Scanning type light source, and projection type display device

Abstract

To solve the problem in which: in the field of a projection type image display device modulating and projecting a laser beam according to an image signal, a scanning type light source capable of achieving a high-luminance display device has been demanded.SOLUTION: A scanning type light source comprises: a laser light source that includes a semiconductor laser, and a collimator lens collimating a laser beam output from the semiconductor laser; and an optical deflector that deflects the laser beam output from the laser light source. The optical deflector includes an optical path switching unit that switches, in a predetermined period, between a first optical path and a second optical path in the optical deflector through which the laser beam passes; a first optical deflection element that is arranged on the first optical path and includes a light reflection surface making a reciprocating rotating motion; and a second optical deflection element that is arranged on the second optical path and includes a light reflection surface making a reciprocating rotating motion. The laser beam deflected and scanned by the first optical deflection element, and the laser beam deflected and scanned by the second optical deflection element are alternately output from the optical deflector for every predetermined period as a laser beam deflected and scanned in the same direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Projection display devices using laser light have been known for some time. Patent Document 1 discloses a projection display device including a laser light source, an acousto-optic modulator that optically modulates the laser light in response to a video signal, a polygonal mirror that horizontally scans the modulated laser light, and a galvanometer mirror that vertically scans the modulated laser light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-180759 A Summary of the Invention [Problem to be solved by the invention]

[0004] The projection display device described in Patent Document 1 is equipped with an optical scanning means that combines a polygonal mirror for horizontal scanning and a galvanometer mirror for vertical scanning. However, because optical scanning is performed in both the horizontal and vertical directions, a large optical path space is required, resulting in a problem of the device becoming large.

[0005] Therefore, a projection display device equipped with an optical system that uses, for example, a MEMS mirror (Micro Electro Mechanical Systems Mirror) to scan laser light in one direction and illuminate a light modulation element is conceivable. Figure 18(a) shows a schematic diagram of a 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 rotating the mirror surface M back and forth around the rotation axis BX.

[0006] However, in an optical scanning device that rotates the mirror surface M back and forth, such as a MEMS mirror, the laser light can be scanned in only one direction (either the forward or backward path) of the reciprocating motion. For example, if it is desired to deflect and scan the laser light only from the +θ direction to the -θ direction, only half of one scanning period (one period of reciprocating rotation) can be used. The dotted line graph at the bottom of Figure 18(b) shows the time transition of the reflection direction of the mirror surface M. As shown in the figure, the graph of the reflection direction of the mirror surface M draws a SIN curve, but scanning from the +θ direction to the -θ direction is only half of one scanning period. Moreover, in order to increase the uniformity of the scanning speed to a certain extent, the vicinity of the apex of the SIN curve needs to be excluded from the scanning period. Therefore, only the part indicated by the solid arrow SCAN can be used as the effective scanning period. As shown in the upper graph of Figure 18(b), it is possible to reduce power consumption by turning on the laser light only during the effective scanning period, but since the light modulation element can only be illuminated for less than half of one scanning period, the brightness of the projection display device could not be increased.

[0007] In the field of projection type image display devices that modulate and project laser light in response to image signals, a scanning light source capable of realizing a high-brightness display device has been desired. [Means for solving the problem]

[0008] A first aspect of the present invention is a scanning light source comprising: a laser light source having a semiconductor laser and a collimating lens that collimates laser light output by the semiconductor laser; and an optical deflector that deflects the laser light output by the laser light source, wherein the optical deflector comprises an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path in the optical deflector; a first optical deflection element that is disposed on the first optical path and has an optical reflection surface that rotates back and forth; and a second optical deflection element that is disposed on the second optical path and has an optical reflection surface that rotates back and forth, wherein the laser light deflected and scanned by the first optical deflection element and the laser light deflected and scanned by the second optical deflection element are alternately output from the optical deflector at each of the predetermined periods as laser light deflected and scanned in the same direction.

[0009] A second aspect of the present invention is a scanning light source comprising: a laser light source having a semiconductor laser and a collimating lens that collimates laser light output by the semiconductor laser; and an optical deflector that deflects the laser light output by the laser light source, wherein the optical deflector comprises an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path within the optical deflector; and an optical deflection element having a light reflecting surface that rotates back and forth, wherein the laser light in the first optical path that is deflected and scanned by the light reflecting surface of the optical deflection element during the outward path of the reciprocating rotational motion, and the laser light in the second optical path that is scanned by the light reflecting surface of the optical deflection element during the return path of the reciprocating rotational motion are output alternately from the optical deflector at each of the predetermined periods as laser light deflected and scanned in the same direction. Effect of the Invention

[0010] According to the present invention, in the field of projection type image display devices that modulate and project laser light in response to an image signal, it is possible to provide a scanning light source that can realize a high-brightness display device. [Brief description of the drawings]

[0011] [Figure 1]1A is a schematic diagram showing the configuration of an optical deflector 310 according to the embodiment 1. FIG. [Diagram 2] 2(a) is a diagram showing an optical path (first optical path) when the laser light irradiates a transparent portion TA, and FIG. 2(b) is a diagram showing a spot position of the laser light on an optical path switching unit 501 at the timing of FIG. [Diagram 3] 3(a) is a diagram showing an optical path (second optical path) when the laser light is irradiated onto a reflecting portion RA, and (b) is a diagram showing the spot position of the laser light on an optical path switching portion 501 at the timing of FIG. [Figure 4] FIG. 4 is a diagram showing the operation timing of each unit in the first embodiment. [Diagram 5] 1 shows a color projection display device configured using an optical deflector according to an embodiment. [Figure 6] 1A is a diagram showing the relationship between the screen of the reflective light modulation element 340 and the scanning range SA of the rectangular laser beam, and FIG. 1B is a diagram showing how the screen of the reflective light modulation element 340 is irradiated with rectangular B beams, G beams, and R beams. [Figure 7] 1A is a schematic diagram showing the configuration of an optical deflector 310A according to a modified example of Embodiment 1. FIG. 1B is a plan view of an optical path switching unit 501A included in the optical deflector 310A according to the modified example. [Figure 8] 1A is a schematic diagram showing the configuration of an optical deflector 311 according to embodiment 2. FIG. 1B is a schematic diagram showing the configuration of an optical deflector 311A ​​according to modified example 1 of embodiment 2. [Figure 9] 5A is a diagram showing an optical path (first optical path) when laser light is modulated to P-polarized light by a spatial modulation element 502. FIG. 5B is a diagram showing an optical path (second optical path) when laser light is modulated to S-polarized light by a spatial modulation element 502. [Figure 10] FIG. 10 is a diagram showing the operation timing of each unit in the second embodiment. [Figure 11] FIG. 11 is a schematic diagram showing a configuration of an optical deflector according to a second modification of the second embodiment. [Figure 12] FIG. 11 is a schematic diagram showing a configuration of an optical deflector according to a third modification of the second embodiment. [Figure 13]13(a) is a diagram showing an optical path (first optical path) when the laser light irradiates the transparent portion TA in embodiment 3. (b) is a diagram showing the spot position of the laser light on the optical path switching unit 501 at the timing of FIG. [Figure 14] 14(a) is a diagram showing an optical path (second optical path) when the laser light irradiates the reflecting portion RA in embodiment 3. (b) is a diagram showing the spot position of the laser light on the optical path switching unit 501 at the timing of FIG. [Figure 15] FIG. 11 is a diagram showing the operation timing of each unit in the third embodiment. [Figure 16] 13A is a diagram showing an optical path (first optical path) when laser light is modulated to P-polarized light by a spatial modulation element 502 in embodiment 4. FIG. 13B is a diagram showing an optical path (second optical path) when laser light is modulated to S-polarized light by a spatial modulation element 502 in embodiment 4. [Figure 17] FIG. 13 is a diagram showing the operation timing of each unit in the fourth embodiment. [Figure 18] (a) A schematic diagram of a MEMS mirror, (b) A diagram showing a conventional deflection scanning method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A projection display device according to an embodiment of the present invention will be described with reference to the drawings. The following embodiment is an example, and those skilled in the art can appropriately change the detailed configuration without departing from the spirit of the present invention. In the drawings referred to in the following embodiment and description, elements with the same reference numbers have the same functions unless otherwise noted. Since the optical elements in the drawings are shown diagrammatically, the actual shapes and configurations are not necessarily faithfully represented. For example, even if a single lens is depicted in the drawings, it may be composed of multiple lenses unless otherwise noted.

[0013] In the following description, for example, when the X-plus direction is described, it refers to the same direction as the X-axis arrow in the illustrated coordinate system, and when the X-minus direction is described, it refers to the direction 180 degrees opposite to the X-axis arrow in the illustrated coordinate system. Also, when the X-direction is simply described, it refers to the direction parallel to the X-axis, regardless of whether it is different from the direction indicated by the X-axis arrow in the drawings. The same applies to directions other than X.

[0014] In the following description, red may be referred to as "R", green as "G", and blue as "B". Therefore, for example, R light is synonymous with red light, G light source is synonymous with green light source, and B laser is synonymous with blue laser.

[0015] [Embodiment 1] As described later, the projection display device according to the embodiment includes light sources (B light source, G light source, R light source) and optical deflectors corresponding to the respective colors (B optical deflector 310B, G optical deflector 310G, R optical deflector 310R). The B optical deflector 310B, G optical deflector 310G, and R optical deflector 310R are optical deflectors used to deflect and scan laser beams of different colors, but have the same basic configuration, and therefore may be described below as optical deflector 310 without specifying a color.

[0016] (light deflector) Fig. 1(a) is a schematic diagram showing the configuration of a scanning light source according to the first embodiment, and Fig. 1(b) is a plan view of an optical path switching unit 501 included in an optical deflector 310. In Fig. 1(a), the optical deflector 310 is surrounded by a dotted line. The laser module LM includes a semiconductor laser 12 and a collimator lens 102, and the laser light emitted from the laser module LM is incident on the optical deflector 310.

[0017] The optical deflector 310 includes a MEMS mirror 210A, a MEMS mirror 210B, and an optical path switching unit 501. The MEMS mirror 210A as an optical deflection element can reflect incident light at a deflection angle according to the rotation angle of the mirror surface MA by rotating the mirror surface MA (light reflecting surface) back and forth around the rotation axis BX. Similarly, the MEMS mirror 210B as an optical deflection element can reflect incident light at a deflection angle according to the rotation angle of the mirror surface MB by rotating the mirror surface MB (light reflecting surface) back and forth around the rotation axis BX.

[0018] The optical path switching unit 501 is a disk-shaped member, and can be rotated at a predetermined speed around a rotation axis AX by a motor MT. The rotation of the motor MT is controlled so as to synchronize with frame switching of a moving image displayed by the reflective light modulation element. That is, the optical path switching unit 501 switches between a first optical path and a second optical path, which will be described later, at a predetermined cycle so as to synchronize with the frame frequency of the image.

[0019] 1(b), the optical path switching unit 501 is half-transmitting area TA (light transmitting area) that transmits the laser light, and half-reflecting area RA (light reflecting area) that reflects the laser light. Since the optical path switching unit 501 rotates continuously, the laser light incident on the optical deflector 310 from the laser module LM irradiates either the transmitting area TA or the reflecting area RA depending on the timing.

[0020] Fig. 2(a) shows by a solid line the optical path (first optical path) when the laser light emitted from the laser module LM irradiates the transmission area TA, and Fig. 2(b) shows by a dotted circle the spot position of the laser light on the optical path switching unit 501 at the timing of Fig. 2(a). Fig. 3(a) shows by a dotted line the optical path (second optical path) when the laser light emitted from the laser module LM irradiates the reflection area RA, and Fig. 3(b) shows by a dotted circle the spot position of the laser light on the optical path switching unit 501 at the timing of Fig. 3(a).

[0021] As shown in FIG. 2(a), at the timing when the laser light emitted from the laser module LM irradiates the transmission part TA of the optical path switching unit 501, the laser light passes through the transmission part TA and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MA, so that the laser light is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MA is reflected by the reflection part RA of the optical path switching unit 501, output from the optical deflector 310, and used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 2(a), the optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector 310 can be called the first optical path.

[0022] On the other hand, as shown in FIG. 3(a), when the laser light emitted from the laser module LM irradiates the reflecting portion RA of the optical path switching unit 501, the laser light is reflected by the reflecting portion RA and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MB, so that the laser light is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MB passes through the transmitting portion TA of the optical path switching unit 501, is output from the optical deflector 310, and is used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 3(a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector 310 can be called the second optical path.

[0023] The graph shown in FIG. 4 shows, from the top, the timing of turning on the laser module LM, the timing when the laser light passes through the first optical path in the optical deflector 310, the timing when the laser light passes through the second optical path in the optical deflector 310, the angles of the mirror surfaces of the MEMS mirror 210A and the MEMS mirror 210B, and the deflection direction of the laser light deflected and scanned by the optical deflector 310 and output. 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 scanned in one direction is output from the optical deflector 310 can be called the effective period, and the period during which it is not output can be called the blanking period. When illuminating the reflective optical modulation element 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 modulation element. This makes it possible to display one frame of an image of a moving image using the effective period, and to adjust the synchronization with the image signal using the blanking period.

[0024] According to this embodiment, the laser light is deflected and scanned by alternately using two MEMS mirrors and extracted in the same scanning direction SD using the first and second optical paths, so that the majority of one frame period of the moving image signal can be used for display as an effective period, as shown in the bottom graph of Fig. 4. Therefore, a high-brightness device can be provided in the field of projection type image display devices that modulate and project laser light according to an image signal.

[0025] (Projection type display device) Next, an example of a color projection display device using the above-mentioned optical deflector will be described with reference to Fig. 5. Fig. 5 is a diagram showing a schematic configuration of an optical system of the projection display device according to embodiment 1. For ease of explanation, mechanical mechanisms for installing optical elements, a housing, electrical wiring, etc. are omitted in the figure.

[0026] [Overall configuration] The projection display device 1000 includes a B light source, a G light source, an R light source, a B optical deflector 310B, a G optical deflector 310G, an R optical deflector 310R, a light combining unit 220, an optical path conversion mirror 330, a TIR prism 350, a reflective optical modulation element 340, and a projection lens 360. In addition, a condenser lens 103, a rod 105, and a relay lens (front convex lens 106a) are disposed between the light sources of each color and the deflectors of each color, and a collimator lens 201 (second collimator lens) is disposed between the deflectors of each color and the light combining unit 220. In addition, the projection display device 1000 may include a projection screen 190 as an option.

[0027] The B light source includes a laser module LM-B including a semiconductor laser that emits B light, the G light source includes a laser module LM-G including a semiconductor laser that emits G light, and the R light source includes a laser module LM-R including a semiconductor laser that emits R light.

[0028] The B optical deflector 310B is a deflector that continuously deflects the B light emitted by the B light source 100B in one direction. Similarly, the G optical deflector 310G is a deflector that continuously deflects the G light emitted by the G light source 100G in one direction, and the R optical deflector 310R is a deflector that continuously deflects the R light emitted by the R light source 100R in one direction. The deflectors have already been described with reference to Figs. 1 to 4.

[0029] However, in the configuration shown in Fig. 1, the laser light emitted from the laser module LM is directly input to the optical deflector 310. Although a projection type display device may be implemented using a similar configuration, the projection type display device 1000 shown in Fig. 5 employs a so-called integrator illumination system. That is, a condenser lens 103, a 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, relay lenses (rear convex lens 106b) are arranged between the optical path switching unit 501 and the MEMS mirror 210A and between the optical path switching unit 501 and the MEMS mirror 210B, respectively.

[0030] The laser beams emitted from each of the semiconductor lasers included in the laser module LM are made approximately parallel by the action of the collimating lens 102 (FIG. 1). The approximately collimated laser beams output from the laser module LM are focused by the focusing lens 103 toward the incident surface of the rod 105. In the figure, the focusing lens 103 is shown as a single convex lens, but it may be composed of multiple lenses for the purpose of suppressing aberration, etc.

[0031] A diffusion element (not shown) is disposed near the entrance surface of rod 105, and the laser beam diffused by the diffusion element enters rod 105 from the entrance surface. The beam output from laser module LM has better divergence in the short direction of the rectangle as viewed in the optical path cross section than in the long direction, so that the light intake loss at the entrance surface of rod 105 can be suppressed and the utilization efficiency can be improved. The light incident on rod 105 is repeatedly totally reflected at the side surface before being emitted from the exit surface, and the illuminance distribution at the exit surface can be made uniform by appropriately setting the diffusion ability (diffusion angle) of the diffusion element and the length of rod 105.

[0032] By transferring the image emitted from the emission surface of the rod 105 with a relay lens, a rectangular irradiation area with high uniformity of illuminance can be obtained. By appropriately setting the transfer magnification of the relay lens, it is possible to obtain an irradiation area of ​​a desired size, which can be reduced, equal, or enlarged. In FIG. 5, the relay lens is composed of two lenses, a front convex lens 106a and a rear convex lens 106b, but the configuration of the relay lens is not limited to this example.

[0033] A collimator lens 201 is provided between the B optical deflector 310B and the light combining unit 220. Even if the B light (dotted line) is deflected by the B optical deflector 310B, the action of the collimator lens 201 causes the B light to enter the light combining unit 220 as a light beam parallel to the X direction.

[0034] A collimator lens 201 is provided between the G optical deflector 310G and the light combining unit 220. Even if the G light (solid line) is deflected by the G optical deflector 310G, the action of the collimator lens 201 causes the G light to enter the light combining unit 220 as a light beam parallel to the Z direction.

[0035] A collimator lens 201 is provided between the R optical deflector 310R and the light combining unit 220. Even if the R light (dashed line) is deflected by the R optical deflector 310R, the action of the collimator lens 201 causes the R light to enter the light combining unit 220 as a light beam parallel to the X direction.

[0036] 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 B light and transmitting G light. The dichroic mirror 222 has an optical characteristic of transmitting G light and B light and reflecting R light. On the dichroic mirror 221, each element is arranged so that the optical axis center of the collimating lens 201 for B light and the optical axis center of the collimating lens 201 for G light overlap. Also, on the dichroic mirror 222, each element is arranged so that the optical axis center of the collimating lens 201 for B light, the optical axis center of the collimating lens 201 for G light, and the optical axis center of the collimating lens 201 for R light overlap.

[0037] The light combining unit 220 aligns the directions of travel of the B light (dotted line), G light (solid line), and R light (dash-dotted line) in the Z plus direction, but combines these lights so that they do not overlap with each other at any timing. This is because the timing (deflection phase) of the deflection scanning by the B light deflector 310B, G light deflector 310G, and R light deflector 310R is controlled so that the B light, G light, and R light do not overlap with each other on the screen of the reflective light modulation element 340.

[0038] The B light, G light, and R light emitted from the light combining unit 220 have their course changed to the X-positive direction by the optical path conversion mirror 330, and enter the TIR prism 350. The TIR prism 350 is a total internal reflection prism formed by combining, for example, two prisms, and totally reflects the illumination light (B light, G light, and R light) at an air gap surface, causing it to enter the reflective light modulation element 340 at a predetermined angle. As described above, the B light, G light, and R light each illuminate a part of the screen of the reflective light modulation element 340 so as not to overlap each other.

[0039] B light (dotted line), G light (solid line), and R light (dash line) each form a rectangular illumination area, and are enlarged and transferred at a predetermined magnification onto the screen of the reflective light modulation element 340 by a transfer optical system consisting of a collimator lens 201 (front transfer lens) and a rear transfer lens 202.

[0040] The reflective light modulation element 340 may be, for example, a DMD (Digital Micromirror Device) in which micromirror devices are arranged in an array. The micromirrors corresponding to the respective display pixels are driven so that the reflection direction is changed by pulse width modulation according to the luminance level of the video signal. However, it is also possible to use other types of reflective light modulation devices, such as a reflective liquid crystal device.

[0041] The pixels in the screen area illuminated with the B light are driven according to the luminance level of the B component of the video signal, and reflect the B video light toward the TIR prism 350 at a predetermined angle. Similarly, the pixels in the screen area illuminated with the G light are driven according to the luminance level of the G component of the video signal, and reflect the G video light toward the TIR prism 350 at a predetermined angle. Moreover, the pixels in the screen area illuminated with the R light are driven according to the luminance level of the R component of the video signal, and reflect the R video light toward the TIR prism 350 at a predetermined angle. In this way, the reflective optical modulation device is driven in synchronization with the timing of the deflection scanning by the B optical deflector 310B, the G optical deflector 310G, and the R optical deflector 310R, and modulates the laser light for illumination.

[0042] The image light (B image light, G image light, R image light) passes through the TIR prism 350, is guided to the projection lens 360, and is projected as a color image. The projection lens 360 is composed of one or more lenses, and may also have an automatic focus adjustment function and a zoom function.

[0043] The projection screen 190 is used when configuring a rear projection type display device. It is also often installed in front projection types, but it is not necessarily required to install one if the user wants to project onto a wall or other surface.

[0044] 6(a) shows the relationship between the screen of the reflective light modulation element 340 and the scanning range SA of the rectangular laser beam. If the screen size of the reflective light modulation element 340 is H (horizontal direction) × V (vertical direction), the scanning range SA of the rectangular laser beam covers an area of ​​H' × V' that is larger than the screen size. Note that the scanning range SA of the rectangular laser beam is enlarged by a predetermined transfer magnification by the transfer optical system, relative to the scanning range in which the rectangular irradiation area is scanned by the optical deflector 310.

[0045] 6(b) is a diagram showing how rectangular B, G, and R beams are irradiated onto the screen of the reflective light modulation element 340, with the horizontal axis being the time axis. The B, G, and R beams vertically scan the screen of the reflective light modulation element 340 along the scanning direction SD, completing the scanning of one screen in one frame time. In order to prevent color mixing at the boundary between each color region, the B, G, and R beams are configured not to overlap each other, and the vertical width V2 of each beam is necessarily configured to be 1 / 3 or less of V'. The vertical width of each beam can be set to be 1 / 6 or more and 1 / 3 or less of the vertical width of the screen of the reflective light modulation element 340.

[0046] As described above, the projection display device of this embodiment includes lighting units each having a plurality of semiconductor lasers, a collimator lens, an integrator lighting system, and an optical deflector, each of which is provided for a different color of light, and includes a light combining section that combines the lighting lights output by the lighting units of different color lights, and the rectangular lighting areas output by the lighting units of different color lights are enlarged and transferred to a reflective light modulation element while being deflected and scanned so as not to overlap each other. According to this embodiment, a high-brightness device can be provided in the field of projection image display devices that modulate and project laser light according to an image signal.

[0047] [Modification of the first embodiment] (light deflector) A modified example of the first embodiment will be described. Explanation of matters common to those already described will be omitted here. FIG. 7(a) is a schematic diagram showing the configuration of an optical deflector 310A according to a modified example of the first embodiment, and FIG. 7(b) is a plan view of an optical path switching unit 501A included in the optical deflector 310A. The optical deflector 310A according to the modified example also includes a MEMS mirror 210A and a MEMS mirror 210B. However, as can be seen by comparing FIG. 7(b) with FIG. 1(b), the arrangement of the transmission portion TA and the reflection portion RA in the optical deflector is different.

[0048] As shown in FIG. 7(b), in the light path switching unit 501A of the modified example, two transmitting portions TA that transmit laser light and two reflecting portions RA that reflect laser light are provided in four locations in total. Each of the transmitting portions TA and the reflecting portions RA is fan-shaped with an angle of 90 degrees, and the transmitting portions TA face each other across the rotation axis AX, and the reflecting portions RA face each other across the rotation axis AX. In other words, the main surface of the light path switching unit according to the first embodiment is divided into an even number of portions around the rotation axis AX (two portions in the example of FIG. 1(b) and four portions in the example of FIG. 7(b)), and when rotating around the rotation axis AX, the output light of the laser module LM is alternately irradiated onto the transmitting portions TA and the reflecting portions RA. The number of portions into which the main surface of the light path switching unit is divided is not limited to two or four, and may be any other even number.

[0049] 7(a), for convenience of illustration, both the case where the output light of the laser module LM irradiates the transmitting portion TA and the case where the output light of the laser module LM irradiates the reflecting portion RA are shown together. That is, the optical path (first optical path) when the laser light emitted from the laser module LM irradiates the transmitting portion TA is shown by a solid line, and the optical path (second optical path) when the laser light emitted from the laser module LM irradiates the reflecting portion RA is shown by a dotted line.

[0050] At the timing when the laser light emitted from the laser module LM irradiates the transmission part TA of the optical path switching unit 501A, the laser light passes through the transmission part TA and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MA, so that it is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MA passes through the transmission part TA located on the opposite side of the rotation axis AX, and is output from the optical deflector 310A and used as illumination light for illuminating the reflective optical modulation element. The optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector 310A can be called the first optical path.

[0051] On the other hand, at the timing when the laser light emitted from the laser module LM irradiates the reflecting portion RA of the optical path switching unit 501A, the laser light is reflected by the reflecting portion RA and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MB, so that it is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MB is reflected by the reflecting portion RA located on the opposite side across the rotation axis AX, and is output from the optical deflector 310A and used as illumination light for illuminating the reflective optical modulation element. The optical path when the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector 310A can be called the second optical path.

[0052] 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.

[0053] (Projection type display device) If an optical deflector according to this modification is provided for each different color light, the rectangular illumination areas output by each of the illumination units of different color lights can be enlarged and transferred onto a reflective light modulation element while being deflected and scanned so as not to overlap each other, as shown in Fig. 5. In this modification, the drive timing of each element is controlled so that a quarter rotation of the optical path switching unit 501A corresponds to one frame period of the image. As described above, according to this embodiment, a high-brightness device can be provided in the field of projection type image display devices that modulate and project laser light according to an image signal.

[0054] [Embodiment 2] A scanning light source, a projection display device, and the like according to embodiment 2 will be described with reference to the drawings. Descriptions common to embodiment 1 will be simplified or omitted.

[0055] (light deflector) Fig. 8(a) is a schematic diagram showing the configuration of an optical deflector 311 according to embodiment 2. In Fig. 8(a), the optical deflector 311 is surrounded by a dotted line. The laser module LM includes a semiconductor laser 12 and a collimator lens 102, and the laser light emitted from the laser module LM is incident on the optical deflector 311.

[0056] The optical deflector 311 is the same as in the first embodiment in that it includes a MEMS mirror 210A and a MEMS mirror 210B, but the configuration of the optical path switching unit that switches between the first optical path and the second optical path is different from that in the first embodiment. In the first embodiment, the optical path switching unit includes a rotor in which the transmission sections TA and the reflection sections RA are alternately arranged around the rotation axis AX. In contrast, the optical path switching unit of this embodiment shown in FIG. 8(a) includes a transmission type spatial modulation element 502, a polarizing beam splitter 503A, and a polarizing beam splitter 503B.

[0057] The transmissive spatial modulation element 502 can alternately modulate the linearly polarized light output by the laser module LM into P-polarized light and S-polarized light in synchronization with one frame period of the image. The polarizing beam splitter 503A has the optical property of transmitting P-polarized light and reflecting S-polarized light. The polarizing beam splitter 503B also has the optical property of transmitting P-polarized light and reflecting S-polarized light.

[0058] Figure 9(a) shows, with a solid line, the optical path (first optical path) when the laser light emitted from the laser module LM is modulated to P polarization by the spatial modulation element 502, and Figure 9(b) shows, with a dotted line, the optical path (second optical path) when the laser light emitted from the laser module LM is modulated to S polarization by the spatial modulation element 502.

[0059] As shown in FIG. 9(a), when the laser light emitted from the laser module LM is modulated to P-polarized light, the laser light passes through the polarizing beam splitter 503A and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MA, so that the laser light is deflected and scanned in a direction according to the irradiation timing. The laser light reflected by the mirror surface MA passes through the polarizing beam splitter 503B, is output from the optical deflector 311, and is used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 9(a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector 311 can be called the first optical path.

[0060] On the other hand, as shown in FIG. 9(b), when the laser light emitted from the laser module LM is modulated to S-polarized light, the laser light is reflected by the polarizing beam splitter 503A and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MB, so that the laser light is deflected and scanned in a direction according to the irradiation timing. The laser light reflected by the mirror surface MB is reflected by the polarizing beam splitter 503B and output from the optical deflector 311, and is used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 9(b), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector 311 can be called the second optical path.

[0061] The graph shown in FIG. 10 shows, from the top, the timing of turning on the laser module LM, the output of the spatial light modulation element 502, the timing when the laser light passes through the first optical path in the optical deflector 311, the timing when the laser light passes through the second optical path in the optical deflector 311, and the deflection direction of the laser light deflected and scanned by the optical deflector 311 and output. 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 scanned in one direction is output from the optical deflector 311 can be called the effective period, and the period during which it is not output can be called the blanking period. When illuminating the reflective optical modulation element 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 element. This allows the effective period to be used to display one frame of an image of a moving image, and the blanking period to be used to perform synchronization adjustment with the image signal.

[0062] According to this embodiment, by alternately using two MEMS mirrors to extract laser light deflected and scanned in one direction, more than half of one frame period of a moving image signal can be used for display as an effective period, as shown in the bottom graph of Fig. 10. Therefore, in the field of projection type image display devices that modulate and project laser light according to an image signal, a high-brightness device can be provided.

[0063] [Modification 1 of the second embodiment] (light deflector) A first modified example of the second embodiment will be described. Explanation of matters common to those already described will be omitted here. Fig. 8(b) is a schematic diagram showing the configuration of an optical deflector 311A ​​according to a first modified example of the second embodiment. For convenience of illustration, Fig. 8(b) shows both the case where the output of the spatial modulation element 502 is P-polarized light and the case where the output of the spatial modulation element 502 is S-polarized light.

[0064] In the example of Fig. 8(a), the laser module LM and the spatial modulation element 502 are arranged above the optical deflector 311 on the drawing, but in this modification, these are arranged to the left of the optical deflector 311A. When constructing a projection type display device, this modification can be used when it is difficult to install the configuration of Fig. 8(a) due to spatial restrictions.

[0065] In this modified example, polarizing beam splitter 503A has the optical property of transmitting P polarized light and reflecting S polarized light, while polarizing beam splitter 504 has the optical property of reflecting P polarized light and transmitting S polarized light.

[0066] [Modification 2 of the second embodiment] (light deflector) Modification 2 of embodiment 2 will be described. Explanation of matters common to those already described will be omitted here. Fig. 11 is a schematic diagram showing the configuration of an optical deflector according to modification 2 of embodiment 2. For convenience of illustration, Fig. 11 shows both the case where the output of spatial modulation element 502A is P-polarized light and the case where it is S-polarized light.

[0067] 8(a) uses a transmissive spatial light modulation element 502, but this modification employs a reflective spatial light modulation element 502A. This modification can be suitably used depending on the spatial constraints imposed when constructing a projection display device. In this modification, polarizing beam splitter 504A and polarizing beam splitter 504B have the optical property of reflecting P-polarized light and transmitting S-polarized light.

[0068] [Modification 3 of embodiment 2] (light deflector) Modification 3 of embodiment 2 will be described. Explanation of matters common to those already described will be omitted here. Fig. 12 is a schematic diagram showing the configuration of an optical deflector according to modification 3 of embodiment 2. For convenience of illustration, Fig. 12 shows both the case where the output of spatial modulation element 502 is P-polarized light and the case where it is S-polarized light.

[0069] In the example of Figure 8(a), polarizing beam splitter 503A and polarizing beam splitter 503B are used to switch the optical paths of P polarized light and S polarized light, but this modified example includes a cube-shaped PBS prism 505 and two quarter-wave plates 506.

[0070] When the laser light emitted from the laser module LM is modulated to P-polarized light, the laser light passes through the PBS prism 505 and irradiates the MEMS mirror 210A. The mirror surface MA of the MEMS mirror 210A rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MA, so that it is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MA becomes S-polarized light because it passes through the quarter-wave plate 506 twice, is reflected by the PBS prism 505, is output from the optical deflector, and is used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 12, the optical path when the laser light is deflected and scanned by the MEMS mirror 210A in the optical deflector can be called the first optical path.

[0071] On the other hand, as shown in FIG. 12, when the laser light emitted from the laser module LM is modulated to S-polarized light, the laser light is reflected by the PBS prism 505 and irradiates the MEMS mirror 210B. The mirror surface MB of the MEMS mirror 210B rotates back and forth around the rotation axis BX, and the laser light is reflected by the mirror surface MB, so that it is deflected in a direction according to the irradiation timing and scanned. The laser light reflected by the mirror surface MB becomes P-polarized light because it passes through the quarter-wave plate 506 twice, passes through the PBS prism 505, is output from the optical deflector, and is used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 12, the optical path in which the laser light is deflected and scanned by the MEMS mirror 210B in the optical deflector can be called the second optical path.

[0072] 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.

[0073] (Projection type display device) By providing an optical deflector according to the second embodiment or its modified example for each different color of light, as shown in FIG. 5, the rectangular illumination areas output by each of the illumination units of different colored light can be enlarged and transferred onto a reflective light modulation element while being deflected and scanned so as not to overlap each other.

[0074] According to this embodiment, by alternately using two MEMS mirrors to deflect and scan the laser light in one direction, as shown in the bottom graph of Fig. 10, more than half of one frame period of a moving image signal can be used for display as an effective period. Therefore, in the field of projection type image display devices that modulate and project laser light according to an image signal, a high-brightness device can be provided. According to this embodiment, in the field of projection type image display devices that modulate and project laser light according to an image signal, a high-brightness device can be provided.

[0075] [Embodiment 3] A scanning light source, a projection display device, and the like according to embodiment 3 will be described with reference to the drawings. Descriptions of matters common to embodiment 1 or embodiment 2 will be simplified or omitted.

[0076] As described above, the optical deflector according to the first and second embodiments includes two MEMS mirrors. The optical path switching unit is used to switch between the first and second optical paths for each frame of image display, and the laser beam is deflected and scanned alternately by the two MEMS mirrors to output the scanning light. In contrast, the present embodiment is common to the first and second embodiments in that the optical path switching unit is used to switch between the first and second optical paths for each frame of image display, but is different in that only one MEMS mirror is provided.

[0077] (light deflector) An optical deflector according to the third embodiment will be described with reference to Figs. 13(a), (b), 14(a), (b), and 15. The optical deflector 312 according to this embodiment includes an optical path switching unit 501 on a rotatable disk, as in the first embodiment, and a transmission unit TA that transmits the laser light and a reflection unit RA that reflects the laser light each occupy half of the main surface of the disk. Since the optical path switching unit 501 rotates continuously, the laser light incident on the optical deflector 312 from the laser module LM irradiates either the transmission unit TA or the reflection unit RA depending on the timing.

[0078] Fig. 13(a) shows by a solid line the optical path (first optical path) when the laser light emitted from the laser module LM irradiates the transmission area TA, and Fig. 13(b) shows by a dotted circle the spot position of the laser light on the optical path switching unit 501 at the timing of Fig. 13(a). Fig. 14(a) shows by a dotted line the optical path (second optical path) when the laser light emitted from the laser module LM irradiates the reflection area RA, and Fig. 14(b) shows by a dotted circle the spot position of the laser light on the optical path switching unit 501 at the timing of Fig. 14(a).

[0079] As shown in Fig. 13(a), at the timing when the laser light emitted from the laser module LM irradiates the transmission part TA of the optical path switching unit 501, the laser light passes through 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 an optical deflection element rotates back and forth around the rotation axis BX, and Fig. 13(a) corresponds to the forward path of the reciprocating rotation, and the laser light is reflected by the mirror surface MC and deflected for scanning. The laser light reflected by the mirror surface MC is reflected by the optical path conversion mirror 630B toward the optical path switching unit 501, passes through the transmission part TA of the optical path switching unit 501, is output from the optical deflector 312, and is used as illumination light for illuminating the reflective optical modulation element. As shown in Figure 13(a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210C within the optical deflector 312, and then reflected once by the optical path conversion mirror 630B and extracted from the optical deflector 312 can be called the first optical path.

[0080] 14(a), at the timing when the laser light emitted from the laser module LM irradiates the reflecting portion RA of the optical path switching unit 501, the laser light is reflected by the reflecting portion RA and further irradiates the MEMS mirror 210C via the optical path conversion mirror 630B. The mirror surface MC of the MEMS mirror 210C rotates back and forth around the rotation axis BX, and FIG. 14(a) corresponds to the return path of the reciprocating rotation, and the laser light is reflected by the mirror surface MC and deflected for scanning.

[0081] The laser light reflected by the mirror surface MC is reflected by the optical path conversion mirror 630A toward the optical path switching unit 501, reflected by the reflecting portion RA of the optical path switching unit 501, output from the optical deflector 312, and used as illumination light for illuminating the reflective optical modulation element. As shown in Fig. 14(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 reflected a total of two times by the optical path conversion mirror 630A and the reflecting portion RA of the optical path switching unit 501 and extracted from the optical deflector 312 can be called the second optical path.

[0082] The graph shown in FIG. 15 shows, from the top, the timing of turning on the laser module LM, the angle of the MEMS mirror 210C, the timing when the laser light passes through the first optical path in the optical deflector 312, the timing when the laser light passes through the second optical path in the optical deflector 312, and the deflection direction of the laser light deflected and scanned by the optical deflector and output. 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 312 in the same scanning direction SD. For convenience, the period during which the laser light scanned in one direction is output from the optical deflector 312 can be called the effective period, and the period during which it is not output can be called the blanking period. When illuminating the reflective optical modulation element to display an image, the image signal is synchronized with the driving of the laser module LM, the optical deflector, and the reflective optical modulation element. This allows the effective period to be used to display one frame of a moving image, and the blanking period to be used to adjust the synchronization with the image signal.

[0083] According to this embodiment, the first optical path, which causes the laser beam deflected and scanned on the forward path of the reciprocating rotary motion of the MEMS mirror 210C to be output from the optical deflector 312 with one reflection, and the second optical path, which causes the laser beam deflected and scanned on the backward path of the MEMS mirror 210C to be output from the optical deflector 312 with two reflections, are switched for each frame of the image. This makes it possible to continuously extract laser beams having the same scanning direction SD by using both the forward path and the backward path of the reciprocating rotary motion of the MEMS mirror 210C. As shown in the graph at the bottom of FIG. 15, the majority of the period of one frame period of the moving image signal can be used for display as an effective period. Therefore, in the field of projection type image display devices that modulate and project laser light according to an image signal, a high-brightness device can be provided. In addition, in the optical path switching unit 501, the arrangement method of the transmission portion TA and the reflection portion RA can be modified as in the modified example of the first embodiment.

[0084] (Projection type display device) By providing an optical deflector according to this embodiment for each different color light, the rectangular illumination areas output by the illumination units of different color lights can be enlarged and transferred onto a reflective light modulation element while deflection scanning so as not to overlap each other, as shown in Fig. 5. According to this embodiment, a high-brightness device can be provided in the field of projection type image display devices that modulate and project laser light according to an image signal.

[0085] [Embodiment 4] A scanning light source, a projection display device, and the like according to embodiment 4 will be described with reference to the drawings. Descriptions of matters common to embodiment 1 or embodiment 2 will be simplified or omitted.

[0086] As described above, the optical deflectors according to the first and second embodiments include two MEMS mirrors. The optical path switching unit is used to switch between the first and second optical paths for each frame of image display, and the laser beam is deflected and scanned alternately by the two MEMS mirrors to output the scanning light. In contrast, the present embodiment is common to the first and second embodiments in that the optical path switching unit is used to switch between the first and second optical paths for each frame of image display, but differs in that only one MEMS mirror is provided. The present embodiment is common to the third embodiment in that only one MEMS mirror is provided.

[0087] (light deflector) An optical deflector according to the fourth embodiment will be described with reference to Figs. 16(a), 16(b) and 17. The optical deflector 313 according to this embodiment includes a transmissive spatial modulation element 502, a polarizing beam splitter 503A, an optical path conversion mirror 630A, an optical path conversion mirror 630B and a MEMS mirror 210C. The transmissive spatial modulation element 502 can alternately modulate the linearly polarized light output by the laser module LM into P-polarized light and S-polarized light in synchronization with one frame period of the image. The polarizing beam splitter 503A has an optical characteristic of transmitting P-polarized light and reflecting S-polarized light. The optical path conversion mirror 630A and the optical path conversion mirror 630B are total reflection mirrors.

[0088] Figure 16(a) shows, with a solid line, the optical path (first optical path) when the laser light emitted from the laser module LM is modulated to P polarization by the spatial modulation element 502, and Figure 16(b) shows, with a dotted line, the optical path (second optical path) when the laser light emitted from the laser module LM is modulated to S polarization by the spatial modulation element 502.

[0089] As shown in Fig. 16(a), when the laser light emitted from the laser module LM is modulated to P-polarized light, the laser light passes through the polarizing 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 rotates back and forth around the rotation axis BX, and Fig. 16(a) corresponds to the forward path of the reciprocating rotation, and the laser light is reflected by the mirror surface MC and deflected for scanning. The laser light reflected by the mirror surface MC is reflected by the optical path conversion mirror 630B toward the polarizing beam splitter 503A, passes through the polarizing beam splitter 503A, is output from the optical deflector 313, and is used as illumination light for illuminating the reflective optical modulation element. As shown in Figure 16(a), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210C within the optical deflector 313, and then reflected once by the optical path conversion mirror 630B and extracted from the optical deflector 313 can be called the first optical path.

[0090] On the other hand, as shown in Fig. 16(b), at the timing when the laser light emitted from the laser module LM is modulated to S-polarized light, the laser light is reflected by the polarizing 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 rotates back and forth around the rotation axis BX, and Fig. 16(b) corresponds to the return path of the reciprocating rotation, and the laser light is reflected by the mirror surface MC and deflected for scanning. The laser light reflected by the mirror surface MC is reflected by the optical path conversion mirror 630A toward the polarizing beam splitter 503A, reflected by the polarizing beam splitter 503A, output from the optical deflector 313, and used as illumination light for illuminating the reflective optical modulation element. As shown in FIG. 16(b), the optical path in which the laser light is deflected and scanned by the MEMS mirror 210C within the optical deflector 313, and then reflected a total of two times by the optical path conversion mirror 630A and the polarizing beam splitter 503A before being extracted from the optical deflector 313 can be called the second optical path.

[0091] The graph shown in FIG. 17 shows, from the top, the timing of turning on the laser module LM, the output of the spatial light modulation element 502, the timing when the laser light passes through the first optical path in the optical deflector 313, the timing when the laser light passes through the second optical path in the optical deflector 313, and the deflection direction of the laser light deflected and scanned by the optical deflector 313 and output. 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 313 in the same scanning direction SD. For convenience, the period during which the laser light scanned in one direction is output from the optical deflector 313 can be called the effective period, and the period during which it is not output can be called the blanking period. When illuminating the reflective optical modulation element 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 element. This allows the effective period to be used to display one frame of an image of a moving image, and the blanking period to be used to perform synchronization adjustment with the image signal.

[0092] According to this embodiment, the first optical path, which causes the laser beam deflected and scanned on the forward path of the MEMS mirror 210C that rotates back and forth to be output from the optical deflector 313 with one reflection, and the second optical path, which causes the laser beam deflected and scanned on the backward path of the MEMS mirror 210C to be output from the optical deflector 313 with two reflections, are switched for each frame of the image. This makes it possible to continuously extract laser beams with the same scanning direction SD by using both the forward path and the backward path of the reciprocating rotational motion of the MEMS mirror 210C. As shown in the graph at the bottom of FIG. 17, the majority of the period of one frame period of the moving image signal can be used for display as an effective period. Therefore, in the field of projection type image display devices that modulate and project laser light according to an image signal, a high-brightness device can be provided. In addition, the optical path switching unit can change the polarizing element and the optical path conversion element as in the modified example of the second embodiment.

[0093] (Projection type display device) By providing an optical deflector according to this embodiment for each different color of light, as shown in FIG. 5, the rectangular illumination areas output by each of the lighting units of different colored light can be enlarged and transferred onto a reflective light modulation element while being deflected and scanned so as not to overlap each other.

[0094] [Other embodiments] The present invention is not limited to the above-described embodiment and modifications, and many modifications are possible within the technical spirit of the present invention. For example, the above-described different embodiment and modifications may be combined in whole or in part.

[0095] For example, in the third and fourth embodiments, the laser light deflected by the MEMS mirror is reflected once on the first optical path and extracted as output light, and is reflected twice on the second optical path and extracted as output light. However, the number of times that the laser light deflected by the MEMS mirror is reflected before being extracted is not limited to this example, and as long as the first optical path is reflected an odd number of times and the second optical path is reflected an even number of times, a laser beam deflected in the same scanning direction SD can be extracted.

[0096] This specification discloses at least the following: [Item 1] A laser light source including a semiconductor laser and a collimating lens that collimates a laser beam outputted from the semiconductor laser; an optical deflector that deflects the laser light output from the laser light source; Equipped with The optical deflector includes: an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path in the optical deflector; A first optical deflection element disposed in the first optical path and having a light reflecting surface that rotates back and forth; A second optical deflection element disposed in the second optical path and having a light reflecting surface that rotates back and forth; Equipped with the laser light deflected and scanned by the first optical deflection element and the laser light deflected and scanned by the second optical deflection element are alternately output from the optical deflector at every predetermined period as laser light deflected and scanned in the same direction; 1. A scanning light source comprising: [Matter 2] the reciprocating rotational motion of the first optical deflection element and the reciprocating rotational motion of the second optical deflection element have the same period and phase; 2. The scanning light source according to item 1, [Matter 3] the optical path switching unit includes a rotating body in which light transmitting sections and light reflecting sections 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 section, and travels along the second optical path when incident on the light reflecting section; 3. The scanning light source according to item 1 or 2, [Matter 4] the optical path switching unit extracts the laser light deflected and scanned by the first optical deflection element in the first optical path by reflecting it at the optical reflection unit, and extracts the laser light deflected and scanned by the second optical deflection element in the second optical path by transmitting it through a light transmission unit; 4. The scanning light source according to item 3, [Matter 5] the rotating body includes a plurality of the light transmitting portions and a plurality of the light reflecting portions, the optical path switching unit extracts the laser light deflected and scanned by the first optical deflection element in the first optical path by transmitting it through the light transmitting unit, and extracts the laser light deflected and scanned by the second optical deflection element in the second optical path by reflecting it at the light reflecting unit; 4. The scanning light source according to item 3, [Matter 6] a spatial modulation element that alternately modulates the laser light output from the laser light source into P-polarized light and S-polarized light at the predetermined period, the optical path switching unit switches whether the laser light output from the spatial modulation element is P-polarized or S-polarized in the optical deflector, so that the laser light passes through a first optical path or a second optical path. 3. The scanning light source according to item 1 or 2, [Matter 7] The optical path switching unit includes a dichroic mirror that transmits either P-polarized light or S-polarized light and reflects the other light. 7. The scanning light source according to item 6, [Matter 8] The optical path switching unit includes a PBS prism that transmits either P polarized light or S polarized light and reflects the other. 7. The scanning light source according to item 6, [Matter 9] A laser light source including a semiconductor laser and a collimating lens that collimates a laser beam outputted from the semiconductor laser; an optical deflector that deflects a laser beam outputted from the laser light source; Equipped with The optical deflector includes: an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path in the optical deflector; an optical deflection element having a light reflecting surface that rotates back and forth; Equipped with the laser light deflected and scanned by the light reflecting surface of the light deflector element during the forward path of the reciprocating rotational motion in the first optical path and the laser light deflected by the light reflecting surface of the light deflector element during the return path of the reciprocating rotational motion in the second optical path are output alternately from the light deflector at every predetermined period as laser light deflected and scanned in the same direction; 1. A scanning light source comprising: [Matter 10] the first optical path is an optical path in which the laser light is reflected by the light reflecting surface of the light deflection element and then reflected an odd number of times during the forward path of the reciprocating rotational motion of the light reflecting surface of the light deflection element, The second optical path is an optical path in which the laser light is reflected by the light reflecting surface of the optical deflection element and then reflected an even number of times during the return path of the reciprocating rotational motion of the light reflecting surface of the optical deflection element. 10. The scanning light source according to item 9, [Matter 11] the optical path switching unit includes a rotating body in which light transmitting sections and light reflecting sections 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 section, and travels along the second optical path when incident on the light reflecting section; 11. The scanning light source according to item 9 or 10, [Matter 12] a spatial modulation element that alternately modulates the laser light output from the laser light source into P-polarized light and S-polarized light at the predetermined period, the optical path switching unit switches whether the laser light passes through a first optical path or a second optical path in the optical deflector depending on whether the laser light output from the spatial light modulation element is P-polarized or S-polarized. 11. The scanning light source according to item 9 or 10, [Matter 13] The optical path switching unit includes a dichroic mirror that transmits either P-polarized light or S-polarized light and reflects the other light. 13. The scanning light source according to item 12, [Matter 14] Laser light sources of different color light; A scanning light source according to any one of claims 1 to 13, provided for each of the laser light sources of different color light; a light combining unit that combines the beams output from the respective scanning light sources such that the beams of different colors do not overlap each other; an optical path conversion mirror that guides the light output from the light combining unit to a reflective optical modulation element; a projection lens that projects the image light output by the reflective light modulation element. 1. A projection display device comprising: [Explanation of symbols]

[0097] 12···Semiconductor laser / 102···Collimating lens / 103···Condensing lens / 105···Rod / 106a···Front convex lens / 106b···Rear convex lens / 190···Screen / 201···Collimating lens / 210A, 210B···MEMS mirror / 211A, 211B···MEMS mirror / 220···Light combining section / 221···Dichroic mirror / 222···Dichroic mirror / 310, 310A, 311, 311A, 312, 313···Optical deflector / 310B···Optical deflector for B / 310G···Optical deflector for G / 310R···Optical deflector for R / 330···Optical path conversion mirror / 340···Reflector Type light modulation element / 350···TIR prism / 360···Projection lens / 501, 501A···Light path switching section / 502···Spatial modulation element / 502A···Spatial modulation element / 503A···Polarizing beam splitter / 503B···Polarizing beam splitter / 504···Polarizing beam splitter / 504A···Polarizing beam splitter / 504B···Polarizing beam splitter / 505···PBS prism / 506···1 / 4 wavelength version / 630A, 630B···Light path conversion mirror / AX···Rotation axis / BX···Rotation axis / LM···Laser module / MA, MB, MC···Mirror surface / MT···Motor / RA···Reflection section / TA···Transmission section

Claims

1. A laser light source including a semiconductor laser and a collimating lens that collimates a laser beam outputted from the semiconductor laser; an optical deflector that deflects the laser light output from the laser light source; Equipped with The optical deflector includes: an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path in the optical deflector; a first optical deflection element disposed in the first optical path and having a light reflecting surface that rotates back and forth; a second optical deflection element disposed in the second optical path and having a light reflecting surface that rotates back and forth; Equipped with the laser light deflected and scanned by the first optical deflection element and the laser light deflected and scanned by the second optical deflection element are output alternately from the optical deflector at every predetermined period as laser light deflected and scanned in the same direction; 1. A scanning light source comprising:

2. the reciprocating rotational motion of the first optical deflection element and the reciprocating rotational motion of the second optical deflection element have the same period and phase; 2. The scanning light source according to claim 1.

3. the optical path switching unit includes a rotating body having light transmitting sections and light reflecting sections 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 section, and travels along the second optical path when incident on the light reflecting section; 2. The scanning light source according to claim 1.

4. the optical path switching unit reflects the laser light deflected and scanned by the first optical deflection element in the first optical path at the optical reflection unit, and extracts the laser light deflected and scanned by the second optical deflection element in the second optical path by transmitting the laser light through a optical transmission unit; 4. The scanning light source according to claim 3.

5. the rotating body includes a plurality of the light transmitting portions and a plurality of the light reflecting portions, the optical path switching unit extracts the laser light deflected and scanned by the first optical deflection element in the first optical path by transmitting it through the light transmitting unit, and extracts the laser light deflected and scanned by the second optical deflection element in the second optical path by reflecting it at the light reflecting unit.

4. The scanning light source according to claim 3.

6. a spatial modulation element that alternately modulates the laser light output from the laser light source into P-polarized light and S-polarized light at the predetermined period, the optical path switching unit switches whether the laser light output from the spatial modulation element is P-polarized or S-polarized in the optical deflector, so that the laser light passes through a first optical path or a second optical path.

2. The scanning light source according to claim 1.

7. The optical path switching unit includes a dichroic mirror that transmits either P-polarized light or S-polarized light and reflects the other light.

7. The scanning light source according to claim 6.

8. The optical path switching unit includes a PBS prism that transmits either P-polarized light or S-polarized light and reflects the other.

7. The scanning light source according to claim 6.

9. A laser light source including a semiconductor laser and a collimating lens that collimates a laser beam outputted from the semiconductor laser; an optical deflector that deflects a laser beam outputted from the laser light source; Equipped with The optical deflector includes: an optical path switching unit that switches, at a predetermined period, whether the laser light passes through a first optical path or a second optical path in the optical deflector; an optical deflection element having a light reflecting surface that rotates back and forth; Equipped with the laser light deflected and scanned by the light reflecting surface of the light deflector element during the forward path of the reciprocating rotational motion in the first optical path and the laser light deflected by the light reflecting surface of the light deflector element during the return path of the reciprocating rotational motion in the second optical path are output alternately from the light deflector at every predetermined period as laser light deflected and scanned in the same direction; 1. A scanning light source comprising:

10. the first optical path is an optical path in which the laser light is reflected by the light reflecting surface of the optical deflection element during an outward path of the reciprocating rotational motion thereof, and then is reflected an odd number of times to be extracted; The second optical path is an optical path for reflecting the laser light by the light reflecting surface of the optical deflection element an even number of times during the return path of the reciprocating rotational motion of the light reflecting surface and then extracting the laser light.

10. The scanning light source according to claim 9.

11. the optical path switching unit includes a rotating body having light transmitting sections and light reflecting sections 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 section, and travels along the second optical path when incident on the light reflecting section; 10. The scanning light source according to claim 9.

12. a spatial modulation element that alternately modulates the laser light output from the laser light source into P-polarized light and S-polarized light at the predetermined period, the optical path switching unit switches whether the laser light passes through a first optical path or a second optical path in the optical deflector, depending on whether the laser light output from the spatial modulation element is P-polarized or S-polarized.

10. The scanning light source according to claim 9.

13. The optical path switching unit includes a dichroic mirror that transmits either P-polarized light or S-polarized light and reflects the other light.

13. The scanning light source of claim 12.

14. Laser light sources of different color light; A scanning light source according to any one of claims 1 to 13, provided for each of the laser light sources of different color lights; a light combining unit that combines the beams output from the respective scanning light sources such that the beams of different colors do not overlap each other; an optical path conversion mirror that guides the light output from the light combining unit to a reflective optical modulation element; a projection lens that projects the image light output by the reflective light modulation element.

1. A projection display device comprising:

Images