Diffusion member, light source device, and projection device

Abstract

To provide a diffusion member, a light source device, and a projection device including the light source device that can reduce color unevenness.SOLUTION: A diffusion member 200 includes: an incident side total reflection surface 202 that is provided on an incident side of light, has an incident side opening 202a on which the light is incident, and totally reflects the light; a semi-transparent mirror surface 208 that is provided on an emission side of the light, and reflects part of the incident light; and a transmission and diffusion surface 206 that is provided between the incident side total reflection surface 202 and the semi-transparent mirror surface 206, and transmits and diffuses the incident light.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Nowadays, projection devices are used that project image data stored on a personal computer screen, video screen, memory card, 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 to display a color image on a screen. Among these types of projection devices, those equipped with an optical path switching unit that switches the incoming light to different optical paths in a time-division manner are known.

[0003] For example, Patent Document 1 discloses a light source device including an excitation light irradiating device that emits blue wavelength band light, a fluorescent light emitting device that excites green wavelength band light, a red light source device that emits red wavelength band light, an optical path switching means that switches the light emitted from the excitation light irradiating device to two directions in a time-division manner, two dichroic mirrors, and a reflecting mirror. In this light source device, the blue wavelength band light emitted from the excitation light irradiating device is incident on the optical path switching means, and is switched by the optical path switching means to a first light irradiated in a first direction and a second light irradiated in a second direction. The blue wavelength band light irradiated in the first direction is reflected by one dichroic mirror and emitted from the light source device. The blue wavelength band light irradiated in the second direction passes through the other dichroic mirror and enters the fluorescent light emitting device, and the green wavelength band light excited in the fluorescent light emitting device by the blue wavelength band light is reflected by the other dichroic mirror and emitted from the light source device. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-141581 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the light source device of Patent Document 1, the blue wavelength band light emitted from the excitation light irradiation device and then from the light source device is in the form of a thin beam, whereas the green wavelength band light excited by the fluorescent light-emitting device is diffuse light, and since there is a difference in the size of the light beams of the two, there is a risk of color unevenness occurring on the projection target when the light emitted from the light source device is projected onto the projection target.

[0006] In view of the above, an object of the present invention is to provide a diffusion member and a light source device capable of reducing color unevenness, and a projection device including the light source device. [Means for solving the problem]

[0007] The diffusing member of the present invention includes a first total reflection surface provided on the light incident side, having an incident portion into which the light is incident and totally reflecting the light, a partial reflection surface provided on the light exit side, reflecting a portion of the incident light, and a transmission diffusion surface provided between the first total reflection surface and the partial reflection surface, which transmits and diffuses the incident light.

[0008] The light source device of the present invention includes the above-mentioned diffusing member, a light source that emits a first wavelength band light, and a fluorescence emitting device that emits fluorescence including second wavelength band light and / or third wavelength band light when the first wavelength band light is incident on the diffusing member, and when the first wavelength band light is incident on the diffusing member, the diffusing member diffuses and emits the first wavelength band light.

[0009] 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. Effect of the Invention

[0010] According to the present invention, it is possible to provide a diffusing member capable of reducing color unevenness, a light source device, and a projection device including this light source device. [Brief description of the drawings]

[0011] [Figure 1] 2 is a diagram showing functional circuit blocks of the projection device according to the first embodiment. FIG. [Diagram 2] 1 is a schematic plan view showing the internal structure of a projection device according to a first embodiment. [Diagram 3] 3 is a schematic side view of a diffusion member of the projection device according to the first embodiment. FIG. [Figure 4] FIG. 1A is a front view of an incident-side total reflection surface of a diffusing member of a projection device according to a first embodiment, and FIG. 1B is a front view of an exit-side total reflection surface. [Diagram 5] 4 is a plan view showing a state in which light in a blue wavelength band passes through a diffusing member and reaches a light-guiding optical system in the first embodiment. FIG. [Figure 6] 4 is a plan view schematic diagram showing a state in which blue wavelength band light is irradiated onto the fluorescent wheel device and fluorescence emitted from the fluorescent wheel device reaches a light-guiding optical system in the first embodiment. FIG. [Figure 7] 13 is a schematic side view of a diffusion member of a projection device according to a second embodiment. FIG. [Figure 8] 13 is a schematic side view of a diffusion member of a projection device according to a third embodiment. FIG. [Figure 9] 13 is a schematic side view of a diffusion member of a projection device according to a fourth embodiment. FIG. [Figure 10] 13 is a front view showing an incident-side reflective surface of a diffusing member of a projection device according to a fourth embodiment. FIG. [Figure 11] 13 is a front view showing an exit side reflecting surface of a diffusing member of a projection device according to a fourth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (First embodiment) A first embodiment of the present invention will be described below with reference to Fig. 1 to Fig. 6. Fig. 1 is a functional circuit block diagram 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, a display drive unit 26, etc. 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.

[0013] Furthermore, 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 .

[0014] The display drive unit 26 drives a display element 50 such as a DMD, 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 reflected light from the display element 50 by irradiating the light beam emitted from the light source device 60 to the display element 50 via a light guide optical system 170 (see FIG. 2), 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). 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.

[0015] Moreover, 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 the image data recorded on the memory card 32 in the playback mode, expands each piece of 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.

[0016] The control unit 38 is responsible for controlling the operation of each circuit in 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.

[0017] The key / indicator section 37 is composed of a main key and an indicator provided on the housing. An operation signal of the key / indicator section 37 is directly sent to the control section 38. In addition, a key operation signal from the remote controller is received by the Ir receiving section 35, demodulated into a code signal by the Ir processing section 36, and output to the control section 38.

[0018] 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 emit amplified sound.

[0019] The control unit 38 controls the light source control circuit 41. The light source control circuit 41 individually controls the operations of the excitation light irradiating device 70, the fluorescent wheel device 100, and the switching wheel device 150 (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.

[0020] 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 52 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 52 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 based on the results of temperature detection by the temperature sensors.

[0021] Next, the internal structure of the projection device 10 will be described with reference to Fig. 2. 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 an upper panel and 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 port 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 relative to the projection direction from the projection port 12a, and the front and rear refer to the front and rear directions relative to the projection target side of the projection device 10 and the traveling direction of the light beam bundle.

[0022] The projection device 10 includes a control circuit board 242 near the left panel 15. The control circuit board 242 includes a power circuit block, a light source control block, etc. The projection device 10 also includes a light source device 60 disposed approximately in the center of the projection device 10. Between the light source device 60 and the right panel 14, a power connector 52, a light source side heat sink 54, a cooling fan 56, etc. are disposed.

[0023] The light source device 60 includes an excitation light irradiating device (light source) 70 which is a light source of blue wavelength band light (first wavelength band light) and also a light source of excitation light, and a red / green light source device 80 which is a light source of red wavelength band light (second wavelength band light) and green wavelength band light (third wavelength band light). The red / green light source device 80 is composed of the excitation light irradiating device 70 and a fluorescent wheel device (fluorescent light emitting device) 100. The light source device 60 also includes a light source optical system 140 which guides the blue wavelength band light, the red wavelength band light, and the green wavelength band light.

[0024] The excitation light irradiation device 70 is disposed in a portion near the rear panel 13 at approximately the center of the housing of the projection device 10. The excitation light irradiation device 70 has a semiconductor package 71 and a collimator lens 72. The semiconductor package 71 is held in the housing of the projection device 10 by a holding member (not shown). The excitation light irradiation device 70 is connected to the light source side heat sink 54 via a heat pipe (not shown) so as to be cooled.

[0025] In the semiconductor package 71, a plurality of blue laser diode chips, which are semiconductor light emitting elements that emit blue wavelength band light as excitation light, are mounted closely in a line or matrix. A collimator lens 72 is disposed corresponding to each of the plurality of blue laser diode chips, and collimates the emitted light so as to increase the directivity of the light emitted from each blue laser diode. The blue wavelength band light emitted from each blue laser diode becomes a light beam limited to a predetermined range by the collimator lens 72. The semiconductor package 71 is a so-called MCP (Multi Chip Package), which allows the light source device 60 to be made compact.

[0026] The light source optical system 140 has a first condenser lens 141, a second condenser lens 142, a reflecting mirror 144, a fluorescent wheel device (fluorescence light emitting device) 100, a fluorescent side lens group 104, a switching wheel device (switching member) 150, a diffusing member 200, and a dichroic mirror 250. The light source optical system 140 condenses light beams emitted from the excitation light irradiation device 70 and the red / green light source device 80 onto an incident surface of a microlens array 172, which will be described later. In addition, the light source device 60 is provided with a light guiding optical system 170 that guides light from the light source optical system 140 to a projection optical system 220, which will be described later.

[0027] The first condenser lens 141 and the second condenser lens 142 are provided on the light emission side of the excitation light irradiation device 70. The first condenser lens 141 is a convex lens, and condenses the blue wavelength band light emitted from each blue laser diode of the excitation light irradiation device 70 and guides it to the second condenser lens 142 side. The second condenser lens 142 is a concave lens, and collimates the blue wavelength band light condensed by the first condenser lens 141 and guides it to the switching wheel device 150 side. The reflection mirror 144 is provided on the light emission side of the diffusion member 200 described later, and reflects the blue wavelength band light (excitation light) transmitted through the diffusion member 200 and emitted from the diffusion member 200 to the dichroic mirror 250 side.

[0028] Fluorescent wheel device 100 includes fluorescent wheel 101 provided in a disk shape or annular shape, fluorescent motor 102 that drives and rotates fluorescent wheel 101, and a drive control device (not shown) that drives and controls fluorescent motor 102. The drive control device is controlled by light source control circuit 41 described above. Fluorescent wheel device 100 is disposed in a position in which the surface side of fluorescent wheel 101 (the side opposite to the side on which fluorescent motor 102 is disposed) on which blue wavelength band light is incident faces dichroic mirror 250, which will be described later. Furthermore, fluorescent wheel device 100 is disposed in such a position that blue wavelength band light reflected in a second direction D2 (see FIG. 6) by switching wheel device 150, which will be described later, passes through dichroic mirror 250 and enters fluorescent wheel 101.

[0029] The fluorescent wheel 101 is made of a metal material such as copper or aluminum, and its surface is mirror-finished by silver deposition or the like. On the surface of the fluorescent wheel 101, a red light-emitting region that receives the blue wavelength band light emitted from the excitation light emitting device 70 as excitation light and emits fluorescence containing red wavelength band light, and a green light-emitting region that receives the blue wavelength band light emitted from the excitation light emitting device 70 as excitation light and emits fluorescence containing green wavelength band light are arranged within an angular range of approximately 120 degrees with respect to the center position of the fluorescent wheel 101. The proportions of the red light-emitting region and the green light-emitting region that each occupy are not limited to the angular range of approximately 120 degrees, and may be changed as appropriate.

[0030] The switching wheel device 150 is a member that switches the optical path of the blue wavelength band light emitted from the excitation light irradiating device 70 and reflected by the switching wheel device 150 in a time-division manner, and includes a switching wheel 151 provided in a disk shape or annular shape, a switching motor 152 that drives and rotates the switching wheel 151, and a drive control device (not shown) that drives and controls the switching motor 152. The drive control device is controlled by the above-mentioned light source control circuit 41. The switching wheel device 150 is disposed in a position in which the surface side of the switching wheel 151 onto which the blue wavelength band light is incident (the side opposite to the side on which the switching motor 152 is disposed) faces the excitation light irradiating device 70.

[0031] On the surface of the switching wheel 151, two regions are arranged with different inclination angles with respect to the optical axis of the blue wavelength band light emitted from the excitation light irradiating device 70. One of the regions is a first direction reflection region (not shown) that reflects the blue wavelength band light emitted from the excitation light irradiating device 70 in a first direction D1 (see FIG. 5) toward the diffusion member 200 described later. The other region is a second direction reflection region (not shown) that reflects the blue wavelength band light emitted from the excitation light irradiating device 70 in a second direction D2 (see FIG. 6) toward the fluorescent wheel device 100. That is, the switching wheel device 150 switches the blue wavelength band light between light (first light) toward the first direction D1 and light (second light) toward the second direction D2 in a time-division manner and emits it. The first direction reflection region and the second direction reflection region are arranged, for example, within an angle range of approximately 120 degrees with respect to the center position of the switching wheel 151.

[0032] Instead of the first direction reflection region and the second direction reflection region described above, two regions provided with reflective diffraction gratings with different optical paths of reflected light may be arranged on the surface of the switching wheel 151. In this case, the diffraction grating provided in one region may reflect the blue wavelength band light emitted from the excitation light irradiating device 70 in a first direction D1 (see FIG. 5) toward the diffusion member 200 described later. The diffraction grating provided in the other region may reflect the blue wavelength band light emitted from the excitation light irradiating device 70 in a second direction D2 (see FIG. 6) toward the fluorescent wheel device 100.

[0033] The diffusing member 200 is disposed so that the blue wavelength band light reflected in the first direction D1 by the switching wheel device 150 is incident thereon, and the diffusing member 200 thickens the luminous flux of the incident blue wavelength band light (in other words, increases the degree of diffusion of the light) and emits it by diffusing and reflecting it. As shown in Fig. 3, the diffusing member 200 is provided by subjecting one glass base material G having a substantially rectangular thick plate shape to various processes. One plate surface side of the diffusing member 200 (the left plate surface side shown in Fig. 3) is the incident side of the blue wavelength band light, and the other plate surface side (the right plate surface side shown in Fig. 3) is the exit side of the blue wavelength band light.

[0034] In the diffusing member 200, the plate surface on the entrance side of the blue wavelength band is an entrance side total reflection surface (first total reflection surface) 202 that has been processed to totally reflect the incident blue wavelength band light, and the plate surface on the exit side of the blue wavelength band is an exit side total reflection surface (second total reflection surface) 204 that has been processed to totally reflect the incident blue wavelength band light. Between the entrance side total reflection surface 202 and the exit side total reflection surface 204, a transmission diffusion surface 206 that has been processed to diffuse the blue wavelength band light while transmitting it is provided. The transmission diffusion surface 206 is provided at a position closer to the entrance side of the blue wavelength band than the exit side of the blue wavelength band in the diffusing member 200, specifically, directly below the entrance side total reflection surface 202 (the glass base material G side of the entrance side total reflection surface 202).

[0035] A half mirror surface (partially reflective surface) 208 that is processed to reflect a predetermined proportion of the incident blue wavelength band light is provided directly below exit-side total reflection surface 204 (on the glass substrate G side of exit-side total reflection surface 204). Half mirror surface 208 may be, for example, a dichroic mirror surface, and may be configured to reflect blue wavelength band light incident at an angle equal to or greater than a predetermined angle and transmit blue wavelength band light incident at an angle smaller than the predetermined angle.

[0036] As shown in FIG. 4(a), the central portion of the incident-side total reflection surface 202 is provided with an incident-side opening (incident portion) 202a that opens in a substantially circular shape. Of the incident-side total reflection surface 202, the incident-side opening 202a is, for example, AR-coated, and the other portions are totally reflective to totally reflect light. The incident-side opening 202a is provided so as to be located on the optical axis of the blue wavelength band that is incident on the diffusing member 200 along the first direction D1 from the switching wheel device 150, and has a width dimension W1 that is just large enough to accommodate the incident light beam of the blue wavelength band. In this specification, the size of the light beam means the size of the cross-sectional area of ​​the light on a certain surface perpendicular to the traveling direction of the light (thickness of the light beam). In other words, the size of the light beam can also be said to be the degree of diffusion of the light.

[0037] As shown in FIG. 4(b), the exit-side total reflection surface 204 has an exit-side opening (exit portion) 204a in a substantially circular shape at its center. The exit-side opening 204a of the exit-side total reflection surface 204 is, for example, AR-coated, and the other portions are totally reflective to totally reflect light. The exit-side opening 204a has a width dimension W2 larger than the width dimension W1 of the entrance-side opening 202a so that blue wavelength band light that is incident from the entrance-side opening 202a and diffused by the diffusing member 200 is emitted (in other words, the area of ​​the portion of the exit-side opening 204a from which light is emitted is larger than the area of ​​the portion of the entrance-side opening 202a from which light is incident). Specifically, the width dimension W2 is about three times the width dimension W1. The width dimension W2 of the exit side opening 204a can be appropriately adjusted according to the position and size of the microlens array 172 so that all of the blue wavelength band light emitted from the diffusion member 200 is incident on the microlens array 172 of the light-guiding optical system 170 described later.

[0038] Here, referring to Fig. 3, a description will be given of how the blue wavelength band light incident on the diffusing member 200 from the entrance side opening 202a along the first direction D1 travels. The blue wavelength band light that reaches the diffusing member 200 along the first direction D1 is incident approximately perpendicularly to the opening surface of the entrance side opening 202a. The blue wavelength band light that is incident from the entrance side opening 202a is diffused by transmitting through the transmission diffusion surface 206. A part of the blue wavelength band light that has transmitted through the transmission diffusion surface 206 travels directly through the glass base material G toward the exit side opening 204a in a traveling direction approximately perpendicular to the opening surface of the exit side opening 204a, and transmits through the half mirror surface 208 without being reflected by the half mirror surface 208 to be emitted from the exit side opening 204a (see light L1 indicated by a dashed line in Fig. 3). In addition, a portion of the blue wavelength band light diffused by the transmitting diffusion surface 206 travels through the glass substrate G toward the exit side opening 204a while being diffused, passes through the half mirror surface 208, and is emitted from the exit side opening 204a (see light L2 indicated by the dashed line in Figure 3).

[0039] On the other hand, another part of the blue wavelength band light diffused by the transmitting and diffusing surface 206 is reflected by the half mirror surface 208 toward the incident side total reflection surface 202 at various angles and is totally reflected by the incident side total reflection surface 202. A part of the light totally reflected by the incident side total reflection surface 202 passes through the half mirror surface 208 and is emitted from the exit side opening 204a (see light L3 and L4 shown by dashed lines in FIG. 3), or is reflected again by the half mirror surface 208 toward the incident side total reflection surface 202. Another part of the light totally reflected by the incident side total reflection surface 202 reaches the exit side total reflection surface 204 and is totally reflected again by the exit side total reflection surface 204 toward the incident side total reflection surface 202. Still another part of the light totally reflected by the incident side total reflection surface 202 is emitted to the outside of the diffusion member 200 from the side surface of the diffusion member 200. Furthermore, a portion of the blue wavelength band light reflected by the half mirror surface 208 and the exit-side total reflection surface 204 toward the entrance-side total reflection surface 202 is emitted to the outside of the diffusion member 200 from the entrance-side opening 202a or the side surface of the diffusion member 200. In this way, the diffusion member 200 repeats diffusion and reflection to thicken the luminous flux of the incident blue wavelength band light (in other words, to increase the degree of diffusion of light), and emits the blue wavelength band light from the exit-side opening 204a.

[0040] As described above, a part of the blue wavelength band light incident from the entrance opening 202a is emitted to the outside of the diffusion member 200 without being emitted from the exit opening 204a, but it is extremely small compared to the blue wavelength band light emitted from the exit opening 204a, and most of the blue wavelength band light incident from the entrance opening 202a is emitted from the exit opening 204a in a diffused state. That is, the blue wavelength band light incident from the entrance opening 202a is emitted from the exit opening 204a with a larger (thicker) light flux than when it was incident. The blue wavelength band light emitted from the exit opening 204a is diffused by the diffusion member 200 until the light flux becomes approximately equal to the light fluxes of the red wavelength band light and the green wavelength band light emitted by the fluorescent wheel device 100.

[0041] Incidentally, diffusing member 200 may be configured without exit-side total reflection surface 204 and exit-side opening 204a. Even in such a configuration, blue wavelength band light incident on diffusing member 200 is diffused by transmitting through transmitting diffusion surface 206, and blue wavelength band light reflected by half mirror surface 208 toward entrance-side total reflection surface 202 is diffused by being reflected by entrance-side total reflection surface 202 again toward the exit side.

[0042] The dichroic mirror 250 is disposed between the switching wheel device 150 and the fluorescent wheel device 100, and is provided so that the blue wavelength band light reflected in the second direction D2 by the switching wheel device 150, the blue wavelength band light transmitted through the diffusing member 200 and reflected by the reflecting mirror 144, and the red wavelength band light and green wavelength band light emitted by the fluorescent wheel device 100 are incident on the dichroic mirror 250. The dichroic mirror 250 transmits the blue wavelength band light and reflects the red wavelength band light and green wavelength band light. For this reason, the dichroic mirror 250 transmits light with a wavelength band of 440 to 465 nm, for example, and reflects light with a wavelength band of 465 to 650 nm.

[0043] Fluorescence side lens group 104 collects the blue wavelength band light (excitation light) transmitted through dichroic mirror 250 into the fluorescence emission region toward fluorescent wheel device 100, and guides the fluorescence emitted from the fluorescence emission region toward dichroic mirror 250. Fluorescence side lens group 104 is composed of two collecting lenses of different sizes.

[0044] Returning to FIG. 2, the light guide optical system 170 has a microlens array 172, a concave lens 174, a third condenser lens 175, an irradiation mirror 185, and a condenser lens 195. The microlens array 172 homogenizes the light of each wavelength band (blue wavelength band light, red wavelength band light, green wavelength band light) incident on the incident surface facing the dichroic mirror 250 side, and irradiates the image forming surface of the display element 50. The concave lens 174 is disposed between the microlens array 172 and the third condenser lens 175. The condenser lens 195 emits the image light emitted from the display element 50 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.

[0045] Here, dichroic mirror 250 is disposed so that the blue wavelength band light reflected by reflecting mirror 144 passes through dichroic mirror 250 and is guided to the microlens array 172 side, and the blue wavelength band light transmitted through dichroic mirror 250 in second direction D2 is guided to the fluorescent wheel device 100 side. Furthermore, dichroic mirror 250 is disposed so that the optical axis of the blue wavelength band light reflected by reflecting mirror 144 and transmitted through dichroic mirror 250 overlaps with the optical axes of the red wavelength band light and green wavelength band light emitted by fluorescent wheel device 100 and reflected by dichroic mirror 250.

[0046] The projection optical system 220 has a condenser lens 195, a movable lens group 235, and a fixed lens group 225. The fixed lens group 225, which is arranged on the optical axis of the condenser lens 195 on the front panel 12 side, is built into a fixed lens barrel, and can be moved manually or automatically to enable zoom adjustment and focus adjustment. A projection-side heat sink 190 is provided on the rear panel 13 side of the display element 50. The display element 50 is cooled by this projection-side heat sink 190. The projection device 10 according to this embodiment is configured as described above.

[0047] Next, the incidence and emission of light in each member constituting the light source device 60 will be described. First, the case where blue wavelength band light, which is excitation light, is emitted will be described with reference to FIG. 5. As shown in FIG. 5, when blue wavelength band light is emitted from the light source device 60, the irradiation position on the switching wheel 151 where the blue wavelength band light (light L5 shown by a solid line in FIG. 5) is incident is defined as a first irradiation spot SP1. In this case, a first directional reflection area is located on the first irradiation spot SP1. Note that in FIG. 5 and FIG. 6, only the optical axis of the blue wavelength band light L5 is illustrated.

[0048] The blue wavelength band light (excitation light) emitted from each blue laser diode of the excitation light irradiation device 70 is collected and collimated by the first condenser lens 141 and the second condenser lens 142, and enters the first irradiation spot SP1 of the switching wheel 151. The blue wavelength band light entering the switching wheel 151 is reflected in the first direction D1 by the first direction reflection area located in the first irradiation spot SP1, and enters the diffusing member 200.

[0049] The blue wavelength band light incident on the diffusing member 200 passes through the diffusing member 200 and is emitted to the reflecting mirror 144 in a more diffused state than when it was incident on the diffusing member 200. The blue wavelength band light emitted to the reflecting mirror 144 is reflected by the reflecting mirror 144 to the dichroic mirror 250, passes through the dichroic mirror 250, and is emitted toward the microlens array 172. In this way, the excitation light that is made into the blue wavelength band light can be used as light source light in a state where it is diffused by the diffusing member 200.

[0050] Next, a case where red wavelength band light and green wavelength band light are emitted will be described with reference to Fig. 6. As shown in Fig. 6, when red wavelength band light and green wavelength band light are emitted from the light source device 60, the position on the switching wheel 151 where the blue wavelength band light (light L5 shown by solid lines in Fig. 5) is incident is defined as a second irradiation spot SP2. In this case, the second directional reflection area is located on the second irradiation spot SP2. In addition, in this case, the position on the fluorescent wheel 101 where the blue wavelength band light is incident is defined as a third irradiation spot SP3. In Fig. 6, a red light emitting area or a green light emitting area is located on the third irradiation spot SP3.

[0051] The blue wavelength band light (excitation light) emitted from each blue laser diode of the excitation light irradiation device 70 is collected and collimated by the first condenser lens 141 and the second condenser lens 142, and enters the second irradiation spot SP2 of the switching wheel 151. The blue wavelength band light entering the switching wheel 151 is reflected in the second direction D2 by the second direction reflection area located in the second irradiation spot SP2, passes through the dichroic mirror 250, and is emitted toward the fluorescent wheel device 100. The blue wavelength band light emitted toward the fluorescent wheel device 100 is collected by the fluorescent side lens group 104 and enters the fluorescent wheel 101. When the red light emitting area is located in the third irradiation spot SP3, the blue wavelength band light entering the fluorescent wheel 101 irradiates the red phosphor layer, and when the green light emitting area is located in the third irradiation spot SP3, the blue wavelength band light entering the fluorescent wheel 101 irradiates the green phosphor layer.

[0052] When blue wavelength band light, which is excitation light, is irradiated onto the red light-emitting region of the fluorescent wheel 101, fluorescence containing red wavelength band light (light L6 shown by dashed lines in FIG. 6) is emitted. When blue wavelength band light is irradiated onto the green light-emitting region of the fluorescent wheel 101, fluorescence containing green wavelength band light (light L6 shown by dashed lines in FIG. 6) is emitted. Here, the light emitted in the red light-emitting region and the green light-emitting region includes fluorescence containing red wavelength band light or fluorescence containing green wavelength band light, and excitation light that is not irradiated onto the red light-emitting region or the green light-emitting region and is reflected by the mirror-finished surface of the fluorescent wheel 101 (hereinafter referred to as "residual excitation light").

[0053] The red wavelength band light emitted in the red light emission region of the fluorescent wheel 101 and the green wavelength band light emitted in the green light emission region are diffused at a certain angle and are emitted to the dichroic mirror 250 side via the fluorescent side lens group 104 (in FIG. 6, only the optical axes of the red wavelength band light L6 and the green wavelength band light L6 are illustrated). The red wavelength band light and the green wavelength band light emitted to the dichroic mirror 250 side are reflected by the dichroic mirror 250 to the microlens array 172 side and enter the microlens array 172. In this way, the red wavelength band light and the green wavelength band light can be used as light source light. Note that the residual excitation light reflected by the fluorescent wheel 101 is emitted to the dichroic mirror 250 side via the fluorescent side lens group 104. The residual excitation light that enters the dichroic mirror 250 is not reflected and passes through the dichroic mirror 250 to be removed.

[0054] As described above, when red wavelength band light and green wavelength band light are emitted from the light source device 60, the red wavelength band light and green wavelength band light are diffused at a certain angle from the fluorescent wheel 101 and enter the microlens array 172 of the light guiding optical system 170. On the other hand, when blue wavelength band light is emitted from the light source device 60, the blue wavelength band light is diffused to a size approximately equal to that of the red wavelength band light and green wavelength band light by transmitting through the diffusion member 200 and enters the microlens array 172 of the light guiding optical system 170. For this reason, when the blue wavelength band light, red wavelength band light, and green wavelength band light emitted from the light source device 60 are projected onto the projection target, the occurrence of color unevenness due to the difference in the size of the luminous flux of each of these wavelength band lights is suppressed.

[0055] In this embodiment, the configuration in which the diffusion member 200 made of the glass base material G is subjected to various processes to provide the diffusion member 200 with the incident side total reflection surface 202, the exit side total reflection surface 204, the transmission diffusion surface 206, and the half mirror surface 208 is illustrated, but for example, the incident side total reflection surface and the exit side total reflection surface may be provided by attaching a sheet metal member having an opening to the glass base material G, or the half mirror surface may be provided by attaching a dichroic film to the glass base material G. By providing the incident side total reflection surface 202 and the like by performing various processes on the glass base material G as in this embodiment, it is possible to prevent light reflection at the attachment interface compared to a configuration in which various members are attached to the glass base material G, and therefore the blue wavelength band light can be suitably diffused by the diffusion member 200.

[0056] Furthermore, in the present embodiment, a configuration in which the glass base G is exposed on the side surface of the diffusing member 200 has been exemplified (see FIG. 3), but a configuration in which a total reflection surface that totally reflects blue wavelength band light is provided on the side surface of the diffusing member 200 may also be used. In this case, the blue wavelength band light that has been guided inside the diffusing member 200 and headed toward the side surface of the diffusing member 200 can be reflected back into the diffusing member 200 by this total reflection surface, so that the blue wavelength band light can be diffused more suitably by the diffusing member 200.

[0057] In the present embodiment, a configuration in which a red light emitting region and a green light emitting region are provided in fluorescent wheel device 100 has been exemplified, but a configuration in which a yellow light emitting body layer that emits fluorescence including yellow wavelength band light is provided in fluorescent wheel device 100 and a color filter having a red transmission region and a green transmission region is provided between dichroic mirror 250 and fluorescent wheel device 100 may also be used. In this case, the fluorescent light emitting device includes fluorescent wheel device 100 and the above-mentioned color filter, a filter coating is applied to the surface of the yellow light emitting body layer or a filter sheet is overlaid on it, and fluorescent wheel device 100 and the above-mentioned color filter rotate together. Then, blue wavelength band light, which is excitation light, is irradiated onto the yellow light emitting body layer to emit yellow wavelength band light, and the emitted yellow wavelength band light is incident on the color filter. When the red transmission region is located at the third irradiation spot SP3, the yellow wavelength band light incident on the color filter becomes red wavelength band light as it passes through the red transmission region and other green wavelength band light is reflected and removed, and when the green transmission region is located at the third irradiation spot SP3, the yellow wavelength band light becomes green wavelength band light as it passes through the green transmission region and other red wavelength band light is reflected and removed. In this case, a fixed phosphor that emits yellow fluorescence may be used instead of the fluorescent wheel device 100.

[0058] As described above, the light source device 60 according to this embodiment includes the excitation light irradiation device 70 that emits blue wavelength band light, the switching wheel device 150 that switches the blue wavelength band light between light traveling in a first direction D1 and light traveling in a second direction D2 in a time-division manner and emits the light, the diffusion member 200 that diffuses and emits the blue wavelength band light when light traveling in the first direction D1 is incident, and the fluorescent light source 201 that emits fluorescence including red wavelength band light or green wavelength band light when light traveling in the second direction D2 is incident. The optical wheel device 100 includes a diffusion member 200 which is provided on the incident side of light proceeding in a first direction D1, has an incident side opening 202a which opens to allow the light proceeding in the first direction D1 to enter, and includes an incident side total reflection surface 202 which totally reflects the light, a half mirror surface 208 which is provided on the exit side of the light proceeding in the first direction D1 and reflects the incident light at a predetermined rate, and a transmission diffusion surface 206 which is provided between the incident side total reflection surface 202 and the half mirror surface 208 and which diffuses the incident light while transmitting it.

[0059] The light source device 60 of the present embodiment is configured as described above, and therefore the optical path of the blue wavelength band light emitted from the excitation light irradiation device 70 is switched to either the first direction D1 or the second direction D2 by the switching wheel device 150. The blue wavelength band light traveling in the first direction D1 is diffused by passing through the diffusion member 200, so that the degree of diffusion (magnitude of light flux) of the blue wavelength band light emitted from the diffusion member 200 can be made substantially equal to the degree of diffusion of the red wavelength band light and the green wavelength band light emitted by the fluorescent wheel device 100 by the blue wavelength band light traveling in the second direction D2. Therefore, the difference between the magnitude of the light flux of the blue wavelength band light emitted from the light source device 60 and the magnitude of the light flux of the red wavelength band light and the green wavelength band light can be reduced, and color unevenness occurring on the projection target when each light emitted from the light source device 60 is projected onto the projection target can be reduced.

[0060] Furthermore, in the light source device 60 of the present embodiment, by providing one diffusion member 200, it is not necessary to provide multiple diffusion plates on the optical path of the blue wavelength band light as in the past, and the degree of diffusion of the blue wavelength band light can be made substantially equal to the degree of diffusion of the red wavelength band light and the green wavelength band light, so that the light source device 60 can be made smaller and less expensive than the conventional configuration requiring multiple diffusion plates. In addition, when the blue wavelength band light is diffused by multiple diffusion plates, there is a risk that the parallelism of the blue wavelength band light is lost and a difference occurs between the parallelism of the red wavelength band light and the parallelism of the green wavelength band light. However, by using the diffusion member 200 of the present embodiment instead of multiple diffusion plates, it is possible to suppress the parallelism of the blue wavelength band light from being lost.

[0061] Furthermore, in light source device 60, diffusion member 200 is provided on the emission side of light proceeding in first direction D1 relative to half mirror surface 208, has emission-side opening 204a that opens larger than incident-side opening 202a so that diffused light proceeding in first direction D1 is emitted, and includes emission-side total reflection surface 204 that totally reflects light. This allows the size of the luminous flux of blue wavelength band light emitted from diffusion member 200 to be set to a size corresponding to width dimension W2 of emission-side opening 204a, so that the size of the luminous flux of blue wavelength band light diffused and emitted by diffusion member 200 can be adjusted to a desired size.

[0062] Furthermore, in light source device 60, transmissive diffusing surface 206 is provided at a position closer to the incident side of light traveling in the first direction D1 than to the emission side of light (blue wavelength band light) traveling in the first direction D1 in diffusing member 200. With this configuration, light traveling in the first direction D1 that has entered diffusing member 200 is diffused by transmissive diffusing surface 206 at an earlier stage than in the case where transmissive diffusing surface 206 is provided on the emission side of light traveling in the first direction D1, so that the diffusing effect of diffusing member 200 on blue wavelength band light can be improved.

[0063] Moreover, the projection device 10 according to the present embodiment includes the above-mentioned light source device 60, the 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. Furthermore, the projection device 10 includes a light guide optical system 170 that guides the light emitted from the light source device 60 to the display element 50, and the diffusion member 200 diffuses the blue wavelength band light emitted toward the light guide optical system 170 so that the light beam has a size substantially equal to the light beam of the red wavelength band light or the green wavelength band light emitted from the fluorescent wheel device 100 toward the light guide optical system 170. This makes it possible to realize the projection device 10 that can reduce the occurrence of color unevenness on the projection target due to the emitted light of each wavelength band.

[0064] Second embodiment Next, a second embodiment of the present invention will be described with reference to Fig. 7. As shown in Fig. 7, the projection device according to the second embodiment differs from the projection device 10 of the first embodiment in the configuration of the diffusion member 400. The configuration of the projection device other than the diffusion member 400 is the same as that of the first embodiment, so the description thereof will be omitted or simplified. Furthermore, in the diffusion member 400 according to the second embodiment, members having the same configuration as the diffusion member 200 according to the first embodiment are given the same reference numerals.

[0065] As shown in FIG. 7, in the diffusion member 400 according to this embodiment, the transmissive diffusion surface 206 is provided on the exit side of the blue wavelength band, specifically, directly below the half mirror surface 208 (the opposite side of the exit side total reflection surface 204 of the half mirror surface 208). In this embodiment, the blue wavelength band light incident on the diffusion member 400 from the entrance side opening 202a along the first direction D1 is guided in the same manner as the diffusion member 200 according to the first embodiment. That is, the blue wavelength band light incident from the entrance side opening 202a proceeds in the glass base material G toward the exit side opening 204a and is diffused by transmitting through the transmissive diffusion surface 206. A part of the blue wavelength band light transmitted through the transmissive diffusion surface 206 proceeds directly to the exit side opening 204a in a traveling direction approximately perpendicular to the opening surface of the exit side opening 204a, and is transmitted through the half mirror surface without being reflected by the half mirror surface 208 to be emitted from the exit side opening 204a (see light L7 indicated by a dashed line in FIG. 7).

[0066] A part of the blue wavelength band light diffused by the transmitting and diffusing surface 206 proceeds toward the exit side opening 204a while being diffused, passes through the half mirror surface 208, and is emitted from the exit side opening 204a (see light L8 shown by a dashed line in FIG. 7). Meanwhile, another part of the blue wavelength band light diffused by the transmitting and diffusing surface 206 is reflected by the half mirror surface 208 toward the entrance side total reflection surface 202 at various angles, and is totally reflected by the entrance side total reflection surface 202 toward the exit side opening 204a. At least a part of the light totally reflected by the entrance side total reflection surface 202 passes through the half mirror surface 208 and is emitted from the exit side opening 204a (see light L9 shown by a dashed line in FIG. 7). The light is reflected again by the half mirror surface 208 toward the entrance side total reflection surface 202, or reaches the exit side total reflection surface 204 and is totally reflected again by the exit side total reflection surface 204 toward the entrance side total reflection surface 202. In the present embodiment, similarly to the first embodiment, the blue wavelength band light incident on the diffusing member 400 is repeatedly reflected and diffused, and is then emitted from the exit side opening 204a. A part of the blue wavelength band light is emitted to the outside of the diffusing member 400 from the entrance side opening 202a and the side surface of the diffusing member 400.

[0067] As described above, in the diffusion member 400 according to this embodiment, the blue wavelength band light traveling in the first direction D1 is diffused by transmitting through the diffusion member 400, so that the degree of diffusion (magnitude of light flux) of the blue wavelength band light emitted from the diffusion member 400 can be made substantially equal to the degree of diffusion of the red wavelength band light and the green wavelength band light emitted by the fluorescent wheel device 100 by the blue wavelength band light traveling in the second direction D2. Therefore, it is possible to reduce the difference between the magnitude of the light flux of the blue wavelength band light emitted from the light source device of this embodiment and the magnitude of the light flux of the red wavelength band light and the green wavelength band light, and it is possible to reduce color unevenness that occurs on the projection target when each wavelength band light emitted from the light source device is projected onto the projection target.

[0068] Third embodiment Next, a third embodiment of the present invention will be described with reference to Fig. 8. As shown in Fig. 8, the projection device according to the third embodiment differs from the projection device 10 of the first embodiment in the configuration of the diffusion member 600. The configuration of the projection device other than the diffusion member 600 is the same as that of the first embodiment, so the description thereof will be omitted or simplified. Furthermore, in the diffusion member 600 according to the third embodiment, members having the same configuration as the diffusion member 200 according to the first embodiment are given the same reference numerals.

[0069] As shown in Fig. 8, in the diffusing member 600 according to this embodiment, the half mirror surface 608 is provided only at a position facing the entrance side opening 202a. The exit side opening 204a and the exit side total reflection surface 204 are provided around the half mirror surface 608. In this embodiment, the blue wavelength band light incident on the diffusing member 600 from the entrance side opening 202a along the first direction D1 is guided in the following manner. The blue wavelength band light incident on the entrance side opening 202a is diffused by transmitting through the transmission diffusion surface 206. A part of the blue wavelength band light transmitted through the transmission diffusion surface 206 proceeds directly to the exit side opening 204a in a traveling direction substantially perpendicular to the opening surface of the exit side opening, transmits through the half mirror surface 608, and is emitted from the exit side opening 204a (see light L10 indicated by a dashed line in Fig. 8). In addition, a portion of the blue wavelength band light diffused by the transmitting diffusion surface 206 travels toward the exit side opening 204a while being diffused, passes through the half mirror surface 608, and is emitted from the exit side opening 204a (see light L11 indicated by the dashed line in Figure 8).

[0070] On the other hand, the other part of the blue wavelength band light diffused by the transmitting and diffusing surface 206 is reflected by the half mirror surface 608 toward the incident-side total reflection surface 202 at various angles, and is totally reflected by the incident-side total reflection surface 202 toward the exit-side opening 204a. The blue wavelength band light totally reflected by the incident-side total reflection surface 202 is emitted from the half mirror 608 or the exit-side opening 204a (see light L12 indicated by a dashed line in FIG. 8), or is reflected by the half mirror 608 or the exit-side total reflection surface 204. At this time, the part of the blue wavelength band light totally reflected toward the exit-side opening 204a is emitted from the exit-side opening 204a provided around the half mirror surface 608 without reaching the half mirror surface 608, and is therefore not reflected again toward the incident-side total reflection surface 202.

[0071] In this manner, the diffusion member 600 of the present embodiment can increase the emission efficiency of the blue wavelength band light incident from the entrance side opening 202a along the first direction D1 to the diffusion member 600 by providing the half mirror surface 608 only at a position facing the entrance side opening 202a. This can efficiently reduce the difference between the size of the luminous flux of the blue wavelength band light emitted from the light source device of the present embodiment and the size of the luminous flux of the red wavelength band light and the green wavelength band light, and can further reduce color unevenness that occurs on the projection target when each wavelength band light emitted from the light source device is projected onto the projection target. By adjusting the position at which the half mirror surface 608 is provided as in the present embodiment, the transmission and reflection of the blue wavelength band light by the half mirror surface 608 can be adjusted.

[0072] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to Fig. 9. As shown in Fig. 9, the projection device according to the fourth embodiment differs from the projection device 10 of the first embodiment in the configuration of the diffusion member 800. The configuration of the projection device other than the diffusion member 800 is the same as that of the first embodiment, so the description thereof will be omitted or simplified. Furthermore, in the diffusion member 800 according to the fourth embodiment, members having the same configuration as the diffusion member 200 according to the first embodiment are given the same reference numerals.

[0073] 9, in the diffusing member 800 according to this embodiment, the half mirror surface 808 is provided only at a position facing the entrance side opening 202a, and further, the transmissive diffusing surface 806 is provided only directly below the half mirror surface 808 (on the glass base material G side of the half mirror surface 808). For this reason, the width dimension W3 of the half mirror surface 808 is made substantially equal to the width dimension of the transmissive diffusing surface 806, as shown in FIG.

[0074] In addition, in the diffusion member 800, the incident-side total reflection surface 802 includes a Fresnel lens (lens member) 803, and the incident-side total reflection surface 802 is provided in a shape that conforms to the shape of the Fresnel lens 803. As shown in Fig. 9 and Fig. 10, the Fresnel lens 803 has an incident-side recess 803a that is concave at a position corresponding to the incident-side opening 802a, and has a shape in which a plurality of reflecting surfaces 802b are provided at different angles in a concentric circle shape centered on the incident-side recess 803a. Each reflecting surface 802b of the Fresnel lens 803 is provided at an angle such that the blue wavelength band light reflected by the half mirror surface 808 toward the incident-side total reflection surface 802 is reflected by each reflecting surface in a direction substantially perpendicular to the opening surface of the exit-side opening 204a.

[0075] In this embodiment, the blue wavelength band light incident on the diffusion member 800 from the entrance opening 802a along the first direction D1 is guided in the following manner. The blue wavelength band light incident on the entrance recess 803a from the entrance opening 802a proceeds through the glass base material G toward the exit opening 204a and is diffused while passing through the transmission diffusion surface 206. A part of the blue wavelength band light that passes through the transmission diffusion surface 206 passes through the half mirror surface 808 without being reflected by the half mirror surface 808 and is emitted from the exit opening 204a (see light L13 indicated by a dashed line in FIG. 9). On the other hand, the other part of the blue wavelength band light that passes through the transmission diffusion surface 206 is reflected by the half mirror surface 808 toward the entrance total reflection surface 802 at various angles.

[0076] The blue wavelength band light reflected at a certain angle by the half mirror surface 808 toward the incident side total reflection surface 802 is reflected by the incident side total reflection surface 802 in a direction substantially perpendicular to the aperture surface of the exit side opening 204a, and is emitted from the exit side opening 204a (see light L14 shown by a dashed line in FIG. 9). The blue wavelength band light reflected at a different angle by the half mirror surface 808 toward the incident side total reflection surface 802 is reflected by another reflecting surface of the Fresnel lens 803 in a direction substantially perpendicular to the aperture surface of the exit side opening 204a, and is emitted from the exit side opening 204a (see light L15 shown by a dashed line in FIG. 9). Therefore, each blue wavelength band light emitted from the exit side opening 204a is made into a parallel light. Since the transmitting / diffusing surface 806 is provided only at a position opposite to the half mirror surface 808 , the blue wavelength band light reflected by the incident-side total reflection surface 802 is unlikely to be incident on the transmitting / diffusing surface 806 again.

[0077] As described above, in the diffusion member 800 of the projection device according to this embodiment, the incident-side total reflection surface 802 includes a Fresnel lens (lens member) 803, and the incident-side total reflection surface 802 is provided in a shape that conforms to the shape of the Fresnel lens 803. As a result, the blue wavelength band light that transmits through the diffusion member 200 is not only diffused but also collimated, so that the size and parallelism of the light flux of the blue wavelength band light emitted from the diffusion member 200 can be made substantially equal to the size and parallelism of the light flux of the red wavelength band light and the green wavelength band light emitted from the fluorescent wheel device 100. Therefore, the difference between the size and parallelism of the light flux of the blue wavelength band light emitted from the light source device and the size and parallelism of the light flux of the red wavelength band light and the green wavelength band light can be reduced, and the occurrence of color unevenness on the projection target when each wavelength band light emitted from the light source device is projected onto the projection target can be effectively reduced.

[0078] Furthermore, in the diffusion member 800 of the projection device according to this embodiment, a dichroic mirror surface that transmits blue wavelength band light incident at an angle along the normal direction and reflects blue wavelength band light incident at an angle other than the normal direction may be provided instead of the half mirror surface 808. This allows the blue wavelength band light that transmits through the dichroic mirror surface and is output from the output side opening 204a to be only parallel light, and the parallelism of the blue wavelength band light output from the output side opening 204a can be further increased.

[0079] Furthermore, in the diffusion member 800 of the projection device according to this embodiment, the transmissive diffusing surface 806 is provided only at a position directly below the half-mirror surface 808 facing the half-mirror surface 808, so that the blue wavelength band light reflected by the incident-side total reflection surface 802 is unlikely to be incident on the transmissive diffusing surface 806 again, and it is possible to suppress loss of parallelism of the blue wavelength band light that has been made parallel by the Fresnel lens 803. Note that in this embodiment, the transmissive diffusing surface 806 may be provided not only directly below the half-mirror surface 808 but also on the entire surface of the glass base material G.

[0080] 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. For example, in each of the above embodiments, a configuration in which the light source of the laser diode, which is the excitation light irradiation device, is one, and red wavelength band light and green wavelength band light are generated by a phosphor, is exemplified, but the diffusing member of the present invention may be applied to a configuration in which all of the blue wavelength band light, red wavelength band light, and green wavelength band light are laser diodes. In addition, for example, in each of the above embodiments, a configuration in which the entrance portion and the exit portion are openings are exemplified, but the entrance portion and the exit portion are not limited to openings, and may be transparent members that transmit light, such as glass, for example. [Explanation of symbols]

[0081] 10 Projection device 12 Front panel 12a Projection port 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 52 Cooling fan 54 Light source side heat sink 57 Power connector 60 Light source device 70 Excitation light irradiation device 71 Semiconductor package 72 Collimator lens 80 Red / green light source device 100 Fluorescent wheel device 101 Fluorescent wheel 102 fluorescent motor 104 fluorescent side lens group 140 light source optical system 141 first condenser lens 142 Second focusing lens 144 Reflecting mirror 150 Switching wheel device 151 Switching wheel 152 Switching motor 170 Light guide optical system 172 Microlens array 174 Concave lens 175 3rd focusing lens 185 Irradiation mirror 190 Projection side heat sink 195 Condenser lens 200 Diffusion member 202 Incident side total reflection surface 202a Inlet side aperture 204 Output side total reflection surface 204a: Exit aperture 206: Transmissive diffusion surface 208 Half mirror surface 220 Projection optical system 225 Fixed lens group 235 Movable lens group 242 control circuit board 250 dichroic mirror 400 Diffusion material 600 Diffusion material 608 Half mirror surface 800 Diffusion material 802 Total reflection surface on the incident side 802a Aperture on the incident side 802b Reflective surface 803 Fresnel lens 803a Incident side concave portion 806 Transmissive diffusion surface 808 Dichroic mirror surface D1 First direction D2 Second direction G Glass substrate L1~L15 Optical SB system bus SP1 First irradiation spot SP2 Second irradiation spot SP3 Third irradiation spot W1~W3 Width dimension

Claims

1. a first total reflection surface that is provided on a light incident side, has an incident portion on which the light is incident, and totally reflects the light; a partial reflection surface provided on the light exit side and configured to reflect a portion of the incident light; A transmission diffusion surface is provided between the first total reflection surface and the partial reflection surface, and transmits and diffuses the incident light. Diffusion material.

2. The diffusing member according to claim 1 , wherein the partial reflection surface is a half mirror surface that reflects a predetermined proportion of the incident light.

3. a second total reflection surface that is provided on the light exit side of the partial reflection surface, has an exit portion from which the diffused light exits, and totally reflects the light; The diffusing member according to claim 1 , wherein the area of ​​the light exiting portion is larger than the area of ​​the light entering portion of the light incident portion.

4. the partial reflection surface is provided at a position facing the entrance opening, The diffusing member according to claim 1 , wherein the partial reflection surface is surrounded by an exit portion from which the light exits.

5. The diffusing member according to claim 1 , wherein the transmitting and diffusing surface is provided in contact with the first total reflection surface.

6. The first total reflection surface has a shape in which a plurality of reflection surfaces are provided concentrically with the entrance portion as a center and at different angles, The diffusing member according to claim 4 , wherein each of the reflecting surfaces is provided at an angle such that the light reflected by the partial reflecting surface is reflected in a direction substantially perpendicular to the light exit portion.

7. The diffusion member according to any one of claims 1 to 6, a light source that emits light in a first wavelength band; a fluorescence emitting device configured to emit fluorescence including second wavelength band light and / or third wavelength band light when the first wavelength band light is incident thereon, The diffusing member diffuses and emits the first wavelength band light when the first wavelength band light is incident on the diffusing member. Light source device.

8. The light source device according to claim 7 ; A display element for generating 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.

9. a light guide optical system that guides the light emitted from the light source device to the display element; the diffusing member diffuses the first wavelength band light emitted toward the light-guiding optical system so as to form a light flux having a size substantially equal to a light flux of the second wavelength band light or the third wavelength band light emitted from the fluorescent light-emitting device toward the light-guiding optical system.

9. The projection device of claim 8.

Images