Light source device and projection apparatus

Abstract

To provide a light source device that can be reduced in size, and a projection apparatus including the light source device.SOLUTION: A light source device 60 comprises: a blue laser diode 71 that emits blue wavelength band light; a red light emitting diode 81 that emits red wavelength band light; a light path switching device 142 that is disposed on a light path of the blue wavelength band light emitted from the blue laser diode 71 and switches the incident blue wavelength band light between a light path in a first direction D1 and a light path in a second direction D2; a fluorescence emitting device 100 that is disposed on the light path in the second direction D2 and has a fluorescence emitting region that emits fluorescence including green wavelength band light using the blue wavelength band light as excitation light; and a light source optical system 140 that guides the blue wavelength band light switched to the light path in the first direction D1 by the light path switching device 142, the red wavelength band light emitted from the red light emitting diode 81, and the fluorescence emitted from the fluorescence emitting region to a combined light path.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Today, projection devices are used to project image data stored on personal computer screens, video screens, memory cards, etc. onto a screen. These projection devices focus light emitted from a light source onto a micromirror display element called a DMD (Digital Micromirror Device) or a liquid crystal panel, and display a color image on the screen.

[0003] For example, Patent Document 1 discloses a fluorescent device having a fluorescent wheel with a fluorescent light-emitting region including a phosphor layer and a transmission region, and a projection device including a light source device including this fluorescent device. This projection device irradiates the phosphor with blue wavelength band light from a blue light source as excitation light, thereby guiding fluorescence in a green wavelength band emitted from the phosphor to a combined light path. Meanwhile, by irradiating the transmission region of the fluorescent wheel with blue wavelength band light from the blue light source, this blue wavelength band light is guided to the opposite side of the fluorescent wheel, and then guided to a combined light path using mirrors and lenses, and then guided to a display element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-45778 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the projection device of Patent Document 1, lens members, mirror members, etc. for guiding red wavelength band light and green wavelength band light must be arranged separately from the optical path for guiding blue wavelength band light, which makes the optical path within the device complicated and makes it difficult to reduce the size of the device.

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

[0007] A light source device of the present invention includes a first light source that emits first wavelength band light, a second light source that emits second wavelength band light, an optical path switching device that is provided on an optical path of the first wavelength band light emitted from the first light source and switches the incident first wavelength band light between at least a first-direction optical path and a second-direction optical path, a fluorescence light emitting device that is provided on the second-direction optical path and has a fluorescence emission region that uses the first wavelength band light as excitation light to emit fluorescence containing third wavelength band light, and a light source optical system that guides the first wavelength band light switched to the first-direction optical path by the optical path switching device, the second wavelength band light emitted from the second light source, and the fluorescence emitted in the fluorescence emission region to a combined optical path.

[0008] The projection device of the present invention comprises the above-mentioned light source device, a display element that generates image light, a projection optical system that projects the image light emitted from the display element onto a projection target, and a control unit that controls the light source device and the display element. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a light source device that can be made smaller in size, and a projection device that includes this light source device. [Brief explanation of the drawings]

[0010] [Figure 1] 2 is a diagram showing functional circuit blocks of the projection device according to the first embodiment. FIG. [Figure 2] 1 is a plan view schematically illustrating the internal structure of a projection device according to a first embodiment. [Figure 3] 2 is a schematic plan view showing the manner in which light is emitted and incident in the light source device of the projection device according to the first embodiment. FIG. [Figure 4]2 is a front view showing how light is emitted from the fluorescent light emitting device of the projection device according to the first embodiment. FIG. [Figure 5] 10 is a plan view schematically illustrating the manner in which light is emitted and incident in a light source device of a projection device according to a second embodiment. FIG. [Figure 6] FIG. 10 is a schematic front view of an optical wheel of a projection device according to a second embodiment. [Figure 7] 10 is a schematic plan view showing the manner in which light is emitted and incident in a light source device of a projection device according to a third embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] A first embodiment of the present invention will be described below with reference to Figures 1 to 4. As shown in Figure 1, the projection device control unit of a projection device 10 according to this embodiment is made up 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 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 system bus SB 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 expands and stores the input image signal in the video RAM 25, generates a video signal from the stored contents of the video RAM 25, and outputs the video signal to the display driver 26. The display driver 26 drives a display element 50 such as a DMD, which is a spatial light modulator (SOM), at an appropriate frame rate in response to the image signal output from the display encoder 24.

[0013] The projection device 10 irradiates a light beam emitted from the light source device 60 onto the display element 50 via a light-guiding optical system 170 (see FIG. 2) described later, thereby forming an optical image with the light reflected from the display element 50, and projects and displays the image on a projection target such as a screen (not shown) via a projection optical system 220 (see FIG. 2) described later. A first lens group 235 of the projection optical system 220 can perform zoom adjustment and focus adjustment by driving a lens motor 45.

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

[0015] The control unit 38 controls 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, and a RAM used as work memory. The key / indicator unit 37 is composed of main keys and indicators provided on the housing. Operation signals from the key / indicator unit 37 are sent directly to the control unit 38. Key operation signals from the remote controller are received by the IR receiving unit 35, demodulated into code signals by the IR processing unit 36, and output to the control unit 38. The control unit 38 is connected to the audio processing unit 47 via the system bus SB. The audio processing unit 47 is equipped with a sound source circuit such as a PCM sound source, and converts audio data into analog format in the projection mode and playback mode, driving the speaker 48 to emit amplified sound.

[0016] The control unit 38 controls the light source control circuit 41. The light source control circuit 41 individually controls the operation of the excitation light irradiation device 70 and the red light source device 80 (see FIG. 2) in the light source device 60 so that light in a predetermined wavelength band required for image generation is emitted from the light source device 60. Furthermore, the control unit 38 causes the cooling fan drive control circuit 43 to detect temperatures using multiple temperature sensors provided in the light source device 60, etc., and to control the rotation speed of the cooling fan 56 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 56 using a timer or the like even after the power to the projection device 10 main body is turned off, or to turn off the power to the projection device 10 main body based on the results of temperature detection by the temperature sensors.

[0017] Next, the internal structure of the projection device 10 will be described with reference to Fig. 2. As shown in Fig. 2, the housing of the projection device 10 is formed in a substantially box shape and includes an upper panel, a lower panel (not shown), a front panel 12, a rear panel 13, a right panel 14, and a left panel 15. The projection device 10 also has a projection opening 12a on the front side. In the following description, the left and right of the projection device 10 refer to the left and right directions when the projection object is viewed from the projection opening 12a in the projection direction, and the front and rear refer to the front and rear directions along the traveling direction of the light beam when projected from the projection device 10 onto the object.

[0018] The projection device 10 includes a control circuit board 242 near the left panel 15. This control circuit board 242 includes a power circuit block, a light source control block, and the like. The projection device 10 also includes a light source device 60 located approximately in the center of the projection device 10. Between the light source device 60 and the right panel 14, a power connector 57, a first heat sink 130, a cooling fan 240, and the like are arranged. In addition, a display element 50 is provided on the left side of the light source device 60. The display element 50 is connected to a second heat sink 190.

[0019] The light source device 60 includes an excitation light irradiation device 70 that is a light source of blue wavelength band light (first wavelength band light) and also a light source of excitation light, a red light source device 80 that is a light source of red wavelength band light (second wavelength band light), and a fluorescence light emitting device 100 that can emit green wavelength band light (third wavelength band light). The light source device 60 is provided with a light source optical system 140 that guides the blue wavelength band light, the red wavelength band light, and the green wavelength band light. The light source device 60 also includes a light guide optical system 170 that guides light from the light source optical system 140 to the projection optical system 220.

[0020] The excitation light irradiation device 70 is disposed on the rear side of the housing of the projection device 10. The excitation light irradiation device 70 has a plurality of blue laser diodes (first light sources) 71 and a collimator lens 72. In this embodiment, two blue laser diodes 71 and two collimator lenses 72 are arranged in parallel in the horizontal direction. The blue laser diodes 71 and the collimator lenses 72 are held by a holding member (not shown). The blue laser diodes 71 are semiconductor light-emitting elements that emit blue wavelength band light, which is excitation light. The collimator lenses 72 are disposed on the optical axes of the blue laser diodes 71, respectively, and convert the light emitted from the blue laser diodes 71 into parallel light to enhance directivity. The excitation light irradiation device 70 is connected to a first heat sink 130 via a heat pipe (not shown) so as to be cooled.

[0021] The red light source device 80 has a red light emitting diode (second light source) 81, a first condenser lens 84, and a second condenser lens 86. The red light emitting diode 81 is a semiconductor light emitting element that emits light in the red wavelength band. The first condenser lens 84 and the second condenser lens 86 are different in size, are arranged on the optical axis of the red light emitting diode 81, and condense the light emitted from the red light emitting diode 81. The light emitted from the red light emitting diode 81 is condensed via the first condenser lens 84 and the second condenser lens 86 and directed toward the light source optical system 140. Note that, although the first condenser lens 84 and the second condenser lens 86 are different in size in the example shown in FIG. 2, the first condenser lens 84 and the second condenser lens 86 may be the same size.

[0022] Fluorescence-emitting device 100 is a so-called fixed phosphor, and as shown in Fig. 4, has a plate-shaped substrate 101 made of a metal such as copper or aluminum, a fluorescence-emitting region 102 provided on substrate 101, and a filter region 103 provided so as to overlap fluorescence-emitting region 102. The surface of substrate 101 is mirror-finished by silver deposition or the like. A yellow phosphor layer coated with a yellow phosphor is provided on fluorescence-emitting region 102, which is provided in a substantially rectangular shape.

[0023] When the yellow phosphor layer of the fluorescent-light-emitting region 102 is irradiated with blue wavelength band light emitted from the excitation light irradiation device 70 as excitation light, the yellow wavelength band light is fluorescently emitted in all directions from the yellow phosphor in the yellow phosphor layer, some of which is emitted directly and the other part is reflected by the base material 101 and emitted. The filter region 103 is provided in a substantially elongated rectangular shape that is larger than the fluorescent-light-emitting region 102. Thus, the fluorescent-light-emitting region 102 is covered by the filter region 103. Specifically, the filter region 103 is provided by applying a filter coating to the upper surface of the fluorescent-light-emitting region 102 or by overlapping a filter sheet on the upper surface of the fluorescent-light-emitting region 102. The filter region 103 transmits blue wavelength band light and green wavelength band light and reflects red wavelength band light.

[0024] 2 and 3, a third condenser lens 104 and a fourth condenser lens 106 are provided on the light-emitting side (second dichroic mirror 148 side) of the fluorescence light-emitting device 100. The third condenser lens 104 and the fourth condenser lens 106 are different in size and condense light emitted from the fluorescence light-emitting device 100. The light emitted from the fluorescence light-emitting device 100 is condensed via the third condenser lens 104 and the fourth condenser lens 106 and directed toward the second dichroic mirror 148 side. Note that, although the third condenser lens 104 and the fourth condenser lens 106 are different in size in the example shown in the figures, the third condenser lens 104 and the fourth condenser lens 106 may also be the same in size.

[0025] 2, the light source optical system 140 includes a light path switching device 142, a diffuser plate (diffusion member) 144, a first microlens array (first optical member) 146, a first dichroic mirror (first mirror member) 147, and a second dichroic mirror (second mirror member) 148. The light source optical system 140 guides, toward a combined light path of the light guide optical system 170, the blue wavelength band light switched to the light path in the first direction D1 by the light path switching device 142, the red wavelength band light emitted from the red light emitting diode 81, and the green wavelength band light included in the fluorescence emitted by the fluorescence emitting device 90, as will be described later.

[0026] 3, the optical path switching device 142 transmits the blue wavelength band light emitted from the excitation light irradiator 70 and switches the optical path of the blue wavelength band light between at least a first direction D1 and a second direction D2. The first direction D1 is the direction from the optical path switching device 142 toward the first dichroic mirror 147 via the diffuser 144, and the second direction D2 is the direction from the optical path switching device 142 toward the fluorescence light-emitting device 100 via the first microlens array 146 and the second dichroic mirror 148. Specifically, the optical path switching device 142 can be, for example, an optical element made of KTN crystal, the refractive index of which can be freely changed by applying a voltage.

[0027] The diffuser 144 is provided on the optical path in the first direction D1, and diffuses the blue wavelength band light, which has been switched to the optical path in the first direction D1 by the optical path switching device 142, toward the first dichroic mirror 147 while transmitting the blue wavelength band light. The first microlens array 146 is provided between the optical path switching device 142 and the fluorescence light-emitting device 100, and receives the blue wavelength band light, which has been switched to the optical path in the second direction D2 by the optical path switching device 142, and shapes and emits a beam pattern of the incident blue wavelength band light. The first microlens array 146 shapes, for example, elliptical laser light into a substantially elongated rectangular beam pattern. The first microlens array 146 may be a diffuser having a function of shaping the beam pattern.

[0028] The first dichroic mirror 147 is provided on the optical path of the blue wavelength band light that has passed through the diffuser plate 144 (on the optical path in the first direction D1) and on the optical path of the red wavelength band light that has been emitted from the red light emitting diode 81. The first dichroic mirror 147 reflects the blue wavelength band light and transmits the red wavelength band light. The first dichroic mirror 147 is provided in an arrangement such that it reflects the blue wavelength band light that has passed through the diffuser plate 144 toward the light-guiding optical system 170. Note that the first dichroic mirror 147 of this embodiment may be configured to reflect or transmit the green wavelength band light and the yellow wavelength band light.

[0029] The second dichroic mirror 148 is provided on the optical path of the blue wavelength band light emitted from the first microlens array 146 (on the optical path in the second direction D2) and on the optical path of the red wavelength band light emitted from the red light emitting diode 81. The second dichroic mirror 148 transmits the blue wavelength band light and the red wavelength band light and reflects the green wavelength band light. The second dichroic mirror 148 is provided in an arrangement such that it reflects the green wavelength band light contained in the fluorescence emitted by the fluorescence light emitting device toward the light-guiding optical system 170.

[0030] 2, the light-guiding optical system 170 includes a second microlens array (second optical member) 172, a concave lens 174, a fifth condenser lens 175, an irradiation mirror 185, and a condenser lens 195. The second microlens array 172 is provided on a combined optical path of the light of each wavelength band (blue wavelength band light, red wavelength band light, and green wavelength band light) guided by the light source optical system, and shapes a beam pattern of the light of each wavelength band incident on the incident surface of the second microlens array 172, and irradiates the light onto the image forming surface of the display element 50. The concave lens 174 is disposed between the second microlens array 172 and the fifth condenser lens 175. The condenser lens 195 emits image light emitted from the display element 50, which is disposed 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.

[0031] The projection optical system 220 has a condenser lens 195, a first lens group 235, and a second lens group 225. The first lens group 235 and the second lens group 225, which are arranged on the optical axis of the condenser lens 195 on the front panel 12 side, are housed in a fixed lens barrel and can be moved manually or automatically to enable zoom adjustment and focus adjustment.

[0032] In the projection device 10 configured as described above, the blue wavelength band light emitted from the blue laser diode 71 and switched to the optical path in the first direction D1 by the optical path switching device 142, the red wavelength band light emitted from the red light emitting diode 81, and the green wavelength band light emitted from the fluorescence light emitting device 100 using, as excitation light, the blue wavelength band light emitted from the blue laser diode 71 and switched to the optical path in the second direction D2 by the optical path switching device 142 are guided by the light guiding optical system 170 to a composite optical path with the same optical axis, and are incident on the display element 50. Then, 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 onto the projection target.

[0033] Next, with reference to FIG. 3, the incidence and emission of light in each component constituting the light source device 60 will be described. First, the case where blue wavelength band light, which is excitation light, is incident on the display element 50 will be described. Blue wavelength band light (light L1 indicated by a solid line in FIG. 3) emitted from the blue laser diode 71 is incident on the optical path switching device 142. The blue wavelength band light, which has been switched to an optical path in the first direction D1 by the optical path switching device 142, is incident on the diffuser 144, is diffused while passing through the diffuser 144, and is incident on the first dichroic mirror 147. The blue wavelength band light that has entered the first dichroic mirror 147 is reflected by the first dichroic mirror 147 toward the second dichroic mirror 148. The blue wavelength band light that has been reflected toward the second dichroic mirror 148 passes through the second dichroic mirror 148 toward the combined optical path of the light-guiding optical system 170, is incident on the display element 50, and is guided to the projection optical system 220.

[0034] Next, a case where red wavelength band light is incident on the display element 50 will be described. Red wavelength band light (light L2 indicated by a dashed line in FIG. 3) emitted from the red light emitting diode 81 is incident on the first dichroic mirror 147. The red wavelength band light incident on the first dichroic mirror 147 passes through the first dichroic mirror 147 and is guided to the second dichroic mirror 148. The red wavelength band light guided to the second dichroic mirror 148 passes through the second dichroic mirror 148 and heads toward the combined optical path of the light guide optical system 170, enters the display element 50, and is guided to the projection optical system 220.

[0035] Next, a case where green wavelength band light is incident on the display element 50 will be described. The blue wavelength band light that enters the optical path switching device 142 and has its optical path switched to the second direction D2 by the optical path switching device 142 enters the first microlens array 146, passes through the first microlens array 146, and is emitted toward the second dichroic mirror 148. At this time, the light emitted from the blue laser diode 71 normally has an elliptical beam pattern, but by passing through the first microlens array 146, the beam pattern is shaped into a substantially square shape. The blue wavelength band light whose beam pattern has been shaped by the first microlens array 146 in this way passes through the second dichroic mirror 148 and is irradiated onto the filter region 103 of the fluorescence light-emitting device 100 via the fourth condenser lens 106 and the third condenser lens 104.

[0036] The blue wavelength band light irradiated onto the filter region 103 of the fluorescence-emitting device 100 has a beam pattern shaped as described above, so that its irradiation range IR is substantially square, as shown in Fig. 4. The blue wavelength band light irradiated onto the filter region 103 in the irradiation range IR passes through the filter region 103 and is irradiated onto the fluorescence-emitting region 102. When the fluorescence-emitting region 102 is irradiated with blue wavelength band light, which serves as excitation light, yellow wavelength band light is emitted from the yellow phosphor layer of the fluorescence-emitting region 102. This yellow wavelength band light is light that includes red wavelength band light and green wavelength band light. Therefore, the yellow wavelength band light emitted by the fluorescence-emitting region 102 passes through the filter region 103, and the red wavelength band light is reflected, so that the yellow wavelength band light is emitted from the fluorescence-emitting device 100 as green wavelength band light (light L3 indicated by a two-dot chain line in Fig. 3).

[0037] The green wavelength band light emitted from the fluorescence-emitting device 100 is incident on the second dichroic mirror 148 via the third condenser lens 104 and the fourth condenser lens 106. The green wavelength band light incident on the second dichroic mirror 148 is reflected by the second dichroic mirror 148 toward the combined optical path of the light-guiding optical system 170, enters the display element 50, and is guided to the projection optical system 220.

[0038] In this embodiment, a configuration in which green wavelength band light is emitted from fluorescent light-emitting device 100 via filter region 103 has been exemplified, but as a modified example, a green phosphor layer formed by applying a green phosphor may be provided in fluorescent light-emitting region 102 of fluorescent light-emitting device 100, and a configuration without filter region 103 may be employed. In this case, when blue wavelength band light is irradiated onto fluorescent light-emitting region 102, green wavelength band light is emitted from the green phosphor layer, and therefore green wavelength band light can be emitted from fluorescent light-emitting device 100 without providing filter region 103.

[0039] As described above, the light source device 60 according to this embodiment includes the blue laser diode 71 that emits blue wavelength band light, the red light-emitting diode 81 that emits red wavelength band light, an optical path switching device 142 that is provided on the optical path of the blue wavelength band light emitted from the blue laser diode 1 and switches the incident blue wavelength band light between at least an optical path in the first direction D1 and an optical path in the second direction D2, the fluorescence light-emitting device 100 that is provided on the optical path in the second direction D2 and has a fluorescence light-emitting region 102 that uses the blue wavelength band light as excitation light to emit fluorescence containing green wavelength band light, and a light source optical system 140 that guides the blue wavelength band light switched to the optical path in the first direction D1 by the optical path switching device 142, the red wavelength band light emitted from the red light-emitting diode 81, and the fluorescence emitted in the fluorescence light-emitting region 102 to a combined optical path.

[0040] In the light source device 60 according to the present embodiment configured as described above, the blue wavelength band light emitted from the blue laser diode 71 and switched to the optical path in the first direction D1 by the optical path switching device 142, the red wavelength band light emitted from the red light-emitting diode 81, and the green wavelength band light emitted from the fluorescence light-emitting device 100 using the blue wavelength band light emitted from the blue laser diode 71 and switched to the optical path in the second direction D2 by the optical path switching device 142 as excitation light are guided to the same combined optical path. Therefore, the optical path of the blue wavelength band light and the optical paths of the red wavelength band light and the green wavelength band light are the same optical path, eliminating the need to separately provide a lens member, mirror member, or the like for guiding one wavelength band light independently from the other wavelength band lights. As a result, the light source device 60 can be made more compact.

[0041] In the light source device 60, the light source optical system 140 includes a first dichroic mirror 147 that is disposed on the optical path in the first direction D1 and on the optical path of the red wavelength band light emitted from the red light-emitting diode 81, and that reflects blue wavelength band light and transmits red wavelength band light, and a second dichroic mirror 148 that is disposed on the optical path in the second direction D2 and on the optical path of the red wavelength band light emitted from the red light-emitting diode 81, and that transmits blue wavelength band light and red wavelength band light and reflects green wavelength band light. This allows the following light components to be guided to the same combined optical path: blue wavelength band light guided to the optical path in the first direction D1 and reflected by the first dichroic mirror 147; red wavelength band light emitted from the red light-emitting diode 81 and transmitted through the first dichroic mirror 147 and the second dichroic mirror 148; and green wavelength band light emitted from the fluorescence light-emitting device 100 using the blue wavelength band light guided to the optical path in the second direction D2 and reflected by the second dichroic mirror 148 as excitation light and reflected by the second dichroic mirror 148. This makes it possible to realize a specific configuration for making the optical path of the blue wavelength band light and the optical paths of the red and green wavelength band lights the same optical path, without complicating the optical path configuration.

[0042] Furthermore, the light source device 60 includes a diffusion plate 144 that is provided on the optical path in the first direction D1 and diffuses the blue wavelength band light. This allows the blue wavelength band light that is emitted from the blue laser diode 71 and switched to the optical path in the first direction D1 by the optical path switching device 142 to be used as light source light.

[0043] Furthermore, the light source device 60 includes a first microlens array 146 that is provided between the optical path switching device 142 and the fluorescence light-emitting device 100 and that shapes a beam pattern of the blue wavelength band light that has been switched to the optical path in the first direction D1 by the optical path switching device 142. This makes it possible to obtain shaped light for the fluorescence emitted from the fluorescence light-emitting device 100. Furthermore, shaping the beam pattern makes it possible to fit the irradiation range IR of the blue wavelength band light within the fluorescence light-emitting region 102, thereby preventing excitation light reflected by the mirror-finished surface of the fluorescence light-emitting device 100 (so-called residual excitation light) from being included in the light emitted from the fluorescence light-emitting device 100.

[0044] Furthermore, the light source device 60 is provided with a second microlens array 172 that is disposed on the combined optical path and shapes the beam pattern, thereby enabling more appropriate light source light to be obtained, reducing color unevenness and producing a clearer projected image.

[0045] Furthermore, in the light source device 60, the fluorescence-emitting device 100 has a filter region 103 provided so as to overlap the fluorescence-emitting region 102, and emits fluorescence as green wavelength band light via the filter region 103. This allows the fluorescence-emitting device 100 to have a simple configuration provided with a yellow light-emitting layer, and makes it possible to make the fluorescence-emitting device 100 more compact.

[0046] Furthermore, the projection device 10 according to this embodiment includes the above-described light source device 60, a display element 50 that generates image light, a projection optical system 220 that projects the image light emitted from the display element 50 onto a projection target, and a control unit 38 that controls the light source device 60 and the display element 50. This allows the blue wavelength band light, red wavelength band light, and green wavelength band light guided from the light source device 60 to the light-guiding optical system 200 side to follow the same optical path, thereby realizing a projection device 10 in which the light source device 60 is made compact.

[0047] Next, a second embodiment of the present invention will be described with reference to Figures 5 and 6. As shown in Figure 5, a light source device 260 according to the second embodiment differs from the light source device 60 of the first embodiment in the configuration of an optical path switching device 342, and further does not include the diffuser plate 144 and first microlens array 146 included in the first embodiment. Since the other configurations in the second embodiment are the same as those in the first embodiment, their description will be omitted or simplified. Furthermore, in the projection device according to the second embodiment, components having the same configuration as those in the projection device according to the first embodiment are assigned the same reference numerals.

[0048] As shown in FIG. 5, the light path switching device 342 in the light source device 260 of this embodiment is a rotating wheel device having an optical wheel 342a. That is, the light path switching device 342 has the optical wheel 342a and a rotation shaft 342b with a built-in wheel motor. The optical wheel 342a is rotatable by the rotation shaft 342b. As shown in FIG. 6, the optical wheel 342a is provided with two transmissive diffraction grating regions (a first diffraction grating region 342a1 and a second diffraction grating region 342a2). The diffraction grating regions 342a1 and 342a2 are provided so that the emission angles of the light beams emitted from the diffraction gratings are different from each other. Furthermore, the diffraction grating regions 342a1 and 342a2 have a diffusing function for diffusing light. Note that, in this embodiment, the diffraction grating regions 342a1 and 342a2 are arranged at equal intervals of 180 degrees, but this is not limited thereto, and the arrangement angles can be set appropriately.

[0049] The first diffraction grating region 342a1 diffracts (switches) the blue wavelength band light emitted from the blue laser diode 71 and incident on the back side (blue laser diode 71 side) of the optical wheel 342a so that the light path is in the first direction D1. The second diffraction grating region 342a2 diffracts (switches) the blue wavelength band light emitted from the blue laser diode 71 and incident on the back side of the optical wheel 342a so that the light path is in the second direction D2. Furthermore, the optical path switching device 342 can change the size of the irradiation range of the blue wavelength band light that is switched to the optical path in the second direction D2 and irradiated onto the filter region of the fluorescence light-emitting device 100, depending on the setting of the diffraction grating of the second diffraction grating region 342b2.

[0050] With the above-described configuration, in the light source device 260 of the present embodiment, as shown in FIG. 5, blue wavelength band light (light L4 indicated by a solid line in FIG. 5) emitted from the blue laser diode 71 and switched to the optical path in the first direction D1 by the first diffraction grating region 342a1 of the optical path switching device 342 is diffused by being emitted from the first diffraction grating region 342a and enters the first dichroic mirror 147. The subsequent light guide mode of the blue wavelength band light that entered the first dichroic mirror 147 is the same as in the first embodiment. In this way, in the present embodiment, the blue wavelength band light on the optical path in the first direction D1 is diffused by being emitted from the optical path switching device 342, so there is no need to provide the diffuser 144 or the like on the optical path in the first direction D1 as in the first embodiment, and component costs can be reduced.

[0051] Furthermore, in the light source device 260 of the present embodiment, the blue wavelength band light (light L4 shown by a solid line in FIG. 5) emitted from the blue laser diode 71 and switched to the optical path in the second direction D2 by the second diffraction grating region 342b2 of the optical path switching device 342 has the size of the irradiation range changed by being emitted from the second diffraction grating region 342b2, and is irradiated onto the filter region in a substantially rectangular irradiation range close to the width of the fluorescence light-emitting region of the fluorescence light-emitting device 100. As a result, green wavelength band light (light L6 shown by a two-dot chain line in FIG. 5) is emitted from the fluorescence light-emitting device 100 via the filter region. In this way, in the present embodiment, the size of the irradiation range of the blue wavelength band light on the optical path in the second direction D2 is changed by being emitted from the optical path switching device 342, so there is no need to provide the first microlens array 146 or the like on the optical path in the second direction D2 as in the first embodiment, thereby reducing component costs. The manner in which red wavelength band light (light L5 indicated by a dashed line in FIG. 5) emitted from the red light emitting diode 81 is guided is the same as in the first embodiment.

[0052] Next, a third embodiment of the present invention will be described with reference to Fig. 7. As shown in Fig. 7, a light source device 360 ​​according to the third embodiment differs from the light source device 60 of the first embodiment in the configuration of the optical path switching device 442, the arrangement of the excitation light irradiation device 70, the light guide mode of the blue wavelength band light, and the sizes of the first dichroic mirror 447 and the second dichroic mirror 448. The other configurations of the third embodiment are the same as those of the first embodiment, and therefore their description will be omitted or simplified. Furthermore, in the projection device according to the third embodiment, components having the same configuration as those of the projection device according to the first embodiment are denoted by the same reference numerals.

[0053] As shown in FIG. 7 , the optical path switching device 442 in the light source device 360 ​​of this embodiment is a reflective type, rather than a transmissive type like the optical path switching devices 142 and 342 of the first and second embodiments. That is, the optical path switching device 442 switches the optical path in a direction that reflects incident blue wavelength band light. Therefore, the blue laser diode 71 in this embodiment is disposed on the reflective side of the optical path switching device 442, specifically, on the opposite side of the optical path switching device across the first dichroic mirror 447 and the second dichroic mirror 448, between the red light source device 80 and the fluorescent light-emitting device 100. The optical path switching device 442 has an optical wheel 442a and a rotating shaft 442b with a built-in wheel motor. The optical wheel is provided with two reflective diffraction grating regions. The optical path switching device 442 is similar to the optical path switching device 342 of the second embodiment in that it has the ability to change the emission angle of light emitted from each diffraction grating region, the ability to diffuse light, and the size of the light irradiation range.

[0054] 7, in the light source device 360 ​​of this embodiment, blue wavelength band light emitted from the blue laser diode 71 and incident on the optical path switching device 342 from the front side is switched to an optical path in the first direction D1 by one of the diffraction grating regions, reflected, and directed toward the first dichroic mirror 447. The subsequent light guide mode of the blue wavelength band light (light L7 indicated by the solid line in FIG. 7) incident on the first dichroic mirror 447 is the same as in the first embodiment. By using the reflective optical path switching device 442 in this way, the degree of freedom in the arrangement positions of the excitation light irradiator 70 and the optical path switching device 442 can be increased.

[0055] Furthermore, in the light source device 360 ​​of this embodiment, blue wavelength band light emitted from the blue laser diode 71 and incident on the light path switching device 342 from the front side is switched to a light path in the second direction D2 by the other diffraction grating region, reflected, and transmitted through the second dichroic mirror 448 to be incident on the fluorescence light-emitting device 100. As a result, green wavelength band light (light L9 shown by the two-dot chain line in FIG. 7) is emitted from the fluorescence light-emitting device 100 via the filter region. By using the reflective light path switching device 442 in this manner, it is possible to increase the degree of freedom in the arrangement positions of the excitation light irradiator 70 and the light path switching device 442. Note that the light guide mode of red wavelength band light (light L8 shown by the one-dot chain line in FIG. 7) emitted from the red light-emitting diode 81 is the same as in the first embodiment.

[0056] The above has described each embodiment of the present invention. However, in addition to the above-described optical path switching devices 141, 342, and 442, optical path switching devices according to modified examples may be configured to switch incident blue wavelength band light between an optical path that passes through the optical path switching device and an optical path that is reflected by the optical path switching device, or may be configured to use an MEMS mirror or a mirror wheel. Furthermore, instead of the fluorescent light emitting device 100 using the fixed phosphor described above, a fluorescent light emitting device having, for example, a fluorescent wheel may be used. Furthermore, in the second and third embodiments, configurations in which the light diffusion and shaping functions are realized by the optical path switching devices 342 and 442 have been exemplified. However, if the optical path switching device does not have the light diffusion and shaping functions, the light diffusion and shaping functions may be realized by using a diffuser plate and a microlens array.

[0057] The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0058] 60: Light source device, 71: Blue laser diode, 81: Red light emitting diode, 100: Fluorescent light emitting device, 102: Fluorescent light emitting region, 140: Light source optical system, 142, 342, 442: Optical path switching device, D1: First direction, D2: Second direction

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; an optical path switching device that is provided on an optical path of the first wavelength band light emitted from the first light source and that switches the incident first wavelength band light between at least an optical path in a first direction and an optical path in a second direction; a fluorescence light-emitting device provided on an optical path in the second direction and having a fluorescence light-emitting region that emits fluorescence containing light in a third wavelength band using light in the first wavelength band as excitation light; a light source optical system that guides the first wavelength band light switched to the optical path in the first direction by the optical path switching device, the second wavelength band light emitted from the second light source, and the fluorescence emitted in the fluorescence emission region to a combined optical path, Light source device.

2. the light source optical system includes: a first mirror member that is provided on an optical path in the first direction and on an optical path of the second wavelength band light emitted from the second light source, and that reflects the first wavelength band light and transmits the second wavelength band light; and a second mirror member that is provided on an optical path in the second direction and on an optical path of the second wavelength band light emitted from the second light source, and that transmits the first wavelength band light and the second wavelength band light and reflects the third wavelength band light. The light source device according to claim 1 .

3. the optical path switching device switches the optical path in a direction that reflects the incident first wavelength band light, the first light source is provided on the reflection side of the optical path switching device; The light source device according to claim 1 .

4. the fluorescence emitting device has a filter region superimposed on the fluorescence emitting region, and emits the fluorescence as the third wavelength band light through the filter region; The light source device according to claim 1 .

5. The optical path switching device is an optical element made of KTN crystal whose refractive index can be freely changed by applying a voltage. The light source device according to claim 1 .

6. the optical path switching device is a rotary wheel device having an optical wheel provided with a plurality of diffraction grating regions each having a different emission angle of emitted light; The light source device according to claim 1 .

7. the optical path switching device switches the optical path in a direction to reflect the incident first wavelength band light, The light source device according to claim 1 .

8. The light source device according to any one of claims 1 to 7, a display element that generates image light; a projection optical system that projects the image light emitted from the display element onto a projection target; a control unit that controls the light source device and the display element, Projection device.

Images