Light source device, projection device

Abstract

The present invention relates to providing a light source device and a projection device that can achieve miniaturization and reduce grayscale unevenness and color spots. The light source device of the present invention comprises a light source unit, including a setting area provided with a plurality of light sources, the setting area being divided into divided areas including at least one of the light sources, and the division directions of the divided areas in the setting area being aligned; an optical system that forms a first image of the light source unit, through which a light beam emitted from the light source passes through the vicinity of the optical axis of the optical system on an image plane formed with the first image, so that the light output of the light source contained in each of the divided areas changes.

Description

Technical Field

[0001] The invention relates to a light source device and a projection device. Background Art

[0002] Projectors (an example of projection devices) for magnifying and projecting various images are now widely used. The projector focuses the light emitted by a light source onto a spatial light modulator such as a digital micromirror device (DMD) or a liquid crystal display element, and displays the light emitted from the spatial light modulator as a color image on a screen after being modulated according to an image signal.

[0003] In the past, projectors mainly used ultra-high pressure mercury lamps with high grayscale, but due to their short lifespan, frequent maintenance was required. In order to solve these problems, in recent years, the number of projectors using lasers and LEDs (Light Emitting Diodes) instead of ultra-high pressure mercury lamps has gradually increased. This is also because lasers have a longer lifespan than ultra-high pressure mercury lamps, and have good monochromaticity and color reproducibility.

[0004] The projector forms an image by irradiating the spatial light modulation element such as the DMD mentioned above with red, green and blue colors. All three colors can be generated by laser light sources, but the luminous efficiency of green lasers and red lasers is lower than that of blue lasers. Therefore, the general method is to irradiate the phosphor with blue laser as excitation light, and generate green and red light from the fluorescent light after the wavelength conversion of the phosphor. Regarding the use of laser light sources, a method of increasing the amount of light by placing laser elements on a matrix has been developed.

[0005] Another method of reducing grayscale unevenness and color spots is to lengthen the light tunnel, but this will cause the light source and projector to become larger.

[0006] Patent Document 1: JP Patent No. 5408494 Summary of the invention

[0007] The present invention is a technical solution proposed in view of the above-mentioned problems, and its object is to provide a light source device and a projection device that can achieve miniaturization and reduce grayscale unevenness and color spots.

[0008] In order to solve the above-mentioned problems and achieve the above-mentioned objectives, the present invention proposes a light source device, which comprises a light source part, including a setting area provided with a plurality of light sources, the setting area is divided into divided areas including more than one light source, and the dividing directions of the divided areas in the setting area are aligned; an optical system, which forms a first image of the light source part, through which a light beam emitted from the light source passes through the vicinity of the optical axis of the optical system on the image plane where the first image is formed, so that the light output of the light source contained in each of the divided areas changes.

[0009] The effects of the present invention are to realize miniaturization of a light source device and a projection device, and to reduce grayscale unevenness and color spots. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram for explaining the features of the projector according to the first embodiment.

[0011] Figure 2 This is a schematic diagram showing an example of the relationship between a part of the light source optical system and the image of the light source of the projector according to the first embodiment.

[0012] Figure 3 This is a schematic diagram showing an example of the structure of the projector according to the first embodiment.

[0013] Figure 4 This is a schematic diagram of an example of the light source device according to the first embodiment.

[0014] Figure 5 The diagram is a schematic diagram showing an example of the configuration of a first optical system, a reflecting surface, and a second optical system (condensing optical system) included in the projector according to the first embodiment.

[0015] Figure 6 This is a schematic diagram of an example of a projected image on the second surface of the projector according to the first embodiment.

[0016] Figure 7 This is a schematic diagram of an example of light entering the fluorescent wheel in the projector according to the first embodiment.

[0017] Figure 8 It is a schematic diagram showing an example structure of a fluorescent wheel included in the projector according to the first embodiment.

[0018] Fig. 9 It is a schematic diagram showing an example structure of a color wheel included in the projector according to the first embodiment.

[0019] Fig.10 It is a schematic diagram showing an example structure of an LD light source included in the projector according to the first embodiment.

[0020] Fig.11 It is a schematic diagram showing an example of a laser light source and a collimator lens included in the projector according to the first embodiment.

[0021] Fig.12 This is a schematic diagram showing an example of an arrangement of laser light sources in the LD light source included in the projector according to the first embodiment.

[0022] Fig.13 This is a schematic diagram showing an example of the outline of a light spot after the collimator lens and on the fluorescent body in the projector according to the first embodiment.

[0023] Fig.14 FIG. 1 is a schematic diagram showing an example of the distribution of the incident angles of the excitation light on the phosphor wheel in the projector according to the first embodiment.

[0024] Fig.15 FIG. 1 is a schematic diagram showing an example of the light spot shape on the phosphor wheel and the light spot shape at the entrance of the light tunnel in the projector according to the first embodiment.

[0025] Fig.16 This is a schematic diagram showing an example of a first image formed on an opening surface of a light tunnel included in the projector according to the first embodiment.

[0026] Fig.17 This is a schematic diagram showing an example of a first image formed on an opening surface of a light tunnel included in the projector according to the first embodiment.

[0027] Fig.18 This is a schematic diagram of an example of a screen projection image generation process performed by the projector according to the first embodiment.

[0028] Fig.19 It is a cross-sectional view of the middle part of the screen projected image along the horizontal direction.

[0029] Fig. 20 It is a cross-sectional view of the middle part of the screen projected image along the horizontal direction.

[0030] Fig.21 This is an example of the light intensity distribution diagram of blue excitation light and fluorescent light when the light tunnel length is sufficient.

[0031] Fig. 22 This is an example of a light quantity distribution diagram of blue excitation light and fluorescent light in the projector according to the first embodiment.

[0032] Fig.23 This is an example of the horizontal light distribution diagram at a certain position of the screen projection image.

[0033] Fig.24 This is a schematic diagram showing an example of the correspondence relationship between the LD light source, the opening surface of the light tunnel, and the light quantity distribution of the screen projection image in the projector according to the first embodiment.

[0034] Fig.25 This is an example of a light quantity distribution diagram of the light emitting surface of the LD light source of the projector according to the first embodiment.

[0035] Fig.26 This is an example of a light quantity distribution diagram of an opening surface of a light tunnel of the projector according to the first embodiment.

[0036] Fig. 27 This is a diagram showing an example of light amount distribution of an image projected on a screen by the projector according to the first embodiment.

[0037] Fig.28 This is a functional block diagram of the projector according to the first embodiment.

[0038] Fig.29 This is an example of an operation flow chart of the light source device included in the projector according to the first embodiment.

[0039] Fig.30 This is a signal control timing chart for driving the LD light source in the projector according to the first embodiment.

[0040] Fig.31 This is a timing chart of the input current amount in one cycle of each divided region of the laser light source included in the LD light source in the projector according to the first embodiment.

[0041] Fig.32 This is an example of a light quantity distribution diagram of fluorescent light projected onto a screen by the projector according to the first embodiment.

[0042] Fig.33 This is an example of a light quantity distribution diagram of excitation light projected onto the screen by the projector according to the first embodiment.

[0043] Fig.34 This is a light quantity distribution diagram of an example of a screen projection image projected onto the screen by the projector according to the first embodiment.

[0044] Fig.35 This is a timing chart of the amount of input current to the laser light source in each divided area of ​​the LD light source in the projector according to the first embodiment within one cycle.

[0045] Fig.36 This is a schematic diagram showing an example of overlapping images projected on screens of projectors of the same model through multi-projection.

[0046] Fig.37 This is another schematic diagram showing another example of overlapping the screen projection images of projectors of the same model through multi-projection.

[0047] Fig.38 It is a schematic diagram showing an example of the structure of a fluorescent wheel included in the projector according to the second embodiment.

[0048] Fig.39 This is a timing chart of the input current amount in each divided area of ​​the LD light source in the projector according to the second embodiment within one cycle.

[0049] Fig.40 FIG. 1 is a schematic diagram showing an example of horizontal light quantity distribution in the middle portion of a screen projection image projected by the projector according to the second embodiment.

[0050] Fig.41FIG. 1 is another schematic diagram showing another example of light quantity distribution in the horizontal direction of the middle portion of the screen projection image projected by the projector according to the second embodiment.

[0051] Fig.42 This is a diagram showing an example of the positional relationship between an optical system other than a light tunnel included in a light source optical system of a projector according to a third embodiment and the light tunnel.

[0052] Fig.43 This is a schematic diagram showing an example of the relationship between an optical system other than a light tunnel included in a light source optical system of a projector according to the third embodiment and the position of the light tunnel.

[0053] Fig.44 This is a schematic diagram showing an example of the arrangement relationship between the light source optical system and the illumination optical system in the projector according to the third embodiment.

[0054] Fig.45 This is an example of a light quantity distribution diagram on a DMD in the projector according to the third embodiment.

[0055] Fig.46 This is another example of a light quantity distribution diagram on a DMD in the projector according to the third embodiment.

[0056] Fig.47 This is another example of a light quantity distribution diagram on a DMD in the projector according to the third embodiment.

[0057] Fig.48 This is another example of a light quantity distribution diagram on a DMD in the projector according to the third embodiment. DETAILED DESCRIPTION

[0058] The following describes in detail embodiments of a light source device and a projection device with reference to the accompanying drawings.

[0059] <First Embodiment>

[0060] Figure 1 1 is a schematic diagram for briefly explaining the features of the projector involved in the first embodiment. Figure 1 The projector of this embodiment (an example of a projection device) reduces grayscale unevenness and color spots of a projected image (hereinafter referred to as a screen projected image) projected onto a screen. Figure 1 As shown, when the projector of this embodiment projects a screen projection image having a short side Y in the vertical direction onto the screen, the grayscale unevenness and color spots in the vertical and horizontal directions of the screen projection image are reduced through the optical system (light source device or light source optical system), and the grayscale unevenness and color spots in the horizontal direction of the screen projection image are mainly reduced by controlling the LD output (one example of light output) of the LD light source (one example of light source unit) (hereinafter referred to as LD control).

[0061] The projector involved in this embodiment controls the LD output by changing the input current value of the LD light source, adjusts the light distribution of the screen projection image, and thus reduces the gray scale unevenness and color spots of the screen projection image. However, instead of changing the LD output of the LD light source, the light amount passing through the liquid crystal or shutter can be reduced for adjustment, and both methods can be used.

[0062] The projector of this embodiment can reduce the gray scale unevenness and color spots of the screen projection image that cannot be resolved by the light source optical system alone through LD control. In addition, when the projector of this embodiment projects a screen projection image with a long side Y in the vertical direction, the light source optical system can be used to reduce the gray scale unevenness and color spots in the horizontal and vertical directions of the screen projection image, and the LD control is mainly used to reduce the gray scale unevenness and color spots in the vertical direction.

[0063] Figure 2 FIG. 1 is a schematic diagram showing the relationship between a part of the light source optical system and the image of the light source in an example of a projector according to the first embodiment. Figure 2 The optical system of the projector according to the present embodiment will be briefly described. In the following description, the lens center axis connecting the second optical system 205 and the lens center of the condenser lens 207 is defined as the optical axis.

[0064] The LD light source light excited (emitted) from the LD light source Md is reflected by the dichroic mirror 204 and converged by the second optical system 205, and then formed into a second image on the light source image plane X1 (indicated by a dotted line) on the phosphor wheel 206. The second image is a conjugate image of the LD light source Md. Here, the phosphor wheel 206 functions as an example of a wavelength conversion unit, and is used to emit wavelength-converted light (fluorescent light) after the wavelength of the LD light source light (excitation light) emitted from the LD light source Md is converted. The phosphor wheel 206 is disposed near the light source image plane X1. It is assumed that the conjugate position of the wavelength-converted light emitted from the phosphor wheel 206 is substantially consistent with the conjugate position of the LD light source light emitted from the LD light source Md. That is, the second optical system 205 and the focusing lens 207 form an image of the wavelength-converted light that is conjugate with the light source image formed on the phosphor wheel 206 near the conjugate image plane X2. The LD light source light is reflected by the mirror of the fluorescent wheel 206, refracted by the second optical system 205, and refracted by the focusing lens 207 to form a first image on the conjugate image plane X2 (indicated by the dotted line). The first image is the conjugate image of the LD light source Md. Figure 2 Although the dotted line representing the conjugate image plane X2 and the opening surface of the light tunnel LT are depicted as having a gap, they are actually basically consistent. In this embodiment, the second optical system 205 and the focusing lens 207 function as an optical system having an optical axis that forms a conjugate image of the LD light source Md. That is, in the laser light source 201 (see Figure 4 ) and the conjugate image plane X2, the second optical system 205 and the condensing lens 207 form a first image conjugate with the LD light source Md. Then, the second optical system 205 and the condensing lens 207 guide the light beam of the LD light source light emitted from the LD light source Md to pass through the optical axis of the optical system (the second optical system 205 and the condensing lens 207) on the conjugate image plane X2 formed with the first image. Specifically, the LD light source light emitted from the LD light source Md is guided to pass through the optical system at a substantially conjugate position (conjugate image plane X2) when viewed from the short side direction of the first image. In other words, the LD light source light emitted from the LD light source Md is directed at a position θ relative to the short side direction (corresponding to the Z axis) of the first image. S (0<θ S <90[deg]), and advances at about 0° with respect to the long side direction of the first image (corresponding to the Y axis). The light tunnel LT is provided near the position of the conjugate image plane X2 where the first image is formed, and functions as a light homogenizing element having an opening for incident light beams emitted from the second optical system 205 and the focusing lens 207. In the present embodiment, the light tunnel LT has an opening that is roughly rectangular in a cross section perpendicular to the traveling direction of the LD light source light beam emitted from the LD light source Md (a cross section direction perpendicular to the traveling direction).

[0065] Since the first image and the second image are reduced images of the LD light source light emitted from the LD light source Md, when, for example, the opening size of the light homogenizing element (light tunnel LT) has a short side distance of SE and a long side distance of LE, by adjusting the vertical and horizontal dimensions of the first image to be less than the short side SE and the long side LE of the opening surface, the light source device 102 can enable the light homogenizing element to efficiently take in the LD light source light.

[0066] The LD light source light passes through the focusing lens 207 in the Z-axis direction at θ S (0[deg]≤θ S ), in the Y-axis direction with θ L (0[deg]≤θ L ) refraction. For example, preferably θ S It is about 5 to 60°. It is also preferred that θ L It is about 3 to 5°, and can also be 0°. S and θ LThey will not be 0° at the same time, and at least one of them will be greater than 0°. In the present embodiment, the LD light source light refracted by the focusing lens 207 and advancing along the optical axis direction (in other words, through the focusing lens 207, the light beam of the LD light source light passes through the vicinity of the optical axis of the optical system (focusing lens 207) on the conjugate image plane X2) is defined as "passing through the optical axis". Specifically, the so-called "passing through the optical axis" means that, from the viewpoint in the direction of the optical axis of the optical system, the light beam of the LD light source light moves from the peripheral part of the focusing lens 207 toward the optical axis and then leaves the optical axis of the LD light source light (including the case where the center of the LD light source light does not intersect the optical axis). In the present embodiment, the "near the optical axis" in "near the optical axis" means that after the LD light source light passes through the optical axis, the short side / tan(θ S ) or less or longer side / tan(θ L ) below the distance.

[0067] Figure 3 FIG. 1 is a schematic diagram showing an example of the structure of a projector according to the first embodiment. Figure 3 The basic structure of the projector 101 of the present embodiment is described. The projector 101 of the present embodiment uses a light tunnel LT (an example of a light homogenizing element) to mix and homogenize the LD light source light emitted from the light source device 102. Next, the projector 101 uses the illumination optical system 104 to roughly uniformly irradiate the image forming element 105 with the LD light source light homogenized by the light tunnel LT, and enlarges and projects (imaging) the image (screen projection image) formed by the image forming element 105 onto the screen SC through the projection optical system 106. The image forming element 105 functions as an example of an image forming element arranged at a position (conjugate position) that forms an image of the emission portion (opening) of the light emitted from the light tunnel LT. Figure 3 1 shows an example of the structure of the projector 101 using the DMD, but the present invention is not limited to this. The specific structure of the light source device 102 will be described in detail below.

[0068] Here, a light tunnel composed of four reflectors, a rod integrator, a fly-eye lens, etc. are used as light homogenizing elements. A light valve such as a DMD, a transmissive liquid crystal panel, a reflective liquid crystal panel, etc. is used as the image forming element 105. The illumination optical system 104 and the projection optical system 106 are not given examples here.

[0069] The meanings of various symbols in this embodiment are as follows.

[0070] f: focal distance of the entire system

[0071] R: radius of curvature (for aspherical surfaces, the paraxial radius of curvature)

[0072] D: Mirror spacing

[0073] Nd: refractive index

[0074] vd: Abbe value

[0075] K: Aspheric cone constant

[0076] Ai: aspheric constant of the i-th power

[0077] The aspheric shape is determined by the reciprocal of the paraxial curvature radius (paraxial curvature): C, the height relative to the optical axis: H, the cone constant: K, and the aspheric coefficients of each power mentioned above. X is used as the aspheric amount in the direction of the optical axis and is expressed using a well-known calculation formula. The shape is determined by giving the paraxial curvature radius, cone constant, and aspheric coefficient.

[0078] Figure 4 FIG. 1 is a schematic diagram of an example of a light source device according to the first embodiment. Figure 4 The general structure of the light source device 102 involved in this embodiment is described. In this embodiment, the light source device 102 includes a laser light source 201 as a solid light source, a collimating lens 202 corresponding to each laser light source 201, a first optical system 203, a dichroic mirror 204, a second optical system (condensing optical system) 205, a phosphor wheel 206, a condensing lens 207, and a color wheel 208. In this embodiment, the light source device 102 is provided with the collimating lens 202, the first optical system 203, the dichroic mirror 204, the second optical system (condensing optical system) 205, the phosphor wheel 206, the condensing lens 207, and the color wheel 208 in order along the propagation direction of the excitation light (LD light source light) emitted from the laser light source 201.

[0079] The light source 201 (an example of a light source) serves as an excitation light for exciting the phosphor of the phosphor wheel 206 described later, for example, an LD light source light (blue excitation light) of a blue band with a central wavelength of 455 nm of luminous intensity. The blue excitation light emitted from the laser light source 201 is a linearly polarized light having a certain polarization state, and is set to be S-polarized light relative to the dichroic mirror 204. Regarding the wavelength band of the excitation light, as long as it is light of a wavelength that can excite the phosphor of the phosphor wheel 206 described later, it is not limited to the excitation light of the blue band. Here, a plurality of laser light sources are used as an example of the laser light source 201, but a single laser light source may also be used. As a plurality of laser light sources, a light source unit arranged in an array on a substrate may also be used, but is not limited to this. Here, the center line of the light beam formed by a plurality of or a single laser light source is taken as the main light.

[0080] The excitation light emitted from the plurality of laser light sources 201 is basically formed into parallel light by the collimating lenses 202 corresponding to the respective laser light sources 201. The basically parallel excitation light enters the first optical system 203. The first optical system 203 is arranged so that its optical axis passes through the center of the light source array of the laser light source 201. That is, the main ray of the excitation light is consistent with the optical axis of the first optical system 203. The excitation light passing through the first optical system 203 is guided to the dichroic mirror 204 which is arranged at an angle of 45 degrees relative to the optical axis of the first optical system 203. This embodiment shows a configuration in which the dichroic mirror 204 is arranged at an angle of 45 degrees, but it may also be at other angles. The dichroic mirror 204 is coated to reflect the light in the wavelength band of the excitation light and to allow the fluorescent light generated by the fluorescent body of the fluorescent body wheel 206 described later to pass through. Although a flat dichroic mirror 204 is used in this embodiment, a prism-type dichroic mirror 204 may also be used. The excitation light reflected by the dichroic mirror 204 changes its optical path by 90 degrees and enters the second optical system 205 (condensing optical system). Here, the optical axes of the first optical system 203 and the second optical system 205 (condensing optical system) are substantially eccentric.

[0081] Figure 5 It is a schematic diagram of an example of the first optical system, the reflection surface, and the second optical system (light-converging optical system) of the projector involved in the first embodiment. When the surface including the excitation light incident surface (reflection surface) of the dichroic mirror 204 is set as the first surface Y1, the intersection of the first surface Y1 and the optical axis of the first optical system 203 is set as point P, and the intersection of the first surface Y1 and the optical axis of the second optical system 205 (light-converging optical system) is set as point Q, the maximum distance between the point P and the point Q in the in-plane direction perpendicular to the optical axis of the second optical system 205 (light-converging optical system) is set as ΔL. Thus, the excitation light is incident in an eccentric state relative to the second optical system 205 (light-converging optical system). Here, as Figure 5 As shown, let the outer diameter of the optical element arranged on the incident side of the second optical system 205 (light-focusing optical system) be D, and the plane including the surface vertices of the optical element on the incident side of the second optical system 205 (light-focusing optical system) and perpendicular to the optical axis of the second optical system 205 (light-focusing optical system) be the second surface Y2.

[0082] Figure 6 1 is a schematic diagram of an example of a projection image of the second surface of the projector involved in the first embodiment. Specifically, Figure 61 is a schematic diagram of a projection image of the excitation light (first color light) beam passing through the second surface Y2 on the optical path from the laser light source 201 to the wavelength conversion element (phosphor wheel 206) in the projector 101 according to the first embodiment, and a projection image on the second surface Y2 on the incident surface of the second optical system 205 (condensing optical system). Here, the area of ​​the first color light beam is expressed as the peak intensity 1 / e 2 The area of ​​the strength part above.

[0083] The excitation light passing through the second optical system 205 (condensing optical system) is guided to the phosphor wheel 206. In this embodiment, the spot diameter of the excitation light guided to the surface of the phosphor wheel 206 is enlarged by deviating from the conjugate surface (light source image plane X1) on the phosphor wheel 206, and the fluorescence conversion efficiency is improved by reducing the heat of the phosphor region of the phosphor wheel 206. The excitation light is incident on the second optical system 205 (condensing optical system) eccentrically, so that the excitation light is incident obliquely with respect to the phosphor wheel 206.

[0084] Figure 7 Schematic diagram of an example of light incident on the fluorescent wheel in the projector according to the first embodiment. In the projector 101 of this embodiment, the optical axis of the second optical system 205 and the excitation light incident on the fluorescent wheel 206 form an angle θ.

[0085] Figure 8 1 is a schematic diagram of an example of the structure of the phosphor wheel of the projector involved in the first embodiment. In the projector 101 involved in this embodiment, the phosphor wheel 206 on the disk is installed on the driving motor 801. By rotating the phosphor wheel 206 at a high speed, the position of the phosphor wheel 206 irradiated with the LD light source light moves over time. In this embodiment, the phosphor of the phosphor wheel 206 is divided into a phosphor region 206a coated with the phosphor and an excitation light reflection region 206b that reflects the LD light source light. Although this embodiment shows an example in which the phosphor wheel 206 is divided into two regions, the phosphor region 206a and the excitation light reflection region 206b, the phosphor region 206a can also be divided into a plurality of regions, and the excitation light reflection region 206b can also be divided into a plurality of regions.

[0086] As the substrate 802 of the phosphor wheel 206, a transparent substrate or a metal substrate such as aluminum can be used, but it is not limited to this. In the excitation light reflection area 206b, for example, a reflective coating 802a having a high reflectivity for the LD light source light can be formed on the substrate 802, or a metal substrate can be used as the substrate 802, and the substrate 802 itself can be used as the excitation light reflection area 206b. The phosphor area 206a is an example of a reflective coating 206c that reflects light in the wavelength region of the light emitted from the phosphor, a phosphor layer 206d, and a reflective coating 206e (AR coating) that reduces the reflection on the phosphor surface formed on the substrate 802, but it is not limited to this. When a metal is used as the substrate 802, the reflective coating 206e may not be required. The phosphor layer 206d may be a layer in which the phosphor material is dispersed in an organic and inorganic binder, or a layer in which the phosphor material crystals are directly formed. The phosphor material may use a rare earth phosphor such as Ce:YAG series, but it is not limited to this, and phosphors and nonlinear optical crystals may also be used. The wavelength band of light emitted by the fluorescent body may be, for example, yellow, blue, green, or red. However, in this embodiment, only fluorescent light having a yellow wavelength band is described.

[0087] return Figure 4 The excitation light reflected by the excitation light reflection area 206b of the fluorescent wheel 206 is positively reflected in the excitation light reflection area 206b. Figure 4 As shown, the light passes through the side opposite to the incident side of the second optical system 205 (light-converging optical system) and is emitted from the second optical system 205 (light-converging optical system).

[0088] The excitation light emitted from the second optical system 205 (condensing optical system) does not pass through the dichroic mirror 204, enters the condensing lens 207, passes through the color wheel 208, and is guided to the light homogenizing element 209 near the position of the conjugate plane (conjugate image plane X2) of the LD light source Md. Although the present embodiment shows a configuration in which the excitation light reflected by the phosphor wheel 206 does not pass through the dichroic mirror 204, the dichroic mirror 204 may be enlarged, and a dichroic mirror 204 may be used in which the coating on one half of the surface has the characteristic of reflecting the excitation light and allowing the fluorescent light to pass through, and the coating on the other half of the surface has the characteristic of allowing the excitation light and the fluorescent light to pass through. When the excitation light enters the coating area of ​​the phosphor, the fluorescent light is emitted from the incident surface side of the excitation light and enters the second optical system 205 (condensing optical system). A part of the excitation light passing through the second optical system 205 (condensing optical system) passes through the excitation light reflecting portion of the dichroic mirror 204, enters the condensing lens 207, and is guided to the color wheel 208 and the light tunnel LT. At this time, the conjugate positions of the excitation light and the wavelength converted light (fluorescent light) of the LD light source Md are substantially consistent.

[0089] The condenser lens 207 is a single optical element, and both surfaces are spherical surfaces of the rotating object. The condenser lens 207 is not limited to a spherical surface, and may be an aspherical surface on one or both sides. The image (first image) of the light source unit (LD light source Md) is formed at a conjugate position by the optical system including the condenser lens 207. Figure 4 For example, after passing through the color wheel 208, the excitation light (LD light source light) is guided obliquely (i.e., passes through the optical axis) relative to the optical axis near the conjugate position when looking at the optical axis of the condenser lens 207 from the plane of the drawing, thereby forming an image (first image) of the LD light source Md. Before and after the image of the LD light source Md is formed, as shown in FIG. Figure 4 As shown, the light path passes through the optical axis.

[0090] Fig. 9 208 is a schematic diagram of an example of the color wheel of the projector according to the first embodiment. In this embodiment, the color wheel 208 is divided into four areas: blue area B, yellow area Y, red area R, and green area G. The blue area B corresponds to Figure 5 The excitation light reflecting region 206 b of the phosphor wheel 206 , the color wheel 208 and the phosphor wheel 206 rotate synchronously, so that the yellow region Y, the red region R and the green region G correspond to the phosphor region 206 a of the phosphor wheel 206 , respectively.

[0091] A transmission diffuser (an example of a diffusion element) is provided in the blue region B, and the transmission diffuser is offset from the position of the conjugate image plane X2 where the first image is formed, and is used to diffuse the light beam of the LD light source light emitted from the second optical system 205 and the condenser lens 207. In this embodiment, by displacing the transmission diffuser from the conjugate position of the light source optical system where the LD light source Md is generated substantially conjugate, the coherence of the LD light source Md can be reduced, and the speckle on the screen can be reduced. The yellow region Y allows the yellow wavelength region emitted from the phosphor wheel 206 to pass directly. The red region R and the green region G respectively reflect light from the yellow wavelength to the unnecessary wavelength region by using the dichroic mirror 204, thereby obtaining light of high-purity color. The colors generated in time are guided to the image forming element 105 through the color wheel 208 after passing through the illumination optical system 104, and an image corresponding to each color (screen projection image) is formed, which is enlarged and projected onto the screen by the projection optical system 106, thereby obtaining a color image.

[0092] The LD light source Md corresponds to each area of ​​the color wheel 208, and can change the input current of the laser light source 201. Without changing the expected value of the input current of the LD light source in one cycle of the color wheel 208, by reducing the blue LD light source light with lower visual sensitivity and increasing the red, green, and yellow LD light source light, the grayscale can be improved without increasing the power consumption of the laser light source 201.

[0093] Next, a specific configuration example of the projector 101 according to this embodiment will be described. Figure 4 As shown, the first optical system 203 has a positive lens and a negative lens from the side where the excitation light is incident, the second optical system 205 (light-gathering optical system) has an aspheric lens and a plano-convex lens with positive focal length, and the light-gathering lens 207 has a biconvex lens. The following Table 1 is the lens data of the first optical system 203 and the second optical system 205 (light-gathering optical system). In Table 1, the mirror number with an * indicates an aspheric surface.

[0094] Table 1

[0095]

[0096] Aspheric coefficient

[0097] K A4 A6 A8 6 sides -0.5587 3.4062E-05 -2.4706E-07 -2.1131E-09 7 sides -10.8169 4.8564E-05 -6.3144E-07 2.2753E-09

[0098] The lens data of the condenser lens 207 is shown in Table 2 below. The condenser lens 207 is spaced 32 mm from the vertex of the second optical system 205 (condenser optical system) on which the excitation light is incident.

[0099] Table 2

[0100]

[0101] The offset ΔL between the first optical system 203 and the second optical system 205 (light-converging optical system) is 2.35 mm, the outer diameter of the lens on the incident side of the second optical system 205 (light-converging optical system) is 23.5 mm, and the outer diameter of the lens on the emitting side of the first optical system 203 is 12.3 mm. The synthesis magnification β of the second optical system 205 (light-converging optical system) and the condensing lens 207 is 2.88.

[0102] Fig.10 FIG. 1 is a schematic diagram showing an example of the structure of an LD light source included in the projector according to the first embodiment. Fig.10 As shown, the laser light source (LD) 201 uses a light source arranged in a two-dimensional array. In this embodiment, a plurality of laser light sources 201 are arranged into a module, referred to as an LD light source Md, and the laser light source 201 is a semiconductor laser. The laser light source 201 is not limited to LD, but may also be an individual light emitting element such as an LED (Light Emitting Diode), and the description is based on the premise of LD. For example, a laser light source having LD arranged on a metal block, or a multi-chip product having LD chips arranged in an array shape on a substrate can be used as the laser light source 201.

[0103] Among the laser light sources 201 arranged in an array shape in the LD light source Md of the present embodiment, 5 laser light sources 201 are arranged in the X-axis direction, and 4 laser light sources 201 are arranged in the Y-axis direction. The distance between adjacent laser light sources 201 in the X-axis direction is Px (= 3.5 mm), and the distance between adjacent laser light sources 201 in the Y-axis direction is Py (= 6.0 mm). When the X-axis direction is horizontal, the distance between the laser light source 201 at the left end and the laser light source 201 at the right end is Lx (= 14.0 mm), and when the Y-axis direction is vertical, the distance between the laser light source 201 at the upper end and the laser light source 201 at the lower end is Ly (= 18.0 mm). When the distance between any two laser light sources 201 is S, and the maximum distance is Smax, since the distance S between two points in the diagonal direction is the largest, it is set to Smax (= 22.8 mm).

[0104] However, the number of laser light sources 201 is not limited to 5×4, and may be 3×5 or 4×6, and there is no particular limitation. The arrangement of the laser light sources 201 may also be a square arrangement, but in this embodiment, the first image and the second image described below as conjugate images of the LD light source Md function most effectively when they have a rectangular shape with long and short sides that match the shape of the image forming element 105, so the LD light source Md that forms the first image and the second image is also preferably rectangular.

[0105] In this embodiment, the laser light sources 201 are arranged in a rectangular configuration to match the shape of the image forming element 105. However, the substrate on which the laser light sources 201 are arranged may be, for example, circular or polygonal, or any other shape. The arrangement of the laser light sources 201 on the substrate is not limited.

[0106] Fig.11 1 is a schematic diagram of an example of a laser light source and a collimating lens of a projector according to the first embodiment. The distance between the laser light source 201 and the incident surface of the collimating lens 202 is L (= 4.3 mm), and when the direction with the largest divergence angle among the divergence angles of the laser light source 201 is X, the divergence angle in the X direction is θx (= 45°).

[0107] Fig.12 FIG. 1 is a schematic diagram of an arrangement of an example of laser light sources among the LD light sources included in the projector according to the first embodiment. Fig.12 As shown, the arrangement area includes a plurality of laser light sources 201. The arrangement area in this embodiment is basically a rectangular area having a short side and a long side. Fig.12As shown, it is divided into divided areas R1 to R4 (in the following description, when the divided areas R1 to R4 are not distinguished, they are recorded as divided areas R) containing more than one laser light source 201. The LD light source Md acts as an example of a light source unit in which the division directions of multiple divided areas R1 to R4 in the setting area are roughly the same. In this embodiment, the division directions of the multiple divided areas R1 to R4 are parallel to one of the long sides of the setting area. Each laser light source 201 in each divided area R can make the LD output change, and each divided area R has a light quantity distribution. For example, the wiring of the laser light source 201 can also be connected in series in each divided area R as the same LD output. It is also possible to set a common input current of the laser light source 201 for each divided area R, and drive the laser light source 201 according to the divided area R. This embodiment exemplifies that the setting area of ​​the LD light source Md is divided into four divided areas R1 to R4 in the direction where the laser light sources 201 are more arranged, but the number of divided areas R is not limited to this.

[0108] Fig.13 Schematic diagram of the light spot profile after a collimating lens and on a fluorescent body in a projector according to the first embodiment. In particular, the LD light source Md shown in (a) has an array of laser light sources 201 with a large spacing, and the LD light source Md shown in (b) has an array of laser light sources 201 with a small spacing.

[0109] When the overall size B of the light spot profile on the phosphor region 206a (phosphor) of the phosphor wheel 206 is the same, if the interval between the laser light sources 201 is large, the reduction ratio must be increased compared to when the interval between the laser light sources 201 is small. Therefore, each light spot on the phosphor region 206a becomes smaller, the light concentration density increases, and the conversion efficiency of the phosphor region 206a decreases. On the other hand, when the interval between the laser light sources 201 is appropriate, such as Fig.13 As shown in (b), the light spots are arranged in a way to fill the space, so they are evenly distributed on the phosphor area 206a, which can reduce the focusing density and improve the conversion efficiency.

[0110] Fig.14 FIG. 1 is a schematic diagram showing an example of the distribution of the incident angles of the excitation light of the projector according to the first embodiment with respect to the phosphor wheel. Fig.14 As shown, in the projector 101 of this embodiment, the peak intensity of the excitation light on the fluorescent wheel 206 is 1 / e 2 The incident angle of the light in the above range is distributed between 0 and 50 degrees. Thus, the reflectivity of one surface of the fluorescent wheel 206 of the second optical system 205 (light-collecting optical system) can be suppressed, thereby improving efficiency.

[0111] Fig.15This is a schematic diagram showing an example of the light spot shape on the phosphor wheel and the light spot shape at the entrance of the light tunnel in the projector according to the first embodiment. The short side SE of the opening of the light tunnel LT is 3.4 mm, and the long side LE is 5.7 mm.

[0112] like Fig.15 As shown, in the projector 101 of the present embodiment, the entrance of the light tunnel LT is incident in a state of almost no halo. In order to obtain a more uniform distribution on the exit surface of the light tunnel LT, it is preferred that there is basically no halo on the entrance surface of the light tunnel LT and the incident is uniformly distributed. To this end, the long side direction of the first image of the opening surface of the light tunnel LT (i.e., the long side direction of the opening of the light tunnel LT) of each segmented area R of the LD light source Md is consistent with the segmentation direction of the segmented area R of the LD light source Md (the arrangement direction of the image of the segmented area R in the first image), and the long side direction and short side direction of the light tunnel LT are consistent with the first image. In this way, by emitting light into the light tunnel LT in the short side direction of the opening of the light tunnel LT, the light amount distribution in the long side direction of the light tunnel LT can be expanded, thereby obtaining a more uniform distribution. However, the segmentation direction of the segmented area R of the LD light source Md is not limited to this. In this embodiment, the LD light source light beam emitted from the second optical system 205 and the condenser lens 207 passes through the vicinity of the optical axis of the second optical system 205 and the condenser lens 207 along the arrangement direction of the images of the divided regions R on the conjugate image plane X2.

[0113] Fig.16 and Fig.17 1 and 2 are schematic diagrams of an example of a first image formed on an opening surface of a light tunnel of a projector according to the first embodiment. Fig.13 As shown, on the conjugate image plane X2, the image (first image) of each laser light source 201 of the LD light source Md is substantially elliptical. Fig.16 As shown in FIG. 1 , the major axis direction of the ellipse is consistent with the long side direction of the opening of the light tunnel LT, so the glare of the incident light can be reduced at the entrance of the light tunnel LT. Fig.17 As shown, when the short axis direction of the ellipse is aligned with the long side direction of the light tunnel LT, the number of laser light sources 201 arranged in the long side direction of the light tunnel LT increases, but by changing the LD output, the color spots and grayscale unevenness in the left and right directions of the screen projection image can be more finely adjusted.

[0114] Fig.18 This is a schematic diagram of an example of screen projection image generation processing executed by the projector according to the first embodiment. Fig.18 The respective optical paths of blue excitation light and fluorescent light for generating a screen projection image projected onto the screen SC are shown.

[0115] The blue excitation light of the LD light source Md is irradiated onto the phosphor region 206a and the excitation light reflection region 206b of the phosphor wheel 206, and is divided into two types of light: blue excitation light and fluorescent light. Fig.18 The optical path between the phosphor wheel 206 and the light tunnel LT is Fig.18 The parts of the phosphor wheel 206 (phosphor region 206a, excitation light reflection region 206b) are depicted side by side up and down correspondingly, but in fact, as the phosphor wheel 206 rotates, the phosphor moves to the optical path of the blue excitation light, so the optical path is in the same space. The fluorescent light is emitted at an angle close to Lambertian light in the phosphor layer (phosphor region 206a) and enters the incident light tunnel LT. In contrast, the blue excitation light is reflected from the excitation light reflection region 206b of the phosphor wheel 206 and converged until it passes through the diffusion region of the color wheel 208. Therefore, as Fig.18 The arrows of the blue excitation light and the fluorescent light shown are different in size, and the light quantity distributions of the blue excitation light and the fluorescent light on the opening surface of the light tunnel LT are different.

[0116] People perceive the screen projection image on the screen SC formed by the time-sharing blue excitation light and the screen projection image on the screen SC formed by the fluorescent light as a composite. If the shapes of the composite light quantity distributions are different from each other, for example, Fig.18 As shown in the screen projection image, people will perceive color unevenness due to the difference in illumination between the center and the surrounding areas.

[0117] Fig.19 and Fig. 20 It is the light distribution diagram of the middle section of the screen projection image in the horizontal direction. Fig.19 and Fig. 20 In the figure, the horizontal axis represents the position of the middle part of the screen projection image in the horizontal direction, and the vertical axis represents the illumination. Fig.19 and Fig. 20 In FIG. 1 , it is assumed that the LD light source Md emits the same light intensity in all the divided regions R, and the cross-section of the light intensity distribution of the blue excitation light and the light intensity distribution of the fluorescent light is shown in the figure.

[0118] exist Fig.19 and Fig. 20 Below the curve, three lines are used to represent the light emission of each divided area R of the LD light source Md. Here, the light emission of the laser light source 201 is simply represented by the number of lines. The more lines there are, the greater the light emission and the higher the illumination. Fig.19In the case of the light quantity distribution, the blue excitation light has high illumination on the left and right sides of the screen SC, and the fluorescent light has high illumination in the middle of the screen SC. Therefore, the illumination difference between the middle and the surrounding parts of the screen SC is different from each other. This difference in illumination difference will cause color spots when the screen projection image of the blue excitation light and the screen projection image of the fluorescent light are synthesized. On the other hand, Fig. 20 The light intensity distribution of the blue excitation light and the light intensity distribution of the fluorescent light shown do not change in any position on the screen SC. In this case, there is no color unevenness in the projection.

[0119] Fig.21 This is an example of the light quantity distribution diagram of blue excitation light and fluorescent light when the light tunnel is long enough. Regarding eliminating the color spots of the screen projection image, there is a method of extending the light tunnel LT. For example, Fig.21 As shown, assuming that the length of the light tunnel LT is the gray area, we can get Fig.19 The light intensity distribution of the blue excitation light and the fluorescent light shown in FIG. 1 is shown in FIG. 1 , and when the length of the light tunnel LT is extended, the light intensity distribution of the blue excitation light and the fluorescent light can be obtained. Fig.21 The light intensity distribution of blue excitation light and fluorescent light is shown.

[0120] Extended light tunnel LT, such as Fig.21 As shown in the light distribution diagram, the light distribution of the blue excitation light and the fluorescent light can obtain uniform light distribution in the left and right directions of the screen SC, thereby improving color spots. However, if the light tunnel LT is lengthened, the optical system will become larger, and the larger optical system will lead to a larger projector 101. Therefore, in this embodiment, the setting area of ​​the LD light source Md is divided into a plurality of divided areas R, and the LD output between the plurality of divided areas R is changed, thereby reducing the color spots of the screen projected image. For example, in this embodiment, the projector 101 changes the LD output of at least one laser light source 201 contained in each divided area R.

[0121] Fig. 22 FIG. 1 is an example of a light quantity distribution diagram of blue excitation light and fluorescent light in the projector according to the first embodiment. Fig. 22 As shown in FIG. 1 , when the illumination of the blue excitation light is high around the screen SC, by reducing the LD output of the divided regions R1 and R4, the light quantity distribution of the screen projection image of the blue excitation light and the light quantity distribution of the screen projection image of the fluorescent light can be made consistent, thereby eliminating color spots. That is, the projector 101 changes the LD output of each divided region R on the screen SC so that the light quantity distribution of the LD light source light emitted from the LD light source Md and the light quantity distribution of the fluorescent light emitted from the fluorescent body wheel 206 are consistent. Fig. 22 The light quantity distribution of the blue excitation light and the light quantity distribution of the fluorescent light are such that the LD output in the divided regions R1 and R4 is lower than the LD output in the divided regions R2 and R3 . Fig. 22The LD outputs of the divided areas R1 and R4 of the LD power supply below the lower curve of the graph are represented by one line, and the LD outputs of the divided areas R2 and R3 are represented by three lines, indicating that the LD outputs of the divided areas R2 and R3 are larger.

[0122] Regarding the method of reducing color spots, for ease of understanding, the color spots in the horizontal direction of the screen SC are focused on, but the color spots also need to be reduced for the two-dimensional light distribution on the screen SC including the vertical direction. Here, the light distribution of the screen projection image formed by the excitation light is consistent with the light distribution of the screen projection image formed by the fluorescent light, which means that, for example, in the two-dimensional light distribution obtained from the illuminance meter, the error of the maximum illumination difference between the excitation light and the fluorescent light at any position of the light distribution is within 50% (preferably within 30%). When the light distribution of the screen projection image formed by the excitation light is consistent with the light distribution of the screen projection image formed by the fluorescent light, it can be said that the color spots are improved. In addition, in the illumination difference histogram of the two-dimensional light distribution, it is sufficient as long as more than 68% of the area is satisfied, and preferably more than 95% of the area has an illumination difference within 50% to 30%.

[0123] If the shape of the light quantity distribution in the left and right directions on the screen SC is different, people will feel that the grayscale is uneven. Fig.21 As shown, when there is a certain amount of light distribution in the horizontal direction on the screen SC, no grayscale unevenness will occur. Fig. 22 In the case of the light quantity distribution shown, the middle part of the screen SC is bright and the surrounding part is dark. Therefore, it is preferable that the two-dimensional light quantity distribution including the vertical direction on the screen SC can obtain uniform illumination at any position of the screen projection image.

[0124] Therefore, the LD output between the divided areas R1 to R4 of the LD light source Md may be changed so that the grayscale of the light quantity distribution of the screen projection image formed by the fluorescent light is uniform. That is, the projector 101 of this embodiment changes the LD output of the LD light source Md so that the light quantity distribution of the fluorescent light emitted from the fluorescent body wheel 206 on the screen SC (an example of the irradiation position) is uniform. In addition, by making the light quantity distribution of the excitation light consistent with the light quantity distribution of the wavelength converted light (fluorescent light) after homogenization, grayscale unevenness and color spots can be improved at the same time.

[0125] Fig.23 is an example of the light distribution diagram in the horizontal direction at a certain position of the screen projection image. For example, when all pixels of the input image are the same color (for example, white), the light distribution of the screen projection image is Fig.23When the light intensity distribution shown in FIG. 1 is uniform, the light intensity distribution is considered uniform when the illumination difference between the maximum illumination of the wavelength-converted light (fluorescent light) emitted from the fluorescent wheel 206 and the average illumination of the entire screen SC is within 50% (more preferably within 30%) of the maximum illumination. In addition, it is sufficient that more than 68% of the area in the illumination difference histogram of the two-dimensional light intensity distribution satisfies the illumination difference within 50%, and preferably more than 95% of the area satisfies the illumination difference within 50% to 30%.

[0126] As described above, when reducing the grayscale unevenness of the light distribution of the screen projection image on the screen SC, it is preferable to change the LD output between the divided areas R1 to R4 when irradiating the excitation light to the phosphor region 206a of the phosphor wheel 206. When reducing the color spots of the light distribution of the screen projection image, it is preferable to change the LD output between the divided areas R1 to R4 when irradiating the screen SC with blue excitation light.

[0127] The reason is that since the visual sensitivity of blue excitation light is lower than that of wavelength-converted light, the color spot can be adjusted with little influence on gray scale unevenness. On the contrary, since the visual sensitivity of fluorescent light is higher than that of blue excitation light, the gray scale unevenness can be adjusted more by changing the LD output between the divided areas R1 to R4 when irradiating the fluorescent light to the screen projected image.

[0128] Fig.24 This is a diagram showing an example of the light quantity distribution correspondence relationship among an LD light source, an opening surface of a light tunnel, and a screen projection image in the projector according to the first embodiment. Fig.25 This is an example of a light quantity distribution diagram of the light emitting surface of the LD light source of the projector according to the first embodiment. Fig.26 This is an example of a light quantity distribution diagram of an opening surface of a light tunnel of the projector according to the first embodiment. Fig. 27 This is a diagram showing an example of light intensity distribution of an image projected on a screen of the projector according to the first embodiment. Figures 24 to 27 The light distribution shown is intended to indicate the correspondence between the LD light source Md, the opening surface of the light tunnel LT, and the light distribution of the screen projection image. It does not change the LD output of each divided area R, but only the light distribution when a specific laser light source 201 is turned on.

[0129] In this embodiment, if the segmented area R above the LD light source Md, such as the segmented area R1, is illuminated, the illuminance of the light distribution on the left side of the screen projection image becomes larger, and if the segmented area R below the LD light source Md, such as the segmented area R4, is illuminated, the illuminance of the light distribution on the right side of the screen projection image becomes larger. However, a reflector may be used to fold back the optical path to change the corresponding relationship between the light emitting surface of the LD light source Md and the light distribution of the opening surface of the light tunnel LT, and the corresponding relationship between the opening surface of the light tunnel LT and the light distribution of the screen projection image may also be changed.

[0130] The LD light source Md, the incident position of the light tunnel LT, the exit of the light tunnel LT, the image forming element 105, and the screen SC are optically conjugate. Depending on the reflection of the reflector or the presence or absence of the intermediate image, the LD light source Md, the incident position of the light tunnel LT, the exit of the light tunnel LT, the image forming element 105, and the screen SC are flipped upside down or left to right. Fig.24 In FIG. 1 , the positions of the respective LD light sources Md, the positions on the light tunnel LT, and the position of the screen SC are schematically displayed.

[0131] Fig.25 The light intensity distribution on the opening surface of the light tunnel LT is shown. The horizontal axis is the horizontal direction of the multi-chip of the LD light source Md, and the vertical axis is the vertical direction of the multi-chip of the LD light source Md. The higher the light intensity, Fig.25 The whiter the light distribution is, the brighter it is. Fig.24 When the two laser light sources 201 on the right side of the divided area R1 and the one laser light source 201 on the left side of the divided area R4 are turned on, the Fig.25 In the light quantity distribution shown, the illuminance at the position corresponding to the turned-on laser light source 201 becomes large.

[0132] Fig.25 The light distribution shown is based on the short side direction of the multi-chip of the LD light source Md as the horizontal axis (corresponding to the vertical direction on the screen SC when projecting a horizontally long image), and the long side direction of the multi-chip of the LD light source Md as the vertical axis (similarly, corresponding to the horizontal direction on the screen). The higher the illumination, the whiter the distribution. Fig.24 As shown in the LD light source Md, when two laser light sources 201 on the right side of the divided area R1 and one laser light source 201 on the left side of the divided area R4 are turned on, Fig.25 In the light quantity distribution shown, the illuminance at the position corresponding to the turned-on laser light source 201 becomes high.

[0133] Fig.26 The light quantity distribution on the opening surface of the light tunnel LT is shown. The horizontal direction corresponds to the short side SE of the light tunnel LT, and the vertical direction corresponds to the long side LE of the light tunnel LT. Fig.25 The light quantity distribution on the light emitting surface of the LD light sources Md shown is the same. Fig. 27 The area with the lowest illumination in the light distribution on the screen SC shown is the area where the screen SC is not projected. In order to equalize the blue excitation light incident on the light tunnel LT, the light distribution projected on the screen SC cannot distinguish the light emission position of the laser light source 201. However, the gradient of the light distribution corresponds to the light emission position of the laser light source 201. When the two laser light sources 201 on the right are turned on in the divided area R1, a light distribution with a peak appears at the lower left of the screen SC.

[0134] Fig.28 This is an example functional structure block diagram of a projector involved in the first embodiment. The light source device 102 of the projector 101 involved in this embodiment has the following components: LD light source Md, which is an excitation light source that emits excitation light; phosphor wheel 206, which is arranged on the optical path of the excitation light and serves as a wavelength conversion component, and is excited by the excitation light to generate fluorescence in a specified wavelength band; color wheel 208, which is arranged on the optical path of the excitation light and extracts four areas of blue area B, yellow area Y, red area R, and green area G from the excitation light and the fluorescence generated by the phosphor wheel 206; light source unit control unit 130, which controls the light emission of the LD light source Md and the phase of the phosphor wheel 206, and controls the light emission of the LD light source Md and the phase of the phosphor wheel 206; second optical system 205, which converges the fluorescence generated from the phosphor wheel 206. The phosphor wheel 206 is installed on the motor unit 12d ( Figure 8 The color wheel 208 is mounted on the rotating shaft 13c of the motor part 13d which is a driving device such as an electric motor. The motor part 13d is also driven and controlled by the motor driving part 17.

[0135] The motor unit 12d has a function of generating a rotation detection signal MIDX1 indicating the rotation speed of the rotating shaft 12c and outputting it to the motor drive unit 17. This function can be set inside the motor unit 12d or outside the motor unit 12d. When this function is installed in an external manner, a well-known method is, for example, to apply an optical mark on a part of the rotating shaft 12c of the motor unit 12d or a part that rotates with the rotating shaft 12c, and detect the mark with a photosensor or the like. That is, whenever the mark is detected, the photosensor generates a pulse and outputs the rotation detection signal MIDX1. Similar to the above, the motor unit 13d also has a function of generating a rotation detection signal MIDX2 indicating the rotation speed of the rotating shaft 13c and outputting it to the motor drive unit 17.

[0136] The light source control unit 130 includes a synchronization signal generating unit 15 for outputting a synchronization signal of a certain period; an LD driving unit 16 for controlling the light emission (lighting and extinguishing) of the LD light source Md; a motor driving unit 17 for controlling the phase of the motor unit 12d of the fluorescent body rotating wheel 206 and the motor unit 13d of the color wheel 208; a control unit 14 for controlling these units; and a memory 18 in which various data such as the light emission timing data of the LD light source Md, the light emission period, and the rotation phase data of the motor units 12d and 13d are stored. The LD driving unit 16, the motor driving unit 17, and the control unit 14 of the light source control unit 130 are connected to the memory 18 via a memory bus (MBI) 20.

[0137] The hardware structure of the light source control unit 130 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The light source control unit 130 controls the driving of the LD light source Md, the phosphor wheel 206, and the color wheel 208 according to the program pre-stored in the ROM and uses the RAM as a working memory.

[0138] The synchronization signal generating unit 15 has a function of outputting a synchronization signal SYNC (SYN_O) of a certain period T0. According to the output time of the synchronization signal SYN_O, the phase control of the motor parts 12d and 13d of the motor driving unit 17 and the light emission control of the LD light source Md of the LD driving unit 16 are performed. For example, when the periodic signal SYN_I is input to the synchronization signal generating unit 15 from the outside via an HDMI (registered trademark) cable, the synchronization signal generating unit 15 outputs a signal having the same period and phase as the periodic signal SYN_I as the synchronization signal SYN_O. Regarding the output step of the synchronization signal SYN_O, as another different example, a signal of an arbitrary period and phase can also be generated inside the synchronization signal generating unit 15 and output as the synchronization signal SYN_O. The synchronization signal SYN_O is output to the LD driving unit 16 and the motor driving unit 17.

[0139] When the start signal ST inputted from the outside via the external interface is asserted, the control unit 14 has a function of outputting the motor start signal MST to the motor drive unit 17. The control unit 14 further confirms the LD light emission start signal LDEN and outputs it to the LD drive unit 16 after confirming the signal MGD indicating that the motor units 12d and 13d are both in the normal rotation state from the motor drive unit 17.

[0140] The motor drive unit 17 has a function of outputting a motor drive signal MTD to start driving the motor units 12d and 13d when the motor start signal MST from the control unit 14 is affirmed. The motor drive unit 17 also has a function of detecting the period of the rotation detection signal (phase signal) MIDX1 from the motor unit 12d of the fluorescent body wheel 206. Similarly, the motor drive unit 17 has a function of detecting the period of the rotation detection signal MIDX2 from the motor unit 13d of the color wheel 208. More specifically, after the motor unit 12d of the fluorescent body wheel 206 starts to output the rotation detection signal MIDX1 based on the affirmation of the motor start signal MST, the motor drive unit 17 monitors whether the rotation detection signal MIDX1 has reached a prescribed period. Similarly, after the motor unit 13d of the color wheel 208 starts to output the rotation detection signal MIDX2, the motor drive unit 17 monitors whether the rotation detection signal MIDX2 has reached a prescribed period. After detecting that the rotation detection signal MIDX1 has reached a predetermined period, the motor driving unit 17 asserts the signal MGD1 for notifying that the motor unit 12d of the fluorescent body wheel 206 has reached a normal rotation state, and outputs it to the control unit 14. After detecting that the rotation detection signal MIDX2 has reached a predetermined period, the motor driving unit 17 asserts the signal MGD2 for notifying that the motor unit 13d of the color wheel 208 has reached a normal rotation state, and outputs it to the control unit 14.

[0141] The motor drive unit 17 has a function of controlling the phases of the motor unit 12d and the motor unit 13d. In order to perform this control, the motor drive unit 17 has a register R3 inside, which reads the rotation phase data T3 of the motor unit 12d of the fluorescent body wheel 206 stored in the memory 18 and stores it in the register R3. Then, the motor drive unit 17 detects the phase of the rotation detection signal MIDX1 relative to the synchronization signal SYN_O (period T0) on the basis of confirming that the motor unit 12d has become a normal rotation state, and compares its phase difference with the content in the register R3. The motor drive unit 17 controls the motor drive signal MTD so that the phase difference is consistent with the rotation phase data T3 stored in the register R3. Specifically, the motor unit 12d of the present embodiment adopts a three-phase brushless DC motor, and the motor drive unit 17 generates a three-phase current signal as the motor drive signal MTD1. The three-phase current signal can be realized by controlling the phase relative to the synchronization signal SYN_O.

[0142] Similarly, the motor driving unit 17 has a register R4 inside, and reads the rotation phase data T4 of the motor unit 13d of the color wheel 208 stored in the memory 18 and stores it in the register R4. Then, after confirming that the motor unit 13d of the color wheel 208 has become a normal rotation state, the phase of the rotation detection signal MIDX2 relative to the synchronization signal SYN_O (cycle T0) is detected, and its phase difference is compared with the content of the register R4. The motor driving unit 17 controls the motor driving signal MTD so that the phase difference is consistent with the rotation phase data T4 stored in the register R4. Specifically, the motor unit 13d of the present embodiment adopts a three-phase brushless DC motor, and the motor driving unit 17 generates a three-phase current signal as the motor driving signal MTD2. The three-phase current signal can be realized by controlling the phase of the synchronization signal SYN_O.

[0143] After the LD light emission start signal LDEN is asserted, the LD driving unit 16 outputs the LD driving signal LDD for driving (emitting light) the laser light source 201 having the LD light source Md with the specified light emission period (light emission period T2) and the specified light emission amount at the specified light emission start time (start period T1) relative to the synchronization signal SYN_O. The start period T1 is the phase from the output of the LD driving signal LDD to the LD light emission, which is used for correction. The light emission period T2 is the time for the phosphor wheel 206 or the color wheel 208 to rotate one circle. For example, when rotating at 120 Hz, the light emission period T2 is 1 / 120 second, that is, about 8.3 ms. The phosphor wheel 206 and the color wheel 208 rotate at the same speed. The light emission amount of the laser light source 201 is the specified light emission amount. In this embodiment, in the start period T1 and the light emission period T2, the input current amounts D10, D11, D12, and D13 of the four divided regions R1 to R4 are output as the LD driving signal LDD.

[0144] As an example, the specific structure and operation of the LD driving unit 16 can be realized in the following manner. First, in this embodiment, the LD driving unit 16 has six registers R1, R2, DR10, DR11, DR12, DR13 and two timers TM1 and TM2 that read the light-emitting start time T1 and light-emitting period T2 stored in the memory 18 and store the input current D10, D11, D12, and D13. Let the timing values ​​of the timers TM1 and TM2 be t10 and t20 respectively. After obtaining the LD light-emitting start signal LDEN confirmed by the control unit 14, the LD driving unit 16 starts the timer TM1 at a specified time relative to the synchronization signal SYN_O. When the time count value t10 of the timer TM1 coincides with the light-emitting start timing T1 of the register R1, the LD driving signal LDD is output, and the timer TM2 is started at the same time, and the LD driving signal LDD is output with the input current D10, D11, D12, and D13, and the LD light source Md is lit. At the earlier time between the time count value t20 of the timer TM2 and the light emission period T2 of the register R2 and the time when the synchronization signal SYN_O of the next cycle is output, the output of the LD drive signal LDD is stopped and the LD light source Md is turned off.

[0145] The memory 18 stores the rotation phase data T3 of the motor part 12d of the fluorescent body wheel 206, the rotation phase data T4 of the motor part 13d of the color wheel 208, the light emission start T1 and the light emission period T2 of the LD light source Md, and the input current D10, D11, D12, and D13 at the light emission time of the light emission period T2 as information. For example, when the power of the light source device 10 is turned on, this information is read from the memory 18 through the memory bus (MBI) 20 and written (stored) to the registers R3 and R4 of the motor driving part 17 and the registers R1, R2, DR10, DR11, DR12, and DR13 of the LD driving part 16. In this way, the operation of the light source device 10 reflecting the contents of the memory 18 can be realized. The memory 18 can be a RAM, or an external storage device such as a HDD or USB.

[0146] The rotation phase data T3, the rotation phase data T4, the light emission start time T1, the light emission period T2, the input current amounts D10, D11, D12, and D13 stored in the memory 18 can be rewritten from the outside. Specifically, the control signal CNT is input from the outside to the control unit 14, and the control signal CNT includes an interface signal with the outside. According to the interface signal, the control unit 14 rewrites the rotation phase data T3 of the phosphor wheel 206, the rotation phase data T4 of the color wheel 208, the light emission start time T1 for light emission control of the LD light source Md, or the light emission period T2 in the memory 18. In this way, since the contents of the memory 18 can be rewritten, for example, when the lighting device having the light source device 102 is used in an image display device or a projection display device, the following operation can be performed. That is, depending on the type and frame rate of the image signal input to these image display devices and projection display devices, the frame rate of the output image signal of the projection may change. By rewriting the data of the memory 18 in accordance with the change in the frame frequency, fluorescent light (illumination light) can be emitted in accordance with the frame frequency, while grayscale unevenness can be suppressed and fluorescent light with a good light emission state can be emitted.

[0147] Fig.29 This is an example of an operation flow chart of the light source device included in the projector according to the first embodiment. Fig.30 1 is a signal control timing chart for driving the LD light source in the projector according to the first embodiment. Fig.30 In the timing chart shown, the horizontal axis represents time, and the vertical axis represents the signal values ​​of the synchronization signal SYN_I of the LD light source Md light trigger, the rotation detection signal MIDX1 of the phosphor wheel 206, the rotation detection signal MIDX2 of the color wheel 208, and the LD drive signal LDD. The signal value is "0" when the signal is set to OFF, and "1" when it is set to ON.

[0148] First, when the start signal ST inputted from the outside through the external interface is affirmed, the control unit 14 inputs the synchronization signal SYN_I to the synchronization signal generating unit 15, and the synchronization signal generating unit 15 outputs the synchronization signal SYN_O of the period T0 (step S2901). Furthermore, since the start signal ST is affirmed, the motor start signal MST1 of the fluorescent body rotating wheel 206 and the motor start signal MST2 of the color wheel 208 are outputted to the motor driving unit 17 (step S2902).

[0149] When the motor start signals MST1 and MST2 are both affirmed, the motor drive signal MTD1 of the phosphor wheel 206 composed of the three-phase current signals Iu1, Iv1, and Iw1 and the motor drive signal MTD2 of the color wheel 208 composed of the three-phase current signals Iu2, Iv2, and Iw2 are output to the motor parts 12d and 13d, and the driving of the motor parts 12d and 13d is started (step S2903). The rotation is driven by these motor drive signals MTD1 and MTD2, and the rotation detection signal MIDX1 of the phosphor wheel 206 and the rotation detection signal MIDX2 of the color wheel 208 are output to the motor drive part 17 (step S2904).

[0150] The motor driving unit 17 obtains the phase data of the rotation detection signal MIDX1 of the phosphor wheel 206 and the phase data of the rotation detection signal MIDX2 of the color wheel 208 with respect to the synchronization signal SYN_O. Then, the motor driving unit 17 determines whether the rotation phase data T3 in the register R3 of the phosphor wheel 206 is consistent with the rotation detection signal MIDX1 (step S2905). Similarly, the motor driving unit 17 determines whether the rotation phase data T4 in the register R4 of the color wheel 208 is consistent with the rotation detection signal MIDX2 (step S2905).

[0151] When the rotation phase data T3 in the register R3 of the fluorescent body wheel 206 is inconsistent with the rotation detection signal MIDX1, for example, when the motor unit 12d is started to drive, the rotation detection signal MIDX1 is inconsistent with the rotation phase data T4 in the register R3, the motor driving unit 17 controls Iu1, Iv1, and Iw1 of the motor driving signal MTD1 to repeatedly determine whether the rotation phase data T3 is consistent with the rotation detection signal MIDX1 (step S2905). The color wheel 208 also performs the same process.

[0152] When the rotation phase data T3 of the phosphor wheel 206 is consistent with the rotation detection signal MIDX1, and the rotation phase data T4 of the color wheel 208 is also consistent with the rotation detection signal MIDX2, the phosphor wheel 206 and the color wheel 208 both set the motor parts 12d and 13d to the normal rotation state, and the normal rotation signal MGD is affirmed and output to the control unit 14 (step S2906). That is, when at least one of them has not reached the normal rotation state, the normal rotation signal MGD is not output to the control unit 14. When the normal rotation signal MGD is affirmed, the control unit 14 affirms the LD light emission start signal LDEN and outputs it to the LD driving unit 16 (step S2907).

[0153] After the LD light emission start signal LDEN is asserted, the LD driving unit 16 outputs the LD driving signal LDD at the light emission start time T1 of the register R1 and only during the light emission period T2 of the register R2 with respect to the synchronization signal SYN_O to make the LD light source Md emit light.

[0154] After the LD light source Md is made to emit light at the light-emission start time T1 relative to the synchronization signal SYN_O, the LD light source Md emits light during the period of delayed light-emission start time T1. A slight delay in the light-emission start time T1 generated when the LD light source Md emits light for the first time is allowed, and the light-emission time after the second time is synchronized by making the LD light source Md emit light at the same time as the synchronization signal SYN_O, which is approximately in advance of the light-emission start time T1, so that the synchronization signal SYN_O and the light-emission time of the LD light source Md. In addition to this synchronization method, for example, an input current detection unit may be provided to the LD light source Md, and feedback control may be used to make the synchronization signal SYN_O arrive at the timing of detecting the current.

[0155] The LD light source Md stops outputting the LD drive signal LDD and turns off the LD light source Md at the earlier time between the time that coincides with the light-emitting period T2 and the time that the synchronization signal SYN_O of the next cycle is output. That is, the LD light source Md is lit only during the period that satisfies MIN(T2, T0-T1). MIN(A, B) compares A and B and returns the same or smaller value.

[0156] Through the above actions, such as Fig.30 As shown in the timing chart of FIG. 1 , in the first cycle of the phosphor wheel 206, the rotation detection signal MIDX1 from the motor unit 12d transitions from "0" to "1" after the period of the rotation phase data T3. After the second cycle, the rotation detection signal MIDX1 from the motor unit 12d transitions from "0" to "1" earlier than the previous cycle by the period of the rotation phase data T3, so that the synchronization signal SYN_O is synchronized with the phosphor wheel 206. The same processing as above is also performed in the color wheel 208.

[0157] In summary, after the second cycle of the synchronization signal SYN_O, the light emission of the LD, the start of rotation of the phosphor wheel 206, and the start of rotation of the color wheel 208 can be made substantially simultaneous.

[0158] Fig.31This is a timing diagram of one cycle of the input current amount of each divided area of ​​the laser light source of the LD light source in the projector according to the first embodiment. In this embodiment, the LD output (input current amount D10, D11, D12, D13) is changed so that the LD output between the divided areas R1 to R4 of the LD light source Md is the same during the yellow period, red period, blue period, and green period when the excitation light of the LD light source Md is incident on the yellow area Y, red area R, blue area B, and green area G of the color wheel 208. By increasing the input current amount D10, D11, D12, D13 during the red period, green period, and yellow period with higher visual sensitivity and reducing the input current amount D10, D11, D12, D13 during the blue period with lower visual sensitivity, the monochrome grayscale ratio can be improved without changing the power consumption.

[0159] The phosphor wheel 206 is divided into a phosphor region 206a coated with phosphor and an excitation light reflecting region 206b reflecting excitation light, so that the fluorescent light excited by the phosphor region 206a and the blue light emitted by the excitation light reflecting region 206b are synthesized and projected onto the screen SC. In other words, in order to obtain a light quantity distribution with uniform color distribution, the light quantity distribution obtained from the fluorescent light needs to be similar to the light quantity distribution obtained from the blue light.

[0160] Fig.32 This is an example of a light quantity distribution diagram of fluorescent light projected onto a screen by the projector according to the first embodiment. Fig.33 FIG. 1 is an example of a light quantity distribution diagram of the excitation light projected onto the screen by the projector according to the first embodiment. Fig.32 As shown in FIG. 1 , the light intensity distribution of the fluorescent light projected onto the screen SC by the projector 101 according to the present embodiment has a peak in the middle lower portion, and the grayscale (light intensity) decreases as it approaches the peripheral portion. Fig.33 As shown in FIG. 1 , the light intensity distribution of the excitation light (blue excitation light) projected onto the screen SC by the projector 101 according to this embodiment has peaks in the middle lower part and on the left and right sides thereof, and the light intensity distribution and shape of the fluorescent light are different. Fig.32 The fluorescence light intensity distribution and Fig.33 When the light quantity distribution of the blue excitation light shown is synthesized, the screen projection image on the screen SC produces color unevenness in the left and right directions and in the lower center portion thereof.

[0161] Therefore, in the projector 101 of the present embodiment, as a method of eliminating the chromatic aberration (in other words, a method of making the light quantity distribution of the fluorescent light and the light quantity distribution of the excitation light similar), Fig.12As shown, the plurality of laser light sources 201 of the LD light source Md are divided into a plurality of divided areas R, and the input current D10, D11, D12, and D13 (LD output) of each divided area R is controlled by the light source unit control unit 130, thereby adjusting the light quantity distribution of the fluorescent light and the excitation light. Other methods for eliminating color spots include a method of lengthening the light tunnel LT as a light homogenizing element to homogenize the light quantity distribution, and a method of adjusting the position of the optical system to make the light quantity distribution of the fluorescent light and the excitation light similar. However, the method of lengthening the light tunnel LT has a problem of enlarging the size of the projector 101 due to the enlargement of the illumination optical system 104. When the position of the optical system is adjusted, it is impossible to deal with color spots caused by machine errors after the product is shipped. Therefore, for example, when overlapping is desired, if there are color spots or grayscale differences due to machine errors, it can be adjusted by rewriting the six registers R1, R2, DR10, DR11, DR12, and DR13 that read the input current D10, D11, D12, and D13 from the outside and store them. The method of changing the LD output between the divided areas R1 to R4 is simpler, and in addition to adjusting the light distribution through optical design, the light distribution can also be adjusted by controlling the LD output. Therefore, the light distribution can be controlled more finely, which has the effect of equalizing color spots.

[0162] Fig.34 This is a light quantity distribution diagram of an example of a screen projection image projected onto the screen by the projector according to the first embodiment. Fig.35 1 is a timing diagram of one cycle of the input current amount of the laser light source of each divided area of ​​the LD light source of the projector according to the first embodiment. Fig.35 As shown in FIG. 1 , the input current amount to the divided regions R1 and R4 in the blue period is reduced. Therefore, the light intensity distribution of the fluorescent light does not change. Fig.34 The light quantity distribution of the screen projection image shown has a peak in the middle part, and the grayscale gradually decreases as it approaches the surrounding parts. That is, Fig.34 The light quantity distribution of the screen projection image shown can be obtained with Fig.32 The light intensity distribution of the fluorescent light shown in the figure has the same characteristic shape. By changing the LD output between the divided areas R1 to R4 of the LD light source Md, the color spots on the screen SC can be further reduced. In addition, the LD output between the divided areas R1 to R4 of the LD light source Md can also be changed at the time of irradiating the fluorescent light. For example, when the wiring connected to the divided area R1 of the LD light source Md is broken, causing the LD in the area L1 to be unable to emit light, even during the fluorescent light emission period T2, the light source unit control unit 130 can increase the LD output of the divided area R2 to be higher than the LD output of the divided areas R3 and R4, thereby equalizing the light intensity distribution of the fluorescent light.

[0163] In this embodiment, although the description is omitted, Fig. 22 As shown in FIG. 1 , in a case where the light quantity distribution of the fluorescent light on the screen SC has a light quantity distribution in which the illuminance becomes higher in the middle and becomes lower in the peripheral part in the horizontal direction, at the moment when the blue excitation light irradiates the wavelength conversion region of the fluorescent body wheel 206, that is, at the moment when the fluorescent light is emitted from the fluorescent body wheel 206, the gray scale unevenness in the peripheral part in the horizontal direction of the screen SC can be improved as follows by increasing the LD output (for example, the LD output of the divided regions R1 and R4). Fig.21 The light distribution shown.

[0164] Fig.36 This is a schematic diagram of an example of overlapping screen projection images of projectors of the same model using multi-projection. When overlapping screen projection images of projectors 101 of the same model using multi-projection, due to mechanical errors of projectors 101, the overlapped screen projection images will have grayscale unevenness and color spots as a whole. Fig.36 The screen projection image shown is an example of projecting screen projection images on the screen SC using the same two projectors 101. The screen projection image on the left is projected darkly, and there is no color spot on the screen projection image as a whole, but grayscale unevenness occurs. The causes of grayscale unevenness include, for example, individual differences in the LD light source Md and the degradation of the projection lens over time. To solve the grayscale unevenness caused by overlapping use, the brightness of the projector 101 that can project brightly can be adjusted to match the brightness of the darker one. This is because adjusting the darker projector 101 to match the brighter projector may increase power consumption, and the temperature inside the machine may exceed the rated temperature and shorten the life. To make the brighter projector 101 darker, the overall LD output can be reduced proportionally. That is, for example, the LD output during the yellow period, red period, blue period, and green period in the input current timing diagram of the divided areas R1 to R4 in the projector 101 is reduced at the same ratio.

[0165] Fig.37 FIG. 1 is another example of using multi-projection to overlap the screen projection images of projectors of the same model. Fig.37 As shown in FIG. 1 , when there is a dark spot in the upper left corner of the screen projection image projected by the projector 101 on the left side onto the screen SC, as shown in FIG. Fig.35 As shown in the timing diagram, for example, when the divided area R1 corresponds to the light intensity distribution on the left side of the screen projection image, the color unevenness can be improved by reducing the LD output of the blue period of the divided area R1 to make it lower than the LD output of other divided areas R2 to R4.

[0166] As described above, the projector 101 involved in the first embodiment can adjust the light distribution by controlling the LD output of the divided area R instead of adjusting the light distribution by optical design, thereby reducing grayscale unevenness and color spots without increasing the size of the projection device.

[0167] <Second Embodiment>

[0168] This embodiment is an example of LD control when the phosphor wheel includes an excitation light reflecting region (reflecting mirror) and two or more phosphor regions (wavelength conversion regions).

[0169] Fig.38 It is a schematic diagram showing an example of the structure of a fluorescent wheel included in the projector according to the second embodiment. Fig.39 : is a timing diagram of one cycle of the input current amount of each divided area of ​​the LD light source in the projector involved in the second embodiment. Fig.38 As shown, the phosphor wheel 206 includes an excitation light reflection region 206b and a plurality of phosphor regions 206a (a first phosphor region 206a1 and a second phosphor region 206a2). That is, in this embodiment, the phosphor wheel 206 includes two or more phosphor layers (a first phosphor region 206a1 and a second phosphor region 206a2). When the divergence angles of the fluorescent light of the plurality of phosphor regions 206a are different from each other, since the light amount distribution of the projection image (screen projection image) of the fluorescent light of each phosphor region 206a is different, the LD output between the divided regions R1 to R4 of the incident LD light source Md of each phosphor region 206a can also be changed.

[0170] For example, the first phosphor region 206a1 emits yellow fluorescent light, and the second phosphor region 206a2 emits green fluorescent light. In this case, the yellow fluorescent light emitted from the first phosphor region 206a1 passes through the yellow region Y and the red region R of the color wheel 208, so the light quantity distribution of the screen projection image of the first phosphor region 206a1 is changed (generated) by changing the LD output during the yellow period corresponding to the yellow region Y. The green fluorescent light emitted from the second phosphor region 206a2 also passes through the red region R of the color wheel 208, so the screen projection image of the second phosphor region 206a2 is changed (generated) by changing the LD output during the red period corresponding to the red region R. The blue excitation light reflected by the excitation light reflection region 206b passes through the diffusion region, and the light quantity distribution of the blue excitation light is formed on the screen projection image.

[0171] According to the above, when the light quantity distribution of the screen projection image of the first phosphor region 206a1, the second phosphor region 206a2, and the excitation light reflection region 206b is synthesized (changed), the LD output between the divided regions R1 to R4 is changed so that the screen projection image does not have color spots. When the fluorescent light emitted from one phosphor region 206a passes through a plurality of regions of the color wheel 208, for example, when the fluorescent light emitted from the first phosphor region 206a1 passes through the yellow region Y and the red region R of the color wheel 208, it is preferable to change the LD output between the divided regions R1 to R4 at the same magnification. The reason is that the shapes of the light quantity distribution of the screen projection image passing through the yellow region Y of the color wheel 208 and the light quantity distribution of the screen projection image passing through the red region R are roughly similar because the light quantity distribution of the fluorescent light emitted from the same phosphor region 206a is approximately similar. If the LD output is not changed at the same magnification, an illumination difference will occur, resulting in color spots.

[0172] Fig.40 and Fig.41 1 is an example of a light quantity distribution diagram of the central middle part of the screen projection image projected by the projector according to the second embodiment in the horizontal direction. Here, an example of a method for adjusting (changing) the LD output between the divided areas R1 to R4 of the LD light source Md is described, for example, so that the light quantity distribution of the yellow fluorescent light, the green fluorescent light, and the blue excitation light in the horizontal direction of the middle part of the screen projection image projected by the projector 101 according to this embodiment becomes a target light quantity distribution (hereinafter referred to as the target distribution). For example, when the light quantity distribution of the screen projection image is made close to the target distribution by reducing the LD output of the divided area R1 of the fluorescent light emitted from the first fluorescent body area 206a1 by 50%, the LD output of the divided area R1 during the yellow period and the red period is reduced by 50%. Similarly, when the light quantity distribution of the screen projection image is made close to the target distribution by reducing the LD output of the divided area R4 of the fluorescent light emitted from the second fluorescent body area 206a2 by 60%, the LD output of the divided area R4 is reduced by 60% only during the green period.

[0173] Here, for the sake of illustration, the light quantity distribution of the yellow fluorescent light and the light quantity distribution of the green fluorescent light are adjusted by changing the LD output between the divided regions R1 to R4 of the LD light source Md. The target distribution can also be determined arbitrarily, for example, Fig.41 As shown, a target distribution close to the light quantity distribution of green fluorescent light is set, and the LD output between the divided regions R1 to R4 of the LD light source Md is changed so that the light quantity distribution of fluorescent light is close to the light quantity distribution of blue excitation light.

[0174] The input current value input to each divided region R1 to R4 of the LD light source Md has a limit, for example, there is a permissible current value that cannot reach the combustion temperature of the lens or the phosphor region 206a of the phosphor wheel 206. For this reason, it is preferable to change the LD output between the divided regions R1 to R4 of the LD light source Md when the average current amount of the input current amount relative to the lighting time of the LD light source Md is less than the permissible current amount. It is also preferable to change the LD output between the divided regions R1 to R4 by using power consumption instead of the input current value, so as not to accelerate the deterioration of the lens and the phosphor wheel 206.

[0175] In this way, the projector 101 according to the second embodiment can obtain the same operational effects as those of the first embodiment.

[0176] <Third Embodiment>

[0177] This embodiment is an example in which the optical system other than the light tunnel of the light source device is arranged so that the excitation light is irradiated on the side surface in the longitudinal direction of the opening surface of the light tunnel. The same configuration as the above embodiment is omitted below.

[0178] Fig.42 and Fig.43 FIG. 1 is a schematic diagram showing an example of the positional relationship between the optical system other than the light tunnel and the light tunnel in the light source optical system of the projector according to the third embodiment. In this embodiment, the optical system other than the light tunnel LT of the light source device (light source optical system) 102 is as follows: Fig.42 As shown, the blue excitation light is configured to irradiate the side of the long side (LE=5.7 mm) of the opening surface of the light tunnel LT. In this case, the optical system other than the light tunnel LT of the light source device 102 has a Y axis in the vertical direction (the direction corresponding to the long side direction LE of the light tunnel LT), an X axis in the horizontal direction corresponding to the depth direction of the light tunnel LT, and a Z axis in the horizontal direction corresponding to the short side direction SE of the light tunnel LT.

[0179] In addition, the optical system other than the light tunnel LT of the light source device 102 may also be configured as follows: Fig.43 As shown, the blue excitation light is irradiated on the side of the short side direction SE (= 3.4 mm) of the opening surface of the light tunnel LT. The optical system of the light source device 102 other than the light tunnel LT has a Z axis in the vertical direction (the direction corresponding to the long side direction LE of the light tunnel LT), an X axis in the horizontal direction corresponding to the depth direction of the light tunnel LT, and a Y axis in the horizontal direction corresponding to the short side direction SE of the light tunnel LT.

[0180] However, if the excitation light is incident in the long side direction LE of the light tunnel LT, the number of reflections in the light tunnel LT increases compared to the short side direction SE, which has a more even effect. The blue excitation light is incident on the focusing lens 207, and at the position where the image of the laser light source 201 is formed, when the image is viewed from the short side SE side, the light is emitted at an angle of 0<θ<90[deg]. That is, at Fig.42 In the light source device 102 shown in FIG. 1 , light is emitted at an angle of 0<θ<90[deg] in the Z-axis direction. Fig.43 In the light source device 102 shown, light is emitted at an angle of 0<θ<90[deg] in the Y-axis direction. The light emitted from the condenser lens 207 passes through the diffusion area of ​​the color wheel 208 and enters the light tunnel LT. Since the exit surface of the condenser lens 207 is parallel to the incident surface of the light tunnel LT, the angle of the incident light relative to the opening surface of the light tunnel LT is the angle opposite to the emission angle of the condenser lens 207. The light entering the light tunnel LT is reflected by the end face in the light tunnel LT and then reflected by the opposite end face, the distance between them is Fig.42 In the light source device 102 shown, the short side direction is SE / tanθ[mm], Fig.43 In the light source device 102 shown in FIG. 1 , the long side direction LE / tanθ [mm] and the short side direction SE / tanθ < the long side direction LE / tanθ. Fig.42 As shown, the light is incident on the long side LE (Z-axis direction) of the opening surface of the light tunnel LT, and Fig.43 As shown, compared with the incident light in the short side direction SE (Y-axis direction) of the opening surface of the light tunnel LT, the number of reflections in the light tunnel LT increases, and the light homogenization effect is improved.

[0181] In addition, the light homogenization effect of the light tunnel LT is Fig.42In the case of the light source device 102 shown, the light is improved in the short side direction SE of the light tunnel LT, so the light amount distribution on the projection surface of the screen conjugate with the exit surface of the light tunnel LT is in the short side direction SE of the light tunnel LT, that is, in the vertical direction of the short side of the screen SC, which can reduce color spots and gray scale unevenness. As described above, the light homogenization effect in the short side direction SE of the light tunnel LT can be improved by obliquely incident light with respect to the long side direction LE of the light tunnel LT, so that color spots and gray scale unevenness can be reduced. In addition, under the guidance of an optical system such as a condenser lens 207, the light from the LD light source Md passes through the optical axis at a substantially conjugate position when viewed from the short side direction of the first image of the LD light source Md, and is configured so that the long side of the first image is aligned with the long side direction LE of the light tunnel LT, and the short side of the first image is aligned with the short side direction SE of the light tunnel LT. Furthermore, by changing the LD output between the divided areas R1 to R4 that divide the installation area of ​​the LD light source Md in the long side direction LE of the light tunnel LT, the light quantity distribution of the fluorescent light can be adjusted to reduce gray scale unevenness, and by adjusting the blue excitation light, color spots can be reduced, so that the light homogenization effect in the long side direction LE of the light tunnel LT can be improved. Accordingly, in this embodiment, since the light homogenization effect in the short side direction SE and the long side direction LE of the light tunnel LT can be improved, the gray scale unevenness and color spots of the screen projection image projected on the screen SC can be reduced.

[0182] Fig.44 It is a schematic diagram of an example of the configuration relationship between the light source optical system and the illumination optical system in the projector involved in the third embodiment. When the excitation light is incident on the short side direction SE of the light tunnel LT, the DMD of the illumination optical system 104 and the light quantity distribution on the exit surface of the light tunnel LT have a conjugate relationship, so it is necessary to rotate the light source device 102 and the heat sink from the horizontal direction to the vertical direction with the light tunnel LT as the center. Therefore, since the long side direction when the light source device 102 and the heat sink are used as a component and the long side direction when the illumination optical system and the projection optical system are used as a component are different, the problem of the overall enlargement of the projector 101 arises. When the excitation light is incident on the long side direction LE of the light tunnel LT, the long side directions are roughly aligned, so the projector 101 can be miniaturized.

[0183] Although the blue excitation light enters the light tunnel LT in the long side direction LE compared to the short side direction SE, the reflection times in the light tunnel LT become more and are homogenized. The fluorescent light becomes Lambertian light in the fluorescent body region 206a and enters the light tunnel LT, so the light is originally homogenized, and the homogenization effect of the light tunnel LT is less than that of the blue excitation light.

[0184] Figures 45 to 48 This is an example of a light quantity distribution diagram on a DMD in the projector according to the third embodiment. Fig.45This is an example of the light quantity distribution diagram of the blue excitation light on the DMD when the blue excitation light enters the long side direction LE of the light tunnel LT. Fig.46 This is an example of the light distribution diagram of blue excitation light on the DMD when the LD light source Md is rotated 90 degrees. Fig.47 1 is an example of a light quantity distribution diagram of the fluorescent light on the DMD when the fluorescent light enters the short side direction SE of the light tunnel LT. Fig.48 This is an example of the light quantity distribution diagram of the fluorescent light when the LD light source Md is rotated 90 degrees. Since the exit surface of the light tunnel LT and the image of the DMD are in a conjugate relationship, the long side direction LE of the light tunnel LT corresponds to the long side direction of the DMD, and the short side direction SE of the light tunnel LT corresponds to the short side direction of the DMD. Figures 45 to 48 In the light intensity distribution shown, the larger the value, the higher the grayscale, and the smaller the value, the lower the grayscale. Fig.46 The light intensity distribution of the blue excitation light shown in the figure is greatly different due to the different incident directions of the light entering the light tunnel LT. Fig.48 The light quantity distribution of the fluorescent light shown does not change much compared to the light quantity distribution of the blue excitation light on the DMD. The reason is that unlike the blue excitation light which is continuously focused by the focusing lens group before passing through the diffuser in front of the light tunnel LT, the fluorescent light emits Lambertian light in the wavelength conversion area (phosphor area 206a) of the phosphor wheel 206, so light with various incident angles enters the light tunnel LT, and therefore the homogenizing effect of the light tunnel LT is small. In addition, after the blue excitation light is focused, the light is incident on the long side direction LE of the light tunnel LT, which can increase the number of reflections, so the light uniformity is greatly improved. It can be seen that the incident surface of the light tunnel LT of the LD light source Md makes a great contribution to light homogenization.

[0185] In this way, the projector 101 involved in the third embodiment can increase the number of reflections in the light tunnel LT and improve the homogenization effect of the light tunnel LT by incident excitation light in the long side direction LE of the light tunnel LT compared with the incidence in the short side direction SE, thereby further reducing the grayscale unevenness and color spots of the screen projection image on the screen SC.

[0186] Explanation of symbols

[0187] 101 projector, 102 light source device, 104 illumination optical system, 105 image forming element, 106 projection optical system, 201 laser light source, 202 collimating lens, 203 first optical system, 204 dichroic mirror, 205 second optical system, 206 phosphor wheel, 206a phosphor area, 206b excitation light reflection area, 207 focusing lens 208 color wheel, LT light tunnel, SC screen, R1~R4 dividing area, MdLD light source.

Claims

1. A light source device, comprising a light source section including a setting area provided with a plurality of light sources, the setting area being divided into divided areas including at least one of the light sources, and the division directions of the divided areas in the setting area being aligned; and an optical system that forms a first image of the light source portion, The light beam emitted from the light source passes through the vicinity of the optical axis of the optical system on the image plane where the first image is formed through the optical system. controlling the input current amount of each of the divided areas to adjust the light quantity distribution of the light emitted from the light source unit and the wavelength converted light obtained by converting the wavelength of the light emitted from the light source at the irradiation position; in, A single light homogenizing element is provided near an image plane where the first image is formed, the light homogenizing element having an opening for the light beam emitted from the optical system to enter; Among them, on the image plane where the first image is formed, the image of each of the light sources is elliptical, and the length direction of the ellipse is consistent with the long side direction of the opening of the single light homogenizing element, or the short side direction of the ellipse is consistent with the long side direction of the single light homogenizing element.

2. The light source device according to claim 1, wherein: The setting area is a rectangular area having a short side and a long side, and the dividing direction is parallel to the long side.

3. The light source device according to claim 1, wherein: The light output of at least one of the light sources included in each of the divided areas is changed.

4. The light source device according to claim 1, wherein: The optical system forms a second image of the light source section on the optical path of the light beam between the light source and the first image, and the light beam emitted from the light source section passes through the vicinity of the optical axis near the image plane where the second image is formed.

5. The light source device according to claim 1, wherein: The opening has a rectangular cross section perpendicular to the traveling direction of the incident light beam.

6. The light source device according to claim 5, wherein: The long side direction of the opening is consistent with the arrangement direction of the images of the divided regions on the first image.

7. The light source device according to claim 6, wherein: The light beam emitted from the optical system passes through the vicinity of the optical axis along the arrangement direction of the images of the divided regions on the image plane of the first image.

8. The light source device according to any one of claims 1 to 7, wherein: The optical system further includes a diffusion element disposed at a position offset from an image plane forming the first image and configured to diffuse the light beam emitted from the optical system.

9. The light source device according to claim 4, wherein: The optical system further comprises a wavelength conversion unit for emitting wavelength-converted light obtained by converting the wavelength of the light emitted from the light source, the wavelength conversion unit being arranged near an image plane on which the second image is formed, and the optical system forms an image of the wavelength-converted light conjugate with the image of the light source formed by the wavelength conversion unit near the image plane on which the first image is formed.

10. The light source device according to claim 9, wherein: The light output of the light source included in each of the divided areas is changed so as to make the light quantity distribution of the wavelength-converted light at the irradiation position uniform.

11. The light source device according to claim 9 or 10, wherein: The light output of each of the divided areas is changed so that the light quantity distribution of the light emitted from the light source unit at the irradiation position matches the light quantity distribution of the wavelength-converted light.

12. A projection device, comprising The light source device according to any one of claims 1 to 7; an illumination optical system that forms an image of an emission portion of light emitted from the light homogenizing element; an image forming element disposed at a position where an image of the emitting portion is formed; and The projection optical system projects the image formed on the image forming element onto a screen to form an image.

Images