Illumination device and projection type image display device

Abstract

To provide an illumination device including a plurality of light source units each including a plurality of laser elements, and emitting illumination light with high luminance.SOLUTION: An illumination device 20 includes: a first light source unit 70 including a plurality of laser elements and emitting a first light flux LF1 in a first direction; a second light source unit 72 including the plurality of laser elements and disposed apart from the first light source unit 70 with a first distance D1 in a second direction orthogonal to the first direction so as to emit a second light flux LF2 in the first direction; and an optical path shift optical system 84 having a first reflection surface 84a reflecting the second light flux LF2, which is emitted from the second light source unit 72, toward the first light flux LF1, and a second reflection surface 84b disposed parallel to the first reflection surface 84a and reflecting the second light flux LF2, which is reflected by the first reflection surface 84a, so as to be parallel to the first light flux LF1 with a second distance D2 smaller than the first distance D1.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an illumination device and a projection-type image display device including the same. [Background technology]

[0002] As described in Patent Document 1, there is known an illumination device that is used in a projection type image display device and emits high-luminance illumination light by concentrating at high density emitted light from a plurality of light sources such as LEDs and laser elements. In the case of the illumination device described in Patent Document 1, the emission of high-luminance illumination light is realized by concentrating at high density light beams from a plurality of light source units each including a plurality of light sources via optical elements such as mirrors. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-211603 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when high-brightness illumination light is achieved by densely aggregating the luminous fluxes of multiple light source units, each of which contains multiple light sources, as in the lighting device described in Patent Document 1, the close arrangement of the light source units may be limited due to the size and shape of the light source units, the size and shape of options for the light source units, such as a cooling device, etc., which may limit the dense aggregation of the luminous fluxes.

[0005] Therefore, an object of the present disclosure is to provide an illumination device including a plurality of light source units each including a plurality of laser elements, which can concentrate the luminous fluxes of each of the light source units at a high density and emit high-brightness illumination light, even if the proximity arrangement of the plurality of light source units is restricted. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, according to one aspect of the present disclosure, a first light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, and configured to emit a first light flux in a first direction; a second light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, the second light source unit being disposed at a first distance in a second direction perpendicular to the first direction so as to emit a second light flux in the first direction; An illumination device is provided having an optical path shift optical system including a first reflecting surface that reflects the second light beam emitted from the second light source unit in the first direction toward the first light beam, and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light beam reflected by the first reflecting surface so that the second light beam is parallel to the first light beam at a second distance smaller than the first distance.

[0007] According to another aspect of the present disclosure, an illumination unit including at least one illumination device; an image display unit that modulates the illumination light from the illumination unit and outputs it as image light; and a projection optical system that enlarges and projects the image light, The lighting device comprises: a first light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, and configured to emit a first light flux in a first direction; a second light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, the second light source unit being disposed at a first distance in a second direction perpendicular to the first direction so as to emit a second light flux in the first direction; There is provided a projection type image display device having an optical path shift optical system including a first reflecting surface that reflects the second light beam emitted from the second light source unit in the first direction toward the first light beam, and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light beam reflected by the first reflecting surface so that the second light beam is parallel to the first light beam at a second distance smaller than the first distance. Effect of the Invention

[0008] According to the present disclosure, in an illumination device including a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the plurality of light source units is restricted, the luminous fluxes of each of the light source units can be concentrated at a high density to emit high-brightness illumination light. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a projection type image display device according to a first embodiment of the present disclosure; [Diagram 2] FIG. 1 is a perspective view of a lighting device according to a first embodiment; [Diagram 3] FIG. 1 is a front view of a lighting device according to a first embodiment; [Figure 4] 1 is a side view of a lighting device according to a first embodiment; [Diagram 5] 1 is a top view of a lighting device according to a first embodiment. [Figure 6] FIG. 1 is a diagram showing an image of a first light beam and an image of a second light beam. [Figure 7] FIG. 11 is a front view of an illumination device in a projection type image display device according to a second embodiment of the present disclosure. [Figure 8] FIG. 13 is a front view of an illumination device in a projection type image display device according to a third embodiment of the present disclosure. [Figure 9] FIG. 13 is a front view of an illumination device in a projection type image display device according to a fourth embodiment of the present disclosure. [Figure 10] 13 is a top view of a lighting device according to the fourth embodiment. [Figure 11] FIG. 13 is a front view of an illumination device in a projection type image display device according to a fifth embodiment of the present disclosure. [Figure 12] 13 is a top view of a lighting device according to the fifth embodiment. [Figure 13] FIG. 13 is a schematic configuration diagram of a projection type image display device according to another embodiment of the present disclosure. [Figure 14] Diagram showing images of multiple light beams [Figure 15] FIG. 13 is a top view of another example of the light source unit; [Figure 16] A front view of another example of a lighting device having three light source units. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An illumination device according to one aspect of the present disclosure includes a first light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, the first light source unit emitting a first light flux in a first direction; a second light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, the second light source unit emitting a second light flux in the first direction and arranged at a first distance from the first light source unit in a second direction perpendicular to the first direction; a first reflecting surface reflecting the second light flux emitted from the second light source unit in the first direction toward the first light flux; and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light flux reflected by the first reflecting surface so as to be parallel to the first light flux at a second distance smaller than the first distance.

[0011] According to this aspect, in an illumination device having a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the plurality of light source units is restricted, the luminous fluxes of each of the light source units can be concentrated at a high density to emit high-brightness illumination light.

[0012] For example, the light path shift optical system may be a parallelogram-shaped prism including the first reflecting surface, the second reflecting surface, a first transmitting surface through which the second light flux emitted from the second light source unit transmits, and a second transmitting surface that is parallel to the first transmitting surface and through which the second light flux reflected by the second reflecting surface transmits.

[0013] For example, the optical path shift optical system may include a first mirror having the first reflecting surface, and a second mirror having the second reflecting surface.

[0014] For example, the plurality of laser elements in each of the first and second light source units may be semiconductor laser elements, and the first and second light source units may include collimating lenses provided for the respective semiconductor laser elements.

[0015] For example, the first and second light source units may include a collimating lens array in which the plurality of collimating lenses are arranged and integrated at the same arrangement pitch as the arrangement pitch of the plurality of semiconductor laser elements.

[0016] For example, the lighting device may further include a heat transfer plate having a first heat transfer surface to which the first and second light source units are attached and a second heat transfer surface opposite the first heat transfer surface, and a cooling device attached to the second heat transfer surface of the heat transfer plate.

[0017] For example, the cooling device includes a first cooling device arranged opposite the first light source unit across the heat transfer plate, and a second cooling device arranged opposite the second light source unit across the heat transfer plate.

[0018] For example, the lighting device may further include a first thermoelectric element having a heat absorption surface abutting the second heat transfer surface of the heat transfer plate and a heat dissipation surface to which the first cooling device is attached, and a second thermoelectric element having a heat absorption surface abutting the second heat transfer surface of the heat transfer plate and a heat dissipation surface to which the second cooling device is attached.

[0019] For example, when viewed in the first direction, the first light source unit may be arranged in a central portion of the heat absorption surface of the first thermoelectric element, and the second light source unit may be arranged in a central portion of the heat absorption surface of the second thermoelectric element.

[0020] For example, the heat transfer plate may include a first heat transfer plate to which the first light source unit is attached and which abuts the first thermoelectric element, and a second heat transfer plate to which the second light source unit is attached and which abuts the second thermoelectric element.

[0021] For example, the semiconductor laser element may emit red laser light.

[0022] A projection type image display device according to another embodiment of the present disclosure includes an illumination section including at least one illumination device, an image display section which modulates illumination light from the illumination section and outputs it as image light, and a projection optical system which enlarges and projects the image light, wherein the illumination device has a first light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, and which emits a first light flux in a first direction, a second light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, and which is arranged at a first distance from the first light source unit in a second direction perpendicular to the first direction to emit a second light flux, and a light path shift optical system including a first reflecting surface which reflects the second light flux emitted from the second light source unit in the first direction toward the first light flux, and a second reflecting surface which is parallel to the first reflecting surface and which reflects the second light flux reflected by the first reflecting surface so that the second light flux is parallel to the first light flux at a second distance smaller than the first distance.

[0023] According to this aspect, in an illumination device for a projection type image display device having a plurality of light source units each including a plurality of laser elements, even if the close arrangement of the plurality of light source units is restricted, the light beams of each of the light source units can be concentrated at a high density to emit high-brightness illumination light.

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0025] (Embodiment 1) FIG. 1 is a schematic diagram illustrating a configuration of a projection type image display device according to an embodiment of the present disclosure.

[0026] As shown in FIG. 1, the projection type image display device 10 according to the first embodiment is a so-called DLP type projector, and includes an illumination unit 12, an image display unit 14 that modulates at least a portion of the illumination light from the illumination unit 12 to output image light, and a projection optical system 16 that enlarges and projects the image light output from the image display unit 14.

[0027] The illumination section 12 of the projection type image display device 10 includes an illumination device 20 that emits red light, an illumination device 22 that emits green light, and an illumination device 24 that emits blue light. The illumination section 12 further includes a green selective reflection mirror 26 that superimposes the green light from the illumination device 22 and the blue light from the illumination device 24 and emits the superimposed light, a red selective reflection mirror 28 that superimposes the light emitted from the green selective reflection mirror 26 and the red light from the illumination device 20 and emits the superimposed light, and a rod integrator 30 that collects the light emitted from the red selective reflection mirror 28. The illumination section 12 further includes a lens 32, a mirror 34, and a lens 36 that are disposed between the red selective reflection mirror 28 and the rod integrator 30. The illumination devices 20, 22, and 24 have substantially the same configuration except that the colors of the emitted light are different, and the details thereof will be described later.

[0028] Illumination light from the illumination unit 12 reaches the image display unit 14 via relay lenses 38 and 40, a mirror 42, and a field lens 44.

[0029] The image display unit 14 includes a total reflection prism 46 that totally reflects the illumination light from the illumination unit 12. The total reflection prism 46 is composed of a triangular prism 48 and a triangular prism 50 that forms an air gap between the triangular prism 48 and the triangular prism 50. The illumination light is totally reflected by a surface 48a of the triangular prism 48 that contacts the air gap, and passes through a surface 48b to enter a color prism unit 52.

[0030] The color prism unit 52 of the image display unit 14 is configured to split the illumination light reflected by the total reflection prism 46 into three light beams, emit each of the split light beams to corresponding DMDs (digital mirror devices) 54R, 54G, and 54B, and combine the reflected light beams from the DMDs 54R, 54G, and 54B to emit the combined light beams toward the total reflection prism 46.

[0031] Specifically, color prism unit 52 is composed of a first prism 56 having a dichroic mirror surface 56a that reflects blue light, a second prism 58 having a dichroic mirror surface 58a that reflects red light and blue light, and a third prism 60. An air gap for total reflection is provided between first prism 56 and second prism 58. Color prism unit 52 emits red light to DMD 54R, emits green light to DMD 54G, and emits blue light to DMD 54B.

[0032] DMDs 54R, 54G, and 54B have substantially the same configuration, and are devices that generally include a base and a plurality of micromirrors arranged on the base in a matrix such that the tilt angle can be changed in an alternative manner. The tilt angle of the micromirror is changed based on an external video signal. For example, the micromirror is selectively tilted at a first tilt angle at which the reflected light is incident on the color prism unit 52 at an incident angle of zero degrees, and a second tilt angle at which the reflected light is incident on the color prism unit 52 at an angle larger than zero degrees. With this configuration, DMD 54R outputs at least partially modulated red light (red image light), and DMDs 54G and 54B similarly output green image light and blue image light.

[0033] The red image light, green image light, and blue image light from DMDs 54R, 54G, and 54B are combined by color prism unit 52, and the combined image light (color image light) is emitted toward total reflection prism 46. The color image light passes through total reflection prism 46 and is enlarged and projected onto a screen or the like via projection optical system 16 including a projection lens and the like.

[0034] From here on, the illumination devices 20, 22, and 24 of the illumination section 12 of the projection type image display device 10 will be described in detail. Note that the illumination devices 20, 22, and 24 have substantially the same configuration, except that the colors of the illumination light are different. Therefore, only the illumination device 20 will be described, and the remaining illumination devices 22 and 24 will not be described.

[0035] Fig. 2 is a perspective view of the lighting device according to the first embodiment. Fig. 3 is a front view of the lighting device according to the first embodiment. Fig. 4 is a side view of the lighting device according to the first embodiment. And Fig. 5 is a top view of the lighting device according to the first embodiment. Note that the XYZ orthogonal coordinate system shown in the drawings is for facilitating understanding of the present disclosure and does not limit the present disclosure. The Z-axis direction indicates the irradiation direction of the light emitted by the lighting device.

[0036] 2 and 3, the illumination device 20 according to the first embodiment has first and second light source units 70, 72. In the case of the first embodiment, the first and second light source units 70, 72 have the same configuration.

[0037] As shown in Fig. 5, the first and second light source units 70, 72 include a plurality of laser elements 74 arranged in a matrix (on the XY plane) with their optical axes parallel to each other (extending in the Z-axis direction). The laser elements 74 are, for example, semiconductor laser elements. In the case of the first embodiment, each of the first and second light source units 70, 72 includes 20 laser elements 74 arranged in a 5 x 4 matrix.

[0038] In the first embodiment, each of the first and second light source units 70 and 72 is provided with a laser element 74 and includes a collimator lens 76 that converts the laser light from the laser element 74 into substantially parallel light. In the first embodiment, the collimator lenses 76 are integrated together to form a collimator lens array 78. In the collimator lens array 78, the collimator lenses 76 are arranged at the same arrangement pitch as the arrangement pitch of the laser elements 74.

[0039] As shown in Fig. 3, the first and second light source units 70, 72 including a plurality of laser elements 74 emit first and second light fluxes LF1, LF2 consisting of a plurality of parallel light beams. The first and second light source units 70, 72 are arranged so as to emit the first and second light fluxes L1, LF2 in the same direction (Z-axis direction). In the case of the first embodiment, the lighting device 20 has a heat transfer plate 80 made of a material having high thermal conductivity such as copper, and the first and second light source units 70, 72 are attached to the planar first heat transfer surface 80a of the heat transfer plate 80 by screws.

[0040] The heat transfer plate 80 is a member for removing heat generated by the output of the first and second luminous fluxes LF1 and LF2 from the first and second light source units 70, 72. In order to improve the efficiency of heat transfer from the first and second light source units 70, 72 to the heat transfer plate 80, a heat transfer promotion member such as thermally conductive grease may be disposed between them.

[0041] In the case of the first embodiment, as shown in Figs. 2 to 4, the lighting device 20 further includes a cooling device 82 for cooling the heat transfer plate 80. The cooling device 82 is attached to a second heat transfer surface 80b on the opposite side of the first heat transfer surface 80a on which the first and second light source units 70 and 72 are attached, via a screw or the like. In the case of the first embodiment, the cooling device 82 is, for example, a device for cooling a member (the heat transfer plate 80 in the case of the first embodiment) in contact with the cooling surface 82a with a liquid (coolant), and includes an inflow pipe 82b through which the coolant flows in, an outflow pipe 82c through which the coolant flows out, and a pump (not shown) for generating a flow of the coolant. By cooling via the heat transfer plate 80 by the cooling device 82, the first and second light source units 70 and 72 can be made to have a high output and a long life. As shown in FIG. 5, in a top view of the lighting device 10 (viewed in the Z-axis direction), the first and second light source units 70, 72 are preferably positioned within the contour of the cooling surface 82a in consideration of cooling performance.

[0042] 3 and 5, the first and second light source units 70, 72 are arranged as close as possible to each other, but due to restrictions such as size and shape, the first and second light source units 70, 72 are arranged in parallel with each other at a first distance D1 in a direction (Y-axis direction) perpendicular to the emission direction (Z-axis direction) of the first and second light fluxes LF1, LF2.

[0043] 3, when the first and second light source units 70, 72 are arranged with a first distance D1 between them, the first and second light beams LF1, LF2 are naturally emitted with a first distance D1 between them. As a result, the image of the illumination light irradiated from the illumination device 20 has uneven brightness with a dark center and a bright outer portion, impairing image quality. Therefore, in order to suppress the uneven brightness and increase the density of the illumination light irradiated from the illumination device 20, the illumination device 20 has an optical path shift optical system 84.

[0044] In the case of the first embodiment, the light path shift optical system 84 is a prism having a parallelogram shape as shown in Fig. 2 and Fig. 3. Specifically, the light path shift optical system 84 has a parallelogram shape when viewed in a direction (X-axis direction) perpendicular to the emission direction (Z-axis direction) of the first and second light fluxes LF1 and LF2 and the parallel direction (Y-axis direction) of the first and second light source units 70 and 72.

[0045] 3, the parallelogram-shaped prism 84 is made of a material that is light-transmitting and does not easily deform even at high temperatures, such as glass. The prism 84 has a first reflecting surface 84a that reflects all of the second light beam LF emitted from the second light source unit 72 toward the first light beam LF1 in the parallel direction (Y-axis direction) of the first and second light source units 70, 72. The prism 84 also has a second reflecting surface 84b that is parallel to the first reflecting surface 84a and reflects the second light beam LF2 reflected by the first reflecting surface 84a so that the second light beam LF2 is parallel to the first light beam LF1 at a second distance D2 smaller than the first distance. Furthermore, the prism 84 includes a first transmitting surface 84c through which the entire second light flux LF2 before being reflected by the first reflecting surface 84a passes, and a second transmitting surface 84d that is parallel to the first transmitting surface 84c and through which the second light flux LF reflected by the second reflecting surface 84b passes. The prism 84 is held, for example, by a housing (not shown) of the lighting device 20 that holds the heat transfer plate 80.

[0046] Such an optical path shift optical system (prism) 84 allows the second light beam LF2 to approach the first light beam LF1 to a second distance D2 that is smaller than the first distance D1 between the first and second light source units 70, 72. This causes the first and second light beams LF1 and LF2 to converge at high density.

[0047] It should be noted that the first light flux LF1 is not related to the optical path shift optical system (prism) 84. That is, the first light flux LF1 propagates from the first light source unit 70 without being reflected by or passing through the optical path shift optical system 84.

[0048] FIG. 6 is a diagram showing an image of a first light beam and an image of a second light beam.

[0049] As shown in Fig. 6, when the optical path shift optical system 84 is present, the image Im2 (solid line) of the second light beam LF2 approaches the image Im1 of the first light beam LF1 compared to when the optical path shift optical system 84 is not present (dotted line). This allows the optical path area Pa (solid line) in the illumination device 20 to be made smaller than when the optical path shift optical system 84 is not present (dotted line). As a result, the illumination light of the illumination device 20 is made denser while suppressing luminance unevenness. In addition, it also becomes possible to reduce the size of optical elements such as lenses in the projection type image display device 10, and as a result, the projection type image display device 10 can be made smaller in size.

[0050] According to the first embodiment as described above, in an illumination device including a plurality of light source units each including a plurality of laser elements, even if there is a restriction on the close arrangement of the plurality of light source units, the light beams of each of the light source units can be concentrated at a high density to irradiate high-brightness illumination light.

[0051] (Embodiment 2) The projection type image display device according to the second embodiment differs from the first embodiment in that the light path shift optical system in the illumination device is different. Therefore, the second embodiment will be described focusing on the difference. Note that the same reference numerals are used to designate the components of the second embodiment that are substantially the same as those of the first embodiment.

[0052] FIG. 7 is a front view of an illumination device in a projection type image display device according to a second embodiment of the present disclosure.

[0053] 7, the illumination device 120 according to the second embodiment has first and second light source units 70, 72 spaced apart by a first distance D1, similar to the above-described first embodiment. In order to bring the second light flux LF2 of the second light source unit 72 closer to the light flux LF1 of the first light source unit 70, the illumination device 120 has an optical path shift optical system.

[0054] In the case of the second embodiment, the optical path shift optical system includes first and second mirrors 184A and 184B. The first mirror 184A has a first reflecting surface 184Aa that reflects all of the second light beam LF emitted from the second light source unit 72 toward the first light beam LF1 in the parallel direction (Y-axis direction) of the first and second light source units 70 and 72. The second mirror 184B has a second reflecting surface 184Ba that is parallel to the reflecting surface 184Aa of the first mirror 184A and reflects the second light beam LF2 reflected by the reflecting surface 184Aa so as to be parallel to the first light beam LF1 at a second distance D2 smaller than the first distance D1.

[0055] According to the above-described second embodiment, in a lighting device including a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the plurality of light source units is restricted, the light beams of each of the light source units can be concentrated at a high density to irradiate high-brightness illumination light, as in the case of the first embodiment described above.

[0056] (Embodiment 3) The projection type image display device according to the third embodiment differs from the first embodiment in that the distance between the first and second light source units in the illumination device is different, and therefore the cooling device is different. Therefore, the third embodiment will be described focusing on this difference. Note that the same reference numerals are used to denote the components of the third embodiment that are substantially the same as those of the first embodiment.

[0057] FIG. 8 is a front view of an illumination device in a projection type image display device according to embodiment 3 of the present disclosure.

[0058] 8, in the illumination device 220 according to the third embodiment, the first and second light source units 70, 72 are arranged at a larger distance D3 (>D1) than in the above-described first embodiment. This is because the cooling device in the illumination device 220 is different from the cooling device in the above-described first embodiment.

[0059] Specifically, in the case of the above-mentioned embodiment 1, as shown in Fig. 3, one cooling device 82 is used in common for the first and second light source units 70, 72. On the other hand, in the case of the embodiment 3, as shown in Fig. 8, first and second cooling devices 282A, 282B are provided for the first and second light source units 70, 72, respectively, in a state where they are as close as possible to each other. The first cooling device 282A is disposed opposite the first light source unit 70 with the heat transfer plate 280 interposed therebetween. Also, the second cooling device 282B is disposed opposite the second light source unit 72 with the heat transfer plate 280 interposed therebetween.

[0060] The first and second light source units 70, 72 are disposed in the central portions of the cooling surfaces 282Aa, 282Ba of the first and second cooling devices 282A, 282B when viewed from above (in the Z-axis direction) of the illumination device 220. As a result, the first and second light source units 70, 72 are separated by a distance D3. That is, the first and second light source units 70, 72 are restricted in their close arrangement due to the size constraints of the first and second cooling devices 282A, 282B.

[0061] In addition, since the first and second light source units 70, 72 are spaced apart by a distance D3 that is larger than the distance D1 in the first embodiment 1, the heat transfer plate 280 and the light path shift optical system (prism 284) are larger than the heat transfer plate 80 and the light path shift optical system 84 in the above-mentioned embodiment 1.

[0062] When the first and second cooling devices 282A, 282B are provided for the first and second light source units 70, 72, respectively, in this manner, the proximity of the first and second light source units 70, 72 is restricted. However, the optical path shift optical system (prism) 284 makes it possible to bring the second light flux LF2 of the second light source unit 72 closer to the first light flux LF1 of the first light source unit 70, as in the first embodiment described above.

[0063] Furthermore, since the first and second cooling devices 282A and 282B are provided for the first and second light source units 70 and 72, respectively, the cooling of the first and second light source units 70 and 72 can be controlled independently.

[0064] According to the third embodiment as described above, in a lighting device including a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the plurality of light source units is restricted, the light beams of each of the light source units can be concentrated at a high density to irradiate high-brightness illumination light, as in the first embodiment described above.

[0065] (Embodiment 4) The present embodiment 4 is an improved version of the above-mentioned embodiment 3. Therefore, the present embodiment 4 will be described focusing on the differences from embodiment 3. Note that the components of the present embodiment 4 that are substantially the same as those of the above-mentioned embodiment 3 are denoted by the same reference numerals.

[0066] Fig. 9 is a front view of an illumination device in a projection type image display device according to embodiment 4 of the present disclosure, and Fig. 10 is a top view of the illumination device according to embodiment 4.

[0067] As shown in FIGS. 9 and 10, the illumination device 320 according to the fourth embodiment has a first thermoelectric element 386A and a second thermoelectric element 386B.

[0068] The first and second thermoelectric elements 386A, 386B are, for example, Peltier elements, and have heat absorption surfaces 386Aa, 386Ba that absorb heat from the object to be cooled (in this embodiment 4, the first and second light source units 70, 72), and heat dissipation surfaces 386Ab, 386Bb that dissipate the absorbed heat.

[0069] Specifically, the first thermoelectric element 386A is disposed between the heat transfer plate 280 and the first cooling device 282A. A heat absorption surface 386Aa of the first thermoelectric element 386A abuts against the second heat transfer surface 280b of the heat transfer plate 280, and a heat dissipation surface 386Ab abuts against the cooling surface 282Aa of the first cooling device 282A. Particularly specifically, as shown in FIG. 10, the heat absorption surface 386Aa overlaps with the first light source unit 70 in a top view of the lighting device 320 (as viewed in the Z-axis direction).

[0070] The second thermoelectric element 386B is disposed between the heat transfer plate 280 and the second cooling device 282B. A heat absorption surface 386Ba of the second thermoelectric element 386B abuts against the second heat transfer surface 280b of the heat transfer plate 280, and a heat dissipation surface 386Bb abuts against the cooling surface 282Ba of the second cooling device 282B. More specifically, as shown in FIG. 10, the heat absorption surface 386Ba overlaps with the second light source unit 72 in a top view of the lighting device 320 (as viewed in the Z-axis direction).

[0071] Such first and second thermoelectric elements 386A, 386B cool (absorb heat) the first and second light source units 70, 72 via the heat transfer plate 280. The heat dissipation surfaces 386Ab, 386Bb of the first and second thermoelectric elements 386A, 386B, which have become hot due to the cooling, are cooled by the first and second cooling devices 282A, 282B.

[0072] Thus, by controlling the drive current supplied to the first and second thermoelectric elements 386A, 386B, it is possible to precisely control the temperatures of the first and second light source units 70, 72. For example, when a red semiconductor laser element is used as the laser element of the light source units 70, 72, the output, wavelength, and lifespan of the red semiconductor laser element change depending on the temperature, so that the temperature is controlled by the first and second thermoelectric elements 386A, 386B to keep the temperature constant.

[0073] 10, in the case of the fourth embodiment, in a top view (viewed in the Z-axis direction) of the illumination device 320, the heat absorbing surfaces 386Aa, 386Ba of the first and second thermoelectric elements 386A, 386B are sufficiently larger than the first and second light source units 70, 72. In this case, it is preferable that the first and second light source units 70, 72 are disposed in the central portions of the heat absorbing surfaces 386Aa, 386Ba in a top view.

[0074] In contrast, when the first and second light source units 70, 72 are disposed in the vicinity of the outer periphery of the heat absorbing surfaces 386Aa, 386Ba in a top view (Z-axis direction view) of the illumination device 320, condensation may occur in a portion of the heat transfer plate 280 facing the portion of the heat absorbing surfaces 386Aa, 386Ba distant from the first and second light source units 70, 72. That is, in the heat transfer plate 280 cooled by the first and second thermoelectric elements 386A, 386B, condensation may occur in a portion distant from the first and second light source units 70, 72, which are heat sources. In order to suppress the occurrence of such condensation, it is preferable to dispose the first and second light source units 70, 72 in the center portion of the heat absorbing surfaces 386Aa, 386Ba of the first and second thermoelectric elements 386A, 386B in a top view of the illumination device 320.

[0075] In this way, when the first and second light source units 70, 72 are disposed in the central portions of the heat absorbing surfaces 386Aa, 386Ba of the first and second thermoelectric elements 386A, 386B in a top view (viewed in the Z-axis direction) of the illumination device 320, the proximity of the first and second light source units 70, 72 is restricted. However, the optical path shift optical system (prism) 284 allows the second light flux LF2 of the second light source unit 72 to be brought closer to the first light flux LF1 of the first light source unit 70, as in the first embodiment described above.

[0076] According to the above-described fourth embodiment, similarly to the first embodiment, in an illumination device including a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the plurality of light source units is restricted, the luminous fluxes of each of the light source units can be concentrated at high density to irradiate high-brightness illumination light.

[0077] (Embodiment 5) The fifth embodiment is an improved version of the fourth embodiment. Therefore, the fifth embodiment will be described focusing on the differences from the third embodiment. Note that the same reference numerals are used to designate the components of the fifth embodiment that are substantially the same as those of the fourth embodiment.

[0078] Fig. 11 is a front view of an illumination device in a projection type image display device according to embodiment 5 of the present disclosure, and Fig. 12 is a top view of the illumination device according to embodiment 5.

[0079] As shown in Figures 11 and 12, the lighting device 420 according to the fifth embodiment differs from the lighting device 320 according to the fourth embodiment shown in Figures 9 and 10 in that first and second heat transfer plates 480A, 480B are provided for the first and second light source units 70, 72, respectively.

[0080] Specifically, the lighting device 420 of the fifth embodiment has a first heat transfer plate 480A to which the first light source unit 70 is attached and which abuts the first thermoelectric element 386A, and a second heat transfer plate 480B to which the second light source unit 72 is attached and which abuts the second thermoelectric element 386B.

[0081] The first and second heat transfer plates 480A and 480B are provided for the first and second light source units 70 and 72, respectively, to form two thermally separated units. One unit is composed of the first light source unit 70, the first heat transfer plate 480A, the first thermoelectric element 386A, and the first cooling device 282A. The other unit is composed of the second light source unit 72, the second heat transfer plate 480A, the second thermoelectric element 386A, and the second cooling device 282B. In this way, by unitizing one light source unit, one heat transfer plate, one thermoelectric element, and one cooling device, the manufacturing of the lighting device becomes easy, and it is possible to easily construct a lighting device having a different number of light source units. In addition, since they are thermally separated, it is possible to easily and highly precisely control the temperature of each of the multiple light source units.

[0082] According to the fifth embodiment as described above, in a lighting device including a plurality of light source units each including a plurality of laser elements, even if the proximity arrangement of the light source units is restricted, the light beams of each of the light source units can be concentrated at a high density to irradiate high-brightness illumination light, as in the first embodiment described above.

[0083] Although the present disclosure has been described above with reference to the above-mentioned first to fifth embodiments, the embodiments of the present disclosure are not limited to the above-mentioned embodiments.

[0084] For example, as shown in Fig. 1, in the case of the above-mentioned first embodiment, the projection type image display device 10 is a DLP type projector, but is not limited to this. The projection type image display device according to the embodiment of the present disclosure may be a 3LCD (Liquid Crystal Display) type projector.

[0085] Furthermore, in the case of the above-described first embodiment, the illumination section 12 of the projection type image display device 10 includes three illumination devices 20, 22, and 24. However, the embodiments of the present disclosure are not limited to this.

[0086] FIG. 13 is a schematic configuration diagram of a projection type image display device according to another embodiment of the present disclosure.

[0087] In the projection type image display device 510 shown in FIG. 13, the illumination section 512 includes two illumination devices 520A and 520B that emit red light, two illumination devices 522A and 522B that emit green light, and two illumination devices 524A and 524B that emit blue light.

[0088] Blue light from two illumination devices 524A, 524B is reflected by mirrors 525A, 525B, passes through green selective reflecting mirrors 526A, 526B and red selective reflecting mirrors 527A, 527B, and passes through lens 528, mirror 529, and lens 530 to enter rod integrator 532.

[0089] Furthermore, the green light from the two illumination devices 522A and 522B is reflected by green selective reflecting mirrors 526A and 526B, passes through red selective reflecting mirrors 527A and 527B, passes through lens 528, mirror 529, and lens 530, and enters rod integrator 532.

[0090] The red light from the two illumination devices 520A and 520B is reflected by red selective reflection mirrors 527A and 527B, passes through lens 528, mirror 529, and lens 530, and enters rod integrator 532.

[0091] FIG. 14 shows images of the light beams from two illuminators.

[0092] As shown in FIG. 14, for example, an image Im1-A of a first light flux of a first light source unit in lighting device 20A, an image Im2-B of a second light flux of a second light source unit in lighting device 20A, a first image Im1-B of the first light source unit in lighting device 20B, and an image Im2-B of the second light flux of the second light source unit in lighting device 20B constitute an image of red light.

[0093] In this case, the number of light source units used to irradiate the illumination light of each color is doubled compared to the projection type image display device 10 shown in FIG. 1, and therefore the brightness is improved.

[0094] Furthermore, in the embodiments of the present disclosure, the light source units are not limited to the light source units 70 and 72 in the first to fifth embodiments described above.

[0095] FIG. 15 is a top view of a light source unit according to another embodiment.

[0096] 15 includes eight laser elements 674 arranged in a matrix. A collimator lens 676 is provided for each of the laser elements 674. In the light source unit 670, the collimator lenses 676 are not integrated. It goes without saying that, in the case of this laser element 674 as well, similar to the laser elements 70 and 72, when a plurality of laser elements are arranged, it is possible to arrange emitted light at a high density using the present disclosure.

[0097] Furthermore, in the case of the above-described first embodiment, the number of light source units included in the illumination device 20 is two, but the embodiments of the present disclosure are not limited to this.

[0098] Fig. 16 is a front view of a lighting device of another example having three light source units, in which a cooling device and a thermoelectric element are omitted.

[0099] As shown in FIG. 16, the illumination device 720 has first to third light source units 770, 772, and 774. The illumination device 720 also has a first optical path shift optical system 776 for bringing the second light beam LF2 of the second light source unit 772 closer to the first light beam LF1 of the first light source unit 770. The illumination device 720 also has a second optical path shift optical system 778 for bringing the third light beam LF3 of the third light source unit 774 closer to the first light beam LF1. Note that, as shown in FIG. 16, each of the multiple light source units included in the illumination device may have a different configuration, for example, a different number of laser elements.

[0100] That is, in a broad sense, an illumination device according to an embodiment of the present disclosure is an illumination device having: a first light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, and emitting a first light flux in a first direction; a second light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, and emitting a second light flux in the first direction and disposed at a first distance from the first light source unit in a second direction perpendicular to the first direction; a first reflecting surface that reflects all of the second light flux emitted from the second light source unit in the first direction toward the first light flux; and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light flux reflected by the first reflecting surface so as to be parallel to the first light flux at a second distance smaller than the first distance.

[0101] Furthermore, a projection type image display device according to an embodiment of the present disclosure includes, in a broad sense, an illumination section including at least one illumination device, an image display section that modulates illumination light from the illumination section and outputs it as image light, and a projection optical system that enlarges and projects the image light, wherein the illumination device includes a first light source unit including a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, the first light source unit emitting a first light flux in a first direction, and a plurality of laser elements whose optical axes are parallel to each other and arranged in a matrix, the second light source unit emitting a second light flux in the first direction, and an optical path shift optical system including: a second light source unit disposed at a first distance from the first light source unit in a second direction perpendicular to the first direction; a first reflecting surface that reflects all of the second light flux emitted from the second light source unit in the first direction toward the first light flux; and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light flux reflected by the first reflecting surface so as to be parallel to the first light flux at a second distance smaller than the first distance.

[0102] As described above, the above-mentioned embodiment has been described as an example of the technology in the present disclosure. For this purpose, drawings and detailed description are provided. Therefore, among the components described in the drawings and detailed description, not only components essential for solving the problem but also components that are not essential for solving the problem in order to illustrate the above-mentioned technology may be included. Therefore, the fact that these non-essential components are described in the drawings or detailed description should not be used to immediately determine that these non-essential components are essential.

[0103] Furthermore, since the above-described embodiments are intended to illustrate the technology in the present disclosure, various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0104] The present disclosure is applicable to lighting devices used in projection-type image display devices. [Explanation of symbols]

[0105] 20 Lighting Equipment 70 First light source unit 72 Second light source unit 84 Optical path shift optical system 84a First Reflecting Surface 84b Second Reflective Surface D1 First distance D2 Second distance LF1 First beam LF2 Second Light Beam

Claims

1. a first light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, and configured to emit a first light flux in a first direction; a second light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, the second light source unit being disposed at a first distance from the first light source unit in a second direction perpendicular to the first direction so as to emit a second light flux in the first direction; and an optical path shift optical system including: a first reflecting surface that reflects the second light flux emitted from the second light source unit in the first direction toward the first light flux; and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light flux reflected by the first reflecting surface so as to be parallel to the first light flux at a second distance smaller than the first distance.

2. The optical path shift optical system is a parallelogram prism, 2. The lighting device according to claim 1, wherein the prism comprises the first reflecting surface, the second reflecting surface, a first transmitting surface through which the second light flux emitted from the second light source unit transmits, and a second transmitting surface that is parallel to the first transmitting surface and through which the second light flux reflected by the second reflecting surface transmits.

3. 2. The illumination device of claim 1, wherein the light path shifting optical system includes a first mirror having the first reflecting surface and a second mirror having the second reflecting surface.

4. the plurality of laser elements of each of the first and second light source units are semiconductor laser elements, The illumination device according to claim 1 , wherein the first and second light source units each include a collimating lens provided for the semiconductor laser element.

5. 5. The illumination device according to claim 4, wherein the first and second light source units include a collimating lens array in which the plurality of collimating lenses are arranged and integrated at the same arrangement pitch as the arrangement pitch of the plurality of semiconductor laser elements.

6. a heat transfer plate including a first heat transfer surface to which the first and second light source units are attached and a second heat transfer surface opposite to the first heat transfer surface; The lighting device according to claim 5 , further comprising: a cooling device attached to the second heat transfer surface of the heat transfer plate.

7. 7. The lighting device according to claim 6, wherein the cooling device includes a first cooling device arranged to face the first light source unit across the heat transfer plate, and a second cooling device arranged to face the second light source unit across the heat transfer plate.

8. a first thermoelectric element including a heat absorbing surface in contact with the second heat transfer surface of the heat transfer plate and a heat dissipating surface to which the first cooling device is attached; The lighting device according to claim 7 , further comprising: a second thermoelectric element having a heat absorbing surface in contact with the second heat transfer surface of the heat transfer plate and a heat dissipating surface to which the second cooling device is attached.

9. 9. The lighting device according to claim 8, wherein, when viewed in the first direction, the first light source unit is disposed in a central portion of the heat absorption surface of the first thermoelectric element, and the second light source unit is disposed in a central portion of the heat absorption surface of the second thermoelectric element.

10. 10. The lighting device according to claim 8 or 9, wherein the heat transfer plate includes a first heat transfer plate to which the first light source unit is attached and which abuts against the first thermoelectric element, and a second heat transfer plate to which the second light source unit is attached and which abuts against the second thermoelectric element.

11. The lighting device according to claim 8 , wherein the semiconductor laser element emits red laser light.

12. an illumination section including at least one illumination device; an image display unit that modulates the illumination light from the illumination unit and outputs it as image light; and a projection optical system that enlarges and projects the image light, The lighting device comprises: a first light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, and configured to emit a first light flux in a first direction; a second light source unit including a plurality of laser elements arranged in a matrix with their optical axes parallel to each other, the second light source unit being disposed at a first distance from the first light source unit in a second direction perpendicular to the first direction so as to emit a second light flux in the first direction; a first reflecting surface that reflects the second light beam emitted from the second light source unit in the first direction toward the first light beam, and a second reflecting surface that is parallel to the first reflecting surface and reflects the second light beam reflected by the first reflecting surface so that the second light beam is parallel to the first light beam at a second distance smaller than the first distance.

Images