Light source device and projection device

Abstract

To provide a light source device and a projection device which are of simple constructions and can be downsized.SOLUTION: A light source device 60 comprises: a first light source 710 for emitting first wavelength band light; a second light source 720 for emitting second wavelength band light; a first dichroic mirror 140 that reflects the first wavelength band light having entered at a first incidence angle and permits the passage of the second wavelength band light having entered at a second incidence angle that is different from the first incidence angle; and a second dichroic mirror 141 that reflects the second wavelength band light having passed through the first dichroic mirror 140. The second wavelength band light, after being reflected by the second dichroic mirror 141, enters the first dichroic mirror 140 at the first incidence angle and is reflected.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a light source device and a projection device including the light source device. [Background technology]

[0002] Today, projectors are in common use, which focus light emitted from a light source onto a micromirror display element called a DMD (Digital Micromirror Device) or a display element such as a liquid crystal panel, and display a color image on a screen.

[0003] For example, Patent Document 1 discloses an image display device (light source device) that includes an excitation light source, an optical wheel on which a phosphor layer is formed, a dichroic mirror provided between the wheel and the excitation light source, and a quarter-wave plate that is a polarization conversion element provided between the wheel and the dichroic mirror and changes the polarization direction of the excitation light. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-212129 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the light source device of Patent Document 1, excitation light is irradiated to each phosphor layer that emits different colors provided on a wheel, and light in the red and green wavelength bands is emitted. However, since the wheel is composed of a substrate that is a rotated body and a rotation control unit that rotates and controls the rotation, the light source device may become large.

[0006] In view of the above, an object of the present invention is to provide a light source device and a projection device that have a simple configuration and can be made compact. [Means for solving the problem]

[0007] A light source device of the present invention includes a first light source that emits a first wavelength band light, a second light source that emits a second wavelength band light, and a first dichroic mirror that reflects the first wavelength band light incident at a first incident angle and transmits the second wavelength band light incident at a second incident angle different from the first incident angle; a second dichroic mirror that reflects the second wavelength band light that has been transmitted through the first dichroic mirror; and Equipped with The second wavelength band light is reflected by the second dichroic mirror and then reflected by the first dichroic mirror. It is characterized by the above.

[0008] The projection device of the present invention is characterized in that it comprises the above-mentioned light source device, a display element that is irradiated with light source light from the light source device and forms image light, a projection optical system that projects the image light emitted from the display element onto a projection target, and a projection device control unit that controls the display element and the light source device. Effect of the Invention

[0009] According to the present invention, it is possible to provide a light source device and a projection device that can be made compact with a simple configuration. Cut. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing functional circuit blocks of a projection device according to a first embodiment of the present invention. [Diagram 2] 1 is a plan view illustrating an internal structure of a projection device according to a first embodiment of the present invention. [Diagram 3] 3 is a diagram showing the transmission characteristics and wavelength band distribution of light of the first dichroic mirror according to the first embodiment of the present invention. FIG. [Figure 4] 1 is a partial schematic plan view of a light source device according to a first embodiment of the present invention. [Diagram 5] 10 is a partial schematic plan view of a light source device according to a second embodiment of the present invention. FIG. [Figure 6] 6(a) is a partial schematic plan view of a light source device according to a third embodiment of the present invention, and (b) is an enlarged view showing the central part of FIG. 6(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Embodiment 1) A first embodiment of the present invention will be described below. Fig. 1 is a diagram showing functional circuit blocks of a projection device 10. The projection device control unit is composed of a CPU including an image conversion unit 23 and a control unit 38, a front-end unit including an input / output interface 22, a display encoder 24, and a formatter unit including a display drive unit 26. Image signals of various standards input from an input / output connector unit 21 are converted by the image conversion unit 23 via the input / output interface 22 and a system bus (SB) so as to be unified into image signals of a predetermined format suitable for display, and then output to the display encoder 24.

[0012] The display encoder 24 develops and stores the input image signal in a video RAM 25 , generates a video signal from the stored contents of the video RAM 25 , and outputs the video signal to a display driver 26 .

[0013] The display drive unit 26 drives the display element 50, which is a spatial light modulation element (SOM), at an appropriate frame rate in response to the image signal output from the display encoder 24. The projection device 10 forms an optical image with the light reflected from the display element 50 by irradiating the light beam emitted from the light source device 60 onto the display element 50 via a light guiding optical system, and projects and displays the image on a projection target such as a screen (not shown) via the projection optical system 220. The movable lens group 235 of the projection optical system 220 can be driven by a lens motor 45 for zoom adjustment and focus adjustment.

[0014] The image compression / expansion unit 31 performs a recording process in which the luminance signal and the color difference signal of the image signal are compressed by processes such as ADCT and Huffman coding, and the data is written sequentially to a memory card 32, which is a removable recording medium. Furthermore, the image compression / expansion unit 31 reads out image data recorded on the memory card 32 in a playback mode, and expands each piece of image data constituting a series of moving pictures on a frame-by-frame basis. The image compression / expansion unit 31 outputs the image data to the display encoder 24 via the image conversion unit 23, and performs a process that enables the display of moving pictures, etc., based on the image data stored in the memory card 32.

[0015] The control unit 38 is responsible for controlling the operation of each circuit within the projection device 10, and is composed of a CPU, a ROM in which operating programs such as various settings are permanently stored, a RAM used as a work memory, and the like.

[0016] An operation signal from a key / indicator section 37 consisting of main keys and indicators provided on the top panel of the housing is sent directly to a control section 38. A key operation signal from a remote controller is received by an Ir receiving section 35, and a code signal demodulated by an Ir processing section 36 is output to the control section 38.

[0017] The control unit 38 is connected to an audio processing unit 47 via a system bus (SB). The audio processing unit 47 includes a sound source circuit such as a PCM sound source, and converts audio data into analog data in the projection mode and the playback mode, and drives a speaker 48 to output audible audible sound.

[0018] The control unit 38 also controls a light source control circuit 41 as a light source control unit. The light source control circuit 41 can control the operation of the light source device 60 including a light source unit 700 (first light source 710 and second light source 720) described later and a red light source device 380 (third light source 310) and the like (for example, the operation of making the light source device 60 emit any light (light created by additively mixing three lights emitted from the second light source 720, the phosphor 110 described later, and the third light source 310) by turning on and off the first light source 710, the second light source 720, and the third light source 310 in a time-division manner) so that light of a predetermined wavelength band required for image generation is emitted from the light source device 60).

[0019] Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to detect temperatures using a plurality of temperature sensors provided in the light source device 60, etc., and controls the rotation speed of the cooling fan based on the results of this temperature detection. The control unit 38 also controls the cooling fan drive control circuit 43 to continue rotating the cooling fan using a timer or the like even after the power supply to the projection device 10 body is turned off, or to turn off the power supply to the projection device 10 body depending on the results of temperature detection by the temperature sensors.

[0020] Next, the internal structure of the projection device 10 will be described. Fig. 2 is a schematic plan view showing the internal structure of the projection device 10. Here, the housing of the projection device 10 is formed in a substantially box shape, and includes a front panel 12, a rear panel 13, a right panel 14, and a left panel 15. In the following description, the left and right of the projection device 10 refer to the left and right directions relative to the projection direction, and the front and rear refer to the screen side direction of the projection device 10 and the front and rear directions relative to the traveling direction of the light beam.

[0021] The projection device 10 is provided with a control circuit board 242 near the left panel 15. This control circuit board 242 is provided with a power circuit block, a light source control block, etc. The projection device 10 is also provided with a light source device 60 in the approximate center of the housing of the projection device 10. Furthermore, in the projection device 10, a light source side optical system 170 and a projection optical system 220 are disposed between the light source device 60 and the left panel 15.

[0022] The light source device 60 includes a first light source 710 that is a light source of a first wavelength band light, a second light source 720 that is a light source of a second wavelength band light, a third light source 310 that is a light source of a fourth wavelength band light, a phosphor 110 that uses the first wavelength band light as excitation light and emits a third wavelength band light, a first dichroic mirror 140, a second dichroic mirror 141, a first reflecting mirror 705, and a second reflecting mirror 706. Between the light source device 60 and the right panel 14, a power connector 57 and a heat sink 150 are arranged in this order from the rear panel 13 side. The light source device 60 also includes a heat pipe 130 that guides heat generated by the red light source device 380 (third light source 310) to the heat sink 150, and a cooling fan 261 that cools the heat sink 150. Red light source device 380 (third light source 310) is cooled by heat sink 81 in addition to cooling fan 261, heat pipe 130, and heat sink 150 described above.

[0023] A light source unit 700, which is a light source section, is disposed on the right panel 14 side of the rear panel 13 side of the projection device 10. The first wavelength band light and the second wavelength band light emitted by the first light source 710 and the second light source 720, respectively, in this embodiment are blue wavelength band light. The first light source 710 and the second light source 720 each include a plurality of blue laser diodes 71 that are semiconductor light emitting elements. The plurality of blue laser diodes 71 of the first light source 710 and the second light source 720 are held by a common holding member 701. A collimator lens 73 that converts the emitted light from each blue laser diode 71 into parallel light so as to increase the directivity of the light. is disposed on the optical axis of each blue laser diode 71.

[0024] In this embodiment, the first light source 710 and the second light source 720 use the same blue laser diode 71, so the wavelength bands of the first wavelength band light and the second wavelength band light are the same. However, the first light source 710 and the second light source 720 may be configured with blue laser diodes of different wavelengths, and the wavelength bands of the first wavelength band light and the second wavelength band light may be different. Alternatively, as an example of the first light source 710 and the second light source 720 being light-emitting elements that emit light of different wavelength bands, the second light source 720 may be a blue laser diode 71, and the first light source 710 may be a light-emitting element such as a laser diode that emits ultraviolet light. In this case, the cut-on wavelength of the P-polarized light, which will be described later in FIG. 3, may be arranged on the shorter wavelength side than the ultraviolet wavelength band light.

[0025] The plurality of blue laser diodes 71 of the first light source 710 and the second light source 720 are arranged in a matrix of two rows and five columns by the holding member 701, although the front view is not shown. The number of blue laser diodes 71 constituting the first light source 710 and the second light source 720 is not limited to a plurality, and each may be one. In other words, the first light source 710 and the second light source 720 are composed of one or a plurality of blue laser diodes 71. In the light source unit 700 of this embodiment, three rows of blue laser diodes 71 (six in total) located in front of the front panel 12 side are the first light source 710, and two rows of blue laser diodes 71 (four in total) on the far side are the second light source 720. The first light source 710 and the second light source 720 each emit light of a predetermined polarization direction. In this embodiment, the polarization directions of all of the blue laser diodes 71 in the first light source 710 and the second light source 720 are aligned so as to be identical, and the blue laser diodes 71 emitted by the first light source 710 and the second light source 720 are all incident on the first dichroic mirror 140 in the P-polarized direction by the first reflecting mirror 705 or the second reflecting mirror 706.

[0026] The first light source 710 includes one or more blue laser diodes 71 and a collimator lens 73 disposed on the optical axis of each blue laser diode 71. The second light source 720 includes one or more blue laser diodes 71 and a collimator lens 73 disposed on the optical axis of each blue laser diode 71.

[0027] A first reflecting mirror 705 and a second reflecting mirror 706 are arranged on the emission side of the light source unit 700 so that light from the light source unit 700 is incident thereon. That is, the first reflecting mirror 705 is arranged so that the first wavelength band light emitted from the first light source 710 is incident thereon, and the second reflecting mirror 706 is arranged so that the second wavelength band light emitted from the second light source 720 is incident thereon. The first reflecting mirror 705 is inclined so that light is incident on the first dichroic mirror 140 within a first incident angle θ1, which will be described later, and the second reflecting mirror 706 is inclined so that light is incident on the first dichroic mirror 140 within a second incident angle θ2, which will be described later. That is, in the first reflecting mirror 705 on which a first reflecting surface that reflects the first wavelength band light is formed, and the second reflecting mirror 706 on which a second reflecting surface that reflects the second wavelength band light is formed, the first reflecting surface and the second reflecting surface are configured to be non-parallel to each other.

[0028] In this embodiment, the first reflecting mirror 705 and the second reflecting mirror 706 are provided in the same number of rows as the blue laser diodes 71 constituting the first light source 710 and the second light source 720 (in this embodiment, the first light source 710 has three rows and the second light source 720 has two rows, so there are three first reflecting mirrors 705 and two second reflecting mirrors 706). The number of the first reflecting mirrors 705 and the second reflecting mirrors 706 may be the same as the number of the blue laser diodes 71. When a plurality of the first reflecting mirrors 705 and the second reflecting mirrors 706 are provided, the total width of the light beams reflected by the first reflecting mirrors 705 and the second reflecting mirrors 706 may be reduced by arranging each of them in a stepped manner. The number of the first reflecting mirrors 705 and the second reflecting mirrors 706 is not limited to the same number of rows as the blue laser diodes 71 constituting the first light source 710 and the second light source 720. For example, even if the first light source 710 includes three rows of blue laser diodes 71, the first reflecting mirror 705 may be a single piece as long as the first reflecting mirror 705 is large enough to reflect all the light from the three rows of blue laser diodes 71. Similarly, the second reflecting mirror 706 may be a single reflecting mirror corresponding to the multiple blue laser diodes 71.

[0029] In the light source device 60 of this embodiment, a diffuser 703 is disposed between a first reflecting mirror 705 and a first dichroic mirror 140, and a diffuser 704 is disposed between a second reflecting mirror 706 and a first dichroic mirror 140. The diffusers 703 and 704 transmit light to diffuse and shape the light. The diffuser 703 can homogenize the intensity distribution of the first wavelength band light irradiated onto the phosphor 110, thereby improving the light emission efficiency and the service life of the phosphor 110. The diffuser 704 can homogenize the intensity distribution of the second wavelength band light, thereby reducing speckle noise in the image projected onto the projection target.

[0030] Red light source device 380 includes third light source 310 and a condenser lens group 311 (condenser lens 312 and condenser lens 313) that condenses light emitted from third light source 310. Third light source 310 is configured with red light emitting diode 300. Red light emitting diode 300 is a semiconductor light emitting element that emits fourth wavelength band light, which is red wavelength band light. Note that although the number of red light emitting diodes 300 constituting third light source 310 is one in FIG. 2 (the same applies to FIGS. 4 and 5), there may be more than one.

[0031] The green light source device 100 includes a phosphor 110 and a condenser lens group 111 (condenser lenses 112 and 113) that condenses the reflected light from the first dichroic mirror 140 and the emitted light from the phosphor 110. The phosphor 110 is a green phosphor that emits fluorescent light (third wavelength band light) using the first wavelength band light as excitation light. The phosphor 110 in this embodiment is a fluorescent plate formed on a mirror-finished flat surface and fixed, but may be a fluorescent wheel on which the green phosphor is formed in the circumferential direction and driven to rotate. However, if the phosphor 110 is a fluorescent wheel, the phosphor 110 may become large and power consumption occurs for the rotation. Therefore, by using a fixed fluorescent plate, the light source device 60 can be made smaller and more energy-efficient.

[0032] The first dichroic mirror 140 is a mirror that transmits light of a predetermined wavelength band that is incident thereon and reflects light of other wavelength bands different from the predetermined wavelength band. The first dichroic mirror 140 has an incident angle-dependent characteristic that transmits or reflects light depending on the incident angle of the incident light. The incident angle-dependent characteristic of the first dichroic mirror 140 will be described with reference to FIG. 3. FIG. 3 is a diagram showing the transmission characteristic of the first dichroic mirror 140 and the wavelength band distribution of light incident on the first dichroic mirror 140 when light having a polarization direction of P polarization and S polarization is incident on the first dichroic mirror 140 at different incident angles. The horizontal axis on the lower side of FIG. 3 indicates the wavelength, and the vertical axis on the left side indicates the transmittance. The vertical axis on the right side indicates the light intensity of the first wavelength band light L1, the second wavelength band light L2, the third wavelength band light L3, and the fourth wavelength band light L4 shown in FIG. 3. The dashed line, single dotted line, double dotted line, and triple dotted line represent the transmission characteristics of first dichroic mirror 140 when P polarized light is incident at 55 degrees, S polarized light is incident at 55 degrees, P polarized light is incident at 25 degrees, and S polarized light is incident at 25 degrees, respectively.

[0033] Here, transmission refers to a case where the light transmittance is 50% or more, and reflection refers to a case where the light transmittance is less than 50%. The characteristics of general dichroic mirrors including the first dichroic mirror 140 are polarization direction dependency and incidence angle dependency, in which the transmitted and reflected wavelengths (cut-on wavelength C1, which is the wavelength that reaches a transmittance of 50%, and cut-off wavelength C2, which is the wavelength that falls to a transmittance of 50% (or less)) differ depending on the polarization direction (P polarization or S polarization) and the incidence angle.

[0034] Regarding the polarization direction dependency, first dichroic mirror 140 transmits a wider range of wavelength components when P-polarized light is incident than when S-polarized light is incident at the same incident angle. The cut-on wavelength C1 of P-polarized light is located on the shorter wavelength side than the cut-on wavelength C1 of S-polarized light, and the cut-off wavelength C2 of P-polarized light is located on the longer wavelength side than the cut-off wavelength C2 of S-polarized light.

[0035] Regarding the incidence angle dependency, the cut-on wavelength C1 and cut-off wavelength C2 of the first dichroic mirror 140 shift to the shorter wavelength side as the incidence angle of the incident light increases for both P-polarized light and S-polarized light. The degree of incidence angle dependency of the first dichroic mirror 140 differs between P-polarized light and S-polarized light, and as the incidence angle of the incident light increases, the cut-on wavelength C1 of the P-polarized light changes more than the S-polarized light. On the other hand, as the incidence angle of the incident light increases, the cut-off wavelength C2 of the S-polarized light changes more than the P-polarized light.

[0036] In addition, the positions of the cut-on wavelength C1 and the cut-off wavelength C2 of the first dichroic mirror 140, and the incidence angle dependence and polarization direction dependence (the degree of change in the cut-on wavelength C1 and the cut-off wavelength C2) of the first dichroic mirror 140 can also be changed by design.

[0037] FIG. 3 shows the transmission characteristics when P-polarized light and S-polarized light are incident on the first dichroic mirror 140 at a relatively small incident angle of 25 degrees and at a relatively large incident angle of 55 degrees. For example, when P-polarized light is incident on the first dichroic mirror 140 at an incident angle of 25 degrees, the cut-on wavelength C1 is about 475 nm and the cut-off wavelength C2 is about 625 nm, as shown by the two-dot chain line. When P-polarized light is incident on the first dichroic mirror 140 at an incident angle of 55 degrees, the cut-on wavelength C1 is about 435 nm and the cut-off wavelength C2 is about 595 nm, as shown by the dashed line. For example, if the wavelength of the incident light is 455 nm, it will be reflected if the incident angle is 25 degrees and will be transmitted if the incident angle is 55 degrees. Furthermore, when light is incident on the first dichroic mirror 140, if the angle of incidence at which it is reflected is the first angle of incidence θ1 and the angle of incidence at which it is transmitted is the second angle of incidence θ2, the second angle of incidence θ2 is an angle greater than the first angle of incidence θ1.

[0038] Here, the first dichroic mirror 140 reflects the first wavelength band light L1 and the second wavelength band light L2 when they are incident at a first incident angle θ1, and transmits the first wavelength band light L1 and the second wavelength band light L2 when they are incident at a second incident angle θ2. For example, for P-polarized light, if the first incident angle θ1 is 25 degrees and the second incident angle θ2 is 55 degrees, the wavelengths of the first wavelength band light L1 and the second wavelength band light L2 may be within a separable band W1 ranging from 435 nm to 475 nm. In this case, the first dichroic mirror 140 can reflect and transmit the optical paths of the first wavelength band light L1 and the second wavelength band light L2, respectively, depending on the incident angle, and can separate them.

[0039] As described above, the cut-on wavelength C1 and the cut-off wavelength C2 of the first dichroic mirror 140 shift toward the shorter wavelength side as the incident angle increases. The cut-on wavelength C1 and the cut-off wavelength C2 of the first dichroic mirror 140 shift toward the longer wavelength side as the incident angle decreases. Therefore, by performing at least one of lowering the first incident angle θ1 or raising the second incident angle θ2, the width of the separable band W1 can be widened, and the selection width of the wavelengths of the first wavelength band light L1 and the second wavelength band light L2 (for example, the range that can be taken as the peak wavelength P1 of the first wavelength band light L1 and the second wavelength band light L2 and the magnitude of the half-width of the first wavelength band light L1 and the second wavelength band light L2) can be widened.

[0040] Here, the third wavelength band light L3 is mainly composed of a wavelength band of 500 nm to 570 nm, and therefore is substantially transmitted through the first dichroic mirror 140 regardless of the angle of incidence of the third wavelength band light L3. The fourth wavelength band light L4 is mainly composed of a wavelength band of 650 nm to 710 nm, and therefore is substantially reflected by the first dichroic mirror 140 regardless of the angle of incidence of the fourth wavelength band light L4. Therefore, the first dichroic mirror 140 has a transmission characteristic of transmitting the third wavelength band light L3 and reflecting the fourth wavelength band light L4. Furthermore, since the first dichroic mirror 140 substantially transmits and substantially reflects the third wavelength band light L3 and the fourth wavelength band light L4, respectively, regardless of the incident angle, the layout flexibility (degree of freedom) of the phosphor 110 that emits the third wavelength band light L3 and the third light source 310 that emits the fourth wavelength band light L4 is increased, which contributes to realizing the miniaturization of the light source device 60 and the projection device 10.

[0041] 2, the second dichroic mirror 141 is a mirror that transmits or reflects incident light. The second dichroic mirror 141 has a transmission characteristic of reflecting the second wavelength band light emitted from the second light source 720 and transmitting the fourth wavelength band light emitted from the third light source 310. Note that, like the first dichroic mirror 140, the second dichroic mirror 141 has an incident angle dependent characteristic of transmitting or reflecting light depending on the incident angle.

[0042] In general, a dichroic mirror is created by applying a reflective coating that reflects light of a specific wavelength to a transparent substrate such as glass. In this embodiment, the second dichroic mirror 141 is applied with a reflective coating that can reflect the second wavelength band light regardless of its incident angle. In addition, if the location where the second wavelength band light emitted from the second light source 720 is irradiated and the location where the fourth wavelength band light emitted from the third light source 310 is irradiated are known, the second dichroic mirror 141 may perform a second wavelength band light reflection process only in the vicinity of the irradiated location of the second wavelength band light. For example, when the optical path of the second wavelength band light is located on the right side in the longitudinal direction of the second dichroic mirror 141 shown in FIG. 2 and the optical path of the fourth wavelength band light is located on the left side in the longitudinal direction of the second dichroic mirror 141, the second dichroic mirror 141 can be created by applying a reflective coating for the second wavelength band light from the right end to the center in the longitudinal direction of the second dichroic mirror 141.

[0043] The light source side optical system 170 includes a condenser lens 173, a light guiding device 175 such as a light tunnel or a glass rod, condenser lenses 178 and 179, an irradiation mirror 185, and a condenser lens 195. The condenser lens 195 emits image light emitted from the display element 50 arranged on the rear panel 13 side of the condenser lens 195 toward the projection optical system 220, and is therefore also a part of the projection optical system 220.

[0044] The condenser lens 173 is disposed near the entrance of the light guide device 175 and condenses the light source light from the light source device 60. The luminance distribution of the light in each color wavelength band condensed by the condenser lens 173 is made uniform by the light guide device 175. The light beam emitted from the exit of the light guide device 175 is condensed by the condenser lenses 178 and 179 and then guided to the irradiation mirror 185 side.

[0045] The irradiation mirror 185 reflects the light beams condensed by the condenser lenses 178 and 179, and irradiates the light beams at a predetermined angle onto the display element 50 via a condenser lens 195. A heat sink 190 is provided on the rear panel 13 side of the display element 50 serving as a DMD, and the display element 50 is cooled by this heat sink 190.

[0046] A light beam, which is light source light irradiated onto the image forming surface of the display element 50 by the light source side optical system 170, is reflected by the image forming surface of the display element 50 and projected as projection light onto a screen via the projection optical system 220. Here, the projection optical system 220 is composed of a condenser lens 195, a movable lens group 235, a fixed lens group 225, etc. The movable lens group 235 is formed so as to be movable by a lens motor or manually. In addition, the movable lens group 235 and the fixed lens group 225 are built into a fixed lens barrel. Therefore, the fixed lens barrel including the movable lens group 235 is a variable focus lens, and is formed so as to be capable of zoom adjustment and focus adjustment.

[0047] By configuring the projection device 10 in this manner, when light is emitted from the light source device 60 at an appropriate timing, light of each wavelength band, such as blue, green, and red, is incident on the display element 50 via the light source side optical system 170. Therefore, the DMD, which is the display element 50 of the projection device 10, displays the light of each color in a time-division manner according to data, thereby projecting a color image on the screen.

[0048] Next, the optical path in the light source device 60 will be described. FIG. 4 shows a part of the optical path of the first wavelength band light to the fourth wavelength band light in this embodiment. The first wavelength band light emitted from the first light source 710 is reflected by the first reflecting mirror 705 toward the first dichroic mirror 140. The first wavelength band light reflected by the first reflecting mirror 705 is diffused to a preset diffusion angle by the diffusion plate 703 and is incident on the first dichroic mirror 140 at a first incidence angle θ1 as P-polarized light. The first incidence angle θ1 in FIG. 4 can be, for example, 25 degrees. The first wavelength band light incident at the first incidence angle θ1 is located on the shorter wavelength side than the cut-on wavelength C1 as shown in FIG. 3, and is reflected toward the phosphor 110. The first wavelength band light from the first light source 710 reflected by the first dichroic mirror 140 is collected by the collecting lens group 111 and irradiated onto the phosphor 110.

[0049] The phosphor 110 is excited by the first dichroic mirror 140 and emits third wavelength band light (green wavelength band light) which is fluorescent light in all directions. The third wavelength band light emitted from the phosphor 110 is collected by the collecting lens group 111 and guided to the first dichroic mirror 140. As shown in FIG. 3, the first dichroic mirror 140 transmits almost all of the third wavelength band light, so that most of the third wavelength band light incident on the first dichroic mirror 140 is incident on the collecting lens 173 of the light source side optical system 170.

[0050] The second wavelength band light emitted from the second light source 720 is reflected by the second reflecting mirror 706 toward the first dichroic mirror 140. The second wavelength band light reflected by the second reflecting mirror 706 is diffused by the diffuser plate 704 at a preset diffusion angle and is incident on the first dichroic mirror 140 at a second incident angle θ2 as P-polarized light. The second incident angle θ2 in FIG. 4 can be, for example, 55 degrees. The second wavelength band light incident at the second incident angle θ2 is located on the longer wavelength side than the cut-on wavelength C1 as shown in FIG. 3, and is transmitted to the second dichroic mirror 141. The second wavelength band light from the second light source 720 that has transmitted through the first dichroic mirror 140 is reflected by the second dichroic mirror 141 and is incident on the first dichroic mirror 140 at a first incident angle θ1 as P-polarized light. The first incident angle θ1 of the second wavelength band light is set to be the same as or different from the first incident angle θ1 of the first wavelength band light. The second wavelength band light incident from the second dichroic mirror 141 at the first incident angle θ1 (for example, an angle of 25 degrees) is located on the shorter wavelength side than the cut-on wavelength C1 as shown in FIG. 3, and is therefore reflected toward the condenser lens 173 of the light source side optical system 170. Therefore, the second wavelength band light reflected by the first dichroic mirror 140 is incident on the condenser lens 173 of the light source side optical system 170.

[0051] The fourth wavelength band light emitted from the third light source 310 is collected by the collecting lens group 311 and guided to the second dichroic mirror 141. As described above, the second dichroic mirror 141 transmits the fourth wavelength band light. Therefore, the fourth wavelength band light incident on the second dichroic mirror 141 transmits the second dichroic mirror 141 and enters the first dichroic mirror 140. The fourth wavelength band light incident on the first dichroic mirror 140 is reflected toward the collecting lens 173 of the light source side optical system 170 because the first dichroic mirror 140 has a characteristic of reflecting the fourth wavelength band light. Therefore, the fourth wavelength band light reflected by the first dichroic mirror 140 enters the collecting lens 173 of the light source side optical system 170.

[0052] As described above, the second wavelength band light to the fourth wavelength band light (blue wavelength band light, green wavelength band light, red wavelength band light) focused by the focusing lens 173 are combined into the same optical path as the light source light of the light source device 60 and are emitted to the projection optical system 220 side via the light source side optical system 170.

[0053] (Embodiment 2) Next, a second embodiment of the present invention will be described. In the description of this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted or simplified. As shown in FIG. 5, in this embodiment, a λ / 2 wave plate 722 is disposed between a first reflecting mirror 705 and a diffuser 703 on the optical path of the first wavelength band light. The λ / 2 wave plate 722 has the effect of rotating the polarization direction by 90 degrees, and can convert the first wavelength band light emitted as P polarized light into S polarized light. Therefore, the first dichroic mirror 140 is incident with the first wavelength band light that is S polarized and the second wavelength band light that remains P polarized.

[0054] For example, assume that the first wavelength band light of S polarized light is incident on the first dichroic mirror 140 at 25 degrees, and the second wavelength band light of P polarized light is incident on the first dichroic mirror 140 at 55 degrees. Referring to FIG. 3, the cut-on wavelength C1 of the S polarized light incident at 25 degrees is higher than that of the P polarized light incident at the same 25 degrees. Therefore, the width of the separable band W2 of the first wavelength band light L1 and the second wavelength band light L2 is wider than the separable band W1. That is, in this embodiment, the selection width of the first wavelength band light and the second wavelength band light (for example, the range that can be taken as the peak wavelength P1 of the first wavelength band light L1 and the second wavelength band light L2 and the half-width of the first wavelength band light L1 and the second wavelength band light L2) is wider than that of the first embodiment.

[0055] Furthermore, a λ / 2 wave plate 722 may be disposed between the second reflecting mirror 706 and the diffuser 704 on the optical path of the second wavelength band light. When the λ / 2 wave plate 722 is disposed between the second reflecting mirror 706 and the diffuser 704, the P-polarized first wavelength band light and the S-polarized second wavelength band light are incident on the first dichroic mirror 140 at the first incident angle θ1 and the second incident angle θ2, respectively, resulting in a separable band W3 having a narrower bandwidth than the separable bands W1 and W2, as shown in FIG. 3. This narrows the range of selection for the first wavelength band light and the second wavelength band light, but has the advantage of increasing the degree of freedom in the configuration layout of the light source device 60. Even if the λ / 2 wave plate 722 is placed between the second reflecting mirror 706 and the diffuser 704, if the blue laser diodes 71 of the first light source 710 and the second light source 720 are positioned so that S-polarized light is emitted to the first dichroic mirror 140, the first wavelength band light L1 and the second wavelength band light L2 can be separated by the separable band W2.

[0056] (Variation 1) Next, a first modified example of the present invention will be described. In the description of this modified example, the description of the same configuration as in the first and second embodiments will be omitted or simplified. In this modified example, the first dichroic mirror 140 is movable around a point that is the center in the long dimension direction and the center in the short dimension direction of the first dichroic mirror 140. The movable first dichroic mirror 140 can adjust the incidence angles of the first wavelength band light and the second wavelength band light in a time-division manner. This allows the light source device 60 to be configured without the first reflecting mirror 705 and the second reflecting mirror 706 that serve to make the first wavelength band light and the second wavelength band light incident on the first dichroic mirror 140 at the first incidence angle θ1 and the second incidence angle θ2 in the first embodiment. Alternatively, even if the first dichroic mirror 140 is fixed, the first light source 710 and the second light source 720 may be arranged to be non-parallel to each other, that is, the first wavelength band light and the second wavelength band light incident on the first dichroic mirror 140 may be non-parallel to each other by tilting the angle of the first light source 710 and the angle of the second light source 720 at a predetermined non-parallel angle, and the first reflection mirror 705 and the second reflection mirror 706 may be unnecessary. Note that the position of the rotation axis of the movable first dichroic mirror 140 is not limited to the center of the first dichroic mirror 140, and may be any position (for example, the center in the short dimension direction and the left end in the long dimension direction). Furthermore, by configuring the first dichroic mirror 140 to include a plurality of first dichroic mirrors 140, each of them may be movable. In addition, this modification is applicable to both the above-mentioned embodiment 1 and embodiment 2.

[0057] (Variation 2) Next, a second modification of the present invention will be described. In the description of this modification, the description of the same configuration as in the first embodiment, the second embodiment, and the first modification will be omitted or simplified. In this modification, the first reflection mirror 705 and the second reflection mirror 706 are not limited to those whose positions and inclination angles are adjusted in advance and fixed, but are movable. The first reflection mirror 705 and the second reflection mirror 706 can be moved closer to or farther away from the light source unit 700 (the first light source 710 and the second light source 720) to change their positions. For example, when the first reflection mirror 705 is moved, the distance between the first reflection mirror 705 and the first light source 710 (the blue laser diode 71) is shortened, thereby shortening the optical path to the phosphor 110, improving the convergence of light, and reducing the size of the phosphor 110.

[0058] Moreover, the movable operation of the first reflecting mirror 705 and the second reflecting mirror 706 may be an operation of changing the inclination angle so that the light from the first light source 710 and the second light source 720 is incident on the first dichroic mirror 140 at the first incident angle θ1 and the second incident angle θ2. By being able to change the inclination angles of the first reflecting mirror 705 and the second reflecting mirror 706, the number of locations that can be adopted as the locations of the first light source 710 and the second light source 720 increases, and as a result, the number of configuration layouts of the light source device 60 increases. In particular, when the first reflecting mirror 705 is made variable, it is possible to change the irradiation location of the first wavelength band light incident on the phosphor 110, and as a result, the service life of the phosphor 110 can be improved. Note that this modification is applicable to both the above-mentioned embodiment 1 and embodiment 2, and can also be used in combination with modification 1.

[0059] In addition, the movable operation of the first reflecting mirror 705 and the second reflecting mirror 706 can be used in combination with the change in the tilt angle of the first reflecting mirror 705 and the second reflecting mirror 706 and the ability to vary the distance between the first reflecting mirror 705 and the second reflecting mirror 706 and the light source unit 700 (the first light source 710 and the second light source 720). In Fig. 4 and Fig. 5, the first dichroic mirror 140 is disposed at a position where all the light from the blue laser diode 71 does not directly hit the first dichroic mirror 140, and then, at the timing of blue, the first reflecting mirror 705 in Fig. 4 and Fig. 5 is moved to a position separated from the blue laser diode 71 in the same manner as the second reflecting mirror 706, and the second reflecting mirror 706 and the first reflecting mirror 705 are disposed so that their entirety is positioned on substantially the same inclined surface, so that all the light from the blue laser diode 71 can be made incident on the first dichroic mirror 140 at the second incident angle θ2. With this configuration, all of the light from blue laser diode 71 passes through first dichroic mirror 140, so that all of the light from blue laser diode 71 can be used as blue light.

[0060] Next, at the timing of green, the second reflecting mirror 706 in Fig. 4 and Fig. 5 is moved close to 71 in the same manner as the first reflecting mirror 705, and the second reflecting mirror 706 and the first reflecting mirror 705 are arranged so that their entirety is positioned on substantially the same inclined surface, so that all the light from the blue laser diode 71 can be made to enter the first dichroic mirror 140 at the first incident angle θ1. With this configuration, all the light from the blue laser diode 71 is reflected by the first dichroic mirror 140 and irradiated onto the phosphor 110, so that the phosphor 110 can be irradiated with the light from all the blue laser diodes 71. Therefore, the light source light can be brightened.

[0061] In addition, in the above-described first and second embodiments and first and second modifications, an example has been shown in which the mirror surface of the fluorescent plate on which the phosphor 110 is formed is arranged facing the first dichroic mirror 140 and the light source side optical system 170, but the fluorescent plate may be arranged at an angle with respect to the optical axis connecting the first dichroic mirror 140 and the light source side optical system 170. This makes it possible to prevent the first wavelength band light from being guided toward the light source side optical system 170 and being mixed with the third wavelength band light, even if the first wavelength band light is reflected by the mirror surface without exciting the phosphor 110.

[0062] (Embodiment 3) Next, a third embodiment of the present invention will be described with reference to Fig. 6(a). Fig. 6(a) is a partial schematic plan view of a light source device according to the third embodiment of the present invention. In the description of the third embodiment, the description of the same configuration as in the first and second embodiments will be omitted or simplified.

[0063] In the third embodiment, the holding member 701 holding the first light source 710 and the second light source 720 is separate. The holding member 701 holding the first light source 710 and the holding member 701 holding the second light source 720 are separated, and the arrangement positions and arrangement orientations of the first light source 710 and the second light source 720 are changed from the arrangement positions and arrangement orientations of the first and second embodiments. That is, the first reflecting mirror 705 and the second reflecting mirror 706 are eliminated, and the light emitted from the first light source 710 and the second light source 720 is directly incident on the first dichroic mirror 140 without passing through the first reflecting mirror 705 and the second reflecting mirror 706.

[0064] The first light source 710 is disposed at a position and at a predetermined angle such that the first wavelength band light emitted from the first light source 710 is incident on the first dichroic mirror 140 at a first incident angle θ1 (e.g., 25 degrees). The second light source 720 is disposed at a position and at a predetermined angle such that the second wavelength band light emitted from the second light source 720 is incident on the first dichroic mirror 140 at a second incident angle θ2 (e.g., 55 degrees) that is larger than the first incident angle θ1 (e.g., 25 degrees).

[0065] Fig. 6(b) shows the first dichroic mirror 140 and the second dichroic mirror 141 in Fig. 6(a), and the approximate optical path of the second wavelength band light emitted from the second light source 720 (one optical path of the second wavelength band light emitted from the second light source 720). Fig. 6(b) is an enlarged view showing a central portion of Fig. 6(a). The second wavelength band light emitted from the second light source 720 is incident on the first dichroic mirror 140 at a second incident angle θ2 (e.g., 55 degrees) larger than the first incident angle θ1 (e.g., 25 degrees), and is transmitted through the first dichroic mirror 140.

[0066] Next, the second wavelength band light transmitted through the first dichroic mirror 140 is incident on the second dichroic mirror 141 at a third incident angle θ3 (e.g., 15 degrees) smaller than the first incident angle θ1 (e.g., 25 degrees), and is reflected by the second dichroic mirror 141. The angle θ4 formed between the surface of the first dichroic mirror 140 and the surface of the second dichroic mirror 141 is approximately 40 degrees.

[0067] The second wavelength band light reflected by the second dichroic mirror 141 is incident on the first dichroic mirror 140 at a first incident angle θ1 (for example, 25 degrees) and is reflected by the first dichroic mirror 140. As a result, the second wavelength band light reflected by the first dichroic mirror 140 is incident on the condenser lens 173 of the light source side optical system 170.

[0068] The first incident angle θ1 (e.g., 25 degrees), the second incident angle θ2 (e.g., 55 degrees), and the third incident angle θ3 (e.g., 15 degrees) of the second wavelength band light described in this embodiment 3 are also the same in embodiments 1 and 2. Furthermore, the angle θ4 (about 40 degrees) formed between the surface of the first dichroic mirror 140 and the surface of the second dichroic mirror 141 described in this embodiment 3 is also the same in embodiments 1 and 2.

[0069] As described above, according to the embodiment of the present invention, the light source device 60 includes a first light source 710 that emits a first wavelength band light, a second light source 720 that emits a second wavelength band light, a phosphor 110 that uses the first wavelength band light as excitation light and emits a third wavelength band light having a wavelength band different from the first and second wavelength band lights, and a first dichroic mirror 140 that reflects the first wavelength band light and transmits the second and third wavelength band lights. The first light source 710, the second light source 720, and the phosphor 110 are provided on one surface side of the first dichroic mirror 140, and the first and second wavelength band lights incident on the first dichroic mirror 140 are non-parallel to each other.

[0070] As a result, the first dichroic mirror 140 can transmit or reflect two types of light (first wavelength band light and second wavelength band light) having different angles of incidence depending on the respective angles of incidence. Then, the phosphor 110 uses the light (first wavelength band light) reflected by the first dichroic mirror 140 as excitation light to emit light (third wavelength band light) having a wavelength band different from that of the light (first wavelength band light) incident on the first dichroic mirror 140. Since the light (third wavelength band light) emitted by the phosphor 110 passes through the first dichroic mirror 140, the light source device 60 can emit two types of light (second wavelength band light and third wavelength band light) together with the light (second wavelength band light) transmitted through the first dichroic mirror 140.

[0071] The light source device 60 further includes a first reflecting mirror 705 having a first reflecting surface that reflects light in the first wavelength band, and a second reflecting mirror 706 having a second reflecting surface that reflects light in the second wavelength band and is non-parallel to the first reflecting surface, or the first light source 710 and the second light source 720 are arranged so as to be non-parallel to each other.

[0072] As a result, the first and second reflecting surfaces formed on the first and second reflecting mirrors 705 and 706, respectively, are non-parallel, so that the angles of incidence of the two lights (the first and second wavelength band lights) on the first dichroic mirror 140 can be made different. Even if a reflecting mirror is not provided, the same effect as when a reflecting mirror is provided can be obtained by arranging the first light source 710 and the second light source 720 non-parallel.

[0073] Furthermore, the light source device 60 includes a λ / 2 wave plate 722 between either the first light source 710 or the second light source 720 and the first dichroic mirror 140. The polarization directions of the first wavelength band light and the second wavelength band light incident on the first dichroic mirror 140 are orthogonal to each other.

[0074] As a result, the difference in cut-on wavelength C1 between two lights (first wavelength band light and second wavelength band light) whose polarization directions are orthogonal to each other may be greater depending on the angle of incidence on first dichroic mirror 140, compared to the case of two lights whose polarization directions are the same. The greater the difference in cut-on wavelength C1, the wider the wavelength range that can be selected as the wavelengths of the two lights incident on first dichroic mirror 140. In addition, since it is sufficient that λ / 2 wave plate 722 is provided in either first light source 710 or second light source 720, the degree of freedom in layout can be increased.

[0075] In addition, in the light source device 60, the first wavelength band light is incident on the first dichroic mirror 140 at a first incident angle θ1, and the second wavelength band light is incident on the first dichroic mirror 140 at a second incident angle θ2 that is greater than the first incident angle θ1, and the excitation light irradiated to the phosphor 110 is the first wavelength band light reflected by the first dichroic mirror 140.

[0076] This allows the first wavelength band light having a small first incident angle θ1 on the first dichroic mirror 140 to be reflected, and the second wavelength band light having a large second incident angle θ2 on the first dichroic mirror 140 to be transmitted. The first wavelength band light reflected by the first dichroic mirror 140 is then irradiated onto the phosphor 110, and can be used as excitation light for the third wavelength band light.

[0077] Furthermore, in the light source device 60, the first wavelength band light and the second wavelength band light are transmitted through a diffusion plate before being incident on the first dichroic mirror 140. This allows the light source device 60 to diffuse and shape the two lights (the first wavelength band light and the second wavelength band light) so as to reduce speckle noise in the second wavelength band light projected onto the projection target and to improve the luminous efficiency and service life of the phosphor 110.

[0078] The light source device 60 also includes a third light source 310 that emits a fourth wavelength band light having a wavelength band different from the first to third wavelength band lights, and a second dichroic mirror 141 that reflects the second wavelength band light that has passed through the first dichroic mirror 140 and transmits the fourth wavelength band light. This allows the light source device 60 to emit another light (fourth wavelength band light) in addition to the two lights (the second wavelength band light and the third wavelength band light).

[0079] In addition, in the light source device 60, the first dichroic mirror 140 transmits the second wavelength band light incident at the second incident angle θ2, and after being reflected by the second dichroic mirror 141, reflects the second wavelength band light incident at the first incident angle θ1, and reflects the fourth wavelength band light transmitted by the second dichroic mirror 141, and combines the second wavelength band light to the fourth wavelength band light into the same optical path. This allows the light source device 60 to combine three lights (the second wavelength band light to the fourth wavelength band light) into the same optical path and emit them.

[0080] In addition, the first light source 710 to the third light source 310 of the light source device 60 emit the first wavelength band light, the second wavelength band light, and the fourth wavelength band light in a time-division manner, respectively. This allows the light source device 60 to perform additive color mixing of the lights emitted from the first light source 710 to the third light source 310.

[0081] In addition, the first wavelength band light is blue wavelength band light or ultraviolet light, the second wavelength band light is blue wavelength band light, the third wavelength band light is green wavelength band light, and the fourth wavelength band light is red wavelength band light in the light source device 60. This allows the light source device 60 to create green light from blue or ultraviolet light, and in addition to the three primary colors of green, blue, and red that have been created, it is possible to emit light of various colors by mixing these three primary colors.

[0082] In the light source device 60, the first dichroic mirror 140 is movable by a rotation shaft provided at a predetermined position, so that the angles of incidence of the first wavelength band light and the second wavelength band light can be set to the first incidence angle θ1 and the second incidence angle θ2, respectively, without using a reflecting mirror.

[0083] In the above embodiment, the first dichroic mirror 140 reflects the first wavelength band light incident at a first incident angle θ1 of, for example, 25 degrees and transmits the second wavelength band light incident at a second incident angle θ2 of, for example, 55 degrees larger than the first incident angle, but is not limited to this configuration. The first dichroic mirror 140 may be configured to transmit the first wavelength band light incident at the first incident angle θ1 and reflect the second wavelength band light incident at a second incident angle θ2 larger than the first incident angle.

[0084] In addition, in the light source device 60, at least one of the first reflecting mirror and the second reflecting mirror is adjustable in position or inclination angle. As a result, the angle of incidence of the first wavelength band light and / or the second wavelength band light incident on the first dichroic mirror 140 can be adjusted and changed by various operations of the reflecting mirror. Furthermore, various operations of the reflecting mirror can cause the light of all the blue laser diodes 71 constituting the first light source 710 to be incident on the first dichroic mirror 140 at a first incident angle θ1 and reflected toward the phosphor 110, so that the third wavelength band light emitted from the phosphor 110 can be used as brighter light. In addition, various operations of the reflecting mirror can cause the light of all the blue laser diodes 71 constituting the second light source 720 to be incident on the first dichroic mirror 140 at a second incident angle θ2 and transmitted, so that the light of all the blue laser diodes 71 can be used as blue light.

[0085] With the above configuration, it is possible to obtain a light source device 60 that has a simple configuration and can be made compact. Then, with this light source device 60, the display element 50, the projection optical system 220, the projection device control unit, etc., it is possible to obtain a projection device 10 that can be made compact.

[0086] It should be noted that the above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0087] The invention described in the first claim of this application is set forth below. [1] A first light source that emits light in a first wavelength band; a second light source that emits light in a second wavelength band; a first dichroic mirror that reflects the first wavelength band light incident at a first incidence angle and transmits the second wavelength band light incident at a second incidence angle different from the first incidence angle; a second dichroic mirror that reflects the second wavelength band light that has been transmitted through the first dichroic mirror; and Equipped with a second dichroic mirror that reflects the second wavelength band light, and then the second dichroic mirror that reflects the second wavelength band light at the first incident angle; [2] The light source device according to [1], wherein the second incident angle is greater than the first incident angle. [3] A phosphor that uses the first wavelength band light as excitation light and emits a third wavelength band light having a wavelength band different from that of the first wavelength band light and the second wavelength band light, the first dichroic mirror transmits the third wavelength band light, The first light source, the second light source, and the phosphor are provided on one surface side of the first dichroic mirror. The light source device according to [1] or [2] above, [4] The excitation light irradiated to the phosphor is the first wavelength band light reflected by the first dichroic mirror. The light source device according to [3] above. [5] a first reflecting mirror having a first reflecting surface that reflects the first wavelength band light; and a second reflecting mirror having a second reflecting surface that reflects the second wavelength band light and is non-parallel to the first reflecting surface. , comprising Or the first light source and the second light source are arranged so as to be non-parallel to each other. The light source device according to any one of [1] to [4] above, [6] A λ / 2 wave plate is provided between either the first light source or the second light source and the first dichroic mirror; a polarization direction of the first wavelength band light and a polarization direction of the second wavelength band light are perpendicular to each other with respect to the first dichroic mirror. The light source device according to any one of [1] to [5] above, [7] The light source device described in any one of [1] to [6], characterized in that the first wavelength band light and the second wavelength band light are transmitted through a diffuser plate before being incident on the first dichroic mirror. [8] further comprising a third light source that emits a fourth wavelength band light having a wavelength band different from the first wavelength band light to the third wavelength band light, the second dichroic mirror transmits the fourth wavelength band light; The light source device according to [4] above. [9] The first dichroic mirror is reflecting the fourth wavelength band light transmitted through the second dichroic mirror; The second wavelength band light to the fourth wavelength band light are combined into the same optical path. The light source device according to [8] above.

[10] The light source device according to [8] or [9], characterized in that the first light source, the second light source, and the fourth wavelength band light are respectively emitted in a time-division manner.

[11] The first wavelength band light is blue wavelength band light or ultraviolet light, the second wavelength band light is blue wavelength band light, the third wavelength band light is a green wavelength band light, The fourth wavelength band light is a red wavelength band light. The light source device according to any one of [8] to

[10] above,

[12] The light source device described in any one of [1] to

[11] , wherein the first dichroic mirror is movable by a rotation axis provided at a predetermined position.

[13] The light source device according to [5], wherein at least one of the first reflecting mirror and the second reflecting mirror is adjustable in position or tilt angle.

[14] The light source device according to any one of [1] to

[13] above, a display element that is irradiated with light from the light source device and forms image light; a projection optical system that projects the image light emitted from the display element onto a projection target; a projection device control unit that controls the display element and the light source device; A projection device comprising: [Explanation of symbols]

[0088] 10 Projection device 12 Front panel 13 Rear Panel 14 Right Panel 15 Left Panel 21 Input / Output Connector Section 22 Input / Output Interface 23 Image conversion unit 24 Display encoder 25 Video RAM 26 Display driver 31 Image compression / expansion section 32 Memory card 35 Ir receiving unit 36 ​​Ir processing unit 37 Key / indicator section 38 Control section 41 Light source control circuit 43 Cooling fan drive control circuit 45 Lens motor 47 Audio processing unit 48 Speaker 50 Display element 57 Power connector 60 Light source device 71 Blue laser diode 73 Collimator lens 81 Heat sink 100 Green light source device 110 Phosphor 111 Condenser lens group 112 Condenser lens 113 Condenser lens 130 Heat pipe 140 1st dichroic mirror 141 2nd dichroic mirror 150 Heatsink 170 Light source side optical system 173 Condenser lens 175 Light guide device 178 Condenser lens 179 Condenser lens 185 Irradiation mirror 190 Heat sink 195 Condenser lens 220 Projection optical system 225 Fixed lens group 235 Movable lens group 242 control circuit board 261 cooling fan 300 Red light emitting diode 310 Third light source 311 Condenser lens group 312 Condenser lens 313 Condenser lens 380 Red light source device 700 light source unit 701 holding member 703 Diffuser 704 Diffuser 705 First reflecting mirror 706 Second reflecting mirror 710 1st light source 720 2nd light source 722 λ / 2 wavelength plate L1 First wavelength band light L2 Second wavelength band light L3 Third wavelength band light L4 Fourth wavelength band light θ1 1st angle of incidence θ2 2nd angle of incidence C1 Cut-on wavelength C2 Cut-off wavelength W1~W3 Separable band P1 Peak wavelength

Claims

1. a first light source that emits light in a first wavelength band; a second light source that emits light in a second wavelength band; a first dichroic mirror that reflects the first wavelength band light incident at a first incidence angle and transmits the second wavelength band light incident at a second incidence angle different from the first incidence angle; a second dichroic mirror that reflects the second wavelength band light that has been transmitted through the first dichroic mirror; and Equipped with the second wavelength band light is reflected by the second dichroic mirror and then reflected by the first dichroic mirror; A light source device characterized by:

2. The light source device according to claim 1 , wherein the second incident angle is greater than the first incident angle.

3. a phosphor that uses the first wavelength band light as excitation light and emits a third wavelength band light having a wavelength band different from the first wavelength band light and the second wavelength band light, The first dichroic mirror transmits the third wavelength band light.

3. The light source device according to claim 1 or 2.

4. The excitation light irradiated to the phosphor is the first wavelength band light reflected by the first dichroic mirror.

4. The light source device according to claim 3.

5. a first reflecting mirror having a first reflecting surface that reflects the first wavelength band light, and a second reflecting mirror having a second reflecting surface that reflects the second wavelength band light and is non-parallel to the first reflecting surface, Or, the first light source and the second light source are arranged so as to be non-parallel to each other.

5. The light source device according to claim 1, wherein the light source device is a light source unit.

6. a polarization direction of the first wavelength band light incident on the first dichroic mirror and a polarization direction of the second wavelength band light incident on the first dichroic mirror are orthogonal to each other; 6. The light source device according to claim 1, wherein the light source device is a light source unit.

7. 2. The light source device according to claim 1, wherein the second dichroic mirror is provided with a reflective coating capable of reflecting the second wavelength band light regardless of the angle of incidence of the second wavelength band light transmitted through the first dichroic mirror.

8. a phosphor that uses the first wavelength band light as excitation light and emits a third wavelength band light having a wavelength band different from those of the first wavelength band light and the second wavelength band light, and a third light source that emits a fourth wavelength band light having a wavelength band different from those of the first wavelength band light to the third wavelength band light, the first dichroic mirror transmits the third wavelength band light, The second dichroic mirror transmits the fourth wavelength band light.

2. The light source device according to claim 1.

9. 9. The light source device according to claim 8, wherein the second dichroic mirror has a first region that is irradiated with the second wavelength band light that has passed through the first dichroic mirror, and a second region that is different from the first region and is irradiated with the fourth wavelength band light, and the first region is coated with a reflective coating for a predetermined wavelength band light.

10. The first dichroic mirror is reflecting the fourth wavelength band light transmitted through the second dichroic mirror; The second wavelength band light to the fourth wavelength band light are combined into the same optical path.

9. The light source device according to claim 8.

11. 11. The light source device according to claim 1, wherein the first dichroic mirror is movable by a rotation shaft provided at a predetermined position.

12. 6. The light source device according to claim 5, wherein at least one of the first reflecting mirror and the second reflecting mirror is adjustable in position or inclination angle.

13. 13. The light source device according to claim 1, wherein the first wavelength band light and the second wavelength band light have the same wavelength band.

14. A first light source that emits light in a first wavelength band; a second light source that emits light in a second wavelength band; a first dichroic mirror that reflects the first wavelength band light incident at a first incidence angle and transmits the second wavelength band light incident at a second incidence angle different from the first incidence angle; Equipped with a polarization direction of the first wavelength band light incident on the first dichroic mirror and a polarization direction of the second wavelength band light incident on the first dichroic mirror are orthogonal to each other; A light source device characterized by:

15. A light source device according to any one of claims 1 to 14, a display element that is irradiated with light from the light source device and forms image light; a projection optical system that projects the image light emitted from the display element onto a projection target; a projection device control unit that controls the display element and the light source device; A projection device comprising:

Images