Lighting device and projector

Abstract

To provide a lighting device having high efficiency of light utilization.SOLUTION: A lighting device according to the present invention comprises a first light source, a collimator element for parallelizing light from the first light source, a condensing element for condensing light from the collimator element, and a deflection element located between the collimator element and the condensing element. The first light source includes a first light-emitting element for emitting first light along a first direction, and a second light-emitting element for emitting second light along the first direction. The first and second light-emitting elements are arranged along a second direction. The collimator element has a first lens including a first region which the first light enters and a second region which the second light enters. The first and second regions are arranged along the second direction, with a first optical axis of the first lens therebetween. The deflection element causes the traveling direction of the first light and the traveling direction of the second light to change so that the principal ray of the first light and the principal ray of the second light each are along the first optical axis.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lighting device and a projector.

Background Art

[0002] For the purpose of improving the performance of projectors, projectors equipped with lighting devices using laser light sources, which are light sources with a wide color gamut and high efficiency, have been proposed. Patent Document 1 below discloses a lighting device including a plurality of semiconductor lasers, a plurality of collimator lenses that parallelize the light emitted from each semiconductor laser, a condenser lens that condenses the plurality of lights, and a phosphor wheel that wavelength-converts a part of the light condensed by the condenser lens.

[0003] Patent Document 2 discloses a light source device including two semiconductor laser chips arranged on one submount and one collimator lens that parallelizes the light emitted from the two semiconductor laser chips. As described above, a laser light source configured to make the light emitted from two laser chips incident on one collimator lens has been conventionally known as a so-called double emitter type laser light source.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the lighting device described in Patent Document 1, in order to suppress the increase in the size of the light source device and improve the light output, as in Patent Document 2, it is conceivable to increase the light density by increasing the number of laser chips per area where the laser light is emitted. Further, Patent Document 2 describes a problem that when two semiconductor laser chips are simply arranged side by side, the spread of the light emitted from the lens occurs, resulting in a decrease in the light utilization efficiency in the subsequent optical system. Therefore, in Patent Document 2, the above problem is solved by arranging two semiconductor laser chips to be inclined with respect to each other in the optical axis direction of the lens.

[0006] However, in the mounting process of mounting the semiconductor laser chips on the substrate, it is very difficult to accurately mount the two semiconductor laser chips to be inclined with respect to each other. Therefore, there is a problem that the load on the mounting process increases.

Means for Solving the Problem

[0007] To solve the above problems, an illumination device according to one aspect of the present invention includes a first light source that emits light, a collimator element that collimates the light emitted from the first light source, a condenser element that condenses the light emitted from the collimator element toward an illuminated area, and a deflection element provided between the collimator element and the condenser element. The first light source includes a first substrate having a first surface, a first light-emitting element provided on the first surface and emitting first light along a first direction, and a second light-emitting element provided on the first surface and emitting second light along the first direction. The first light-emitting element and the second light-emitting element are arranged along a second direction intersecting the first direction. The collimator element has a first lens including a first region where the first light is incident and a second region different from the first region where the second light is incident. The first region and the second region are arranged along the second direction with the first optical axis of the first lens interposed therebetween. The deflection element changes the traveling direction of the first light and the traveling direction of the second light so that the principal rays of the first light emitted from the first region and the principal rays of the second light emitted from the second region each follow the first optical axis.

[0008] A projector according to one aspect of the present invention includes an illumination device according to one aspect of the present invention, a light modulation device that modulates light including the combined light emitted from the illumination device according to image information, and a projection optical device that projects the light modulated by the light modulation device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

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Figure 17

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The projector of the present embodiment is an example of a liquid crystal projector equipped with a lighting device using a laser diode. In each of the following drawings, for the sake of easy viewing of each component, the scale of the dimensions may be shown differently depending on the component.

[0011] The projector 10 of the present embodiment is a projection-type image display device that displays a color image on a screen (projection surface) SCR. The projector 10 includes three light modulation devices corresponding to each of the color lights of red light LR, green light LG, and blue light LB. The projector 10 includes a laser diode as a light emitting element of the light source device, which can obtain high-brightness and high-output light.

[0012] FIG. 1 is a schematic configuration diagram of the projector 10 of the present embodiment. As shown in FIG. 1, the projector 10 includes an illumination device 700, a color separation light guide optical system 200, a red light light modulation device 400R, a green light light modulation device 400G, a blue light light modulation device 400B, a combining optical system 500, and a projection optical device 600. The red light light modulation device 400R, the green light light modulation device 400G, and the blue light light modulation device 400B form image light by modulating light including the combined light LW emitted from the illumination device 700 according to image information. The projection optical device 600 projects the image light onto the screen SCR (projection surface).

[0013] FIG. 2 is a schematic configuration diagram of the illumination device 700. As shown in FIG. 2, the illumination device 700 includes a red light source unit 11, a green light source unit 20, a blue light source unit 30, a light combining element 40, a condenser lens 50, a diffusing device 70, a collimator lens 80, a double-sided multi-lens array 90, and a superimposing lens 100.

[0014] In the following description, as the coordinate axes, an axis parallel to the central axis of the green light LG emitted from the green light source unit 20 is defined as the X axis. An axis parallel to the central axes of the red light LR emitted from the red light source unit 11 and the blue light LB emitted from the blue light source unit 30 is defined as the Y axis. An axis perpendicular to the X axis and the Y axis is defined as the Z axis. Also, an axis parallel to the X axis passing through the focus point P on the diffusion surface 71a of the diffusion plate 71 is defined as the optical axis AX1. An axis parallel to the Y axis passing through the focus point P (the central axis of the combined light LW emitted from the diffusion plate 71) is defined as the optical axis AX2. The central axes of the red light LR emitted from the red light source unit 11 and the blue light LB emitted from the blue light source unit 30 are defined as the optical axis AX3.

[0015] The red light source unit 11 includes a red laser diode array 1, a first collimator lens array 2, and a deflection angle prism array 3. The red light source unit 11 emits red light LR having a predetermined peak wavelength along the Y-axis direction. The Y-axis direction in the present embodiment corresponds to the first direction in the claims.

[0016] The red laser diode array 1 has a plurality of red laser light sources 12 arranged in an array. The red laser light source 12 emits red light LR having a predetermined peak wavelength in the -Y direction. The peak wavelength is, for example, 640 nm. In FIG. 2, the plurality of red laser light sources 12 are arranged in 6 columns along the X-axis direction, and a plurality of them are also arranged in the direction perpendicular to the paper surface. Note that the number and arrangement of the red laser light sources 12 are not particularly limited.

[0017] FIG. 3 is a perspective view of two red laser light sources 12 adjacent to each other in the X-axis direction. In FIG. 3, among the plurality of red laser light sources 12, two red laser light sources adjacent to each other in the X-axis direction are referred to as a first red laser light source 13 and a second red laser light source 14. The first red laser light source 13 is, for example, a laser light source located at the end on the +X side (the uppermost part in FIG. 2) in the red laser diode array 1 shown in FIG. 2. The second red laser light source 14 is, for example, a laser light source located second from the end on the +X side (the second from the top in FIG. 2) in the red laser diode array 1 shown in FIG. 2. The first red laser light source 13 in the present embodiment corresponds to the first light source in the claims. The second red laser light source 14 in the present embodiment corresponds to the second light source in the claims.

[0018] The first red laser light source 13 includes a first substrate 130, a first red laser diode 131, and a second red laser diode 132. The first substrate 130 has a first surface 130a. The first red laser diode 131 is provided on the first surface 130a of the first substrate 130 and emits a first red light LR1 along the Y-axis direction. The second red laser diode 132 is provided on the first surface 130a of the first substrate 130 and emits a second red light LR2 along the Y-axis direction. The first red laser diode 131 and the second red laser diode 132 are arranged along the X-axis direction on the first surface 130a. The first red laser diode 131 in this embodiment corresponds to the first light-emitting element in the claims. The second red laser diode 132 in this embodiment corresponds to the second light-emitting element in the claims. The X-axis direction in this embodiment corresponds to the second direction in the claims. The first red light LR1 in this embodiment corresponds to the first light in the claims. The second red light LR2 in this embodiment corresponds to the second light in the claims.

[0019] The second red laser light source 14 includes a second substrate 140, a third red laser diode 143, and a fourth red laser diode 144. The second substrate 140 has a second surface 140a. The third red laser diode 143 is provided on the second surface 140a of the second substrate 140 and emits a third red light LR3 along the Y-axis direction. The fourth red laser diode 144 is provided on the second surface 140a of the second substrate 140 and emits a fourth red light LR4 along the Y-axis direction. The third red laser diode 143 and the fourth red laser diode 144 are arranged along the X-axis direction on the second surface 140a. The third red laser diode 143 in this embodiment corresponds to the third light-emitting element in the claims. The fourth red laser diode 144 in this embodiment corresponds to the fourth light-emitting element in the claims. The third red light LR3 in this embodiment corresponds to the third light in the claims. The fourth red light LR4 in this embodiment corresponds to the fourth light in the claims.

[0020] Each of the first red laser diode 131, the second red laser diode 132, the third red laser diode 143, and the fourth red laser diode 144 has a rectangular light emitting surface 131a, 132a, 143a, 144a. Each of the red laser diodes 131, 132, 143, 144 is arranged such that the longitudinal direction of the light emitting surfaces 131a, 132a, 143a, 144a faces the X-axis direction and the short side direction of the light emitting surfaces 131a, 132a, 143a, 144a faces the Z-axis direction. Generally, since the light emitted from the laser diode diverges due to diffraction occurring at the light emitting surface, the divergence angle in the short side direction of the light emitting surface is larger than the divergence angle in the long side direction of the light emitting surface. Therefore, in the case of this embodiment, the divergence angle in the Z-axis direction of the red lights LR1, LR2, LR3, LR4 is larger than the divergence angle in the X-axis direction of the red lights LR1, LR2, LR3, LR4. Therefore, the beam diameter Dz in the Z-axis direction of the red lights LR1, LR2, LR3, LR4 is larger than the beam diameter Dx in the X-axis direction of the red lights LR1, LR2, LR3, LR4. The Z-axis direction of this embodiment corresponds to the third direction in the claims.

[0021] As shown in FIG. 2, the first collimator lens array 2 is provided on the light emission side of the red laser diode array 1. The first collimator lens array 2 has a plurality of collimator lenses 24 provided corresponding to each of the plurality of red laser light sources 12. All the collimator lenses 24 have the same shape and the same size. The collimator lens 24 is composed of a convex lens. Since two red lights are emitted from two red laser diodes of one red laser light source 12, the red lights from the two red laser diodes enter one collimator lens 24. The collimator lens 24 collimates each of the red lights emitted from the red laser light source 12. The first collimator lens array 2 of this embodiment corresponds to the collimator element in the claims.

[0022] As shown in FIG. 3, in the first collimator lens array 2, a first collimator lens 25 is provided corresponding to the first red laser light source 13, and a second collimator lens 26 is provided corresponding to the second red laser light source 14. The first collimator lens 25 has a first region 25a into which the first red light LR1 emitted from the first red laser diode 131 is incident, and a second region 25b into which the second red light LR2 emitted from the second red laser diode 132 is incident. The first region 25a and the second region 25b are arranged along the X-axis direction with the first optical axis CX1 of the first collimator lens 25 interposed therebetween. The second collimator lens 26 has a third region 26c into which the third red light LR3 emitted from the third red laser diode 143 is incident, and a fourth region 26d into which the fourth red light LR4 emitted from the fourth red laser diode 144 is incident. The third region 26c and the fourth region 26d are arranged along the X-axis direction with the second optical axis CX2 of the second collimator lens 26 interposed therebetween. The first collimator lens 25 of the present embodiment corresponds to the first lens in the claims. The second collimator lens 26 of the present embodiment corresponds to the second lens in the claims.

[0023] FIG. 4 is a front view of the first collimator lens array 2. As shown in FIG. 4, the length R1 of the first collimator lens 25 in the X-axis direction is shorter than the length R2 of the first collimator lens 25 in the Z-axis direction. That is, the shape of the first collimator lens 25 is a rectangle that is long in the Z-axis direction. Therefore, the pitch P1 of the first collimator lens array 2 in the X-axis direction is shorter than the pitch P2 of the first collimator lens array 2 in the Z-axis direction. The pitch P1 of the first collimator lens array 2 in the X-axis direction is the distance between the centers of two collimator lenses 24 adjacent to each other in the X-axis direction. The pitch P2 of the first collimator lens array 2 in the Z-axis direction is the distance between the centers of two collimator lenses 24 adjacent to each other in the Z-axis direction.

[0024] As described above, the red light LR1, LR2, LR3, and LR4 emitted from each of the red laser diodes 131, 132, 143, and 144 has a cross-sectional shape elongated in the Z-axis direction. Therefore, if a square collimator lens with a side long enough to allow the red light to enter is used, both ends of the collimator lens in the X-axis direction become wasted areas, resulting in a problem that the collimator lens array becomes large. In contrast, according to the configuration of this embodiment, the length of the first collimator lens array 2 in the X-axis direction is not longer than necessary, so that the first collimator lens array 2 can be made smaller.

[0025] FIG. 5 is a perspective view of the deflection prism array 3. As shown in FIG. 5, the deflection prism array 3 has a configuration in which a plurality of quadrangular deflection prisms 34 are arranged along the X-axis direction. The deflection prism array 3 is composed of an integral light-transmitting member including the plurality of deflection prisms 34. The deflection prisms 34 have a trapezoidal cross section perpendicular to the Z-axis, and extend long in the Z-axis direction. The deflection prism 34 has the function of refracting the chief ray of light incident on the deflection prism 34 in a direction parallel to the optical axis of the collimator lens 24 and outputting it. The deflection prism array 3 of this embodiment corresponds to a deflection element in the claims.

[0026] Fig. 6 is an enlarged plan view of the deflection prism array 3. Of the multiple deflection prisms 34, Fig. 6 only shows the first deflection prism 35, the second deflection prism 36, the third deflection prism 37, and the fourth deflection prism 38. Fig. 6 only shows the chief rays of the red lights LR1, LR2, LR3, and LR4.

[0027] As shown in FIG. 6, the first red light LR1 emitted from the first region 25a of the first collimator lens 25 enters the second deflection prism 36. The second red light LR2 emitted from the second region 25b of the first collimator lens 25 enters the first deflection prism 35. The third red light LR3 emitted from the third region 26c of the second collimator lens 26 enters the fourth deflection prism 38. The fourth red light LR4 emitted from the fourth region 26d of the second collimator lens 26 enters the third deflection prism 37.

[0028] The first deflection prism 35 has a first light incident surface 35a on which the second red light LR2 is incident and a first light emitting surface 35b from which the second red light LR2 is emitted. The first light incident surface 35a is a vertical surface perpendicular to the first optical axis CX1 of the first collimator lens 25. The first light emitting surface 35b is an inclined surface inclined with respect to a virtual plane perpendicular to the first optical axis CX1 of the first collimator lens 25. The first light emitting surface 35b is inclined in a direction in which the +X side end is located on the +Y side and the -X side end is located on the -Y side.

[0029] The second deflection prism 36 has a second light incident surface 36a on which the first red light LR1 is incident and a second light emitting surface 36b from which the first red light LR1 is emitted. The second light incident surface 36a is a vertical surface perpendicular to the first optical axis CX1 of the first collimator lens 25. The second light emitting surface 36b is an inclined surface inclined with respect to a virtual plane perpendicular to the first optical axis CX1 of the first collimator lens 25. The second light emitting surface 36b is inclined in a direction in which the +X side end is located on the -Y side and the -X side end is located on the +Y side. That is, the first light emitting surface 35b and the second light emitting surface 36b are inclined in opposite directions. Also, the absolute value of the inclination angle of the first light emitting surface 35b is the same as the absolute value of the inclination angle of the second light emitting surface 36b.

[0030] The deflection prism array 3 changes the traveling directions of the principal rays of the first red light LR1 emitted from the first region 25a of the first collimator lens 25 and the principal rays of the second red light LR2 emitted from the second region 25b so that each of them is along the first optical axis CX1 of the first collimator lens 25. Also, the deflection prism array 3 changes the traveling directions of the principal rays of the third red light LR3 emitted from the third region 26c of the second collimator lens 26 and the principal rays of the fourth red light LR4 emitted from the fourth region 26d so that each of them is along the second optical axis CX2 of the second collimator lens 26. In this specification, the fact that the principal rays of each of the above-described red lights are along the optical axes of the respective collimator lenses means that the principal rays of each of the red lights are substantially parallel to the optical axes of the respective collimator lenses.

[0031] Note that the vertical surface and the inclined surface may be opposite to those in the above example. That is, the first light incident surface 35a and the second light incident surface 36a may be inclined surfaces, and the first light emitting surface 35b and the second light emitting surface 36b may be vertical surfaces.

[0032] The configurations of the third deflection prism 37 and the fourth deflection prism 38 are the same as those of the first deflection prism 35 and the second deflection prism 36. The third deflection prism 37 has a third light incident surface 37a on which the fourth red light LR4 is incident and a third light emitting surface 37b that emits the fourth red light LR4. The fourth deflection prism 38 has a fourth light incident surface 38a on which the third red light LR3 is incident and a fourth light emitting surface 38b that emits the third red light LR3. The positional relationship between the vertical surface and the inclined surface is also the same as that in the first deflection prism 35 and the second deflection prism 36.

[0033] Note that the deflection prism array 3 may have the following configuration. FIG. 7 is an enlarged plan view of the deflection prism array 103 of the first modification. As shown in Fig. 7, in the declination prism array 103 of the first modification, the first light incident surface 135a of the first declination prism 135 is an inclined surface, and the first light emitting surface 135b is a vertical surface. The second light incident surface 136a of the second declination prism 136 is a vertical surface, and the second light emitting surface 136b is an inclined surface. The configurations of the third declination prism 137 and the fourth declination prism 138 are the same as those of the first declination prism 135 and the second declination prism 136.

[0034] Fig. 8 is an enlarged plan view of the declination prism array 203 of the second modification. As shown in Fig. 8, in the declination prism array 203 of the second modification, the first light incident surface 235a of the first declination prism 235 is a vertical surface, and the first light emitting surface 235b is an inclined surface. The second light incident surface 236a of the second declination prism 236 is an inclined surface, and the second light emitting surface 236b is a vertical surface. The configurations of the third declination prism 237 and the fourth declination prism 238 are the same as those of the first declination prism 235 and the second declination prism 236.

[0035] In the declination prism arrays 103 and 203 of the first and second modifications as well, the same operation as that of the declination prism array 3 of the present embodiment shown in Fig. 6 can be obtained. Therefore, in the declination prism array of the present invention, either one of the first light incident surface and the first light emitting surface may be an inclined surface, and either one of the second light incident surface and the second light emitting surface may be an inclined surface. However, it is desirable that either one of the first light incident surface 35a and the second light incident surface 36a, and either one of the first light emitting surface 35b and the second light emitting surface 36b be a vertical surface perpendicular to the first optical axis CX1, as in the declination prism array 3 of the present embodiment. According to this configuration, since either one of the light incident surface and the light emitting surface becomes a vertical surface over all the declination prisms 34, effects such as ease of manufacturing and mounting of the declination prism array 3 and suppression of light loss caused by the step portion at the boundary between the second declination prism and the third declination prism shown in the modifications of Figs. 7 and 8 can be obtained.

[0036] Hereinafter, the operation of the declination prism array will be described. FIG. 9 is a schematic diagram showing the problems of the lighting device 800 of the comparative example. As shown in FIG. 9, the lighting device 800 of the comparative example does not include a declination prism array. The lighting device 800 of the comparative example includes a laser light source of a so-called double emitter type, in which light from two laser diodes 801 is incident on one collimator lens 802. In this case, the red lights LR1 and LR2 do not pass through the optical axis CX3 of the collimator lens 802, but are incident on two regions 802a and 802b of the collimator lens 802 sandwiching the optical axis CX3, respectively. In this case, each of the red lights LR1 and LR2 emitted from each laser diode 801 with a predetermined divergence angle is parallelized by the action of the collimator lens 802. However, since the red lights LR1 and LR2 are incident on positions deviated from the optical axis CX3 of the collimator lens 802, they are emitted not in a direction parallel to the optical axis CX3 but in a direction intersecting the optical axis CX3 from the collimator lens 802.

[0037] Next, when the red lights LR1 and LR2 emitted from the collimator lens 802 are condensed by the condenser lens 803, a secondary light source image of the laser diode 801 is formed on the focal plane of the condenser lens 803. However, since each of the red lights LR1 and LR2 is not incident parallel to the optical axis of the condenser lens 803, the red lights LR1 and LR2 do not converge at one point on the optical axis CX3, and two secondary light source images Z1 are formed at positions sandwiching the optical axis CX3. Therefore, when the illuminated area is arranged at the focal position of the condenser lens 803, there arises a problem that the secondary light source image in the illuminated area spreads spatially.

[0038] FIG. 10 is a schematic diagram showing the operation of the declination prism array 3 of the present embodiment. As shown in FIG. 10, in the present embodiment, a deflection angle prism array 3 is provided between the first collimator lens 25 and the condenser lens 5. Therefore, the red lights LR1 and LR2 emitted from the first collimator lens 25 enter the first deflection angle prism 35 and the second deflection angle prism 36 of the deflection angle prism array 3, respectively. Each of the deflection angle prisms 35 and 36 has an effect of refracting the principal rays of the red lights LR1 and LR2 in a direction parallel to the optical axis CX3. Since the first deflection angle prism 35 and the second deflection angle prism 36 have inclined surfaces that are inclined in opposite directions to each other, the principal rays of the red lights LR1 and LR2 emitted from the deflection angle prism array 3 are parallel to the optical axis CX3. Thus, in the case of the present embodiment, unlike the comparative example, since each of the red lights LR1 and LR2 enters the condenser lens 5 parallel to the optical axis CX3, the red lights LR1 and LR2 converge at one point on the optical axis CX3, and one secondary light source image Z2 is formed. Thus, according to the deflection angle prism array 3 of the present embodiment, it is possible to suppress the spatial spread of the secondary light source image in the illuminated region caused by using the first red laser light source 13 of the double emitter method.

[0039] The inventor of the present invention performed a simulation regarding the angular distribution of light before and after entering the deflection angle prism array 3. FIGS. 11 and 12 are graphs showing the simulation results of the angular distribution of light. FIG. 11 is a graph showing the angular distribution of light before entering the deflection angle prism array 3. FIG. 12 is a graph showing the angular distribution of light after being emitted from the deflection angle prism array 3. In FIGS. 11 and 12, the horizontal axis represents the angle (degrees) of light when the direction parallel to the optical axis CX3 is set to 0 degrees. The vertical axis represents the radiant intensity of light (W / sr).

[0040] As shown in Fig. 11, the light before entering the deflection prism array 3 has two angular components, an angular component with a peak at +1 degree and an angular component with a peak at -1 degree. In contrast, as shown in Fig. 12, the light after being emitted from the deflection prism array 3 has one peak at 0 degree. Thus, it has been demonstrated that most of the light incident on the deflection prism array 3 having two angular distributions is converted into light parallel to the optical axis CX3 by passing through the deflection prism array 3. In the graph of Fig. 12, slight peaks appear at the positions of +2 degrees and -2 degrees. This indicates that a very small part of the light incident obliquely on the deflection prism array 3 enters other deflection prisms adjacent to the deflection prism where it should originally enter, and there is a component that is not refracted in the direction parallel to the optical axis CX3 but is refracted in the direction away from the optical axis CX3.

[0041] Hereinafter, the optimal position of the deflection prism array 3 will be described. The inventor performed simulations regarding the intensity distributions of a plurality of lights when changing the position of the deflection prism array 3 on the optical axis. Fig. 13 shows the simulation results of the intensity distributions of a plurality of lights when the deflection prism array is arranged at the optimal position. The simulation results of Figs. 13 to 15 shown below indicate the intensity distributions when projecting light onto a virtual plane perpendicular to the first optical axis CX1 and the second optical axis CX2 between the first collimator lens array 2 and the condenser lens 50.

[0042] As shown in FIG. 13, when the declination prism array 3 is arranged at an optimal position, the distances between the lights adjacent in the X-axis direction are equal to each other. Note that the distance between the lights adjacent in the X-axis direction is the distance between the central axes of the lights adjacent in the X-axis direction, and is defined as the distance between the centers where the intensity distributions are maximum in the lights adjacent in the X-axis direction in FIG. 13. Specifically, the first distance X1 along the X-axis direction between the first red light LR1 and the second red light LR2, the second distance X2 along the X-axis direction between the second red light LR2 and the third red light LR3, and the third distance X3 along the X-axis direction between the third red light LR3 and the fourth red light LR4 are equal to each other. Note that the distances being equal to each other includes the distances being substantially equal to each other. The distances being substantially equal to each other means that, for example, there may be a difference of about 10% or less between one distance and the other distance.

[0043] In this case, it is desirable that the pitch of the declination prism array 3 is equal to the first distance X1, the second distance X2, and the third distance X3. According to this configuration, the loss that occurs when the red light LR passes through the declination prism 34 that should not be originally incident can be minimized, and the utilization efficiency of the red light LR can be increased. The pitch of the declination prism array 3 described above is defined as the width W in the X-axis direction of one declination prism 34 shown in FIG. 6. Note that the pitch of the declination prism array 3 being equal to each of the distances X1, X2, X3 includes the pitch and each distance being substantially equal to each other. The pitch and the distances being substantially equal to each other means that, for example, there may be a difference of about 10% or less between each distance and the pitch.

[0044] On the other hand, FIG. 14 is a diagram showing the intensity distributions of a plurality of lights when the declination prism array 3 is arranged closer to the first collimator lens array 2 than the optimal position of the declination prism array 3 shown in FIG. 6. When the position of the deflection prism array 3 is closer to the first collimator lens array 2 than the optimum position, as shown in Fig. 14, the distances between the adjacent lights in the X-axis direction are not equal to each other. Specifically, the first distance X1 between the first red light LR1 and the second red light LR2, and the third distance X3 between the third red light LR3 and the fourth red light LR4 are smaller than the second distance X2 between the second red light LR2 and the third red light LR3.

[0045] Fig. 15 is a diagram showing the intensity distributions of a plurality of lights when the deflection prism array 3 is arranged on the side farther from the first collimator lens array 2 with respect to the optimum position of the deflection prism array 3 shown in Fig. 6. When the position of the deflection prism array 3 is farther from the first collimator lens array 2 than the optimum position, as shown in Fig. 15, the distances between the adjacent lights in the X-axis direction are not equal to each other. Specifically, the first distance X1 between the first red light LR1 and the second red light LR2, and the third distance X3 between the third red light LR3 and the fourth red light LR4 are larger than the second distance X2 between the second red light LR2 and the third red light LR3.

[0046] As shown in Figs. 14 and 15, when the deflection prism array 3 is not arranged at the optimum position, a part of the red light is incident on another deflection prism adjacent to the deflection prism where it should originally be incident. As a result, the red light incident on the other deflection prism refracts and advances in a direction away from the optical axis, resulting in loss, and thus the utilization efficiency of the red light decreases. Therefore, in order not to reduce the utilization efficiency of the red light, as shown in Fig. 13, the deflection prism array 3 is arranged on a virtual plane perpendicular to the first optical axis CX1 and the second optical axis CX2 between the first collimator lens array 2 and the condenser lens 50. When the first red light LR1, the second red light LR2, the third red light LR3, and the fourth red light LR4 are projected, it is desirable that the first distance X1 between the first red light LR1 and the second red light LR2, the second distance X2 between the second red light LR2 and the third red light LR3, and the third distance X3 between the third red light LR3 and the fourth red light LR4 are equal to each other.

[0047] As shown in FIG. 2, the green light source unit 20 includes a green laser diode array 22 and a second collimator lens array 23.

[0048] The green laser diode array 22 has a plurality of green laser diodes 221 arranged in an array. The green laser diode 221 emits green light LG0 in the +X direction in the second wavelength band. The second wavelength band is, for example, 535 nm ± 10 nm. The number and arrangement of the green laser diodes 221 are not particularly limited.

[0049] The second collimator lens array 23 is provided on the light emission side of the green laser diode array 22. The second collimator lens array 23 has a plurality of collimator lenses 231 provided corresponding to each of the plurality of green laser diodes 221. The collimator lens 231 is composed of a convex lens. The collimator lens 231 collimates the green light LG0 emitted from the green laser diode 221. Hereinafter, the plurality of green lights LG0 emitted from the second collimator lens array 23 are collectively referred to as green light LG. Therefore, the green light LG is parallel light collimated by the second collimator lens array 23.

[0050] The blue light source unit 30 includes a blue laser diode array 32 and a third collimator lens array 33.

[0051] The blue laser diode array 32 has a plurality of blue laser diodes 321 arranged in an array. The blue laser diode 321 emits blue light LB0 in the +Y direction in the third wavelength band. The third wavelength band is, for example, 455 nm ± 10 nm. The number and arrangement of the blue laser diodes 321 are not particularly limited.

[0052] The third collimator lens array 33 is provided on the light emitting side of the blue laser diode array 32. The third collimator lens array 33 has a plurality of collimator lenses 331 provided corresponding to each of the plurality of blue laser diodes 321. The collimator lens 331 is composed of a convex lens. The collimator lens 331 collimates the blue light LB0 emitted from the blue laser diode 321. Hereinafter, the plurality of blue lights LB0 emitted from the third collimator lens array 33 are collectively referred to as blue light LB. Therefore, the blue light LB is parallel light collimated by the third collimator lens array 33.

[0053] The photosynthetic element 40 is composed of a cross dichroic prism. The cross dichroic prism has a first dichroic mirror 45 and a second dichroic mirror 46. The first dichroic mirror 45 reflects the red light LR and transmits the green light LG and the blue light LB. The second dichroic mirror 46 reflects the blue light LB and transmits the green light LG and the red light LR. Thereby, the photosynthetic element 40 synthesizes the red light LR emitted from the red light source unit 11, the green light LG emitted from the green light source unit 20, and the blue light LB emitted from the blue light source unit 30, and emits the white synthesized light LW toward the condenser lens 50. Since each color light incident on the photosynthetic element 40 is linearly polarized light, the synthesized light LW emitted from the photosynthetic element 40 is also linearly polarized light.

[0054] The condenser lens 50 is provided on the light emitting side of the photosynthetic element 40. The condenser lens 50 is composed of a convex lens. The condenser lens 50 condenses the white synthesized light LW emitted from the photosynthetic element 40 and emits it toward the diffusion plate 71. The condenser lens 50 of the present embodiment corresponds to the condenser element in the claims.

[0055] The diffusion device 70 includes a disc-shaped diffusion plate 71 and a drive device 72. The diffusion plate 71 has a diffusion surface 71a that diffusely reflects the combined light LW emitted from the condenser lens 50. That is, the diffusion plate 71 of the present embodiment is a reflective diffusion plate, not a transmissive diffusion plate. The diffusion plate 71 is disposed at a position where the diffusion surface 71a intersects each of the optical axis AX1 and the optical axis AX2. The diffusion surface 71a forms an angle of 45 degrees with each of the optical axis AX1 and the optical axis AX2. The diffusion surface 71a of the diffusion plate 71 is disposed at the condensing point P of the combined light LW condensed by the condenser lens 50. In other words, the focal point of the condenser lens 50 is located on the diffusion surface 71a of the diffusion plate 71. The diffusion surface 71a of the present embodiment corresponds to the illuminated area in the claims.

[0056] The diffusion plate 71 has, for example, a light-transmissive substrate, a metal reflection film, and a dielectric multilayer film. The light-transmissive substrate is made of optical glass such as BK7, and has an uneven structure including a plurality of concave portions and a plurality of convex portions provided on one surface. The metal reflection film is provided along the uneven structure of the light-transmissive substrate. The metal reflection film is made of a material containing, for example, aluminum. The dielectric multilayer film is provided on the surface of the metal reflection film opposite to the light-transmissive substrate. The dielectric multilayer film has a structure in which a plurality of two types of dielectric films having different refractive indexes are alternately laminated. The diffusion plate 71 may be a microlens array type diffusion plate provided with a microlens array. The dielectric multilayer film may be directly formed on the uneven structure of the light-transmissive substrate. Alternatively, the diffusion plate 71 may be composed of a metal substrate and a dielectric multilayer film.

[0057] The drive device 72 is composed of a motor and rotates the diffusion plate 71 about a rotation axis C1 that intersects the diffusion surface 71a. By rotating the diffusion plate 71, it is possible to reduce the speckle noise that is likely to occur when using a laser light source.

[0058] The collimator lens 80 is provided on the light emission side of the diffusion plate 71 on the optical axis AX2. The collimator lens 80 is composed of a convex lens. The collimator lens 80 collimates the combined light LW emitted from the diffusion plate 71 at a predetermined diffusion angle and emits it toward the double-sided multi-lens array 90.

[0059] The double-sided multi-lens array 90 and the superimposing lens 100 constitute an integrator optical system. The integrator optical system equalizes the illuminance distribution of the combined light LW emitted from the collimator lens 80 in the respective image formation regions of the red light light modulation device 400R, the green light light modulation device 400G, and the blue light light modulation device 400B.

[0060] The double-sided multi-lens array 90 is provided on the light emission side of the collimator lens 80 on the optical axis AX2. The double-sided multi-lens array 90 is a multi-lens array in which the first multi-lens surface 90a and the second multi-lens surface 90b are integrated into one member. The first multi-lens surface 90a has a plurality of lenses for dividing the combined light LW emitted from the collimator lens 80 into a plurality of partial light beams. The plurality of lenses are arranged in a matrix in a plane orthogonal to the optical axis AX2.

[0061] The second multi-lens surface 90b has a plurality of lenses corresponding to the plurality of lenses of the first multi-lens surface 90a. The second multi-lens surface 90b, together with the subsequent superimposing lens 100, forms an image of each lens of the first multi-lens surface 90a in each image formation region of the red light light modulation device 400R, the green light light modulation device 400G, and the blue light light modulation device 400B or in the vicinity thereof. The plurality of lenses are arranged in a matrix in a plane orthogonal to the optical axis AX2. Note that the first multi-lens surface 90a and the second multi-lens surface 90b may be provided separately as two multi-lens arrays. Further, a driving device may be provided to vibrate or swing the double-sided multi-lens array 90 in a direction orthogonal to the optical axis AX2 (a direction along the XZ plane). By vibrating or swinging the double-sided multi-lens array 90, it is possible to reduce the speckle noise that is likely to occur when using a laser diode.

[0062] The superimposing lens 100 condenses each of the plurality of partial light beams emitted from the double-sided multi-lens array 90 and superimposes them on each other in each image formation region of the red light light modulation device 400R, the green light light modulation device 400G, and the blue light light modulation device 400B or in the vicinity thereof.

[0063] As shown in FIG. 1, the color separation light guiding optical system 200 includes a dichroic mirror 240, a dichroic mirror 220, a reflection mirror 210, a reflection mirror 230, and a reflection mirror 250. The color separation light guiding optical system 200 separates the white combined light LW emitted from the illumination device 700 into red light LR, green light LG, and blue light LB, and guides the red light LR, green light LG, and blue light LB to the corresponding red light light modulation device 400R, green light light modulation device 400G, and blue light light modulation device 400B, respectively.

[0064] A field lens 300R is disposed between the color separation light guide optical system 200 and the red light use light modulation device 400R. A field lens 300G is disposed between the color separation light guide optical system 200 and the green light use light modulation device 400G. A field lens 300B is disposed between the color separation light guide optical system 200 and the blue light use light modulation device 400B.

[0065] The dichroic mirror 240 reflects the blue light LB and transmits the red light LR and the green light LG. The dichroic mirror 220 reflects the green light LG and transmits the blue light LB. Each of the reflection mirrors 210 and 230 reflects the red light LR. The reflection mirror 250 reflects the blue light LB.

[0066] The red light use light modulation device 400R is composed of a liquid crystal panel that modulates the red light LR according to image information to form an image. The green light use light modulation device 400G is composed of a liquid crystal panel that modulates the green light LG according to image information to form an image. The blue light use light modulation device 400B is composed of a liquid crystal panel that modulates the blue light LB according to image information to form an image.

[0067] Although not shown, an incident side polarizing plate is disposed between the field lens 300R and the red light use light modulation device 400R, between the field lens 300G and the green light use light modulation device 400G, and between the field lens 300B and the blue light use light modulation device 400B, respectively. An exit side polarizing plate is disposed between the red light use light modulation device 400R and the combining optical system 500, between the green light use light modulation device 400G and the combining optical system 500, and between the blue light use light modulation device 400B and the combining optical system 500, respectively. Note that the incident side polarizing plate may not be provided when the polarization disturbance by the optical system after being emitted from the illumination device 700 is acceptable.

[0068] The synthetic optical system 500 synthesizes the respective image lights emitted from the red light optical modulator 400R, the green light optical modulator 400G, and the blue light optical modulator 400B. The synthetic optical system 500 is composed of a cross dichroic prism having a substantially square shape in plan view formed by bonding four right-angled prisms. In the cross dichroic prism, a dielectric multilayer film is provided on a substantially X-shaped interface where the right-angled prisms are bonded to each other.

[0069] The image light emitted from the synthetic optical system 500 is enlarged and projected onto the screen SCR by the projection optical device 600. The projection optical device 600 is composed of a plurality of lenses.

[0070] [Effects of the First Embodiment] The lighting device 700 of the present embodiment includes a first red laser light source 13 that emits red light LR, a first collimator lens array 2 that collimates the red light LR emitted from the first red laser light source 13, a condenser lens 50 that condenses the red light LR emitted from the first collimator lens array 2 toward a diffusion plate 71, and a declination prism array 3 provided between the first collimator lens array 2 and the condenser lens 50. The first red laser light source 13 has a first substrate 130 having a first surface 130a, a first red laser diode 131 provided on the first surface 130a and emitting a first red light LR1 along the Y-axis direction, and a second red laser diode 132 provided on the first surface 130a and emitting a second red light LR2 along the Y-axis direction. The first red laser diode 131 and the second red laser diode 132 are arranged along the X-axis direction. The first collimator lens array 2 has a first collimator lens 25 including a first region 25a into which the first red light LR1 enters and a second region 25b into which the second red light LR2 enters. The first region 25a and the second region 25b are arranged along the X-axis direction with the first optical axis CX1 of the first collimator lens 25 interposed therebetween. The declination prism array 3 changes the traveling directions of the first red light LR1 and the second red light LR2 so that the principal rays of the first red light LR1 emitted from the first region 25a and the principal rays of the second red light LR2 emitted from the second region 25b each follow the first optical axis CX1.

[0071] According to the lighting device 700 of the present embodiment, as described with reference to FIG. 10, the spatial spread of the secondary light source image on the diffusion plate 71 due to using a double emitter type laser light source for the red laser light source 12 can be suppressed. Thereby, the loss of the red light LR in the subsequent optical system can be suppressed, and the utilization efficiency of the red light LR can be increased. Further, according to the present embodiment, unlike the laser light source of the prior art, it is not necessary to mount two laser diodes in an inclined manner, so the load on the mounting process of the laser diodes does not increase.

[0072] The reason for using a double-emitter type laser light source for the red laser light source 12 is that the light output of the currently available red laser diodes is smaller than that of laser diodes of other colors, and the relative sensitivity to green light is high. Therefore, even if a double-emitter type laser light source is used for the red laser light source 12, if the loss of red light in the subsequent optical system is large, the effect of improving the light output cannot be sufficiently obtained. In this regard, according to the present embodiment, since the loss of the red light LR can be reduced, the effect of improving the light output of the red light LR can be sufficiently exerted, and the lighting device 700 with excellent color balance can be provided. From the above, it is desirable to apply the configuration of the present invention to the red light LR rather than the green light LG and the blue light LB.

[0073] Furthermore, the lighting device 700 of the present embodiment further includes a second red laser light source 14 that emits red light LR, and the second red laser light source 14 includes a second substrate 140 having a second surface 140a, a third red laser diode 143 that is provided on the second surface 140a and emits third red light LR3 along the Y-axis direction, and a fourth red laser diode 144 that is provided on the second surface 140a and emits fourth red light LR4 along the Y-axis direction. The third red laser diode 143 and the fourth red laser diode 144 are arranged along the X-axis direction. The first red laser light source 13 and the second red laser light source 14 are arranged along the X-axis direction. The first collimator lens array 2 further includes a second collimator lens 26 that includes a third region 26c into which the third red light LR3 enters and a fourth region 26d into which the fourth red light LR4 enters. The third region 26c and the fourth region 26d are arranged along the X-axis direction with the second optical axis CX2 of the second collimator lens 26 interposed therebetween. The deflection angle prism array 3 changes the traveling directions of the third red light LR3 and the fourth red light LR4 so that the principal rays of the third red light LR3 emitted from the third region 26c and the principal rays of the fourth red light LR4 emitted from the fourth region 26d each follow the second optical axis CX2. When the first red light LR1, the second red light LR2, the third red light LR3, and the fourth red light LR4 are projected onto a virtual plane perpendicular to the first optical axis CX1 and the second optical axis CX2 between the first collimator lens array 2 and the condenser lens 50, the deflection angle prism array 3 is arranged at a position where a first distance X1 along the X-axis direction between the first red light LR1 and the second red light LR2, a second distance X2 along the X-axis direction between the second red light LR2 and the third red light LR3, and a third distance X3 along the X-axis direction between the third red light LR3 and the fourth red light LR4 are equal to each other.

[0074] According to this configuration, a deflection angle prism array 3 in which deflection angle prisms 34 having the same shape and the same dimensions are regularly arranged can be used, and the design of the deflection angle prism array 3 becomes easy.

[0075] In the lighting device 700 of the present embodiment, the pitch of the deflection prism array 3 is equal to the first distance X1, the second distance X2, and the third distance X3.

[0076] According to this configuration, each of the red lights LR1, LR2, LR3, LR4 incident on the deflection prism array 3 at a predetermined incident angle is less likely to enter the deflection prism 34 adjacent to the deflection prism 34 where the red light should originally enter. As a result, among the red lights emitted from the deflection prism array 3, the red lights LR that are not parallelized with respect to the optical axes CX1, CX2 can be reduced, and the utilization efficiency of the red lights LR can be further increased.

[0077] In order to demonstrate the above effects, the present inventor performed a simulation of the light intensity distribution on the second multi-lens surface 90b of the double-sided multi-lens array 90. FIG. 16 is a diagram showing the simulation results in a lighting device of a comparative example that does not include a deflection prism array. As shown in FIG. 16, in the lighting device of the comparative example, the light intensity distribution B1 emitted from one laser light source is composed of two secondary light source images. Therefore, the intensity distribution B1 spreads widely in the X-axis direction.

[0078] FIG. 17 is a diagram showing the simulation results in the lighting device 700 of the present embodiment including the deflection prism array 3. As shown in FIG. 17, in the lighting device 700 of the present embodiment, different from the comparative example, the light intensity distribution B2 emitted from one laser light source is composed of one secondary light source image. Therefore, the spread of the intensity distribution B2 in the X-axis direction is smaller than that of the comparative example. Thus, it was found that the secondary light source image can be made smaller according to the configuration of the present embodiment.

[0079] The projector 10 of the present embodiment includes the lighting device 700 of the present embodiment, the light modulation devices 400R, 400G, and 400B that modulate light including the combined light LW emitted from the lighting device 700 according to image information, and the projection optical device 600 that projects the light modulated by the light modulation devices 400R, 400G, and 400B.

[0080] According to this configuration, a projector 10 with excellent display quality can be realized.

[0081] Note that the technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, although the lighting device of the above embodiment includes a rotary diffuser plate, the diffuser plate does not necessarily have to be rotary and may be fixed.

[0082] In addition, regarding the specific descriptions of the shapes, numbers, arrangements, materials, etc. of the respective components of the lighting device and the projector, they are not limited to the above embodiment and can be appropriately changed. Further, in the above embodiment, an example in which the lighting device according to the present invention is mounted on a projector using a liquid crystal panel is shown, but the present invention is not limited to this. The lighting device according to the present invention may be applied to a projector using a digital micromirror device as a light modulation device. Further, the projector does not necessarily have to have a plurality of light modulation devices and may be a single-plate type projector having only one light modulation device.

[0083] In the above embodiment, an example in which the lighting device of the present invention is applied to a projector is shown, but the present invention is not limited to this. The lighting device of the present invention can also be applied to lighting fixtures, automobile headlights, etc.

[0084] [Summary of the present disclosure] Hereinafter, a summary of the present disclosure will be appended.

[0085] (Appended Note 1) A first light source that emits light, A collimator element that collimates the light emitted from the first light source, A condensing element that condenses the light emitted from the collimator element toward the illuminated area, A deflecting element disposed between the collimator element and the condensing element, and comprising, The first light source includes a first substrate having a first surface, a first light-emitting element disposed on the first surface and emitting first light along a first direction, and a second light-emitting element disposed on the first surface and emitting second light along the first direction, The first light-emitting element and the second light-emitting element are arranged along a second direction intersecting the first direction, The collimator element has a first lens including a first region where the first light is incident and a second region different from the first region and where the second light is incident, The first region and the second region are arranged along the second direction with the first optical axis of the first lens interposed therebetween, The deflecting element changes the traveling directions of the first light and the second light so that the principal rays of the first light emitted from the first region and the principal rays of the second light emitted from the second region each follow the first optical axis, a lighting device.

[0086] According to the configuration of Supplementary Note 1, by changing the traveling directions of the first light and the second light by the deflecting element, the spatial spread of the secondary light source image in the illuminated area can be suppressed. Thereby, the loss of the first light and the second light in the subsequent optical system can be suppressed, and the light utilization efficiency can be increased.

[0087] (Supplementary Note 2) Further comprising a second light source that emits light, The second light source includes a second substrate having a second surface, a third light-emitting element disposed on the second surface and emitting third light along the first direction, and a fourth light-emitting element disposed on the second surface and emitting fourth light along the first direction, The third light-emitting element and the fourth light-emitting element are arranged along the second direction, The first light source and the second light source are arranged along the second direction, The collimator element further includes a second lens including a third region into which the third light enters and a fourth region different from the third region and into which the fourth light enters, the third region and the fourth region are arranged along the second direction with the second optical axis of the second lens therebetween, the deflection element changes the traveling directions of the third light and the fourth light such that the principal rays of the third light emitted from the third region and the principal rays of the fourth light emitted from the fourth region each follow the second optical axis, the deflection element is arranged at a position where, when the first light, the second light, the third light, and the fourth light are projected onto a virtual plane perpendicular to the first optical axis and the second optical axis between the collimator element and the condenser element, a first distance along the second direction between the first light and the second light, a second distance along the second direction between the second light and the third light, and a third distance along the second direction between the third light and the fourth light are equal to each other. The lighting device according to Supplementary Note 1.

[0088] According to the configuration of Supplementary Note 2, the design of the deflection element becomes easy.

[0089] (Supplementary Note 3) the deflection element is a deflection prism array including a first deflection prism into which the second light emitted from the second region enters, a second deflection prism into which the first light emitted from the first region enters, a third deflection prism into which the fourth light emitted from the fourth region enters, and a fourth deflection prism into which the third light emitted from the third region enters, the first deflection prism, the second deflection prism, the third deflection prism, and the fourth deflection prism are arranged along the second direction, each of the first deflection prism, the second deflection prism, the third deflection prism, and the fourth deflection prism extends along a third direction intersecting the first direction and the second direction. The lighting device according to Supplementary Note 2.

[0090] According to the configuration of Supplementary Note 3, a deflection element that exhibits a desired function can be realized in accordance with the arrangement of the first light-emitting element, the second light-emitting element, the third light-emitting element, and the fourth light-emitting element arranged along the second direction.

[0091] (Supplementary Note 4) The lighting device according to Supplementary Note 3, wherein the pitch of the deflection prism array is equal to the first distance, the second distance, and the third distance.

[0092] According to the configuration of Supplementary Note 4, since each light is likely to enter the deflection prism where it should originally enter, light that does not travel in the desired traveling direction can be reduced, and the light utilization efficiency can be further increased.

[0093] (Supplementary Note 5) The first deflection prism has a first light incident surface on which the second light is incident and a first light emitting surface from which the second light is emitted. The second deflection prism has a second light incident surface on which the first light is incident and a second light emitting surface from which the first light is emitted. One of the first light incident surface and the first light emitting surface is an inclined surface that is inclined with respect to a virtual plane perpendicular to the first optical axis. The lighting device according to Supplementary Note 3 or Supplementary Note 4, wherein one of the second light incident surface and the second light emitting surface is an inclined surface that is inclined with respect to the virtual plane.

[0094] According to the configuration of Supplementary Note 5, a deflection prism having a desired function can be configured.

[0095] (Supplementary Note 6) The lighting device according to Supplementary Note 5, wherein one of the first light incident surface and the second light incident surface and one of the first light emitting surface and the second light emitting surface are surfaces perpendicular to the first optical axis.

[0096] According to the configuration of Supplementary Note 6, effects such as facilitating the manufacture and mounting of the deflection prism array and reducing light loss at the boundary portion of the deflection prism can be obtained.

[0097] (Appendix 7) The lighting device according to any one of Appendices 1 to 6, wherein each of the first light-emitting element and the second light-emitting element is a laser diode.

[0098] According to the configuration of Appendix 7, a lighting device with a wide color gamut and high efficiency can be realized.

[0099] (Appendix 8) The lighting device according to Appendix 7, wherein each of the first light-emitting element and the second light-emitting element is a red laser diode.

[0100] According to the configuration of Appendix 8, the light output of a red laser light source with a smaller light output compared to green light and blue light can be increased.

[0101] (Appendix 9) The red laser diode has a light-emitting surface, and is arranged such that the longitudinal direction of the light-emitting surface faces the second direction, and the short-side direction of the light-emitting surface faces a third direction intersecting the first direction and the second direction. The lighting device according to Appendix 8, wherein the length of the first lens in the second direction is shorter than the length of the first lens in the third direction.

[0102] According to the configuration of Appendix 9, miniaturization of the collimator element can be achieved.

[0103] (Appendix 10) A lighting device according to any one of Appendices 1 to 9, a light modulation device that modulates light including the combined light emitted from the lighting device according to image information, a projection optical device that projects the light modulated by the light modulation device, and a projector comprising the same.

[0104] According to the configuration of Appendix 10, a projector with excellent display quality can be realized.

Explanation of Reference Numerals

[0105] 2... First collimator lens array (collimator element), 3... Deflection angle prism array (deflection element), 10... Projector, 13... First red laser light source (first light source), 14... Second red laser light source (second light source), 25... First collimator lens (first lens), 25a... First region, 25b... Second region, 26... Second collimator lens (second lens), 26c... Third region, 26d... Fourth region, 34... Deflection angle prism, 35... First deflection angle prism, 35a... First light incident surface, 35b... First light emission surface, 36... Second deflection angle prism, 36a... Second light incident surface, 36b... Second light emission surface, 37... Third deflection angle prism, 38... Fourth deflection angle prism, 50... Condensing lens (condensing element), 130... First substrate, 130a... First surface, 131... First red laser diode (first light emitting element), 132... Second red laser diode (second light emitting element), 140... Second substrate, 140a... Second surface, 143... Third red laser diode (third light emitting element), 144... Fourth red laser diode (fourth light emitting element), 400R... Light modulator for red light, 400G... Light modulator for green light, 400B... Light modulator for blue light, 600... Projection optical device, 700... Lighting device, LR1... First red light (first light), LR2... Second red light (second light), LR3... Third red light (third light), LR4... Fourth red light (fourth light), CX1... First optical axis, CX2... Second optical axis, X1... First distance, X2... Second distance, X3... Third distance.

Claims

1. a first light source that emits light; a collimator element that collimates the light emitted from the first light source; a condenser element that condenses the light emitted from the collimator element toward an illuminated area; a deflection element disposed between the collimator element and the condenser element; comprising; the first light source includes a first substrate having a first surface, a first light-emitting element disposed on the first surface and emitting first light along a first direction, and a second light-emitting element disposed on the first surface and emitting second light along the first direction; the first light-emitting element and the second light-emitting element are disposed along a second direction intersecting the first direction; the collimator element has a first lens including a first region where the first light is incident and a second region different from the first region where the second light is incident; the first region and the second region are disposed along the second direction with the first optical axis of the first lens therebetween; the deflection element changes the traveling directions of the first light and the second light such that the principal rays of the first light emitted from the first region and the principal rays of the second light emitted from the second region each follow the first optical axis, an illumination device.

2. further comprising a second light source that emits light; the second light source includes a second substrate having a second surface, a third light-emitting element disposed on the second surface and emitting third light along the first direction, and a fourth light-emitting element disposed on the second surface and emitting fourth light along the first direction; the third light-emitting element and the fourth light-emitting element are disposed along the second direction; the first light source and the second light source are disposed along the second direction; the collimator element further has a second lens including a third region where the third light is incident and a fourth region different from the third region where the fourth light is incident; the third region and the fourth region are disposed along the second direction with the second optical axis of the second lens therebetween; the deflection element changes the traveling directions of the third light and the fourth light such that the principal rays of the third light emitted from the third region and the principal rays of the fourth light emitted from the fourth region each follow the second optical axis; The lighting device according to claim 1, wherein the deflection element is disposed at a position where, when the first light, the second light, the third light, and the fourth light are projected onto a virtual plane perpendicular to the first optical axis and the second optical axis between the collimator element and the condenser element, a first distance along the second direction between the first light and the second light, a second distance along the second direction between the second light and the third light, and a third distance along the second direction between the third light and the fourth light are equal to each other.

3. The deflection element is a deflection prism array having a first deflection prism into which the second light emitted from the second region enters, a second deflection prism into which the first light emitted from the first region enters, a third deflection prism into which the fourth light emitted from the fourth region enters, and a fourth deflection prism into which the third light emitted from the third region enters. The first deflection prism, the second deflection prism, the third deflection prism, and the fourth deflection prism are arranged along the second direction. The lighting device according to claim 2, wherein each of the first deflection prism, the second deflection prism, the third deflection prism, and the fourth deflection prism extends along a third direction intersecting the first direction and the second direction.

4. The lighting device according to claim 3, wherein a pitch of the deflection prism array is equal to the first distance, the second distance, and the third distance.

5. The first deflection prism has a first light incident surface into which the second light enters and a first light emission surface that emits the second light. The second deflection prism has a second light incident surface into which the first light enters and a second light emission surface that emits the first light. One of the first light incident surface and the first light emission surface is an inclined surface inclined with respect to a virtual plane perpendicular to the first optical axis. The lighting device according to claim 3 or claim 4, wherein one of the second light incident surface and the second light emission surface is an inclined surface inclined with respect to the virtual plane.

6. The lighting device according to claim 5, wherein one of the first light incident surface and the second light incident surface and one of the first light emission surface and the second light emission surface are surfaces perpendicular to the first optical axis.

7. The lighting device according to claim 1 or claim 2, wherein each of the first light emitting element and the second light emitting element is a laser diode.

8. The lighting device according to claim 7, wherein each of the first light-emitting element and the second light-emitting element is a red laser diode.

9. The red laser diode has a light-emitting surface, and is arranged such that the longitudinal direction of the light-emitting surface faces the second direction, and the short-side direction of the light-emitting surface faces a third direction that intersects the first direction and the second direction. The lighting device according to claim 8, wherein the length of the first lens in the second direction is shorter than the length of the first lens in the third direction.

10. The lighting device according to claim 1 or claim 2, an optical modulation device that modulates the light emitted from the lighting device according to image information, a projection optical device that projects the light modulated by the optical modulation device, and a projector comprising the same.

Images