Light source device, image projection device, and display device

Abstract

The present application relates to a light source device, an image projection device, and a display device for improving light conversion efficiency of a wavelength conversion element. The light source device includes a light source; an optical element having a lens array in which a plurality of lenses are arranged in an array on one or both surfaces, and a wavelength conversion element that converts the wavelength of light emitted from the light source and passing through the optical element, the distance P between the vertices of adjacent lenses of the optical element being 1 / 4 or less of the width D of the light beam of light incident on the optical element.

Description

TECHNICAL FIELD

[0001] The present application relates to a light source device, an image projection device, and a display device. BACKGROUND

[0002] In recent years, projectors (image projection devices) that enlarge and project various images are being widely spread. A projector is a device that condenses light emitted from a light source on a spatial light modulating element (image display element) such as a digital mirror device (DMD) or a liquid crystal display element, and causes the emitted light (reflected light) from the spatial light modulating element modulated based on an image signal to be displayed on a screen as a color image.

[0003] In recent years, in projectors, there is an increasing demand for higher efficiency of a light source optical system and smaller size of the device. Higher efficiency of the light source optical system requires improvement of light conversion efficiency of a wavelength conversion element. The light conversion efficiency of the wavelength conversion element varies depending on the energy density of excitation light that is incident on the wavelength conversion element. Specifically, when the energy density of the excitation light that is incident on the wavelength conversion element is high, the light conversion efficiency of the wavelength conversion element decreases due to temperature rise or a decrease in excitable electrons in the wavelength conversion layer. Therefore, the improvement of the light conversion efficiency of the wavelength conversion element is achieved by reducing the energy density.

[0004] On the other hand, when the energy density of the excitation light on the wavelength conversion element is reduced and the excitation light spot size on the wavelength conversion element is increased, the light utilization efficiency of the entire projector decreases because the light rays are more diffused in the optical system and the like at the rear stage.

[0005] In Patent Literature 1, a technique for using an optical element for the purpose of improving the light conversion efficiency of a wavelength conversion element is disclosed.

[0006] However, according to the related art, there are problems such as insufficient reduction of the energy density and low light conversion efficiency of the wavelength conversion element.

[0007] The present application was made in view of the above circumstances, and aims to improve the light conversion efficiency of a wavelength conversion element.

[0008]

Patent Literature

[0009]

Patent Literature 1

[0010] To solve the above problems and achieve the object, the present application relates to a light source device characterized by comprising: a light source; an optical element having a lens array in which a plurality of lenses are arranged in an array on one face or both faces, and a wavelength conversion element that converts the wavelength of light emitted from the light source and passing through the optical element, the distance P between the apexes of adjacent lenses of the optical element being 1 / 4 or less of the width D of the light beam of light incident on the optical element.

[0011] According to the present application, the effect of being able to improve the light conversion efficiency of the wavelength conversion element is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 An outline configuration diagram of a projector according to the first embodiment is shown.

[0013] Figure 2 A configuration schematic of a color wheel is shown.

[0014] Figure 3-1 A schematic diagram of the configuration of the light source section is shown.

[0015] Figure 3-2 A schematic diagram of the light beam of the light source section is shown.

[0016] Figure 4 A luminance profile view of the luminance of the light source image of the excitation light as a whole incident on the optical element is shown.

[0017] Figure 5 A luminance profile view of the luminance of the light source image on the optical element corresponding to one light source is shown.

[0018] Figure 6 A front view of the optical element viewed from the excitation light incident side is shown.

[0019] Figure 7 A cross-sectional view of the cross section of the optical element is shown.

[0020] Figure 8 A configuration schematic of a wavelength conversion element is shown.

[0021] Figure 9 A cross-sectional schematic of a wavelength conversion element is shown.

[0022] Figure 10 A dimensional example diagram of each part constituting the light source section according to Embodiment 1 is shown.

[0023] Figure 11 An example diagram of the image on the wavelength conversion element is shown.

[0024] Figure 12 A distribution schematic of the luminance of the image on the wavelength conversion element is shown.

[0025] Figure 13 A dimensional example of each part constituting the light source part according to Example 2 is shown.

[0026] Figure 14 An example of an image on the wavelength conversion element is shown.

[0027] Figure 15 A distribution of brightness of an image on the wavelength conversion element is shown.

[0028] Figure 16 A dimensional example of each part constituting the light source part according to Comparative Example is shown.

[0029] Figure 17 An example of an image on the wavelength conversion element is shown.

[0030] Figure 18 A distribution of brightness of an image on the wavelength conversion element is shown.

[0031] Figure 19 A front view of a modification of the optical element is shown as viewed from the excitation light incident side.

[0032] Figure 20 A cross-sectional view of a cross section of the modification of the optical element is shown.

[0033] Figure 21 A schematic view of a configuration of a light source according to the second embodiment is shown.

[0034] Figure 22 A schematic view of a configuration of a light source according to the third embodiment is shown.

[0035] Figure 23 A schematic view of a configuration of a light source according to the fourth embodiment is shown.

[0036] Figure 24 A schematic view of a configuration of a wavelength conversion element is shown.

[0037] Figure 25 A cross-sectional view of a cross section of the wavelength conversion element is shown.

[0038] Figure 26 A schematic view of a configuration of a light source according to the fifth embodiment is shown.

[0039] Figure 27 A schematic view of a configuration of a wavelength conversion element is shown.

[0040] Figure 28 A cross-sectional view of a cross section of the wavelength conversion element is shown.

[0041] Figure 29Fig. 6 is a schematic view showing the configuration of a light source according to the sixth embodiment.

[0042] Figure 30 Fig. 7 is a diagram showing an example of the relationship between the lens pitch of an optical element and the beam size of a light beam according to the seventh embodiment.

[0043] Figure 31 Fig. 7 is a diagram showing an example of the relationship between the lens pitch of an optical element and the beam size of a light beam according to the seventh embodiment.

[0044] Figure 32 Figs. 8(a) and 8(b) are schematic views showing the light distribution on a wavelength conversion element corresponding to the inclination of a light ray incident on an optical element.

[0045] Figure 33 Fig. 9 is a luminance profile view showing the luminance of a light source image of the entire excitation light incident on an optical element.

[0046] Figure 34 Figs. 10(a) and 10(b) are diagrams showing examples of adjustment of the incident angle of an optical element.

[0047] Figure 35 Fig. 11 is a schematic view showing the configuration of a light source according to the eighth embodiment.

[0048] Figure 36 Figs. 12(a) and 12(b) are diagrams showing examples of adjustment of the incident angle of an optical element using a reflective optical element.

[0049] Figure 37 Fig. 13 is a schematic view showing the configuration of a light source according to the ninth embodiment.

[0050] Figure 38 Figs. 14(a) and 14(b) are diagrams showing examples of adjustment of the incident angle of an optical element using a transmissive optical element.

[0051] Figure 39 Fig. 15 is a block diagram showing the overall configuration of a display device according to the tenth embodiment.

[0052] The symbols in the drawings are explained as follows.

[0053] 1 image projection device

[0054] 20 light source device

[0055] 21 light source

[0056] 23 first optical system

[0057] 24 optical surface

[0058] 25, 34 condensing optical system

[0059] 26 wavelength conversion element

[0060] 28 optical element

[0061] 29 reflection-type optical element

[0062] 30 light homogenizing element

[0063] 31 transmission-type optical element

[0064] 40 illumination optical system

[0065] 50 image forming element

[0066] 60 projection optical system

[0067] 70 irradiated member

[0068] 100 display device DETAILED DESCRIPTION

[0069] Hereinafter, embodiments of a light source device, an image projection device, and a display device will be described in detail with reference to the drawings.

[0070] (First Embodiment)

[0071] Figure 1 An outline configuration of a projector related to the first embodiment is shown.

[0072] The projector (image projection device) 1 has a frame 10, a light source device 20, a light homogenizing element 30, an illumination optical system 40, an image forming element (image display element) 50, a projection optical system 60, a control device 80, and a color wheel 90.

[0073] The frame 10 houses the light source device 20, the light homogenizing element 30, the illumination optical system 40, the image forming element 50, and the projection optical system 60, the control device 80, and the color wheel 90.

[0074] The light source device 20, for example, emits light containing wavelengths corresponding to each color of RGB. The light source device 20 has a light source portion 20A, a light source portion 20B, and a light path combining element 20C as a combining portion. The light source portion 20A and the light source portion 20B are the same configuration and emit light beams of a prescribed shape. In addition, the internal configuration of the light source portion 20A and the light source portion 20B will be described later in detail. The light beams emitted from the light source portion 20A and the light source portion 20B are respectively deflected by the light path combining element 20C and enter the incident side surface of the light homogenizing element 30. In addition, in the present embodiment, a prism is exemplified as the light path combining element 20C, but is not limited thereto.

[0075] As Figure 1As shown, the projector 1 reflects and deflects the light beams in the middle of the condensing path, which are output from the light source sections 20A and 20B toward each other, on two reflection sections (in this embodiment, the light path synthesizing element 20C) that are at an angle of substantially 90 degrees to each other, reflects them toward the same direction, and synthesizes the respective condensing light beams adjacently or partially overlappingly while injecting them into the light homogenizing element 30. Figure 1

[0076] In addition, in the present embodiment, an example in which the light source device 20 uses two light source sections 20A and 20B is shown, but the present application is not limited to this, and a configuration in which two or more, for example, four light source sections are used to synthesize light can also be used.

[0077] The light homogenizing element 30 homogenizes the light emitted from the light source device 20 by mixing it. More specifically, the light homogenizing element 30 emits the light beams that are injected from the incident side surface after repeatedly reflecting them while propagating inside, from the emission surface. The light homogenizing element 30 forms a uniform surface light source on the emission surface by internally reflecting the light beams that are injected from the incident side surface multiple times. As the light homogenizing element 30, for example, a light tunnel in which the inside is hollow and four mirrors are combined on the inner surface, a light integrating rod in which a prism is formed of a transparent material such as glass, a compound eye lens, or the like is used. For example, in the case where a light tunnel is used as the light homogenizing element 30, the light tunnel is made to have substantially the same aspect ratio as the image forming element 50, and the shape of the outlet of the light tunnel is made to be the shape projected onto the surface of the image forming element 50, and thus efficient illumination without waste on the surface of the image forming element 50 can be performed.

[0078] The illumination optical system 40 performs substantially uniform illumination of the image forming element 50 by the light homogenized by the light homogenizing element 30. The illumination optical system 40 has, for example, one or more lenses and one or more reflection surfaces, or the like.

[0079] The image forming element 50 has a light valve such as a digital micromirror device (D), a transmissive liquid crystal panel, a reflective liquid crystal panel, or the like. The image forming element 50 forms an image light by modulating the light illuminated by the illumination optical system 40 (light from the light source optical system of the light source device 20).

[0080] The control device 80 switches the illumination light that is irradiated onto the image forming element 50 according to the input image, for example, reflection or transmission, or the like, in pixel units for the surface of the image forming element 50, and guides it to the projection optical system 60.

[0081] ​The projection optical system 60 enlarges and projects the image light formed by the image forming element 50 onto the screen (illuminated member) 70. The projection optical system 60, for example, includes one or more lenses. The projection optical system 60 is a conjugate relation that images the face of the image forming element 50 as an enlarged image at a desired position of the screen (illuminated member) 70, and thus enlarges and projects the spatially modulated image light onto the face of the image forming element 50 to be projected.

[0082] Further, a color wheel 90 is provided in the exit of the light homogenizing element 30, and the color wheel 90 has a function of switching color filters in such a manner that at least blue light, green light, and red light components are extracted. The color wheel 90 includes color filters that extract desired color components from the fluorescent light. The color wheel 90 synchronizes the rotation of the wavelength conversion elements 26 (see FIG. 2) for the light source sections 20A and 20B, respectively, with the rotation of the color wheel 90, and displays the image on the face of the image forming element 50 in accordance with the timing of the switching of the color filters while synchronously driving the switching of the color filters, and sequentially displays monochromatic images. Since the switching time is faster than the response speed of the eye, the images are recognized as a color image. Figure 3-1

[0083] In more detail, the color wheel 90 extracts the required color components, such as green components or red components, from the fluorescent light in a time-division manner by sequentially switching the color filters. In this case, the desired color filter is switched by rotating the color wheel 90 by a motor.

[0084] Here, Figure 2 A configuration example of the color wheel is shown. As Figure 2 shown, the color wheel 90 is divided into four regions of a blue region B, a yellow region Y, a red region R, and a green region G. The blue region B corresponds to the blue reflection region A3 (see FIG. 2) of the wavelength conversion element 26, and the yellow region Y, the red region R, and the green region G are synchronized in such a manner that they respectively correspond to the phosphor regions Al and A2 (see FIG. 2) of the wavelength conversion element 26. Figure 8 Figure 8

[0085] The blue region B can reduce the coherence of the laser light source and can reduce speckles on the screen (illuminated member) 70 by providing a transmissive diffusion plate. The yellow region Y directly transmits the light of the yellow wavelength region emitted from the phosphor region of the wavelength conversion element 26. In addition, the red region R and the green region G respectively reflect unnecessary wavelength regions from the light of the yellow wavelength region by using a dichroic mirror, and obtain light of a color with high purity.

[0086] ​​​The various colors generated on the color wheel 90 are guided to the image forming element 50 by the illumination optical system 40. The image forming element 50 forms an image corresponding to each color. Also, the image formed by the image forming element 50 is enlarged and projected onto the screen (illuminated member) 70 by the projection optical system 60.

[0087] Here, Figure 3-1 A schematic view of the configuration of the light source section 20A is shown. Figure 3-2 A schematic view of the light beams in the light source section 20A is shown. The light source section 20B is also of the same configuration.

[0088] The light source section 20A (20B) has a laser light source (excitation light source) 21, a collimator lens 22 provided corresponding to each light source constituting the laser light source (excitation light source) 21, a first optical system 23, an optical element 28, a dichroic mirror 24, a second optical system (condensing optical system) 25, a wavelength conversion element 26 as a wavelength conversion plate, and a third optical system 27, which are arranged in this order in the direction of propagation of light. The first optical system 23 is constituted by a positive lens 23a having a positive focal power and a negative lens 23b having a negative focal power. The second optical system 25 is constituted by two positive lenses 25a, 25b. In addition, the outer diameter of the negative lens 23b of the first optical system 23 is 1 / 2 or less of the outer diameter (D opt ) of the positive lens 25a of the second optical system 25, which will be described later. Due to this, since the light beam can be made thin, miniaturization can be achieved. For example, in the light source device 20, the "light source optical system" is constituted by the laser light source 21 and the elements other than the wavelength conversion element 26. The light source section 20A (20B) arranges the above-described sections in the order of propagation of the excitation light emitted from the laser light source 21.

[0089] The laser light source 21 has a plurality of light sources (emission spots). As the laser light source 21, a laser diode in which the emission spots are arranged in a two-dimensional array is used. In Figure 3-1 four light sources are arranged in the vertical direction, but in actuality, the four light sources are arranged in four columns in the direction perpendicular to the plane of the paper (depth direction), and 4 x 4 = 16 light sources are arranged in a two-dimensional array. Each light source of the laser light source 21 emits, for example, blue band light (blue laser light) having a center wavelength of 455 nm of emission intensity as excitation light for the phosphor provided in the wavelength conversion element 26.

[0090] As the light source, for example, a multi-chip product in which laser diodes are arranged on a metal block or laser diode chips are arranged in an array on one substrate can be used. In addition, in the present embodiment, a multi-chip product can be used as the light source, but is not limited thereto, and a light source in which CAN-type lasers are arranged in an array or the like can also be used.

[0091] The blue laser light (first color light) emitted from each light source of the laser light source 21 is linearly polarized light in which the polarization state is constant, and is configured to be S-polarized light with respect to the dichroic mirror 24. Here, it is incident in a manner to be S-polarized light, but can be P-polarized light or another polarization state.

[0092] The blue laser light emitted from each light source of the laser light source 21 is coherent light. In addition, the excitation light emitted from each light source of the laser light source 21 can be light of a wavelength capable of exciting the phosphor provided in the wavelength conversion element 26, and is not limited to light in the blue band.

[0093] In addition, the laser light source 21 is exemplified as a case where a plurality of light sources are used, but can be a single laser light source. In addition, as the laser light source 21, a light source unit configured in an array on a substrate can be used, but is not limited thereto. In the present embodiment, as shown in FIG. 1, the center line of the light beam formed by the plurality of or single laser light source is taken as the chief ray. Figure 3-2

[0094] The collimator lens 22 is provided in 16 corresponding to the 16 light sources of the laser light source 21. Each collimator lens 22 adjusts the excitation light emitted from each light source of the laser light source 21 to be substantially parallel light. The number of collimator lenses 22 can be increased or decreased in accordance with the increase or decrease in the number of light sources of the laser light source 21, as long as it corresponds to the number of light sources of the laser light source 21.

[0095] The optical element 28 is a microlens array having a lens array surface in which a plurality of lenses are arranged in an array. The optical element 28 changes the profile of the light beam. Specifically, the optical element 28 makes the light density of the light spot formed on the wavelength conversion element 26 uniform, suppresses the temperature rise of the local part of the wavelength conversion element 26, and prevents the decrease in the wavelength conversion efficiency. In addition, the lens array surface of the optical element 28 can be either one of the light incident surface or the light exit surface, or can be a plurality of surfaces of the light incident surface and the light exit surface. The optical element 28 has at least two lens array surfaces, whereby a low-loss image projection device can be realized. Furthermore, the optical element 28 has a lens array surface on either one of the light incident surface and the light exit surface, whereby an inexpensive image projection device can be realized. In addition, the optical element 28 can be either one or a plurality. The optical element 28 of the present embodiment is a lens array in which a plurality of spherical lenses of a rectangular shape are arranged in an array on both the front and back surfaces.

[0096] ​Excitation light emitted from multiple laser sources 21 is collimated into approximately parallel light by collimating lenses 22 corresponding to each laser source 21. This approximately parallel excitation light then enters a first optical system 23. The optical axis of the first optical system 23 is configured to pass through the center of the array of laser sources 21. That is, the principal ray is aligned with the optical axis of the first optical system 23. The excitation light beam is narrowed by the first optical system 23 into a beam with a beam width D and enters the optical element 28. Thus, by using the first optical system 23, the beam can be narrowed, thereby enabling miniaturization of the light source optical system. At this time, the beam width of each image of the excitation light emitted from each excitation source on the optical element 28 is D. single The excitation light that has passed through the first optical system 23 passes through the optical element 28 and is guided by the dichroic mirror 24, which is configured at a 45-degree angle relative to the optical axis of the first optical system 23.

[0097] In addition, this embodiment shows a configuration in which the dichroic mirror 24 is arranged at a 45-degree angle, but other angles are also possible.

[0098] here, Figure 4 The image shown is a cross-sectional view of the brightness of the light source image of the entire excitation light incident on the optical element 28. Figure 5 The image shown is a luminance cross-sectional view of the light source image on optical element 28 corresponding to a light source. Figure 4 In the example shown, the excitation light emitted from the multiple light sources of laser source 21 is arranged in a discrete distribution. For example... Figure 4 As shown, the beam width D of the excitation light incident on the optical element 28 is 1 / e of the maximum brightness obtained in the envelope of the brightness profile. 2 The width of the brightness. Additionally, such as... Figure 5 As shown, 1 / e of the maximum brightness of the light source image on the optical element 28 that receives the excitation light emitted from one of the laser light sources 21 will be obtained. 2 The width of the brightness is set to D. single Furthermore, the same definition applies to the beams described later.

[0099] Next, optical element 28 will be described in detail. Here, Figure 6 The image shown is a front view of the optical element 28 as observed from the side where the excitation light is incident. Figure 7 The image shown is a cross-sectional view of the optical element 28. (As shown...) Figure 6 and Figure 7As shown, the optical element 28 in this embodiment is a lens array in which multiple rectangular spherical lenses are arranged in an array on both the front and back sides. By appropriately setting the focal length of the optical element 28, which is such a lens array, and the focal length of the second optical system 25, an image with the same shape as each lens in the lens array can be formed on the wavelength conversion element 26. In addition, by making the lenses rectangular, light can be effectively utilized in the light homogenization element 30 or the image forming element 50.

[0100] like Figure 7 As shown, the distance between adjacent lens vertices of optical element 28 is the lens spacing P. As described above, the spherical lens is rectangular. That is, the lens spacing P of the spherical lens of optical element 28 is different in the X and Y directions. The spherical lens of optical element 28 is shaped as a rectangle so that one side of the rectangle of the multiple lenses is approximately parallel to one side of the entrance of the light homogenizing element 30, thus forming a shape approximately similar to the light homogenizing element 30 or the image forming element 50. As a result, the halos of light in the optical system are reduced, and the light conversion efficiency can be improved. In addition, in this embodiment, the spherical lens of optical element 28 is shaped as a rectangle, but it is not limited to this, and it can also be triangular, hexagonal, or other shapes.

[0101] The dichroic mirror 24 is a glass plate in the shape of a parallel plate. The dichroic mirror 24 reflects the S-polarized light (first polarized light component) of the wavelength band of the excitation light derived from the first optical system 23, and is coated on one side of the incident surface to transmit the P-polarized light (second polarized light component) of the wavelength band of the excitation light derived from the first optical system 23 and the fluorescent light (second color light) from the wavelength conversion element 26.

[0102] The dichroic mirror 24 shifts its center relative to the optical axis of the second optical system 25, causing the excitation light to enter at an angle relative to the normal of the wavelength conversion element 26. That is, the excitation light emitted from the optical element 28 is reflected back by the dichroic mirror 24.

[0103] In this embodiment, a flat dichroic mirror 24 is used as the optical surface for guiding the wavelength conversion element 26 through the optical element 28. The dichroic mirror 24 can efficiently guide excitation light and fluorescence light, thus achieving high efficiency in the light source optical system. However, a prism type can also be used as the optical surface for guiding the wavelength conversion element 26 through the optical element 28. Furthermore, in this embodiment, the dichroic mirror 24 reflects S-polarized light in the wavelength band of the excitation light B and transmits P-polarized light; conversely, it can also reflect P-polarized light in the wavelength band of the excitation light B and transmit S-polarized light. Additionally, the reflective optical element can be a simple mirror with wavelength characteristics like a dichroic mirror, or it can be a diffractive optical element like a DOE (Diffractive Optical Element).

[0104] like Figure 3-1 As shown, the excitation light reflected by the dichroic mirror 24 rotates the optical path by 90 degrees and enters the second optical system 25, which serves as a focusing optical system. Here, the optical axes of the first optical system 23 and the second optical system 25 are substantially off-center. The excitation light passing through the second optical system 25 is guided to the wavelength conversion element 26. The excitation light enters the second optical system 25 off-center. The excitation light is incident at an angle relative to the wavelength conversion element 26, thereby forming the desired focusing spot on the wavelength conversion element 26. In the blue reflective region A3 of the wavelength conversion element 26 (see reference...) Figure 8 The reflected excitation light passes through the second optical system 25 again, and through the opposite side of the dichroic mirror 24 relative to the optical axis of the second optical system 25, passes through the third optical system 27, is deflected by the optical path combining element 20C, and enters the light homogenizing element 30. The light homogenizing element 30 homogenizes the incident light.

[0105] In addition, such as Figure 3-1 As shown, the phosphor regions of wavelength conversion element 26 (yellow phosphor region A1 and green phosphor region A2: reference) Figure 8 When excitation light is incident, fluorescence is emitted in a 360-degree radius around the fluorescent molecules, resulting in wavelength conversion. The fluorescence emitted in the phosphor region of the wavelength conversion element 26 contains yellow or green components. Additionally, the substrate 26a of the wavelength conversion element 26 (see reference...) Figure 9 The excitation light reflected from the surface (substrate surface) of the phosphor region (yellow phosphor region A1 and green phosphor region A2) passes again through the phosphor region (yellow phosphor region A1 and green phosphor region A2), emitting fluorescence in a Lambertian distribution on the surface side of the phosphor region (yellow phosphor region A1 and green phosphor region A2). The fluorescence light emitted by the phosphor region (yellow phosphor region A1 and green phosphor region A2) of the wavelength conversion element 26 passes through the optical path combining element 20C (refer to...). Figure 1 The fluorescent light is guided to the light homogenizing element 30. More specifically, the fluorescent light is made into approximately parallel light by the second optical system 25, refracted by the third optical system 27 in such a way that it is focused to the vicinity of the light homogenizing element 30, and deflected by the optical path combining element 20C before entering the light homogenizing element 30.

[0106] Therefore, as Figure 3-1 As shown, the excitation light reflected by the wavelength conversion element 26 can be guided to the light homogenization element 30 without interference from the dichroic mirror 24, thus preventing efficiency reduction and the scaling up of the optical system.

[0107] Furthermore, this embodiment shows a configuration where the excitation light reflected by the wavelength conversion element 26 does not pass through the dichroic mirror 24, but it is not limited to this. For example, the dichroic mirror 24 can be enlarged so that the coating on one half of the surface has the characteristic of reflecting excitation light and transmitting fluorescence light, while the remaining half has the characteristic of transmitting both excitation light and fluorescence light.

[0108] In this case, when excitation light is incident on the phosphor regions of wavelength conversion element 26 (yellow phosphor region A1 and green phosphor region A2: reference) Figure 8 When the excitation light is emitted from the side of the excitation light incident surface, it enters the second optical system 25. A portion of the light that has passed through the second optical system 25 passes through the excitation light reflecting part of the dichroic mirror 24, enters the condenser lens 27, and is guided to the light homogenizing element 30 and the color wheel 90.

[0109] Figure 8 The diagram shown is a schematic representation of the wavelength conversion element 26. Figure 8 As shown, the wavelength conversion element 26 in this embodiment is disc-shaped. The wavelength conversion element 26 is a wavelength conversion plate formed at a desired angle around the periphery of a disc-shaped plate. The three sections are: a yellow phosphor region (first wavelength conversion region) A1, which is the conversion region of the wavelength conversion component (phosphor) 26f; a green phosphor region (second wavelength conversion region) A2, which is the conversion region of the wavelength conversion component (phosphor) 26g; and a blue reflective region (in other words, a non-conversion region that emits light without converting the wavelength of light received from the laser light source (excitation light source) 21) A3.

[0110] Yellow phosphor region A1 is formed, for example, by a yellow phosphor 26f, which emits fluorescence in a yellow wavelength band when excited by a blue laser. Yellow phosphor region A2 is formed, for example, by a green phosphor 26g, which emits fluorescence in a green wavelength band when excited by a blue laser.

[0111] Furthermore, in this embodiment, both a yellow phosphor region A1 and a green phosphor region A2 are used, but the embodiment is not limited to these. For example, it may only have a yellow phosphor region A1, or a red phosphor region may be added. In addition, the wavelength conversion element 26 may also have multiple blue reflective regions A3.

[0112] Then, the disc-shaped wavelength conversion element 26 is driven at high speed by a driving section controlled by the control device 80, whereby the yellow phosphor region Al, the green phosphor region A2, and the blue reflection region A3 are sequentially moved periodically. The driving section is preferably a rotary motor M in general. Then, the wavelength conversion element 26 is exchanged with the yellow phosphor region Al, the green phosphor region A2, and the blue reflection region A3 at the light condensing spot as a position where light is irradiated from the laser light source (excitation light source) 21, to emit light of different wavelengths in time division.

[0113] Further, the light source section 20A (20B) configures a light absorbing or reflecting section on a wheel of the wavelength conversion element 26 or a section that supports the rotation of the wheel, and detects or the like by a photoelectric coupler, to make the rotation speeds of the two wavelength conversion elements 26 the same.

[0114] Figure 9 A cross-sectional view of the wavelength conversion element 26 is shown. As the substrate 26a of the wavelength conversion element 26, a transparent substrate or a metal substrate such as aluminum can be used. However, the substrate 26a of the wavelength conversion element 26 is not limited to a metal substrate.

[0115] In the blue reflection region A3 that reflects excitation light, a reflection coating 26b having higher reflectivity for excitation light can be formed on the substrate 26a, for example, and a metal substrate can be provided as the reflection region as described above.

[0116] In the phosphor regions (the yellow phosphor region Al and the green phosphor region A2), a reflection coating 26b that reflects light in the wavelength region of emitted light from the phosphors 26f, 26g is provided on the substrate 26a, the phosphors 26f, 26g, and an antireflection coating (AR coating) 26c that reduces the reflection of the phosphor surface are provided in this order. However, the configuration of the phosphor regions (the yellow phosphor region Al and the green phosphor region A2) is not limited to this. Further, in the case where the substrate 26a is a metal substrate, the reflection coating 26b can be omitted.

[0117] As the phosphors 26f, 26g, a phosphor in which a phosphor material is dispersed in an organic or inorganic binder or a phosphor in which a crystal of a phosphor material is directly formed can be used. Further, as the phosphor material, a rare earth phosphor such as a Ce:YAG system can be used, but is not limited thereto, and a phosphor or a nonlinear optical crystal or the like can be used.

[0118] The wavelength band of fluorescent light emitted by the phosphor can use, for example, a yellow, blue, green, or red wavelength band, but in the present embodiment, a case where fluorescent light having a yellow wavelength band and a green wavelength band is used is shown.

[0119] In recent years, the demand for higher efficiency and miniaturization of the light source optical system in projectors has become increasingly strong. Improving the efficiency of the light source optical system requires increasing the light conversion efficiency of the wavelength conversion element 26. The light conversion efficiency of the wavelength conversion element 26 varies depending on the energy density of the excitation light incident on the wavelength conversion material. Specifically, when the energy density incident on the wavelength conversion element 26 is high, the light conversion efficiency of the wavelength conversion element 26 decreases due to a rise in temperature or a reduction in the number of excitable electrons in the phosphor regions (yellow phosphor region A1 and green phosphor region A2). Therefore, the light conversion efficiency of the wavelength conversion element 26 is improved by reducing the energy density.

[0120] On the other hand, when the spot size of the excitation light on the wavelength conversion element 26 is increased in order to reduce the energy density of the excitation light on the wavelength conversion element 26, the overall light utilization efficiency of the projector will decrease because the light halo in the subsequent optical system and the like will become larger.

[0121] That is, in order to improve the light utilization efficiency of projector 1, it is important to reduce the energy density and obtain the optimal light spot size.

[0122] Therefore, in this embodiment, the dimensions of each part constituting the light source unit 20 are set as follows.

[0123] like Figure 3-2 As shown, the beam width of the excitation image formed on the dichroic mirror 24 is irror Furthermore, the outer diameter of the optical element (in this embodiment, a positive lens 25a) on the incident surface side of the second optical system 25 is set to D. opt D opt It is the maximum length from one end of the positive lens 25a passing through the center point to the other when viewed from the incident side. This is the definition that takes into account not only a perfect circle but also an ellipse.

[0124] Here, 1 / e of the maximum brightness of the light source image on the optical element 28 of the excitation light emitted from one of the laser light sources 21 will be obtained. 2 The brightness of the lens spacing P is set as the width D. single The distance is less than 1 / 2. Therefore, by optimizing the spacing of the microlens array, the homogenization of the phosphor-like light source image can be further achieved for a single light source image. Furthermore, the lens spacing P is set to be less than 1 / 4 of the beam width D incident on the optical element 28. Even further, the beam width D incident on the optical element 28 is set to be the outer diameter D of the incident optical element (positive lens 25a) of the second optical system 25. optLess than 1 / 3 of the original size. This allows for miniaturization of the dichroic mirror 24, thus avoiding interference between components and light, and achieving improved efficiency and miniaturization. Furthermore, the beam width of the excitation light image on the dichroic mirror 24 can be increased. irror outer diameter D opt Less than 1 / 3.

[0125] Furthermore, the lens spacing P of the optical element 28, which is a lens array in which multiple rectangular spherical lenses are arranged in an array on both the front and back sides, satisfies the condition on both the front and back sides.

[0126] Here, several embodiments are given to illustrate the intensity distribution of the image on the wavelength conversion element 26.

[0127] (Example 1)

[0128] First, Example 1 will be described.

[0129] here, Figure 10 The diagram shown is an example of the dimensions of the various parts constituting the light source unit 20 according to Embodiment 1. Figure 10 As shown, the dimensions of each part constituting the light source section 20 of Embodiment 1 satisfy the conditions shown below.

[0130] D / D opt <1 / 3

[0131] P / D < 1 / 4

[0132] irror / D opt <1 / 3

[0133] P / D single <1 / 2

[0134] Here, Figure 11 The image shown is an example diagram of the image on the wavelength conversion element 26. Figure 12 The diagram shows the brightness distribution of the image on the wavelength conversion element 26. Figure 12 What is shown is Figure 11 A graph showing the brightness along the X and Y axes.

[0135] The result satisfies the condition that the lens spacing P is less than 1 / 4 of the width D of the beam incident on the optical element 28, according to Figure 12 As can be seen from the brightness distribution of the image on the wavelength conversion element 26, it is close to a flat-top shape, and the image on the wavelength conversion element 26 becomes a uniform image overall. This prevents localized temperature rise in the wavelength conversion element 26, thus improving the light conversion efficiency of the wavelength conversion element 26.

[0136] (Example 2)

[0137] Next, Example 2 will be described.

[0138] here, Figure 13 The diagram shown is an example of the dimensions of each part constituting the light source unit 20 according to Embodiment 2. As... Figure 13 As shown, the dimensions of each part constituting the light source section 20 of Embodiment 2 satisfy the conditions shown below.

[0139] D / D opt <1 / 3

[0140] P / D < 1 / 4

[0141] irror / D opt <1 / 3

[0142] P / D single <1 / 2

[0143] Here, Figure 14 The image shown is an example diagram of the image on the wavelength conversion element 26. Figure 15 The diagram shows the brightness distribution of the image on the wavelength conversion element 26. Figure 15 What is shown is Figure 14 A graph showing the brightness along the X and Y axes.

[0144] The result satisfies the condition that the lens spacing P is less than 1 / 4 of the width D of the beam incident on the optical element 28, according to Figure 15 As can be seen from the brightness distribution of the image on the wavelength conversion element 26, although it is weaker compared to the first embodiment, it is close to a flat-top shape, and the image on the wavelength conversion element 26 becomes a uniform image overall. Therefore, localized temperature rise of the wavelength conversion element 26 can be prevented, thereby improving the light conversion efficiency of the wavelength conversion element 26.

[0145] [Comparative Example]

[0146] Next, the comparative examples will be explained.

[0147] here, Figure 16 The diagram shown is an example of the dimensions of each part constituting the light source section 20 involved in the comparative example. Figure 16 As shown, the dimensions of each part of the light source section 20 involved in the comparative example do not meet the conditions described below. This is because the number of lenses in the lens array of the optical element 28 included in the width D of the beam incident on the optical element 28 is insufficient.

[0148] P / D < 1 / 4

[0149] Here, Figure 17 The image shown is an example diagram of the image on the wavelength conversion element 26. Figure 18A distribution diagram of the brightness of the image on the wavelength conversion element 26 is shown. Figure 18 A graph of the brightness in the X-axis and Y-axis directions in Figure 17

[0150] In the case where the above conditions are not satisfied, as Figure 18 A portion where local concentration of light occurs, particularly in the center portion in the X direction, is shown, and thus the temperature of the wavelength conversion element 26 rises, and the light conversion efficiency is greatly reduced.

[0151] Thus, according to the present embodiment, vignetting of the third optical system 27 in the rear stage does not occur, and a uniform light spot can be imaged on the wavelength conversion element 26, and the light conversion efficiency of the wavelength conversion element 26 can be improved.

[0152] In addition, in the present embodiment, the optical element 28 is a lens array in which a plurality of spherical lenses of a rectangular shape are arranged in an array on both the front and back surfaces, but is not limited thereto. Here, Figure 19 A front view of a modified example of the optical element 28 viewed from the excitation light incident side is shown, Figure 20 A cross-sectional view of a cross section of the modified example of the optical element 28 is shown. As Figure 19 Figure 20 As shown, the optical element 28 can have a lens array on only either the excitation light incident side or the excitation light emission side. Such an optical element 28, although the uniformity is slightly worse than the optical element having a lens array on both the front and back surfaces, can sufficiently uniformize.

[0153] (Second Embodiment)

[0154] Next, the second embodiment will be described.

[0155] The second embodiment differs from the first embodiment in the configuration in which the excitation light passes through the dichroic mirror 24. In the following description of the second embodiment, the description of the same parts as those of the first embodiment will be omitted, and the parts different from those of the first embodiment will be described.

[0156] Figure 21 A schematic view of the configuration of the light source 20A involved in the second embodiment is shown. In addition, the light source portion 20B is also of the same configuration.

[0157] As Figure 21 As shown, the dichroic mirror 24 of the present embodiment is divided into two regions 24a, 24b in the plane, and in the first region 24a through which the excitation light emitted from the first optical system 23 passes, light in the wavelength band of the excitation light is transmitted. In the second region 24b through which the excitation light emitted from the second optical system 25 passes, light in the wavelength band of the excitation light is reflected, and the fluorescent light generated by the wavelength conversion element 26 is reflected on the entire surface.​​

[0158] Further, the dichroic mirror 24 of the present embodiment uses a flat plate dichroic mirror, but is not limited thereto, and a prism type dichroic mirror can also be used.

[0159] In more detail, the excitation light that has passed through the first region 24a of the dichroic mirror 24 is incident on the second optical system (condensing optical system) 25. Here, as shown in FIG. 2, the optical axes of the first optical system 23 and the second optical system (condensing optical system) 25 are substantially off-center. Figure 21

[0160] The excitation light that has passed through the second optical system (condensing optical system) 25 is directed to the wavelength conversion element 26. By being off-centerally incident on the second optical system (condensing optical system) 25, the excitation light is obliquely incident on the wavelength conversion element 26. Here, the wavelength conversion element 26 is configured in the same manner as in the first embodiment.

[0161] The excitation light that has passed through the second optical system (condensing optical system) 25 is directed to the wavelength conversion element 26. By being off-centerally incident on the second optical system (condensing optical system) 25, the excitation light is obliquely incident on the wavelength conversion element 26. Here, the wavelength conversion element 26 is configured in the same manner as in the first embodiment. Figure 21

[0162] The excitation light that has passed through the second optical system (condensing optical system) 25 is directed to the wavelength conversion element 26. By being off-centerally incident on the second optical system (condensing optical system) 25, the excitation light is obliquely incident on the wavelength conversion element 26. Here, the wavelength conversion element 26 is configured in the same manner as in the first embodiment.

[0163] Further, when the excitation light is incident on the phosphor regions (yellow phosphor region Al and green phosphor region A2) of the wavelength conversion element 26, fluorescent light is emitted from the side of the incident surface of the excitation light and is incident on the second optical system (condensing optical system) 25. At least a portion of the light that has passed through the second optical system (condensing optical system) 25 is reflected by the second region 24b of the dichroic mirror 24 and is incident on the third optical system 27, which is directed to the light homogenizing element 30 and the color wheel 90.

[0164] Thus, according to the present embodiment, vignetting of the third optical system 27 of the rear stage does not occur, and a uniform light spot can be imaged on the wavelength conversion element 26, and the light conversion efficiency of the wavelength conversion element 26 can be improved.

[0165] (Third Embodiment)

[0166] Next, the third embodiment will be described.

[0167] ​​The third embodiment differs from the first embodiment in that the excitation light emitted from the laser light source 21 has a thin light flux, and the first optical system 23 is not present. Hereinafter, in the description of the third embodiment, the description of the same parts as those of the first embodiment will be omitted, and the differences from the first embodiment will be described.

[0168] Figure 22 A schematic diagram of the configuration of the light source 20A involved in the third embodiment is shown. Also, the light source section 20B is of the same configuration.

[0169] As Figure 22 shown, the laser light source 21 of the present embodiment has a plurality of light sources (light emitting spots). As the laser light source 21, a laser diode in which light emitting spots are arranged in a two-dimensional array is used. In Figure 22 two light sources arranged in the up-and-down direction are shown, but actually, the two light sources are arranged in four columns in the direction perpendicular to the plane of the paper (depth direction), and 2 x 4 = 8 light sources are arranged in a two-dimensional array. Each light source of the laser light source 21 emits, for example, blue band light (blue laser light) having a center wavelength of 455 nm of the light emitting intensity as excitation light for the phosphor provided in the wavelength conversion element 26. Also, as for the wavelength band, it is not limited to blue band light as long as it is light capable of exciting the phosphor. Also, in Figure 22 , a case where the laser light source 21 uses a plurality of laser light sources is exemplified, but it is not limited thereto, and a single laser light source can also be used. Also, as the plurality of laser light sources constituting the laser light source 21, a light source unit arranged in an array on a substrate can be used, but it is not limited thereto.

[0170] As Figure 22 shown, the center line of the light flux formed by the plurality of or single laser light source constituting the laser light source 21 is taken as the chief ray. As the laser light source 21 of the present embodiment which is a light source having a small light flux, a vertical cavity surface emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser) or the like, which is one type of semiconductor laser, is used.

[0171] The excitation light emitted from the laser light source 21 respectively passes through the collimator lens 22 corresponding to the laser light source, and becomes substantially parallel light. The substantially parallel excitation light passes through the optical element 28, and is guided to the dichroic mirror 24 arranged at an angle of 45 degrees with respect to the chief ray.

[0172] Thus, according to the present embodiment, even with a small and inexpensive configuration, vignetting of the third optical system 27 of the rear stage does not occur, and a uniform light spot can be imaged on the wavelength conversion element 26, and the light conversion efficiency of the wavelength conversion element 26 can be improved.

[0173] (Fourth Embodiment)

[0174] Next, the fourth embodiment will be described.

[0175] The fourth embodiment differs from the first embodiment in that the wavelength conversion element 26 is configured differently, the color wheel 90 is omitted, and the third optical system 27 is omitted. In the following description of the fourth embodiment, the description of the same parts as the first embodiment will be omitted, and the description of the parts different from the first embodiment will be given.

[0176] Figure 23 A schematic view of the configuration of the light source part 20A involved in the fourth embodiment is shown, Figure 24 A plan view of an example of the configuration of the wavelength conversion element 26 is shown, Figure 25 A schematic view of the cross section of the wavelength conversion element 26 is shown. The light source part 20B is also configured the same way.

[0177] As Figure 24 As shown, the wavelength conversion element 26 of the present embodiment differs from the first embodiment in that the area of the wavelength conversion element 26 is not divided, and has a single phosphor region A4 in the circumferential direction.

[0178] As Figure 25 As shown, the wavelength conversion element 26 has a reflective coating 26b that reflects the wavelength regions of the fluorescent light and the excitation light, a phosphor 26f, and a reflective coating 26d that reflects a part of the excitation light and transmits a part of the fluorescent light on the substrate 26a. As the phosphor 26f, a phosphor in which a phosphor material is dispersed in an organic or inorganic binder, or a phosphor in which a crystal of the phosphor material is directly formed, can also be used. As the phosphor material, for example, a rare earth phosphor such as Ce:YAG can be used, but is not limited thereto. When the wavelength band of the light emitted by the phosphor is set to yellow, for example, white light can be obtained by combining it with the blue color of the excitation light. In the present embodiment, the incident side surface is the reflective coating 26d, but can be a diffusing surface or the like.

[0179] Returning Figure 23 The excitation light reflected by the reflective coating 26b of the wavelength conversion element 26 passes through the second optical system 25 again, and the excitation light emitted from the second optical system 25 is guided to the illumination optical system in the subsequent stage without passing through the dichroic mirror 24.

[0180] In addition, the fluorescent light emitted by the excitation light entering the phosphor 26f of the wavelength conversion element 26 becomes substantially parallel light by passing through the second optical system 25, a part of which passes through the dichroic mirror 24, and is guided to the illumination optical system in the subsequent stage.

[0181] In addition, in the present embodiment, a configuration in which the excitation light is reflected by the dichroic mirror 24 is shown, but a configuration in which the excitation light is transmitted by the dichroic mirror 24 can also be used.Figure 21 The excitation light is made to pass through the dichroic mirror and be incident on the phosphor as shown.

[0182] Thus, according to the present embodiment, even with inexpensive configuration with the number of parts reduced, it is possible to image uniform light spots on the wavelength conversion element 26, and it is possible to improve the light conversion efficiency of the wavelength conversion element 26.

[0183] (Fifth Embodiment)

[0184] Next, the fifth embodiment will be described.

[0185] The fifth embodiment differs from the first embodiment in that the blue reflection region of the wavelength conversion element 26 becomes a blue transmission region, and the blue light path becomes another light path. In the following description of the fifth embodiment, the description of the same parts as the first embodiment will be omitted, and the parts different from the first embodiment will be described.

[0186] Figure 26 Fig. 6 is a schematic view of the configuration of the light source part 20A according to the fifth embodiment, Figure 27 Fig. 7 is a plan view of an example of the configuration of the wavelength conversion element 26, Figure 28 Fig. 8 is a schematic view of the cross section of the wavelength conversion element 26. The light source part 20B is also configured in the same way.

[0187] As shown in Fig. 6, the light source part 20A according to the fifth embodiment is configured in the same way as the light source part 20A according to the first embodiment, except that the blue reflection region A3 of the wavelength conversion element 26 is replaced with a blue transmission region A5. Figure 27 As shown in Fig. 7, the wavelength conversion element 26 according to the present embodiment has the blue transmission region A5 in place of the blue reflection region A3 of the wavelength conversion element 26 according to the first embodiment. Figure 28 As shown in Fig. 7, the wavelength conversion element 26 has an anti-reflection coating (AR coating) 26c formed on the transparent substrate 26e in the blue transmission region A5.

[0188] As shown in Fig. 8, the excitation light that has passed through the blue transmission region A5 of the wavelength conversion element 26 becomes substantially parallel light in the condensing optical system, is reflected by the mirrors 31 to 33 via the fourth optical system 29, and is guided to the dichroic mirror 24. The light guided to the dichroic mirror 24 is combined with the light path of the fluorescent light by the dichroic mirror 24, and is guided to the light homogenizing element 30 and the color wheel 90 by the third optical system 27. Figure 26 Thus, according to the present embodiment, vignetting of the third optical system 27 at the rear stage does not occur, and it is possible to image uniform light spots on the wavelength conversion element 26, and it is possible to improve the light conversion efficiency of the wavelength conversion element 26.

[0189] (Sixth Embodiment)

[0190] Next, the sixth embodiment will be described.

[0191] Thus, according to the present embodiment, vignetting of the third optical system 27 at the rear stage does not occur, and it is possible to image uniform light spots on the wavelength conversion element 26, and it is possible to improve the light conversion efficiency of the wavelength conversion element 26.

[0192] The sixth embodiment differs from the first embodiment in that a parabolic mirror is used as the condensing optical system. Hereinafter, in the description of the sixth embodiment, the description of the same parts as the first embodiment is omitted, and the description of the parts different from the first embodiment is given.

[0193] Figure 29 A schematic diagram of the configuration of the light source 20A involved in the sixth embodiment is shown. Also, the light source part 20B is the same configuration.

[0194] As shown, the parabolic mirror 34 as the condensing optical system is arranged in such a manner that the surface of the wavelength conversion element 26 is located at the focal point of the parabolic mirror. Thereby, the light spot can be imaged on the wavelength conversion element 26. Figure 29 As shown, the excitation light reflected by the dichroic mirror 24 is reflected by the parabolic mirror 34 to be condensed, and the light spot is imaged on the wavelength conversion element 26. The fluorescent light emitted by the excitation light passes through the parabolic mirror 34 to be parallel light, and a part thereof passes through the dichroic mirror 24, is condensed by the third optical system 27, and is guided to the light homogenizing element 30 and the color wheel 90.

[0195] Figure 29 Also, as shown, the excitation light reflected by the blue reflection region A3 of the wavelength conversion element 26 passes through the parabolic mirror to be parallel light, and is condensed by the third optical system 27 to be guided to the light homogenizing element 30 and the color wheel 90.

[0196] Thus, according to the present embodiment, vignetting of the third optical system 27 in the rear stage does not occur, and a uniform light spot can be imaged on the wavelength conversion element 26, and the light conversion efficiency of the wavelength conversion element 26 can be improved. Figure 29

[0197] Thus, according to the present embodiment, vignetting of the third optical system 27 in the rear stage does not occur, and a uniform light spot can be imaged on the wavelength conversion element 26, and the light conversion efficiency of the wavelength conversion element 26 can be improved.

[0198] (Seventh Embodiment)

[0199] Next, the seventh embodiment is described.

[0200] The seventh embodiment differs from the first embodiment in that the incident angle of the light on the optical element 28 can be adjusted, and an appropriate range of the incident angle is set. Hereinafter, in the description of the seventh embodiment, the description of the same parts as the first embodiment is omitted, and the description of the parts different from the first embodiment is given.

[0201] ​​The inventors of this patent application have developed a high-brightness laser source as the laser source 21. In such a high-brightness laser source, it has been experimentally determined that the spacing of the lens array of optical element 28 is less than 1 / 4 of the width of the beam of light incident on optical element 28. However, when using such a narrow-spacing lens array, a new problem has been discovered: the requirement for the incident angle of the laser on optical element 28 becomes very strict.

[0202] On the other hand, when assembling the light source optical system configured as described above, due to the tolerances of each component and its fixing mechanism, uneven variations will occur in the incident angle toward the optical element 28. Thus, when uneven variations occur in the incident angle toward the optical element 28, the optical density of the light spot on the wavelength conversion element 26 becomes uneven, and the light conversion efficiency of the wavelength conversion element 28 will decrease.

[0203] Therefore, in the light source optical system of this embodiment, the incident angle of light onto the optical element 28 can be adjusted, and an appropriate range of the incident angle can be set.

[0204] here, Figure 30 The diagram shown is an example of the relationship between lens spacing and beam size in conventional optical elements. Figure 31 The diagram shown illustrates the relationship between the lens spacing and the beam size of the optical element 28 in the seventh embodiment. Furthermore, the beam profile can be either Gaussian or flat-topped; here, the beam refers to the region where more than 80% of the total light intensity is concentrated. Figure 32 The diagram shows the light distribution on the wavelength conversion element 26 corresponding to the tilt of the light rays incident on the optical element 28. Figure 32 (a) shows the case where the light rays entering the optical element 28 are not angled. Figure 32 (b) shows the case where the light entering the optical element 28 is slightly oblique.

[0205] like Figure 31 As shown, in order to make the light distribution on the wavelength conversion element 26 uniform ( Figure 32 (a)) The optical element 28 uses a lens array surface with a lens spacing p2 that is relatively small (less than 1 / 4 of the beam width) relative to the width of the incident beam. In addition, the lens spacing p2 of the lens array surface of the optical element 28 is less than 1 / 4 of the beam width in both the X and Y directions.

[0206] here, Figure 33 The image shown is a brightness cross-sectional view of the overall brightness of the excitation light incident on the optical element 28. Figure 33 In the example shown, the excitation light emitted from the multiple light sources of laser source 21 is arranged in a discrete distribution. For example... Figure 33The beam width D of the excitation light that enters the optical element 28 is 1 / e of the maximum luminance in the envelope of the luminance profile 2 of the luminance.

[0207] In the conventional optical element shown in Figure 30 , a lens array surface having a sufficient pitch pi with respect to the width of the light beam is used. On the other hand, the optical element 28 of the present embodiment uses a lens array surface having a pitch p2 of 1 / 4 or less of the width of the light beam, so as shown in Figure 32 (b), there is a problem that the light spot on the wavelength conversion element 26 becomes non-uniform when the light rays entering the optical element 28 are slightly inclined.

[0208] Therefore, in the present embodiment, at least either one of the positive lens 23a and the negative lens 23b constituting the first optical system 23 is adjusted in displacement or inclination or both by an adjustment mechanism, so as to adjust the incident angle toward the optical element 28 to be within 3 degrees. The adjustment of the adjustment mechanism is performed by clamping a spacer or the like to at least either one of the positive lens 23a and the negative lens 23b constituting the first optical system 23, but it can also be a mechanism of a screw and a spring or the like. In this way, by integrating the first optical system 23 and the adjustment mechanism, a small and inexpensive image projection device can be realized.

[0209] Here, the incident angle refers to the angle formed by the normal line of the incident plane when the trajectory of the center or the center of gravity of the light beam enters the optical element. As shown in Figure 32 , from the viewpoint of light conversion efficiency, it is preferable that the light distribution on the wavelength conversion element 26 forms a small and uniform light spot, and the incident angle toward the optical element 28 is set to be within 3 degrees because it is within the range in which the variation is allowed due to the effect of the efficiency.

[0210] More specifically, if the incident angle to the optical element 28 exceeds 3 degrees, the amount of light of the ghost image due to the light entering the adjacent microlenses will be 50% or more. The reason for setting the amount of light of the ghost image to 50% is that since the human perception is generally on a logarithmic scale, if the amount of light of the light source itself is sufficient like a high-luminance light source, even if the individual difference varies by 50% by adjustment, the difference in human perception is small, and it is acceptable in the standard.

[0211] Here, Figure 34 is an example of adjustment of the incident angle to the optical element 28. In the example shown in Figure 34 , the positive lens 23a constituting the first optical system 23 is displaced (moved) in the direction of the arrow A by the adjustment mechanism not shown, to adjust the incident angle to the optical element 28 to be within 3 degrees.

[0212] Thus, according to the present embodiment, by making the incident angle of the light toward the optical element 28 appropriate, the light density of the light spot on the wavelength conversion element 26 is homogenized and the temperature rise of the wavelength conversion element 26 is suppressed, so that the decrease in the light conversion efficiency of the wavelength conversion element 26 can be avoided, and thus a high-efficiency image projection device can be realized.

[0213] (Eighth Embodiment)

[0214] Next, the eighth embodiment will be described.

[0215] The eighth embodiment differs from the seventh embodiment in that a reflection-type optical element that reflects the excitation light is provided between the first optical system 23 and the optical element 28, and adjustment of displacement or inclination or both of the reflection-type optical element is performed. In the following description of the eighth embodiment, the description of the same parts as those of the seventh embodiment will be omitted, and the differences from the seventh embodiment will be described.

[0216] Figure 35 A schematic view of the configuration of the light source 20A involved in the eighth embodiment is shown. The light source 20B is also of the same configuration.

[0217] As shown in Figure 35 , the light source 20A of the present embodiment is provided with a reflection-type optical element 29 between the first optical system 23 and the optical element 28. In the present embodiment, a dichroic mirror is applied as the reflection-type optical element 29. In addition, a dichroic mirror is applied as the reflection-type optical element 29, but it is not limited thereto, and a mirror, a prism, a diffractive optical element, or the like can also be applied.

[0218] As shown in Figure 35 , the excitation light emitted from the plurality of laser light sources 21 becomes substantially parallel light by the collimator lens 22 corresponding to each light source of the laser light source 21. The excitation light that has become substantially parallel light is incident on the first optical system 23. The light beam of the excitation light is reduced by the first optical system 23, and is guided to the reflection-type optical element 29 after the light beam. The excitation light that is folded back by the reflection-type optical element 29 is incident on the optical element 28. The excitation light that has passed through the optical element 28 is guided to the dichroic mirror 24.

[0219] Figure 36 A diagram illustrating an example of adjustment of the incident angle of the optical element 28 using the reflection-type optical element 29 is shown.

[0220] In Figure 36In the example shown, the adjustment mechanism adjusts the angle of incidence on the optical element 28 to within 3 degrees by tilting the reflective optical element 29 by an angle θ. The adjustment of the adjustment mechanism is performed by clamping a shim such as a shim plate to the reflective optical element 29, but can also be a mechanism of a screw and a spring, or the like. In this way, by applying the reflective optical element 29 to the adjustment object of the adjustment mechanism, it is possible to fold the optical system and achieve a compact image projection device.

[0221] In this way, according to the present embodiment, by appropriately adjusting the angle of incidence of the light rays toward the optical element 28, it is possible to homogenize the light density of the light spot on the wavelength conversion element 26 and suppress the temperature rise of the wavelength conversion element 26, thereby it is possible to avoid the reduction in the light conversion efficiency of the wavelength conversion element 26, and thus it is possible to achieve a high-efficiency image projection device.

[0222] (Ninth Embodiment)

[0223] Next, the ninth embodiment will be described.

[0224] The ninth embodiment differs from the seventh embodiment in that a transmissive optical element that transmits the excitation light is provided between the first optical system 23 and the optical element 28, and adjustment of displacement or tilt or both of the transmissive optical element is performed. In the following description of the ninth embodiment, the description of the same parts as the seventh embodiment will be omitted, and the differences from the seventh embodiment will be described.

[0225] Figure 37 A schematic view of the configuration of the light source 20A involved in the ninth embodiment is shown. In addition, the light source portion 20B is also of the same configuration.

[0226] As shown in Figure 37 The light source portion 20A of the present embodiment provides a transmissive optical element 31 between the first optical system 23 and the optical element 28. In the present embodiment, a dichroic mirror is applied as the transmissive optical element 31. In addition, a dichroic mirror is applied as the transmissive optical element 31, but is not limited thereto, and an element in which the entrance face and the exit face are not parallel such as a parallel flat plate, a wedge prism, a diffractive optical element, or the like can also be applied.

[0227] As shown in Figure 37 As shown in the drawing, the excitation light emitted from the plurality of laser light sources 21 becomes substantially parallel light by the collimator lens 22 corresponding to each light source of the laser light source 21. The excitation light that has become substantially parallel light is incident on the first optical system 23. The beam of the excitation light is reduced by the first optical system 23 and becomes a beam and is incident on the transmissive optical element 31. The excitation light that has passed through the transmissive optical element 31 is guided to the dichroic mirror 24 by the optical element 28.

[0228] Figure 38An adjustment example of the incident angle of the optical element 28 using the transmission-type optical element 31 is shown.

[0229] In Figure 38 In the example shown, the adjustment mechanism adjusts the incident angle of the optical element 28 to within 3 degrees by tilting the transmission-type optical element 31 by an angle θ. The adjustment of the adjustment mechanism is performed by clamping a shim such as a shim plate to the transmission-type optical element 31, but can also be a mechanism of a screw and a spring, or the like. In this way, by applying the transmission-type optical element 31 (diffractive optical element, or the like) to the adjustment object of the adjustment mechanism, a low-cost image projection apparatus is realized.

[0230] In this way, according to the present embodiment, by appropriately adjusting the incident angle of the light rays toward the optical element 28, the light density of the light spot on the wavelength conversion element 26 is homogenized and the temperature rise of the wavelength conversion element 26 is suppressed, thereby the reduction of the light conversion efficiency of the wavelength conversion element 26 can be avoided, and thus a high-efficiency image projection apparatus can be realized.

[0231] (Tenth Embodiment)

[0232] Next, the tenth embodiment will be described.

[0233] The tenth embodiment differs from the first embodiment to the sixth embodiment in that the projector 1 described in the first embodiment to the ninth embodiment as an example of an image projection apparatus is applied to a display apparatus that makes a user visually recognize a three-dimensional image. In the following description of the tenth embodiment, the description of the same parts as the first embodiment to the ninth embodiment is omitted, and the description of the parts different from the first embodiment to the ninth embodiment is given.

[0234] Figure 39 An overall configuration of the display apparatus 100 according to the tenth embodiment is shown in a block diagram. The display apparatus 100 is also called a stereoscopic display that makes a user visually recognize a three-dimensional image. Here, the three-dimensional image refers to a stereoscopic image having a volume that a person can visually recognize, which is displayed in a three-dimensional space.

[0235] As Figure 39 As shown, the display apparatus 100 has an information processing section 110, the projector 1, a screen 70 that is a spiral screen, a motor 140, and a motor control section 141.

[0236] The display apparatus 100 receives three-dimensional model data 901 to make a user of the display apparatus 100 visually recognize a three-dimensional image. The three-dimensional model data 901 is data representing a three-dimensional model for making a user visually recognize a three-dimensional image, and is, for example, data representing a pixel value of each three-dimensional voxel. Specifically, the three-dimensional model data 901 is input to the information processing section 110.

[0237] The information processing section 110 generates image information 903 based on the input three-dimensional model data 901. Specifically, the information processing section 110 sends a rotation instruction signal 201 to the motor control section 141, instructing the start of rotation. The motor control section 141 that receives the instruction sends a rotation control signal 202 to drive the motor 140, for example, in a manner that rotates the screen 70 at a substantially constant speed as prescribed.

[0238] The screen 70 is an example of an irradiated member that includes a helical shape in which a cross section taken in a plane perpendicular to the helical axis is curved.

[0239] The motor 140 is a drive section that rotates the screen 70 around the helical axis. A stepping motor, a direct current motor (DC), an alternating current motor (AC), or the like can be used in the motor 140.

[0240] A rotation encoder is installed on the motor 140. The rotation encoder sends an encoder signal 203 that indicates the rotation angle of the rotation axis of the motor 140 to the motor control section 141. The motor control section 141 generates rotation angle information 904 that indicates the rotation angle of the screen 70 based on the received encoder signal 203, and sends it to the information processing section 110.

[0241] The information processing section 110 generates image information 903 that corresponds to the rotation angle of the screen 70 based on the received rotation angle information 904, and sends it to the projector 1. The image information 903 is information that indicates a two-dimensional image.

[0242] The projector 1 irradiates the image light L to the rotating screen 70. The projector 1 can irradiate the image light L based on the image information 903 output from the information processing section 110 to the screen 70. In other words, the projector 1 can irradiate the image light L that is generated based on the position of the rotating screen 70.

[0243] The display device 100 can cause the user to visually recognize a color three-dimensional image using the afterimage effect by the light reflected by the screen 70 in the image light L irradiated to the screen 70 that rotates at high speed.

[0244] In addition, the irradiated member is not limited to the screen 70, and can be a member that vibrates the screen using the afterimage effect to display an image.

[0245] Thus, the present application is not limited to the contents described in the present embodiment, and can be appropriately changed within the scope of the gist thereof.

[0246] In particular, the specific shapes and values of the respective sections exemplified in the embodiments are merely examples of the specific implementation performed when implementing the present application, and the technical scope of the present application is not construed as being limited by them.

[0247] The present application can be described as follows.

[0248] <1>

[0249] A light source device characterized by comprising: a light source; an optical element having a lens array in which a plurality of lenses are arranged in an array on one face or both faces, and a wavelength conversion element that converts the wavelength of light emitted from the light source and passing through the optical element, a distance P between the apexes of adjacent lenses of the optical element being 1 / 4 or less of the width D of a light beam of light incident on the optical element.

[0250] <2>

[0251] The light source device according to <1>, characterized by further having a second optical system configured between the optical element and the wavelength conversion element, the width D of the light beam being 1 / 3 or less of the outer diameter D opt of a lens on the light source side of the second optical system.

[0252] <3>

[0253] The light source device according to <2>, characterized by having an optical surface that guides light passing through the optical element to the wavelength conversion element, the width irror of a light beam on the optical surface being 1 / 3 or less of the outer diameter D opt .

[0254] <4>

[0255] The light source device according to any one of <1> to <3>, characterized in that the light source has a plurality of light emission points, the distance P being 1 / 2 or less of the width D single of a light beam on the optical element with respect to light emitted from one of the plurality of light emission points.

[0256] <5>

[0257] The light source device according to any one of <1> to <4>, characterized in that the optical element has a lens array in which a plurality of spherical lenses of a rectangular shape are arranged in an array.

[0258] <6>

[0259] The light source device according to <3>, characterized in that the optical surface is a dichroic mirror.

[0260] <7>

[0261] The light source device according to <3>, characterized in that a first optical system is provided between the light source and the optical surface, the first optical system including at least a lens having positive refractive power and a lens having negative refractive power.

[0262] <8>

[0263] The light source device according to <7>, characterized in that an outer diameter of the lens having negative refractive power is 1 / 2 or less of an outer diameter D of the lens on the light source side of the second optical system. opt

[0264] <9>

[0265] An image projection device characterized by comprising the light source device according to any one of <1> to <8>, a light uniformizing element that uniformizes light emitted from the light source device by mixing, an illumination optical system that illuminates light uniformized by the light uniformizing element, an image forming element that forms image light by modulating light illuminated by the illumination optical system, and a projection optical system that projects image light formed by the image forming element onto an irradiated member.

[0266] <10>

[0267] The image projection device according to <9>, characterized in that one side of a rectangle of a plurality of lenses of the optical element is parallel to one side of an entrance of the light uniformizing element.

[0268] <11>

[0269] A display device characterized by comprising the image projection device according to <9> or <10> and an irradiated member irradiated with image light of the image projection device, a three-dimensional image being displayed by rotating or vibrating the irradiated member irradiated with the image light.

[0270] Further, the present application is, for example, as described below.

[0271] <1>

[0272] A light source device characterized by comprising a light source;

[0273] a light shaping element having a lens array surface in which a plurality of lenses are arranged in an array, and

[0274] a wavelength conversion element that converts the wavelength of light emitted from the light source and passed through the light shaping element,

[0275] a pitch of adjacent lenses of the lens array surface is 1 / 4 or less of a width of a light beam of light incident on the light shaping element,

[0276] ​The light shaping element has a lens array surface.

[0277] <2>

[0278] The light source device according to <1>, wherein the light shaping element has at least two lens array surfaces.

[0279] <3>

[0280] The light source device according to <1>, wherein the light shaping element has a lens array surface in one of the entrance surface and the exit surface.

[0281] <4>

[0282] The light source device according to any one of <1> to <3>, comprising: a first optical system provided between the light source and the light shaping element, which reduces the light beam of light emitted from the light source, and an adjustment mechanism which adjusts the angle of incidence of the light beam incident toward the light shaping element by displacement or inclination of the first optical system.

[0283] <5>

[0284] The light source device according to any one of <1> to <3>, comprising: a reflective optical element provided between the light source and the light shaping element, which reflects light emitted from the light source and directs it to the light shaping element, and an adjustment mechanism which adjusts the angle of incidence of the light beam incident toward the light shaping element by displacement or inclination of the reflective optical element.

[0285] <6>

[0286] The light source device according to any one of <1> to <3>, comprising: a transmissive optical element provided between the light source and the light shaping element, which transmits light emitted from the light source, and an adjustment mechanism which adjusts the angle of incidence of the light beam incident toward the light shaping element by displacement or inclination of the transmissive optical element.

[0287] <7>

[0288] The light source device according to any one of <4> to <6>, wherein the adjustment mechanism is a spacer.

[0289] <8>

[0290] An image projection device characterized by comprising: the light source device described in any one of <1> to <7>; a light uniformizing element that uniformizes light emitted from the light source device by mixing; an illumination optical system that illuminates light uniformized by the light uniformizing element; an image forming element that forms image light by modulating light illuminated by the illumination optical system; and a projection optical system that projects image light formed by the image forming element onto an irradiated member.

[0291] <9>

[0292] A display device characterized by comprising: the image projection device described in <8>; and an irradiated member irradiated with image light of the image projection device, a three-dimensional image being displayed by rotating or vibrating the irradiated member irradiated with the image light.

Claims

1. A light source apparatus, characterized by comprising: including: a light source; an optical element having a lens array in which a plurality of lenses are arranged in an array on one face or both faces, and a wavelength conversion element that converts the wavelength of light emitted from the light source and passing through the optical element, a second optical system configured between the optical element and the wavelength conversion element, a distance P between the vertices of adjacent lenses of the optical element is 1 / 4 or less of the width D of a light beam of light incident on the optical element, The width D of the light beam is the outer diameter D of the lens on the light source side of the second optical system. opt Less than 1 / 3.

2. The light source apparatus according to claim 1, characterized by : an optical surface that guides light passing through the optical element to the wavelength conversion element, The width D of the light beam on the optical surface mirror is 1 / 3 or less of the outer diameter D opt .

3. The light source apparatus according to claim 2, characterized by : the optical surface is a dichroic mirror.

4. The light source apparatus according to claim 2, wherein : A first optical system is provided between the light source and the optical surface, the first optical system including at least a lens having positive optical power and a lens having negative optical power.

5. The light source apparatus according to claim 4, characterized by : An outer diameter of the lens having negative optical power is 1 / 2 or less of an outer diameter D of the lens on the light source side of the second optical system opt of the first optical system.

6. A light source apparatus, characterized by comprising: including: a light source; an optical element having a lens array in which a plurality of lenses are arranged in an array on one face or both faces, and a wavelength conversion element that converts the wavelength of light emitted from the light source and passing through the optical element, a distance P between the vertices of adjacent lenses of the optical element is 1 / 4 or less of the width D of a light beam of light incident on the optical element, the light source has a plurality of light emitting points, The distance P is a width D of a light beam on the optical element involved by light emitted from one of the plurality of light emitting points single is 1 / 2 or less.

7. The light source apparatus according to claim 1 or 6, characterized by : the optical element has a lens array in which a plurality of spherical lenses of rectangular shape are arranged in an array.

8. The light source apparatus according to claim 1 or 6, characterized by : An incident angle of light toward the optical element is within 3 degrees.

9. The light source apparatus according to claim 8, characterized by : The optical element has at least two lens array surfaces.

10. The light source apparatus according to claim 8, wherein : The optical element has a lens array surface on one of an incident surface and an emission surface.

11. The light source apparatus according to claim 8, wherein including: a first optical system provided between the light source and the optical element, the first optical system reducing a light beam of light emitted from the light source, and an adjustment mechanism that adjusts an incident angle of a light beam incident on the optical element by displacement or inclination of the first optical system.

12. The light source apparatus according to claim 8, wherein including: a reflection-type optical element provided between the light source and the optical element, the reflection-type optical element reflecting light emitted from the light source and guiding the light to the optical element, and an adjustment mechanism that adjusts an incident angle of a light beam incident on the optical element by displacement or inclination of the reflection-type optical element.

13. The light source apparatus according to claim 8, wherein including: a transmission-type optical element provided between the light source and the optical element, the transmission-type optical element transmitting light emitted from the light source, and an adjustment mechanism that adjusts an incident angle of a light beam toward the optical element by displacement or inclination of the transmission-type optical element.

14. The light source apparatus according to claim 11, wherein : The adjustment mechanism is a spacer.

15. An image projection device, characterized by including: the light source device according to any one of claims 1 to 14; a light uniformization element that homogenizes light emitted from the light source device by mixing; an illumination optical system that illuminates light homogenized by the light uniformization element; an image forming element that forms image light by modulating light illuminated by the illumination optical system; and a projection optical system that projects image light formed by the image forming element onto an irradiated member.

16. The image projection device of claim 15, wherein : One side of a rectangle of the plurality of lenses of the optical element is parallel to one side of an entrance of the light uniformization element.

17. A display device comprising including: the image projection device according to claim 15, and an irradiated member irradiated with image light from the image projection device, A three-dimensional image is displayed by rotating or vibrating the irradiated member irradiated with the image light.

Images