Scanning type light source and projection display device

Abstract

The present invention relates to a scanning-type light source and a projection display device, which can realize a high-brightness display device in the field of projection-type image display devices. The scanning light source includes: a laser light source including a semiconductor laser and a collimator lens that collimates laser light output from the semiconductor laser; and an optical deflector that deflects the laser light outputted from the laser light source, the optical deflector being provided with: an optical path switching unit that switches, at a predetermined period, whether the laser light passes through the first optical path or the second optical path in the optical deflector; a first light deflection device disposed in the first optical path and having a light reflecting surface that rotates back and forth; and a second light deflection device disposed in the second optical path and having a light reflecting surface that performs a reciprocating rotational motion, the laser light that is deflected and scanned by the first light deflection device and the laser light that is deflected and scanned by the second light deflection device being the laser light that is deflected and scanned in the same direction. The light is output alternately at predetermined intervals from the light deflector.

Description

Technical Field

[0001] The present invention relates to a scanning light source and a projection display device having the scanning light source. Background Art

[0002] A projection display device using laser has been known for a long time. Patent document 1 discloses a projection display device comprising: a laser light source; an acousto-optic modulator for light-modulating the laser according to an image signal; a polygonal mirror for horizontally scanning the modulated laser; and a galvanometer mirror for vertically scanning.

[0003] Patent Document 1: Japanese Patent Publication No. 2000-180759

[0004] The projection display device described in Patent Document 1 has an optical scanning unit that uses a polygonal mirror for horizontal scanning and a galvanometer mirror for vertical scanning. Since optical scanning is performed in both horizontal and vertical directions, a large optical path space is required, resulting in a problem of large-scale device.

[0005] Therefore, a projection display device having an optical system that uses, for example, a micro-electromechanical system mirror (MEMS mirror) to scan laser light in one direction to illuminate the light modulation device can be considered. Fig.18 (a) of FIG. 1 shows a typical MEMS mirror. The MEMS mirror can reflect incident light between the +θ direction and the −θ direction according to the rotation angle of the mirror surface M by reciprocating the mirror surface M around the rotation axis BX.

[0006] However, in an optical scanning device that makes the mirror surface M perform reciprocating rotational motion, such as a MEMS reflector, only one side of the reciprocating motion (the outgoing path or the returning path) can make the laser scan in one direction. For example, if you want to make the laser deflect and scan only in the +θ direction to the -θ direction, you can only use half of a scanning cycle (a cycle of the reciprocating rotational motion). Fig.18 On the lower side of (b), the dotted line graph shows the reflection direction of the mirror M over time. As shown in the figure, the graph of the reflection direction of the mirror M depicts a sine curve (SIN curve), but the scanning from the +θ direction to the -θ direction is only half of a scanning cycle. In addition, in order to improve the uniformity of the scanning speed to a certain extent, it is necessary to remove the vicinity of the apex of the SIN curve from the scanning period. For this reason, only the portion indicated by the solid arrow "scan" can be used as the effective scanning period. As shown in Fig.18As shown in the upper graph of (b), power consumption can be reduced by lighting the laser only during the effective scanning period. However, since the light modulator can be illuminated for less than half of the time in a scanning cycle, the brightness of the projection display device cannot be increased.

[0007] Therefore, in the field of projection-type image display devices that modulate laser light according to image signals and project the laser light, a scanning light source that can realize a high-brightness display device is sought. Summary of the invention

[0008] The first mode of the present invention is a scanning light source, characterized in that it comprises: a laser light source, comprising a semiconductor laser and a collimating lens for collimating the laser output by the semiconductor laser; and an optical deflector for deflecting the laser output by the laser light source, the optical deflector comprising: an optical path switching unit for switching, at a prescribed period, which of a first optical path and a second optical path the laser passes through in the optical deflector; a first optical deflection device, arranged in the first optical path, comprising a light reflecting surface for performing reciprocating rotational motion; and a second optical deflection device, arranged in the second optical path, comprising a light reflecting surface for performing reciprocating rotational motion, the laser deflected and scanned by the first optical deflection device and the laser deflected and scanned by the second optical deflection device are output alternately from the optical deflector every prescribed period as lasers deflected and scanned in the same direction.

[0009] A second aspect of the present invention is a scanning light source, characterized in that it comprises: a laser light source comprising a semiconductor laser and a collimating lens for collimating the laser light output by the semiconductor laser; and an optical deflector for deflecting the laser light output by the laser light source, the optical deflector comprising: an optical path switching unit for switching, at a prescribed period, which of a first optical path and a second optical path the laser light passes through in the optical deflector; and an optical deflection device comprising a light reflecting surface for performing reciprocating rotational motion, the laser light that is deflected and scanned when the light reflecting surface of the light deflection device in the first optical path is an outgoing path of the reciprocating rotational motion and the laser light that is deflected and scanned when the light reflecting surface of the light deflection device in the second optical path is a returning path of the reciprocating rotational motion are output alternately from the optical deflector every prescribed period as laser light deflected and scanned in the same direction.

[0010] According to the present invention, in the field of projection type image display devices that modulate laser light according to image signals and project the laser light, a scanning light source that can realize a high-brightness display device can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 (a) is a typical diagram showing the structure of the light deflector 310 involved in Embodiment 1; Figure 1 (b) is a top view of the optical path switching unit 501 included in the optical deflector 310 .

[0012] Figure 2 (a) is a diagram showing the optical path (first optical path) when the laser irradiates the transmissive portion TA; Figure 2 (b) is shown in Figure 2 A diagram showing the spot position of the laser light on the optical path switching unit 501 at time (a).

[0013] Figure 3 (a) is a diagram showing the optical path (second optical path) when the laser irradiates the reflecting portion RA; Figure 3 (b) is shown in Figure 3 A diagram showing the spot position of the laser light on the optical path switching unit 501 at time (a).

[0014] Figure 4 This is a diagram showing the operation sequence of each unit in the first embodiment.

[0015] Figure 5 A color projection display device is constructed using the light deflector according to the embodiment.

[0016] Figure 6 (a) is a diagram showing the relationship between the screen of the reflective light modulation device 340 and the rectangular laser beam scanning range SA; Figure 6 (b) is a diagram showing a state in which the rectangular B light beam, G light beam, and R light beam respectively irradiate the screen of the reflective light modulation device 340 .

[0017] Figure 7 (a) is a typical diagram showing the structure of a light deflector 310A according to a modification of Embodiment 1; Figure 7 (b) is a plan view of an optical path switching unit 501A included in a light deflector 310A according to a modification.

[0018] Figure 8 (a) is a typical diagram showing the structure of the light deflector 311 involved in Embodiment 2; Figure 8 (b) is a typical diagram showing the structure of the light deflector 311A ​​according to the first modification of the second embodiment.

[0019] Fig. 9 (a) is a diagram showing the optical path (first optical path) when the laser is modulated into P polarization by the spatial modulation device 502; Fig. 9 (b) is a diagram showing the optical path (second optical path) when the laser light is modulated into S polarization by the spatial modulation element 502.

[0020] Fig.10This is a diagram showing the operation sequence of each unit in the second embodiment.

[0021] Fig.11 This is a typical diagram showing the structure of a light deflector according to Modification 2 of Embodiment 2.

[0022] Fig.12 This is a typical diagram showing the structure of a light deflector according to Modification 3 of Embodiment 2.

[0023] Fig.13 (a) is a diagram showing an optical path (first optical path) when the laser irradiates the transmissive portion TA in Embodiment 3; Fig.13 (b) is shown in Fig.13 A diagram showing the spot position of the laser light on the optical path switching unit 501 at time (a).

[0024] Fig.14 (a) is a diagram showing an optical path (second optical path) when laser irradiates the reflecting portion RA in Embodiment 3; Fig.14 (b) is shown in Fig.14 A diagram showing the spot position of the laser light on the optical path switching unit 501 at time (a).

[0025] Fig.15 This is a diagram showing the operation sequence of each unit in the third embodiment.

[0026] Fig.16 (a) is a diagram showing an optical path (first optical path) when laser light is modulated into P polarization by the spatial modulation device 502 in Embodiment 4; Fig.16 (b) is a diagram showing the optical path (second optical path) when the laser light is modulated into S polarization by the spatial modulation element 502 in the fourth embodiment.

[0027] Fig.17 This is a diagram showing the operation sequence of each unit in the fourth embodiment.

[0028] Fig.18 (a) is a diagram typically showing a MEMS mirror; Fig.18 (b) is a diagram showing a conventional deflection scanning method.

[0029] Description of Reference Numerals

[0030] 12…Semiconductor laser

[0031] 102…Collimating lens

[0032] 103…Focusing lens

[0033] 105…light stick

[0034] 106a…Front convex lens

[0035] 106b…Rear convex lens

[0036] 190…Screen

[0037] 201…Collimating lens

[0038] 210A, 210B…MEMS mirrors

[0039] 211A, 211B…MEMS mirrors

[0040] 220…Photosynthesis Department

[0041] 221…Dichroic Mirror

[0042] 222…Dichroic mirror

[0043] 310, 310A, 311, 311A, 312, 313…optical deflector

[0044] 310B...B optical deflector

[0045] Optical Deflector for 310G...G

[0046] Optical Deflector for 310R...R

[0047] 330…Optical path conversion mirror

[0048] 340…Reflective light modulation device

[0049] 350…TIR prism

[0050] 360…Projection lens

[0051] 501, 501A…Optical path switching unit

[0052] 502…Spatial modulation device

[0053] 502A…Spatial Modulation Device

[0054] 503A…Polarization beam splitter

[0055] 503B…Polarization beam splitter

[0056] 504…Polarization beam splitter

[0057] 504A…Polarization beam splitter

[0058] 504B…Polarization beam splitter

[0059] 505…Polarization Beam Splitting (PBS) Prism

[0060] 506…1 / 4 wavelength plate

[0061] 630A, 630B…Optical path conversion mirror

[0062] AX…Rotation axis

[0063] BX…Rotation axis

[0064] LM...Laser Module

[0065] MA, MB, MC…Mirror

[0066] MT…Motor

[0067] RA…Reflector

[0068] TA…Transmission DETAILED DESCRIPTION

[0069] The following description will be made of a projection display device as an embodiment of the present invention with reference to the accompanying drawings. In addition, the embodiments shown below are for illustrative purposes only. For example, the technical solutions for the details may be appropriately modified and implemented by those skilled in the art without departing from the scope of the present invention. In addition, in the drawings referenced by the following embodiments and descriptions, the units indicated by the same reference numbers have the same functions unless otherwise specified. In addition, the optical components in the figures are shown typically, so the actual shapes and structures may not necessarily be faithfully shown. For example, even if depicted as a single lens in the drawings, it may be composed of multiple lenses unless otherwise specified.

[0070] In the following description, for example, when the positive X direction is recorded, it points to the same direction as the direction indicated by the X-axis arrow in the coordinate system shown in the figure, and when the negative X direction is recorded, it points to the direction 180 degrees opposite to the direction indicated by the X-axis arrow in the coordinate system shown in the figure. In addition, when only the X direction is recorded, it means that it is a direction parallel to the X axis, regardless of whether it is the same as the direction indicated by the X-axis arrow in the figure. The same applies to directions other than X.

[0071] In the following description, red is sometimes described as “R”, green is described as “G”, and blue is described as “B”. Therefore, for example, R light and red light, G light source and green light source, B laser and blue laser are synonymous.

[0072] [Implementation Method 1]

[0073] As described later, the projection display device according to the embodiment includes light sources (B light source, G light source, R light source) and light deflectors corresponding to the respective colors (B light deflector 310B, G light deflector 310G, R light deflector 310R). The B light deflector 310B, the G light deflector 310G, and the R light deflector 310R are light deflectors for deflecting and scanning laser beams of different colors, and since the basic structure is the same, the following description may be made as the light deflector 310 without specifying a color.

[0074] (Light Deflector)

[0075] Figure 1 (a) is a typical diagram showing the structure of a scanning light source according to Embodiment 1. Figure 1 (b) is a top view of the optical path switching unit 501 included in the optical deflector 310. Figure 1 In (a) of FIG. 8 , the light deflector 310 is shown surrounded by a dotted line. The laser module LM includes the semiconductor laser 12 and the collimator lens 102 , and the laser light emitted from the laser module LM enters the light deflector 310 .

[0076] The light deflector 310 includes a MEMS mirror 210A, a MEMS mirror 210B, and an optical path switching unit 501. The MEMS mirror 210A, which is a light deflection device, can reflect incident light at a deflection angle corresponding to the rotation angle of the mirror MA by causing the mirror surface MA (light reflection surface) to reciprocate and rotate around the rotation axis BX as the center. Similarly, the MEMS mirror 210B, which is a light deflection device, can also reflect incident light at a deflection angle corresponding to the rotation angle of the mirror surface MB by causing the mirror surface MB (light reflection surface) to reciprocate and rotate around the rotation axis BX as the center.

[0077] The optical path switching unit 501 is a disc-shaped component that can be rotated by a motor MT with the rotation axis AX as the center at a predetermined speed. The rotation of the motor MT is controlled in synchronization with the frame switching of the moving image displayed by the reflective light modulation device. That is, the optical path switching unit 501 switches the first optical path and the second optical path described later at a predetermined cycle in synchronization with the frame rate of the image.

[0078] In the optical path switching unit 501, Figure 1 As shown in (b), the transmission part TA (light transmission part) that transmits the laser light and the reflection part RA (light reflection part) that reflects the laser light each occupy half. Since the optical path switching part 501 rotates continuously, the laser light incident on the optical deflector 310 from the laser module LM will irradiate one of the transmission part TA and the reflection part RA according to the timing.

[0079] exist Figure 2In (a), the solid line shows the optical path (first optical path) when the laser light emitted from the laser module LM irradiates the transmission part TA. Figure 2 In (b), the dotted circle shows Figure 2 The spot position of the laser on the optical path switching unit 501 at the time (a). Figure 3 In (a), the dotted line shows the optical path (second optical path) when the laser light emitted from the laser module LM irradiates the reflector RA. Figure 3 In (b), the dotted circle shows Figure 3 The spot position of the laser on the optical path switching unit 501 at the time (a).

[0080] like Figure 2 As shown in (a), at the moment when the laser emitted from the laser module LM irradiates the transmission part TA of the optical path switching part 501, the laser is transmitted from the transmission part TA and irradiates the MEMS reflector 210A. The mirror surface MA of the MEMS reflector 210A performs reciprocating rotational motion around the rotation axis BX, and the laser is reflected by the mirror surface MA, so it is deflected to a direction corresponding to the irradiation moment and scans. The laser reflected by the mirror surface MA is reflected by the reflection part RA of the optical path switching part 501 and output from the optical deflector 310 to be used as illumination light for illuminating the reflective optical modulation device. As shown in FIG. Figure 2 As shown in (a), the optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector 310 can be referred to as the first optical path.

[0081] On the other hand, Figure 3 As shown in (a), when the laser light emitted from the laser module LM irradiates the reflection part RA of the optical path switching part 501, the laser light is reflected by the reflection part RA and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B performs reciprocating rotational motion around the rotation axis BX, and the laser light is reflected by the mirror surface MB and is deflected to a direction corresponding to the irradiation moment for scanning. The laser light reflected by the mirror surface MB is transmitted from the transmission part TA of the optical path switching part 501 and output from the optical deflector 310 to be used as illumination light for illuminating the reflective optical modulation device. Figure 3 As shown in (a), the optical path when the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector 310 can be referred to as the second optical path.

[0082] Figure 4The graph shown shows, in order from top to bottom, the lighting timing of the laser module LM, the timing of the laser passing through the first optical path in the optical deflector 310, the timing of the laser passing through the second optical path in the optical deflector 310, the angle of the mirror surface of the MEMS reflector 210A and the MEMS reflector 210B, and the deflection direction of the laser light that is deflected and scanned and output by the optical deflector 310. In this way, the laser light passing through the first optical path and the laser light passing through the second optical path are output from the optical deflector 310A in the same scanning direction SD. For convenience, the period during which the laser light that is scanned in one direction is output from the optical deflector 310 is called the effective period, and the period during which the laser light is not output is called the retrace period. When the reflective optical modulator is illuminated to display an image, the image signal is synchronized with the driving of the laser module LM, the optical deflector 310, and the reflective optical modulator. Thus, the effective period can be used to display a frame of a moving image, and the retrace period can be used to perform synchronization adjustment with the image signal.

[0083] According to this embodiment, the laser beam is deflected and scanned by using two MEMS mirrors alternately, and the laser beam is emitted in the same scanning direction SD by using the first optical path and the second optical path. Figure 4 As shown in the bottom graph, the half period of one frame period of a moving image signal can be used as an effective period for display. Therefore, in the field of projection type image display devices that modulate laser light according to image signals and project, a high-brightness device can be provided.

[0084] (Projection display device)

[0085] Next, refer to Figure 5 , an example of using the above-mentioned light deflector to form a color projection display device is described. Figure 5 This is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 1. For the sake of convenience, a mechanical structure for installing optical components, a body, electrical wiring, and the like are omitted in this diagram.

[0086] [Overall structure]

[0087] The projection display device 1000 includes: a B light source, a G light source, an R light source, a B light deflector 310B, a G light deflector 310G, an R light deflector 310R, a light synthesis unit 220, an optical path conversion mirror 330, a total internal reflection (TIR) ​​prism 350, a reflective light modulation device 340, and a projection lens 360. In addition, a condenser lens 103, a light rod 105, and a relay lens (front convex lens 106a) are arranged between the light sources of each color and the deflectors of each color, and a collimator lens 201 (second collimator lens) is arranged between the deflectors of each color and the light synthesis unit 220. In addition, the projection display device 1000 may optionally include a projection screen 190.

[0088] The B light source includes a laser module LM-B including a semiconductor laser emitting B light, the G light source includes a laser module LM-G including a semiconductor laser emitting G light, and the R light source includes a laser module LM-R including a semiconductor laser emitting R light.

[0089] The B light deflector 310B is a deflector that continuously deflects the B light emitted by the B light source 100B in one direction. Similarly, the G light deflector 310G is a deflector that continuously deflects the G light emitted by the G light source 100G in one direction, and the R light deflector 310R is a deflector that continuously deflects the R light emitted by the R light source 100R in one direction. Figures 1 to 4 As described.

[0090] However, in Figure 1 In the structure shown in FIG. 1 , the laser light emitted from the laser module LM is directly input to the light deflector 310. The same structure can also be used to implement a projection display device, but in Figure 5 The projection display device 1000 shown in the figure adopts a so-called integrator illumination system. That is, a condenser lens 103, a light rod 105, and a relay lens (front convex lens 106a) are arranged between the laser module LM and the optical deflector. Furthermore, in the optical deflector, a relay lens (rear convex lens 106b) is arranged between the optical path switching section 501 and the MEMS reflector 210A and between the optical path switching section 501 and the MEMS reflector 210B, respectively.

[0091] The laser beam emitted from each of the semiconductor lasers included in the laser module LM is collimated by the collimator lens 102 ( Figure 1 ) becomes roughly parallel under the action of. The roughly collimated laser beam output from the laser module LM is focused toward the incident surface of the light rod 105 by the focusing lens 103. In this figure, the focusing lens 103 is represented by a convex lens, but it can also be composed of multiple lenses for the purpose of suppressing aberrations, etc.

[0092] A diffusion device (not shown) is arranged near the incident surface of the light rod 105, and the laser beam diffused by the diffusion device is incident on the light rod 105 from the incident surface. From the perspective of the optical path cross section, since the divergence angle of the light beam output from the laser module LM in the short side direction of the rectangle is better than that in the long side direction, the capture loss of light on the incident surface of the light rod 105 can be suppressed, thereby improving the utilization efficiency. The light incident on the light rod 105 is emitted from the exit surface after repeated total reflection on the side. By appropriately setting the diffusion capacity (diffusion angle) of the diffusion device and the length of the light rod 105, the illumination distribution on the exit surface can be made uniform.

[0093] By using the relay lens to relay the image emitted from the exit surface of the light rod 105, a rectangular illumination area with high illumination uniformity can be obtained. By appropriately setting the relay lens's relay magnification, an illumination area of ​​a desired size can be obtained after reduction, equalization, or enlargement. Figure 5 In the example, the relay lens is composed of two lenses: the front convex lens 106a and the rear convex lens 106b, but the structure of the relay lens is not limited to this example.

[0094] The collimator lens 201 is provided between the B light deflector 310B and the light combining unit 220. Even if the B light (dashed line) is deflected by the B light deflector 310B, the collimator lens 201 causes the B light to enter the light combining unit 220 as a ray parallel to the X direction.

[0095] The collimator lens 201 is provided between the G light deflector 310G and the light combining unit 220. Even if the G light (solid line) is deflected by the G light deflector 310G, the collimator lens 201 causes the G light to enter the light combining unit 220 as a ray parallel to the Z direction.

[0096] The collimator lens 201 is provided between the R light deflector 310R and the light combining unit 220. Even if the R light (one-dot chain line) is deflected by the R light deflector 310R, the collimator lens 201 causes the R light to enter the light combining unit 220 as a light beam parallel to the X direction.

[0097] The light combining unit 220 includes a dichroic mirror 221 and a dichroic mirror 222. The dichroic mirror 221 has an optical characteristic of reflecting the B light and transmitting the G light. The dichroic mirror 222 has an optical characteristic of transmitting the G light and the B light and reflecting the R light. Each device is configured so that the optical axis center of the collimating lens 201 for the B light and the optical axis center of the collimating lens 201 for the G light overlap on the dichroic mirror 221. In addition, each device is configured so that the optical axis center of the collimating lens 201 for the B light, the optical axis center of the collimating lens 201 for the G light, and the optical axis center of the collimating lens 201 for the R light overlap on the dichroic mirror 222.

[0098] The traveling directions of the B light (dashed line), the G light (solid line), and the R light (one-dot chain line) are all unified in the positive Z direction by the light combining unit 220, but these lights are combined in a manner that they do not overlap each other at any time. This is because the timing (deflection phase) of the deflection scanning performed by the B light deflector 310B, the G light deflector 310G, and the R light deflector 310R is controlled so that each of the B light, the G light, and the R light does not overlap each other on the screen of the reflective light modulation device 340.

[0099] The B light, G light, and R light emitted from the light combining unit 220 are redirected to the positive X direction by the optical path conversion mirror 330 and are incident on the TIR prism 350. The TIR prism 350 is, for example, an internal total reflection prism composed of two prisms, which causes the illumination light (B light, G light, and R light) to be totally reflected at the air gap surface and incident on the reflective light modulator 340 at a predetermined angle. As described above, the B light, G light, and R light illuminate a portion of the screen of the reflective light modulator 340 in a non-overlapping manner.

[0100] B light (dashed line), G light (solid line), and R light (single-point dashed line) respectively form rectangular illumination areas, which are magnified and projected onto the screen of the reflective light modulator 340 at a specified magnification ratio through a projection optical system composed of a collimating lens 201 (front projection lens) and a rear projection lens 202.

[0101] The reflective light modulator 340 uses, for example, a digital micromirror device (DMD) in which micromirror devices are arranged in an array. The micromirrors corresponding to each display pixel are driven according to the brightness level of the image signal so that their reflection direction is changed by pulse width modulation. However, other types of reflective light modulators such as reflective liquid crystal devices may also be used.

[0102] The pixels in the screen area illuminated by the B light are driven according to the brightness level of the B component of the image signal, and the B image light is reflected at a predetermined angle toward the TIR prism 350. Similarly, the pixels in the screen area illuminated by the G light are driven according to the brightness level of the G component of the image signal, and the G image light is reflected at a predetermined angle toward the TIR prism 350. In addition, the pixels in the screen area illuminated by the R light are driven according to the brightness level of the R component of the image signal, and the R image light is reflected at a predetermined angle toward the TIR prism 350. In this way, the reflective light modulation device is driven in synchronization with the timing of the deflection scanning performed by the B light deflector 310B, the G light deflector 310G, and the R light deflector 310R, so as to modulate the illumination laser light.

[0103] The image light (B image light, G image light, R image light) is guided to the projection lens 360 through the TIR prism 350 and projected as a color image. The projection lens 360 is composed of a single lens or a plurality of lenses, and may also have an automatic focus adjustment function and a zoom function.

[0104] The projection screen 190 is used when a rear projection display device is constructed. In addition, although it is often provided in the case of a front projection, it is not necessarily required to be provided when the user projects onto an arbitrary wall surface or the like.

[0105] exist Figure 6 (a) shows the relationship between the screen of the reflective light modulator 340 and the rectangular laser beam scanning range SA. If the screen size of the reflective light modulator 340 is set to H (horizontal direction) × V (vertical direction), the rectangular laser beam scanning range SA covers an area H'×V' that is larger than the screen size. In addition, the rectangular laser beam scanning range SA is magnified by a predetermined projection magnification by the projection optical system relative to the scanning range of the rectangular illumination area scanned by the light deflector 310.

[0106] Figure 6 (b) is a diagram showing the state of the rectangular B light beam, G light beam, and R light beam irradiating the screen of the reflective light modulator 340 respectively, with the horizontal axis as the time axis. The B light beam, the G light beam, and the R light beam vertically scan the screen of the reflective light modulator 340 along the scanning direction SD, and complete the scanning of one screen in one frame time. The B light beam, the G light beam, and the R light beam are constructed to be non-repeating to avoid color mixing at the boundary parts of various color areas, and the vertical width V2 of each light beam must be constructed to be less than 1 / 3 of V'. The vertical width of each light beam can be set to be greater than 1 / 6 and less than 1 / 3 of the vertical width of the screen of the reflective light modulator 340.

[0107] As described above, the projection display device of this embodiment is provided with an illumination assembly for each different color light, and has a light synthesis unit, the illumination assembly has a plurality of semiconductor lasers, a collimating lens, an integrator illumination system and an optical deflector, the light synthesis unit synthesizes the illumination light output by the illumination assembly of different color lights, and the rectangular illumination area output by each of the illumination assemblies of different color lights is deflected and scanned in a mutually non-overlapping manner, and is enlarged and projected onto the reflective light modulation device. According to this embodiment, in the field of projection type image display devices that modulate laser light according to an image signal and project it, a high brightness device can be provided.

[0108] [Variation of Embodiment 1]

[0109] (Light Deflector)

[0110] A description will be given of a modification of Embodiment 1. Description of matters common to matters already described will be omitted. Figure 7 (a) is a typical diagram showing the structure of a light deflector 310A according to a modification of Embodiment 1. Figure 7 (b) is a top view of the optical path switching unit 501A included in the optical deflector 310A. The optical deflector 310A according to the modified example also includes the MEMS mirror 210A and the MEMS mirror 210B. Figure 7 (b) and Figure 1 As can be seen from (b), the configuration methods of the transmission part TA and the reflection part RA in the light deflector are different.

[0111] like Figure 7 As shown in (b), in the optical path switching section 501A of the modified example, the transmission section TA for transmitting the laser light and the reflection section RA for reflecting the laser light are each provided at two locations, for a total of four locations. The transmission section TA and the reflection section RA are sectors with an angle of 90 degrees, and the transmission sections TA are opposite to each other across the rotation axis AX, and the reflection sections RA are opposite to each other across the rotation axis AX. In other words, the main surface of the optical path switching section involved in Embodiment 1 is divided into an even number of parts (at Figure 1 In the example (b), the Figure 7 In the example of (b), the laser module LM outputs light that alternately irradiates the transmissive portion TA and the reflective portion RA when rotating around the rotation axis AX. In addition, the number of parts into which the main surface of the optical path switching portion is divided is not limited to 2 or 4, but may be an even number other than these.

[0112] exist Figure 7 In (a), for the sake of convenience, both the case where the output light of the laser module LM irradiates the transmission part TA and the case where the output light of the laser module LM irradiates the reflection part RA are shown together. That is, the optical path when the laser light emitted from the laser module LM irradiates the transmission part TA (first optical path) is shown by a solid line, and the optical path when the laser light emitted from the laser module LM irradiates the reflection part RA (second optical path) is shown by a dotted line.

[0113] When the laser emitted from the laser module LM irradiates the transmission part TA of the optical path switching part 501A, the laser is transmitted from the transmission part TA and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A performs reciprocating rotational motion around the rotation axis BX, and the laser is reflected by the mirror surface MA, so it is deflected to a direction corresponding to the irradiation time and scanned. The laser reflected by the mirror surface MA is transmitted from the transmission part TA located on the opposite side of the rotation axis AX and output from the optical deflector 310A to be used as illumination light for illuminating the reflective optical modulation device. The optical path when the laser is deflected and scanned by the MEMS mirror 210A in the optical deflector 310A can be called the first optical path.

[0114] On the other hand, when the laser emitted from the laser module LM irradiates the reflection part RA of the optical path switching part 501A, the laser is reflected by the reflection part RA and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B performs reciprocating rotational motion around the rotation axis BX, and the laser is reflected by the mirror surface MB, so it is deflected to a direction corresponding to the irradiation time and scanned. The laser reflected by the mirror surface MB is reflected by the reflection part RA located on the opposite side of the rotation axis AX and output from the optical deflector 310A to be used as illumination light for illuminating the reflective optical modulation device. The optical path when the laser is deflected and scanned by the MEMS mirror 210B in the optical deflector 310A can be called the second optical path.

[0115] In this way, the laser light passing through the first optical path and the laser light passing through the second optical path are both output from the optical deflector 310A in the same scanning direction SD.

[0116] (Projection display device)

[0117] If the light deflector according to this modification is provided for each light of different colors, Figure 5 As shown, the rectangular illumination area output by each of the illumination components of different color lights can be deflected and scanned in a non-overlapping manner, and enlarged and projected onto the reflective light modulation device. In addition, in this modification, the drive timing of each unit is controlled so that a quarter circle of the optical path switching unit 501A corresponds to a frame period of the image. As described above, according to this embodiment, in the field of projection image display devices that modulate laser light according to image signals and project, a high-brightness device can be provided.

[0118] [Implementation Method 2]

[0119] A scanning light source, a projection display device, and the like according to Embodiment 2 will be described with reference to the drawings. The description of matters common to Embodiment 1 will be simplified or omitted.

[0120] (Light Deflector)

[0121] Figure 8 (a) is a typical diagram showing the structure of the light deflector 311 involved in Embodiment 2. Figure 8 In (a) of FIG. 8 , the light deflector 311 is shown surrounded by a dotted line. The laser module LM includes the semiconductor laser 12 and the collimator lens 102 , and the laser light emitted from the laser module LM is incident on the light deflector 311 .

[0122] The light deflector 311 is the same as Embodiment 1 in that it includes the MEMS mirror 210A and the MEMS mirror 210B, but the structure of the optical path switching unit that switches the first optical path and the second optical path is different from that of Embodiment 1. In Embodiment 1, the optical path switching unit includes a rotating body in which the transmissive portion TA and the reflective portion RA are alternately arranged around the rotation axis AX. In contrast, Figure 8 The optical path switching unit of this embodiment shown in (a) includes a transmissive spatial modulation element 502, a polarization beam splitter 503A, and a polarization beam splitter 503B.

[0123] The transmissive spatial modulation device 502 can synchronize the linear polarized light output by the laser module LM with a frame period of the image and modulate it alternately into P polarized light and S polarized light. The polarization beam splitter 503A has the optical property of transmitting P polarized light and reflecting S polarized light. The polarization beam splitter 503B also has the optical property of transmitting P polarized light and reflecting S polarized light.

[0124] exist Fig. 9 In (a), the solid line shows the optical path (first optical path) of the laser light emitted from the laser module LM when it is modulated into P polarization by the spatial modulation device 502. Fig. 9 In (b), the dotted line shows the optical path (second optical path) of the laser light emitted from the laser module LM when it is modulated into S-polarized light by the spatial modulation element 502.

[0125] like Fig. 9 As shown in (a), when the laser emitted from the laser module LM is modulated into P polarized light, the laser is transmitted through the polarization beam splitter 503A and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A performs reciprocating rotational motion around the rotation axis BX, and the laser is reflected by the mirror surface MA, so it is deflected to a direction corresponding to the irradiation moment and scanned. The laser reflected by the mirror surface MA is transmitted through the polarization beam splitter 503B and output from the optical deflector 311 to be used as illumination light for illuminating the reflective optical modulation device. Fig. 9 As shown in (a), the optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector 311 can be referred to as the first optical path.

[0126] On the other hand, Fig. 9 As shown in (b), when the laser emitted from the laser module LM is modulated to S polarization, the laser is reflected by the polarization beam splitter 503A and irradiates the MEMS mirror 210B. The mirror MB of the MEMS mirror 210B performs reciprocating rotation around the rotation axis BX. Since the laser is reflected by the mirror MB, it is deflected to a direction corresponding to the irradiation time and scans. The laser reflected by the mirror MB is reflected by the polarization beam splitter 503B and output from the optical deflector 311 to be used as illumination light for illuminating the reflective optical modulation device. Fig. 9 As shown in (b), the optical path when the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector 311 can be referred to as the second optical path.

[0127] Fig.10 The graph shown shows, in order from top to bottom, the lighting timing of the laser module LM, the output of the spatial modulation device 502, the timing of the laser passing through the first optical path in the optical deflector 311, the timing of the laser passing through the second optical path in the optical deflector 311, and the deflection direction of the laser that is deflected and scanned and output by the optical deflector 311. In this way, the laser through the first optical path and the laser through the second optical path are output from the optical deflector 310A in the same scanning direction SD. For convenience, the period during which the laser scanning in one direction is output from the optical deflector 311 is called the effective period, and the period during which the laser is not output is called the retrace period. When the reflective optical modulation device is illuminated to display an image, the image signal is synchronized with the driving of the laser module LM, the optical deflector 311, and the reflective optical modulation device. As a result, it is possible to use the effective period to display a frame of a moving image, and use the retrace period to perform synchronization adjustment with the image signal.

[0128] According to this embodiment, two MEMS mirrors are alternately used to emit laser light for deflection scanning in one direction, so that Fig.10 As shown in the bottom graph, the half period of one frame period of a moving image signal can be used as an effective period for display. Therefore, in the field of projection type image display devices that modulate laser light according to image signals and project, a high-brightness device can be provided.

[0129] [Variation 1 of Implementation Example 2]

[0130] (Light Deflector)

[0131] A description will be given of Modification 1 of Embodiment 2. Description of matters common to matters already described will be omitted here. Figure 8 (b) is a typical diagram showing the structure of the light deflector 311A ​​according to the first modification of the second embodiment. Figure 8 In (b), for the convenience of illustration, both the case where the output of the spatial modulation device 502 is P-polarized light and the case where it is S-polarized light are illustrated together.

[0132] exist Figure 8 In the example (a) of FIG. 1 , the laser module LM and the spatial modulation device 502 are arranged above the optical deflector 311 in the figure, but in this modified example, they are arranged on the left side of the optical deflector 311A. Figure 8 This variation can be used when the configuration of method (a) is difficult due to space limitations.

[0133] In this modification, polarization beam splitter 503A has an optical characteristic of transmitting P-polarized light and reflecting S-polarized light, while polarization beam splitter 504 has an optical characteristic of reflecting P-polarized light and transmitting S-polarized light.

[0134] [Variation 2 of Implementation Example 2]

[0135] (Light Deflector)

[0136] A description will be given of a modification example 2 of the embodiment 2. Description of matters common to matters already described will be omitted here. Fig.11 2 is a typical diagram showing the structure of a light deflector according to a second variation of the second embodiment. Fig.11 In FIG. 1 , for the convenience of illustration, both the case where the output of the spatial modulation device 502A is P polarized light and the case where it is S polarized light are illustrated together.

[0137] exist Figure 8 In the example (a) of FIG. 1 , a transmissive spatial modulation device 502 is used, but in this modification, a reflective spatial modulation device 502A is used. Due to space limitations when constructing a projection display device, this modification can be preferably used.

[0138] In this modification, polarization beam splitter 504A and polarization beam splitter 504B have optical characteristics of reflecting P-polarized light and transmitting S-polarized light.

[0139] [Variation 3 of Implementation Example 2]

[0140] (Light Deflector)

[0141] A description will be given of a modification example 3 of the embodiment 2. Description of matters common to matters already described will be omitted here. Fig.12 2 is a typical diagram showing the structure of a light deflector according to a third variation of the second embodiment. Fig.12 In FIG. 1 , for the convenience of illustration, both the case where the output of the spatial modulation device 502 is P polarized light and the case where it is S polarized light are illustrated together.

[0142] exist Figure 8 In the example (a), the polarization beam splitter 503A and the polarization beam splitter 503B are used to switch the optical paths of P-polarized light and S-polarized light, but this modification includes a cubic PBS prism 505 and two 1 / 4 wavelength plates 506.

[0143] When the laser emitted from the laser module LM is modulated to P polarization, the laser is transmitted through the PBS prism 505 and irradiates the MEMS reflector 210A. The mirror surface MA of the MEMS reflector 210A performs reciprocating rotational motion around the rotation axis BX, and the laser is reflected by the mirror surface MA, so it is deflected to a direction corresponding to the irradiation time and scanned. The laser reflected by the mirror surface MA becomes S polarization due to passing through the 1 / 4 wavelength plate 506 twice, is reflected by the PBS prism 505, and is output from the optical deflector to be used as illumination light for illuminating the reflective optical modulation device. Fig.12 As shown, the optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector can be referred to as the first optical path.

[0144] On the other hand, Fig.12 As shown, at the moment when the laser emitted from the laser module LM is modulated into S polarization, the laser is reflected by the PBS prism 505 and irradiates the MEMS mirror 210B. The mirror MB of the MEMS mirror 210B performs reciprocating rotational motion around the rotation axis BX. Since the laser is reflected by the mirror MB, it is deflected to a direction corresponding to the irradiation moment and scans. The laser reflected by the mirror MB becomes P polarization due to passing through the 1 / 4 wavelength plate 506 twice, is transmitted from the PBS prism 505, and is output from the optical deflector to be used as illumination light for illuminating the reflective optical modulation device. Fig.12 As shown, the optical path when the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector can be referred to as the second optical path.

[0145] In this way, the laser light passing through the first optical path and the laser light passing through the second optical path are both output from the optical deflector in the same scanning direction SD.

[0146] (Projection display device)

[0147] If the light deflector involved in embodiment 2 or its variant is provided for each different color light, Figure 5 As shown, the rectangular illumination areas output by each of the illumination assemblies of different color lights can be deflected and scanned in a non-overlapping manner, and are enlarged and projected onto the reflective light modulation device.

[0148] According to this embodiment, two MEMS mirrors are used alternately to deflect and scan the laser in one direction, so that Fig.10 As shown in the bottom graph, the half period of one frame period of a moving image signal can be used as an effective period for display. Therefore, in the field of projection type image display devices that modulate laser light according to image signals and project, a high-brightness device can be provided.

[0149] [Implementation method 3]

[0150] A scanning light source, a projection display device, and the like according to Embodiment 3 will be described with reference to the drawings. The description of matters common to Embodiment 1 or Embodiment 2 will be simplified or omitted.

[0151] As described above, the optical deflector involved in Embodiments 1 and 2 includes two MEMS mirrors. Furthermore, the optical path switching unit is used to switch between the first optical path and the second optical path for each frame of image display, so that the two MEMS mirrors alternately deflect and scan the laser beam and output the scanned light. In contrast, this embodiment is the same as Embodiments 1 and 2 in that the optical path switching unit is used to switch between the first optical path and the second optical path for each frame of image display, but is different in that only one MEMS mirror is included.

[0152] (Light Deflector)

[0153] refer to Fig.13 (a) Fig.13 (b) Fig.14 (a) Fig.14 (b) and Fig.15 , the optical deflector involved in Embodiment 3 is described. The optical deflector 312 involved in this embodiment is similar to Embodiment 1, and includes an optical path switching unit 501 on a rotatable circular plate, and the transmission unit TA that transmits the laser light and the reflection unit RA that reflects the laser light each occupy half of the main surface of the circular plate. Since the optical path switching unit 501 rotates continuously, the laser light incident on the optical deflector 312 from the laser module LM irradiates one of the transmission unit TA and the reflection unit RA according to the timing.

[0154] exist Fig.13 In (a), the solid line shows the optical path (first optical path) when the laser light emitted from the laser module LM irradiates the transmission part TA. Fig.13 In (b), the dotted circle shows Fig.13 The spot position of the laser on the optical path switching unit 501 at the time (a). Fig.14 In (a), the dotted line shows the optical path (second optical path) when the laser light emitted from the laser module LM irradiates the reflector RA. Fig.14 In (b), the dotted circle shows Fig.14The spot position of the laser on the optical path switching unit 501 at the time (a).

[0155] like Fig.13 As shown in (a), when the laser light emitted from the laser module LM irradiates the transmission part TA of the optical path switching part 501, the laser light is transmitted from the transmission part TA and irradiates the MEMS mirror 210C via the optical path conversion mirror 630A. The mirror surface MC (light reflecting surface) of the MEMS mirror 210C as a light deflection element reciprocates and rotates around the rotation axis BX. Fig.13 (a) corresponds to the outward path of the reciprocating rotation motion, and the laser light is reflected by the mirror MC and deflected and scanned. The laser light reflected by the mirror MC is reflected by the optical path conversion mirror 630B and goes to the optical path switching unit 501, is transmitted from the transmission unit TA of the optical path switching unit 501, and is output from the optical deflector 312 to be used as illumination light for illuminating the reflective optical modulation device. Fig.13 As shown in (a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210C in the optical deflector 312 and then is reflected only once by the optical path conversion mirror 630B and emitted from the optical deflector 312 can be referred to as the first optical path.

[0156] On the other hand, Fig.14 As shown in (a), when the laser light emitted from the laser module LM irradiates the reflection part RA of the optical path switching part 501, the laser light is reflected by the reflection part RA and then irradiates the MEMS mirror 210C via the optical path conversion mirror 630B. The mirror surface MC of the MEMS mirror 210C performs reciprocating rotational motion around the rotation axis BX. Fig.14 (a) corresponds to a reciprocating rotational motion loop, and the laser is reflected by the mirror MC and deflected and scanned.

[0157] The laser light reflected by the mirror surface MC is reflected by the optical path conversion mirror 630A and goes to the optical path switching unit 501, is reflected by the reflection unit RA of the optical path switching unit 501, and is output from the optical deflector 312 to be used as illumination light for illuminating the reflective optical modulation device. Fig.14 As shown in (a), after the laser is deflected and scanned by the MEMS mirror 210C in the light deflector 312, the light path in which it is reflected twice by the light path conversion mirror 630A and the reflection part RA of the light path switching part 501 and emitted from the light deflector 312 can be called the second light path.

[0158] Fig.15The graph shown shows, in order from top to bottom, the lighting timing of the laser module LM, the angle of the MEMS reflector 210C, the timing of the laser passing through the first optical path in the optical deflector 312, the timing of the laser passing through the second optical path in the optical deflector 312, and the deflection direction of the laser that is deflected and scanned by the optical deflector and output. In this way, the laser through the first optical path and the laser through the second optical path are output from the optical deflector 312 in the same scanning direction SD. For convenience, the period during which the laser scanning in one direction is output from the optical deflector 312 is called the effective period, and the period during which no output is performed is called the retrace period. When the reflective optical modulator is illuminated to display an image, the image signal is synchronized with the drive of the laser module LM, the optical deflector, and the reflective optical modulator. Thus, it is possible to use the effective period to display a frame of a moving image, and use the retrace period to perform synchronization adjustment with the image signal.

[0159] According to this embodiment, the first optical path and the second optical path are switched for each frame of an image, wherein the first optical path causes the laser beam deflected and scanned in the outgoing path of the MEMS mirror 210C that performs reciprocating rotation to be output from the optical deflector 312 after one reflection, and the second optical path causes the laser beam deflected and scanned in the return path of the MEMS mirror 210C to be output from the optical deflector 312 after two reflections. Thus, by utilizing both the outgoing path and the return path of the reciprocating rotation of the MEMS mirror 210C, laser beams having the same scanning direction SD can be continuously emitted. Fig.15 As shown in the bottom curve, the half period in one frame period of the motion image signal can be used as an effective period for display. Therefore, in the field of projection type image display devices that modulate laser light according to image signals and project them, a high brightness device can be provided. In addition, regarding the optical path switching unit 501, the configuration method of the transmission unit TA and the reflection unit RA can be modified as in the modified example of the first embodiment.

[0160] (Projection display device)

[0161] If the light deflector according to this embodiment is provided for each light of different colors, Figure 5 As shown, the rectangular illumination area output by each illumination assembly of different color lights can be deflected and scanned in a non-overlapping manner, and enlarged and projected onto the reflective light modulation device. According to this embodiment, in the field of projection image display devices that modulate laser light according to image signals and project, a high-brightness device can be provided.

[0162] [Implementation Method 4]

[0163] A scanning light source, a projection display device, and the like according to Embodiment 4 will be described with reference to the drawings. The description of matters common to Embodiment 1 or Embodiment 2 will be simplified or omitted.

[0164] As described above, the optical deflector involved in Embodiments 1 and 2 includes two MEMS mirrors. Furthermore, the optical path switching unit is used to switch the first optical path and the second optical path for each frame of image display, so that the two MEMS mirrors alternately deflect and scan the laser beam and output the scanning light. In contrast, this embodiment is the same as Embodiments 1 and 2 in that the optical path switching unit is used to switch the first optical path and the second optical path for each frame of image display, but is different in that only one MEMS mirror is included. In addition, the embodiment is the same as Embodiment 3 in that only one MEMS mirror is included.

[0165] (Light Deflector)

[0166] refer to Fig.16 (a) Fig.16 (b) and Fig.17 , the optical deflector involved in embodiment 4 is described. The optical deflector 313 involved in this embodiment includes a transmission type spatial modulation device 502, a polarization beam splitter 503A, an optical path conversion mirror 630A, an optical path conversion mirror 630B and a MEMS reflector 210C. The transmission type spatial modulation device 502 can make the linear polarized light output by the laser module LM be synchronized with a frame cycle of the image and modulate it alternately into P polarization and S polarization. The polarization beam splitter 503A has the optical property of transmitting P polarization and reflecting S polarization. The optical path conversion mirror 630A and the optical path conversion mirror 630B are total reflection mirrors.

[0167] exist Fig.16 In (a), the solid line shows the optical path (first optical path) of the laser light emitted from the laser module LM when it is modulated into P polarization by the spatial modulation device 502. Fig.16 In (b), the dotted line shows the optical path (second optical path) of the laser light emitted from the laser module LM when it is modulated into S-polarized light by the spatial modulation element 502.

[0168] like Fig.16 As shown in (a), when the laser light emitted from the laser module LM is modulated to P polarization, the laser light is transmitted through the polarization beam splitter 503A and irradiates the MEMS mirror 210C via the optical path conversion mirror 630A. The mirror surface MC of the MEMS mirror 210C performs reciprocating rotational motion around the rotation axis BX. Fig.16(a) corresponds to the outward path of the reciprocating rotation motion, and the laser is reflected by the mirror MC and deflected and scanned. The laser reflected by the mirror MC is reflected by the optical path conversion mirror 630B and goes to the polarization beam splitter 503A, is transmitted from the polarization beam splitter 503A, and is output from the optical deflector 313 to be used as illumination light for illuminating the reflective optical modulation device. Fig.16 As shown in (a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210C in the optical deflector 313 and then is reflected only once by the optical path conversion mirror 630B and emitted from the optical deflector 313 can be referred to as the first optical path.

[0169] On the other hand, Fig.16 As shown in (b), when the laser light emitted from the laser module LM is modulated to S polarization, the laser light is reflected by the polarization beam splitter 503A and irradiates the MEMS mirror 210C via the optical path conversion mirror 630B. The mirror surface MC of the MEMS mirror 210C performs reciprocating rotational motion around the rotation axis BX. Fig.16 (b) corresponds to a reciprocating rotational motion loop, and the laser is reflected by the mirror MC and deflected and scanned. The laser reflected by the mirror MC is reflected by the optical path conversion mirror 630A and goes to the polarization beam splitter 503A, is reflected by the polarization beam splitter 503A, and is output from the optical deflector 313 to be used as illumination light for illuminating the reflective optical modulation device. Fig.16 As shown in (b), the optical path in which the laser is deflected and scanned by the MEMS mirror 210C in the optical deflector 313 and then reflected twice by the optical path conversion mirror 630A and the polarization beam splitter 503A and emitted from the optical deflector 313 can be called the second optical path.

[0170] Fig.17 The graph shown shows, in order from top to bottom, the lighting timing of the laser module LM, the output of the spatial modulation device 502, the timing of the laser passing through the first optical path in the optical deflector 313, the timing of the laser passing through the second optical path in the optical deflector 313, and the deflection direction of the laser that is deflected and scanned and output by the optical deflector 313. In this way, the laser through the first optical path and the laser through the second optical path are output from the optical deflector 313 in the same scanning direction SD. For convenience, the period during which the laser scanning in one direction is output from the optical deflector 313 is called the effective period, and the period during which the laser is not output is called the retrace period. When the reflective optical modulation device is illuminated to display an image, the image signal is synchronized with the driving of the laser module LM, the optical deflector 313, and the reflective optical modulation device. As a result, it is possible to use the effective period to display a frame of a moving image, and use the retrace period to perform synchronization adjustment with the image signal.

[0171] According to this embodiment, the first optical path and the second optical path are switched for each frame of an image, wherein the first optical path causes the laser beam deflected and scanned in the outgoing path of the MEMS mirror 210C that performs reciprocating rotation to be output from the optical deflector 313 after one reflection, and the second optical path causes the laser beam deflected and scanned in the return path of the MEMS mirror 210C to be output from the optical deflector 313 after two reflections. Thus, by utilizing both the outgoing path and the return path of the reciprocating rotation of the MEMS mirror 210C, laser beams having the same scanning direction SD can be continuously emitted. Fig.17 As shown in the bottom curve, the half period in one frame period of the motion image signal can be used as an effective period for display. Therefore, in the field of projection type image display devices that modulate laser light according to image signals and project, a high brightness device can be provided. In addition, as for the optical path switching unit, the polarization device or the optical path conversion device can be changed as in the modified example of embodiment 2.

[0172] (Projection display device)

[0173] If the light deflector according to this embodiment is provided for each light of different colors, Figure 5 As shown, the rectangular illumination areas output by each of the illumination assemblies of different color lights can be deflected and scanned in a non-overlapping manner, and are enlarged and projected onto the reflective light modulation device.

[0174] [Other embodiments]

[0175] In addition, the present invention is not limited to the above-described embodiments and modifications, and many modifications are possible within the technical concept of the present invention. For example, all or part of the above-described different embodiments and modifications may be combined for implementation.

[0176] For example, in Embodiments 3 and 4, the laser light deflected by the MEMS mirror is reflected once in the first optical path and emitted as output light, and is reflected twice in the second optical path and emitted as output light. However, the number of times the laser light deflected by the MEMS mirror is reflected before being emitted is not limited to this example, and as long as the reflection is set to an odd number of times in the first optical path and the reflection is set to an even number of times in the second optical path, a laser beam deflected in the same scanning direction SD can be emitted.

[0177] This specification discloses at least the following matters.

[0178] [Item 1]

[0179] A scanning light source, characterized by comprising:

[0180] A laser light source comprises: a semiconductor laser and a collimating lens for collimating laser light outputted from the semiconductor laser; and

[0181] an optical deflector for deflecting the laser light outputted by the laser light source,

[0182] The light deflector comprises:

[0183] an optical path switching unit for switching, at a predetermined period, which of the first optical path and the second optical path the laser beam passes through in the optical deflector;

[0184] A first light deflection device, disposed in the first light path, having a light reflecting surface that performs reciprocating rotational motion; and

[0185] The second light deflection device is arranged in the second light path and has a light reflecting surface that performs reciprocating rotation motion.

[0186] The laser beam deflected and scanned by the first light deflecting device and the laser beam deflected and scanned by the second light deflecting device are output alternately from the light deflector every the predetermined period as laser beams deflected and scanned in the same direction.

[0187] [Item 2]

[0188] The scanning light source according to item 1 is characterized in that

[0189] The reciprocating rotational motion of the first light deflecting element and the reciprocating rotational motion of the second light deflecting element have the same period and phase.

[0190] [Item 3]

[0191] The scanning light source according to item 1 or 2 is characterized in that

[0192] The optical path switching unit includes a rotating body on which a light transmitting unit and a light reflecting unit are alternately arranged around a rotation axis, and the laser light incident from the laser light source travels along the first optical path when incident on the light transmitting unit, and travels along the second optical path when incident on the light reflecting unit.

[0193] [Item 4]

[0194] The scanning light source according to item 3 is characterized in that

[0195] The optical path switching unit causes the laser light deflected and scanned by the first optical deflection element in the first optical path to be reflected by the light reflecting unit and emitted, and causes the laser light deflected and scanned by the second optical deflection element in the second optical path to be transmitted through the light transmitting unit and emitted.

[0196] [Item 5]

[0197] The scanning light source according to item 3 is characterized in that

[0198] The rotating body includes a plurality of the light transmitting parts and a plurality of the light reflecting parts.

[0199] The optical path switching unit allows the laser light deflected and scanned by the first optical deflection element in the first optical path to be transmitted through the light transmitting unit and emitted, and allows the laser light deflected and scanned by the second optical deflection element in the second optical path to be reflected by the light reflecting unit and emitted.

[0200] [Item 6]

[0201] The scanning light source according to item 1 or item 2 is characterized in that:

[0202] The device comprises: a spatial modulation device for modulating the laser light outputted from the laser light source into P polarization and S polarization alternately at the predetermined period;

[0203] The optical path switching unit switches which of the first optical path and the second optical path the laser light outputted from the spatial modulation element passes through in the optical deflector according to whether the laser light outputted from the spatial modulation element is P-polarized light or S-polarized light.

[0204] [Item 7]

[0205] The scanning light source according to item 6 is characterized in that

[0206] The optical path switching unit includes a dichroic mirror that transmits one of the P-polarized light and the S-polarized light and reflects the other.

[0207] [Item 8]

[0208] The scanning light source according to item 6 is characterized in that

[0209] The optical path switching unit includes a PBS prism that transmits one of the P-polarized light and the S-polarized light and reflects the other.

[0210] [Item 9]

[0211] A scanning light source, characterized in that:

[0212] A laser light source comprises: a semiconductor laser and a collimating lens for collimating laser light outputted from the semiconductor laser; and

[0213] an optical deflector for deflecting the laser light outputted by the laser light source,

[0214] The light deflector comprises:

[0215] an optical path switching unit for switching, at a predetermined period, which of the first optical path and the second optical path the laser beam passes through in the optical deflector;

[0216] The light deflection device has a light reflecting surface that performs reciprocating rotation motion.

[0217] The laser that performs deflection scanning when the light reflecting surface of the light deflection device in the first optical path is a forward path of reciprocating rotational motion and the laser that performs deflection scanning when the light reflecting surface of the light deflection device in the second optical path is a return path of reciprocating rotational motion are output alternately from the light deflector every specified period as lasers that perform deflection scanning in the same direction.

[0218] [Item 10]

[0219] The scanning light source according to item 9 is characterized in that

[0220] The first optical path is an optical path that causes the laser to be emitted after being reflected an odd number of times after being reflected by the light reflecting surface when the light reflecting surface of the light deflection device is in a reciprocating rotational motion.

[0221] The second optical path is an optical path in which the laser beam is reflected an even number of times and then emitted after being reflected by the light reflecting surface when the light reflecting surface of the light deflection device is in a reciprocating rotation loop.

[0222] [Item 11]

[0223] The scanning light source according to item 9 or 10 is characterized in that

[0224] The optical path switching unit includes a rotating body on which a light transmitting unit and a light reflecting unit are alternately arranged around a rotation axis, and the laser light incident from the laser light source travels along the first optical path when incident on the light transmitting unit, and travels along the second optical path when incident on the light reflecting unit.

[0225] [Item 12]

[0226] The scanning light source according to item 9 or 10 is characterized in that

[0227] The device comprises: a spatial modulation device for modulating the laser light outputted from the laser light source into P polarization and S polarization alternately at the predetermined period;

[0228] The optical path switching section switches which of the first optical path and the second optical path the laser light passes through in the optical deflector according to whether the laser light outputted from the spatial modulation element is P-polarized light or S-polarized light.

[0229] [Item 13]

[0230] The scanning light source according to item 12 is characterized in that

[0231] The optical path switching unit includes a dichroic mirror that transmits one of the P-polarized light and the S-polarized light and reflects the other.

[0232] [Item 14]

[0233] A projection display device, characterized by comprising:

[0234] Laser light sources of different colors of light;

[0235] A scanning light source according to any one of items 1 to 13, provided for each of the laser light sources of light of different colors;

[0236] a light synthesis unit for synthesizing the light beams outputted by each of the scanning light sources in such a manner that the light beams of different colors do not overlap with each other;

[0237] an optical path conversion mirror for guiding the light outputted by the light synthesizing unit to the reflective light modulation device; and a projection lens for projecting the image light outputted by the reflective light modulation device.

Claims

1. A scanning light source, characterized in that: have: A laser light source comprising a semiconductor laser and a collimating lens for collimating laser light outputted from the semiconductor laser; and an optical deflector for deflecting the laser light outputted by the laser light source, The light deflector comprises: an optical path switching unit for switching, at a predetermined period, which of the first optical path and the second optical path the laser beam passes through in the optical deflector; A first light deflection device, disposed in the first light path, having a light reflecting surface that performs reciprocating rotational motion; and The second light deflection device is arranged in the second light path and has a light reflecting surface that performs reciprocating rotation motion. The laser beam deflected and scanned by the first light deflecting device and the laser beam deflected and scanned by the second light deflecting device are output alternately from the light deflector every the predetermined period as laser beams deflected and scanned in the same direction.

2. The scanning light source according to claim 1, characterized in that: The reciprocating rotational motion of the first light deflecting element and the reciprocating rotational motion of the second light deflecting element have the same period and phase.

3. The scanning light source according to claim 1, characterized in that: The optical path switching unit includes a rotating body on which a light transmitting unit and a light reflecting unit are alternately arranged around a rotation axis, and the laser light incident from the laser light source travels along the first optical path when incident on the light transmitting unit, and travels along the second optical path when incident on the light reflecting unit.

4. The scanning light source according to claim 3, characterized in that: The optical path switching unit causes the laser light deflected and scanned by the first optical deflection element in the first optical path to be reflected by the light reflecting unit and emitted, and causes the laser light deflected and scanned by the second optical deflection element in the second optical path to be transmitted through the light transmitting unit and emitted.

5. The scanning light source according to claim 3, characterized in that: The rotating body includes a plurality of the light transmitting parts and a plurality of the light reflecting parts. The optical path switching unit allows the laser light deflected and scanned by the first optical deflection element in the first optical path to be transmitted through the light transmitting unit and emitted, and allows the laser light deflected and scanned by the second optical deflection element in the second optical path to be reflected by the light reflecting unit and emitted.

6. The scanning light source according to claim 1, characterized in that: The device comprises: a spatial modulation device for modulating the laser light outputted from the laser light source into P polarization and S polarization alternately at the predetermined period; The optical path switching unit switches which of the first optical path and the second optical path the laser light outputted from the spatial modulation element passes through in the optical deflector according to whether the laser light outputted from the spatial modulation element is P-polarized light or S-polarized light.

7. The scanning light source according to claim 6, characterized in that: The optical path switching unit includes a dichroic mirror that transmits one of the P-polarized light and the S-polarized light and reflects the other.

8. The scanning light source according to claim 6, characterized in that: The optical path switching unit includes a polarization splitting prism that transmits one of the P-polarized light and the S-polarized light and reflects the other.

9. A scanning light source, characterized in that: A laser light source comprising a semiconductor laser and a collimating lens for collimating laser light outputted from the semiconductor laser; and an optical deflector for deflecting the laser light outputted by the laser light source, The light deflector comprises: an optical path switching unit that switches, at a predetermined period, which of the first optical path and the second optical path the laser light passes through in the optical deflector; and The light deflection device has a light reflecting surface that performs reciprocating rotation motion. The laser that performs deflection scanning when the light reflecting surface of the light deflection device in the first optical path is a forward path of reciprocating rotational motion and the laser that performs deflection scanning when the light reflecting surface of the light deflection device in the second optical path is a return path of reciprocating rotational motion are output alternately from the light deflector every specified period as lasers that perform deflection scanning in the same direction.

10. The scanning light source according to claim 9, characterized in that: The first optical path is an optical path that causes the laser to be emitted after being reflected an odd number of times after being reflected by the light reflecting surface when the light reflecting surface of the light deflection device is in a reciprocating rotational motion. The second optical path is an optical path in which the laser beam is reflected an even number of times and then emitted after being reflected by the light reflecting surface when the light reflecting surface of the light deflection device is in a reciprocating rotation loop.

11. The scanning light source according to claim 9, characterized in that: The optical path switching unit includes a rotating body on which a light transmitting unit and a light reflecting unit are alternately arranged around a rotation axis, and the laser light incident from the laser light source travels along the first optical path when incident on the light transmitting unit, and travels along the second optical path when incident on the light reflecting unit.

12. The scanning light source according to claim 9, characterized in that: The device comprises: a spatial modulation device for modulating the laser light outputted from the laser light source into P polarization and S polarization alternately at the predetermined period; The optical path switching section switches which of the first optical path and the second optical path the laser light passes through in the optical deflector according to whether the laser light outputted from the spatial modulation element is P-polarized light or S-polarized light.

13. The scanning light source according to claim 12, characterized in that: The optical path switching unit includes a dichroic mirror that transmits one of the P-polarized light and the S-polarized light and reflects the other.

14. A projection display device comprising: Laser light sources of different colors of light; A scanning light source according to any one of claims 1 to 13, provided for each of the laser light sources of light of different colors; a light synthesis unit for synthesizing the light beams outputted by each of the scanning light sources in such a manner that the light beams of different colors do not overlap with each other; an optical path conversion mirror, for guiding the light outputted from the optical synthesis unit to a reflective optical modulation device; and The projection lens projects the image light output by the reflective light modulation device.

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