diffusion angle of light incident on the phosphor layer can be increased using a diffuser plate, thus suppressing leakage that occurs when the first light is emitted from the phosphor layer.

[0146] Appendix 5

[0147] The lighting device according to any one of Appendices 1 to 4 is characterized in that,

[0148] The lighting device also includes a reflective polarizing plate disposed between the first emission end and the second incident end.

[0149] Therefore, compared to placing the polarizer on the emission side of the second light guide element, the size of the polarizer can be reduced. Furthermore, since the polarizer is reflective, the polarized component of the first light, which is reflected by the polarizer, is reflected again at the surface of the light source after passing through the phosphor layer and then exits from the phosphor layer to reach the polarizer. Here, the first light reaching the polarizer again becomes unpolarized light during its journey up to the polarizer. Therefore, even when the polarizer is placed between the first emission end and the second incident end, the utilization efficiency of the first light can be improved.

[0150] Appendix 6

[0151] The lighting device according to any one of Appendices 1 to 4 is characterized in that,

[0152] The first light guide element and the second light guide element are integrated into one unit.

[0153] Therefore, the first light guide element and the second light guide element can be set as a single component, thereby reducing component costs. In addition, the second light guide element can capture all the first light from the first light guide element, so compared with the case where the first light guide element and the second light guide element are separately constructed, light loss can be reduced and the first light emitted from the second light guide element can be made brighter.

[0154] Appendix 7

[0155] The lighting device according to any one of Appendices 1 to 6 is characterized in that,

[0156] The second exit surface is rectangular.

[0157] Therefore, the beam of the first light emitted from the second emitting surface can be made rectangular, thus enabling efficient illumination of the liquid crystal panel when the lighting device, such as the liquid crystal panel used in the projector, is illuminating it.

[0158] Postscript 8

[0159] The lighting device according to any one of Appendices 1 to 7 is characterized in that,

[0160] The first light guide element and the second light guide element are made of metal.

[0161] Therefore, the interior can be designed as a reflective surface. Furthermore, the first and second light guide elements are easier to manufacture. Additionally, the component strength of the first and second light guide elements can be improved.

[0162] Postscript 9

[0163] The lighting device according to any one of Appendices 1 to 8 is characterized in that,

[0164] The first light guide element has a hollow structure.

[0165] This reduces the weight of the first light guide element. Furthermore, since the first light guide element has a hollow interior, air circulation within it improves its heat dissipation.

[0166] Postscript 10

[0167] The lighting device according to any one of Appendices 1 to 9 is characterized in that,

[0168] The second light guide element has a hollow structure.

[0169] This reduces the weight of the second light guide element. Furthermore, since the second light guide element has a hollow interior, airflow within it improves its heat dissipation.

[0170] Postscript 11

[0171] The lighting device according to any one of Appendices 1 to 10 is characterized in that the lighting device further comprises a collimating lens that parallelizes the first light emitted from the second light guide element.

[0172] This allows a beam of light larger than the emitting surface to become parallel light.

[0173] Postscript 12

[0174] A projector, characterized in that it comprises:

[0175] The lighting device described in any one of Notes 1 to 11;

[0176] A light modulation element that modulates the first light emitted from the illumination device to form a projected image; and

[0177] A projection lens that projects the image as a magnified image.

[0178] Thus, a bright projector can be achieved by using a large-scale lighting device that suppresses optical extension.

[0179] Postscript 13

[0180] The projector according to Appendix 12 is characterized in that,

[0181] The area of ​​the light-emitting surface is 0.3 mm. 2 ~20mm 2 ,

[0182] The area of ​​the first exit surface is 0.15 mm.2 ~10mm 2 ,

[0183] The area of ​​the second incident surface is 0.15 mm. 2 ~10mm 2 ,

[0184] The area of ​​the second exit surface is 57.1424 mm. 2 ~14630.04mm 2 .

[0185] This ensures the brightness of the projector and prevents the projector from becoming too large.

[0186] Postscript 14

[0187] The projector according to appendix 12 or 13 is characterized in that,

[0188] The effective display area of ​​the optical modulation element is 0.3 inches to 7.0 inches in size.

[0189] Therefore, it is possible to suppress the enlargement of optical modulation elements and suppress the reduction of optical efficiency of light source devices.

Claims

1. A lighting device, characterized in that, have: A light source device having a light-emitting surface that emits the first light; The first light guide element has a first reflective surface and a first emitting end. The first reflective surface reflects the first light emitted from the light emitting surface on its inner surface, and the first emitting end emits the first light reflected by the first reflective surface. as well as The second light guide element has a second incident end, a second exit end, and a second reflective surface. The first light emitted from the first exit end is incident on the second incident end, and the second exit end emits the first light incident from the second incident end. The second reflective surface reflects the first light incident from the second incident end on its inner surface. The light source device, the first light guide element, and the second light guide element are arranged along the optical axis of the first light guide element in the following order: The first reflecting surface is tilted toward the optical axis in the direction of the first light's travel. When the area of ​​the emitting surface is set to S1, the area of ​​the first emitting surface of the first emitting end is set to S2, the area of ​​the second incident surface of the second incident end is set to S3, and the area of ​​the second emitting surface of the second emitting end is set to S4, the following condition is satisfied: S4>S1>S3≥S2.

2. The lighting device according to claim 1, characterized in that, The first reflective surface has a curved surface that is radially outward relative to the optical axis of the first light guide element.

3. The lighting device according to claim 1 or 2, characterized in that, The light source device includes: a light source that emits light; and a fluorescent layer that converts the light emitted by the light source into the first light. The light-emitting surface is the emission surface of the fluorescent layer.

4. The lighting device according to claim 3, characterized in that, The light source device has a diffuser plate between the light source and the fluorescent layer to diffuse the light emitted from the light source. The light source is a semiconductor laser.

5. The lighting device according to claim 1, characterized in that, The lighting device also includes a reflective polarizing plate disposed between the first emission end and the second incident end.

6. The lighting device according to claim 1, characterized in that, The first light guide element and the second light guide element are integrated into one unit.

7. The lighting device according to claim 1, characterized in that, The second exit surface is rectangular.

8. The lighting device according to claim 1, characterized in that, The first light guide element and the second light guide element are made of metal.

9. The lighting device according to claim 1, characterized in that, The first light guide element has a hollow structure.

10. The lighting device according to claim 1, characterized in that, The second light guide element has a hollow structure.

11. The lighting device according to claim 1, characterized in that, The lighting device also includes a collimating lens that parallelizes the first light emitted from the second light guide element.

12. A projector, characterized in that, have: The lighting device according to claim 1; A light modulation element that modulates the first light emitted from the illumination device to form a projected image; and A projection lens that projects the image as a magnified image.

13. The projector according to claim 12, characterized in that, The area of ​​the light-emitting surface is 0.3 mm. 2 ~20mm 2 , The area of ​​the first exit surface is 0.15 mm. 2 ~10mm 2 , The area of ​​the second incident surface is 0.15 mm. 2 ~10mm 2 , The area of ​​the second exit surface is 57.1424 mm. 2 ~14630.04mm 2 .

14. The projector according to claim 12 or 13, characterized in that, The effective display area of ​​the optical modulation element is 0.3 inches to 7.0 inches in size.

Images