JP6544520B2 - Lighting device and projector - Google Patents

Description

  The present invention relates to a lighting device and a projector.

  The projector modulates the light emitted from the illumination device with the light modulation device according to the image information, and enlarges and projects the obtained image with the projection device. In recent years, semiconductor light emitting devices such as semiconductor lasers (LDs) have attracted attention as light sources of illumination devices used in such projectors.

  The semiconductor light emitting device is constituted of, for example, an active layer, a cladding layer and the like stacked on a semiconductor substrate. As one of such semiconductor light emitting elements, an edge emitting type semiconductor light emitting element is known which emits light in a direction orthogonal to the stacking direction of the active layer and the cladding layer.

  In the edge-emitting semiconductor light emitting device, light generated in the active layer is emitted from an extremely long region (for example, several tens μm in the width direction of the active layer and several hundreds nm in the thickness direction of the active layer). Therefore, the emission angle of light emitted from the edge-emitting semiconductor light emitting element is wide in the thickness direction of the active layer and narrow in the width direction of the active layer.

  Here, the efficiency in the optical system depends on the product of the light emitting area of the light source and the emission angle (angle distribution range) of the emitted light (inverse proportion). Therefore, when a semiconductor light emitting element is used as a light source, in order to improve the efficiency, a configuration is often adopted in which the emitted light is collimated using a lens or the like.

  For example, Patent Document 1 discloses an illumination device including a light source in which a plurality of semiconductor lasers are disposed, a collimating lens, and an integrator optical system. In the illumination device of Patent Document 1, after the light emitted from each semiconductor laser is collimated by a collimating lens, the collimated light is integrated using an integrator optical system to uniformly illuminate the illumination target. ing.

Japanese Patent Application Publication No. 2004-220016

  Here, in the edge-emitting semiconductor light emitting device, as described above, the emission angle of the emitted light is wide and narrow. Therefore, when a wide direction of the emission angle of emitted light is collected and collimated by a collimating lens, streaked light-and-dark distribution (strike-like bright lines) may occur in the collimated light due to interference. . This is because, in the edge-emitting semiconductor light emitting device, light components in the direction of a wide radiation angle are likely to cause interference.

  Therefore, in the above-described illumination device, when an edge-emitting semiconductor light emitting element is used as a light source, streak-like light and dark distribution is generated in the light collimated by the collimating lens, and high illuminance uniformity in the illumination target It is difficult to get.

One of the objects in accordance with some aspects of the present invention is to provide a lighting device capable of improving the illumination uniformity of the illumination light flux. Moreover, it is one of the objects according to some aspects of the present invention.
One is to provide a projector including the lighting device.

The lighting device according to the present invention is
A first array light source having a plurality of first semiconductor light emitting elements and emitting a first illumination light composed of a first luminous flux emitted from each of the plurality of first semiconductor light emitting elements;
A second array light source having a plurality of second semiconductor light emitting elements and emitting a second illumination light composed of a second light beam emitted from each of the plurality of second semiconductor light emitting elements;
A first collimating optical system that collimates the first light flux;
A second collimating optical system that collimates the second light flux;
The first illumination light composed of the first beam collimated by the first collimating optical system, and the second beam composed of the second beam collimated by the second collimating optical system A light combining optical system that combines illumination light;
An integrator optical system for equalizing the light intensity of the light synthesized by the light synthesizing optical system;
A light diffusion optical system disposed in an optical path between the first collimating optical system and the integrator optical system, and an optical path between the second collimating optical system and the integrator optical system;
Including
The first semiconductor light emitting device and the second semiconductor light emitting device are edge-emitting light emitting devices,
In the light combining surface of the light combining optical system in which the first illumination light and the second illumination light are combined, the radiation direction of the first light beam is wider in the first direction than in the other direction, and the radiation of the second light beam is emitted. The corner intersects with the second direction which is wider than the other directions.

  In such an illumination device, since the first direction and the second direction intersect in the light combining surface, one or more appear in the light-dark distribution of the light intensity of the first light beam in the combined light of the first illumination light and the second illumination light The direction of the bright line intersects with the direction of the bright line or lines appearing in the light-dark distribution of the light intensity of the second luminous flux. Therefore, in such a lighting device, for example, compared with the case where the direction of the bright line of the first light beam and the direction of the bright line of the second light beam in the combined light are the same direction, the brightness distribution of the combined light can be reduced. . Therefore, in such an illumination device, the illumination uniformity of the illumination light flux can be improved.

In the lighting device according to the present invention,
The first light flux and the second light flux may not overlap on the light combining surface.

  In such an illumination device, since the first light flux and the second light flux do not overlap in the light combining surface, one of the light fluxes, for example, when the polarization direction of the first light flux is different from the polarization direction of the second light flux. By rotating the polarization direction of the light source, it is possible to obtain combined light having the same polarization direction.

In the lighting device according to the present invention,
The first light flux and the second light flux may overlap on the light combining surface.

  In such an illumination device, since the first light flux and the second light flux overlap in the light combining surface, it is possible to increase the density of the bright line (bright and dark distribution) in the combined light.

In the lighting device according to the present invention,
The light diffusion optical system may be disposed in an optical path between the light combining optical system and the integrator optical system.

  In such an illumination device, the combined light combined by the light combining optical system can be diffused to be incident on the integrator optical system.

In the lighting device according to the present invention,
The light diffusion optical system is
A first light diffusing element disposed in a light path between the first collimating optical system and the light combining optical system;
A second light diffusing element disposed in a light path between the second collimating optical system and the light combining optical system;
May be included.

  In such an illumination device, for example, the light path between the light diffusion element and the integrator optical system can be made longer as compared to the case where the light diffusion element is disposed at a later stage than the light combining optical system. The strength can be made more uniform.

In the lighting device according to the present invention,
The light combining optical system has a light transmitting region for transmitting the second light beam, and a light reflecting portion for reflecting the first light beam in the same direction as the traveling direction of the second light beam transmitted through the light transmitting region. And
The light diffusion optical system may have a light diffusion element provided in at least one of the light transmission area and the light reflection area.

  In such an illumination device, for example, the light path between the light diffusion element and the integrator optical system can be made longer as compared to the case where the light diffusion element is disposed at a later stage than the light combining optical system. The strength can be made more uniform.

In the lighting device according to the present invention,
The light diffusion optical system may be a diffractive element that diffuses light in a predetermined direction.

  In such an illumination device, since light can be diffused in a desired direction in the light diffusion optical system, as described later, the light diffusion optical system can be disposed upstream of the light combining optical system, and so on. It is possible to increase the freedom of arrangement of the system.

In the lighting device according to the present invention,
In the light combining surface, the first direction and the second direction may be orthogonal to each other.

  In such an illumination device, when combining illumination light from two array light sources to form combined light, combining is performed as compared with, for example, the case where the first direction and the second direction are not orthogonal in the light combining plane. Light-dark distribution of light can be further reduced, and light intensity can be made more uniform.

The projector according to the present invention is
A lighting device according to the present invention;
A light modulation device that modulates light emitted from the lighting device according to image information;
A projection device for projecting an image formed by the light modulation device;
including.

  Such a projector can reduce brightness unevenness of a projected image and can display a high quality image.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows typically the structure of the illuminating device which concerns on 1st Embodiment. The top view which shows typically the 1st array light source of the illuminating device which concerns on 1st Embodiment. FIG. 2 is a perspective view schematically showing a semiconductor light emitting element constituting a first array light source. The figure which shows 1st illumination light typically. The top view which shows typically the 2nd array light source of the illuminating device which concerns on 1st Embodiment. The figure which shows 2nd illumination light typically. FIG. 2 is a perspective view schematically showing a light combining optical system of the illumination device according to the first embodiment. FIG. 2 is a cross-sectional view schematically showing a light combining optical system of the illumination device according to the first embodiment. The figure which shows typically the synthetic | combination light in the illuminating device which concerns on 1st Embodiment. FIG. 2 is a plan view schematically showing a polarization conversion element of the illumination device according to the first embodiment. Sectional drawing which shows typically the polarization conversion element of the illuminating device which concerns on 1st Embodiment. The figure which shows typically the structure of the illuminating device which concerns on a 1st modification. The figure which shows typically the structure of the illuminating device which concerns on a 2nd modification. The perspective view which shows typically the light combining optical system of the illuminating device which concerns on a 2nd modification. The perspective view which shows typically the light combining optical system of the illuminating device which concerns on a 3rd modification. Sectional drawing which shows typically the photosynthesis optical system which concerns on a 3rd modification. Sectional drawing which shows typically the modification of the light combining optical system which concerns on a 3rd modification. The perspective view which shows typically the light combining optical system of the illuminating device which concerns on a 4th modification. The figure which shows typically the structure of the illuminating device which concerns on 2nd Embodiment. The figure which shows typically the synthetic | combination light in the illuminating device which concerns on 2nd Embodiment. FIG. 10 is a perspective view schematically showing a light combining optical system of the illumination device according to the second embodiment. The figure which shows typically the light combining optical system of the illuminating device which concerns on the modification of 2nd Embodiment. The figure which shows typically the projector which concerns on 3rd Embodiment. The figure which shows typically the projector which concerns on 4th Embodiment. The figure for demonstrating the modification of an array light source.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the contents of the present invention described in the claims. Further, not all of the configurations described below are necessarily essential configuration requirements of the present invention.

1. First Embodiment 1.1. Lighting Device First, the lighting device according to the first embodiment will be described with reference to the drawings. FIG. 1 is a view schematically showing the configuration of the illumination device 100 according to the first embodiment. Note that FIG. 1 illustrates the X axis, the Y axis, and the Z axis as three axes orthogonal to each other.

  As shown in FIG. 1, the illumination device 100 includes a first array light source 10a, a second array light source 10b, a first collimating optical system 20a, a second collimating optical system 20b, and a light combining optical system 30. A polarization conversion element (an example of a polarization conversion optical system) 40, a light diffusion optical system 50, and an integrator optical system 60 are included.

  The first array light source 10a has a plurality of semiconductor light emitting elements, and emits the first illumination light 4a composed of the first luminous flux 2a emitted from each of the plurality of semiconductor light emitting elements. The first array light source 10 a is disposed such that the first illumination light 4 a travels in the −X axis direction.

  FIG. 2 is a plan view schematically showing the first array light source 10a. FIG. 3 is a perspective view schematically showing a semiconductor light emitting element 12 (an example of a first semiconductor light emitting element) constituting the first array light source 10a.

  As shown in FIG. 2, the first array light source 10 a includes a plurality of semiconductor light emitting elements 12, a thermally conductive support substrate 14, and a common substrate 16.

  The semiconductor light emitting element 12 is a light emitting element using a semiconductor. Although not shown, the semiconductor light emitting device 12 is a stacked body formed on the semiconductor substrate in the order of the first cladding layer, the active layer, and the second cladding layer, and an electrode for injecting a current into the active layer. Is composed including. The semiconductor light emitting element 12 is, for example, a semiconductor laser (laser diode).

  The semiconductor light emitting device 12 is an edge emitting light emitting device. Note that an edge-emitting light-emitting element refers to a light-emitting element that emits light in a direction orthogonal to the stacking direction in which the active layer and the cladding layer are stacked.

  The emission angle of the first light flux 2a emitted from the light emitting portion 13 of the semiconductor light emitting element 12 is wide in the thickness direction of the active layer and narrow in the width direction of the active layer.

  The light emitting portion 13 from which the first light beam 2a of the semiconductor light emitting element 12 is emitted is on the YZ plane as shown in FIG. 2 and FIG. 3, the longitudinal direction is along the Z axis, and the lateral direction is Y Along the axis. Therefore, the first luminous flux 2a emitted from the light emitting portion 13 has a wide radiation angle in the Y-axis direction as compared to the other directions, and a narrow radiation angle in the Z-axis direction as compared to the other directions. Note that the radiation angle refers to the diffusion angle of the emitted light flux. For example, the radiation angle in the Y-axis direction refers to an angle range in which the width (half width full width) of half the peak intensity is measured when the intensity of the light flux in the direction along the Y axis is measured. The radiation angle in the X-axis direction and the radiation angle in the other directions can also be defined in the same manner as the radiation angle in the Y-axis direction.

  Since the semiconductor light emitting element 12 is an edge emitting type light emitting element, light emitted from the semiconductor light emitting element 12 has linear polarization. Linear polarization means that the vibration direction of the electric field (and magnetic field) is constant. The polarization direction of the linearly polarized light (the vibration direction of the electric field) depends on the crystal structure of the light emitting element. The first light beam 2 a emitted from the semiconductor light emitting element 12 is S-polarized light (the polarization direction is the Y-axis direction) with respect to the light combining surface 3 of the light combining optical system 30.

  The first array light source 10 a forms a single light source by arraying a plurality of semiconductor light emitting elements 12. The number of semiconductor light emitting elements 12 constituting the first array light source 10a is twelve in the illustrated example, but the number is not particularly limited. The plurality of semiconductor light emitting elements 12 constituting the first array light source 10 a are arranged in a two-dimensional array. The plurality of semiconductor light emitting elements 12 are arranged in a plurality of rows and a plurality of columns (in a matrix) along the Z axis and the Y axis. In the illustrated example, three semiconductor light emitting devices 12 are arranged along the Z axis, and four semiconductor light emitting devices 12 are arranged along the Y axis. That is, the semiconductor light emitting elements 12 are arranged in four rows and three columns. It is desirable that the specifications of each of the plurality of semiconductor light emitting elements 12 constituting the first array light source 10 a be in alignment. Thereby, the diameters and the intensities of the plurality of first light beams 2a constituting the first illumination light 4a can be made uniform.

  The semiconductor light emitting device 12 is supported by a thermally conductive support substrate 14. In the illustrated example, three semiconductor light emitting devices 12 are supported by one thermally conductive support substrate 14.

  The thermally conductive support substrate 14 is disposed on the common substrate 16. A plurality of thermally conductive support substrates 14 are disposed on the common substrate 16. In the illustrated example, four thermally conductive support substrates 14 are arranged side by side in the Y-axis direction. Thereby, in the first array light source 10a, the semiconductor light emitting elements 12 are arranged in an array (4 rows and 3 columns).

The heat conductive support substrate 14 has a function of dissipating the heat generated in the semiconductor light emitting element 12. The material of the heat conductive support substrate 14 is, for example, a material having excellent heat conductivity such as copper. The common substrate 16 may be thermally connected to a Peltier element, a heat sink, or the like. Although not illustrated, the heat conductive support substrate 14 and the common substrate 16 are provided with wires, electrodes, and the like for driving the semiconductor light emitting device 12.

  The first illumination light 4a emitted from the first array light source 10a is composed of a plurality of first light beams 2a emitted from a plurality of semiconductor light emitting elements 12 arranged in an array. That is, the first illumination light 4a is light in which a plurality of (12 in the illustrated example) first light beams 2a are arranged in an array (4 rows and 3 columns). The first illumination light 4 a emitted from the first array light source 10 a travels in the −X axis direction.

  The first illumination light 4a emitted from the first array light source 10a enters the first collimating optical system 20a.

  The first collimating optical system 20 a collimates (or substantially collimates) the first light beam 2 a that constitutes the first illumination light 4 a. The first collimating optical system 20a is configured of a lens array in which a plurality of collimating lenses 22a are arranged in an array. The collimating lens 22 a corresponds to the semiconductor light emitting element 12 (light emitting unit 13) in a one-to-one manner. The plurality of collimating lenses 22a constituting the first collimating optical system 20a are arranged in an array (four rows and three columns), similarly to the plurality of semiconductor light emitting elements 12 constituting the first array light source 10a. Each of the plurality of first light fluxes 2a constituting the first illumination light 4a is incident on the corresponding collimating lens 22a. Since the radiation angle of the light beam emitted from the semiconductor light emitting element 12 is wide in the thickness direction of the active layer and narrow in the width direction of the active layer, the collimating lens 22a has two refracting surfaces having different focal lengths. Is desirable. However, if it is not necessary to obtain very high collimated light flux, or if one radiation angle is very narrow, a parallel with one refracting surface for collimating the light component in the direction of wide radiation angle A conversion lens may be used, and this is effective in that the cost of the collimating lens can be easily reduced, and it can be easily integrated with the array light source.

  The collimating lens 22a collimates the first light beam 2a. The collimating lens 22 a collimates the first light beam 2 a and emits parallel light (or substantially parallel light). In order to maximize the light collection efficiency of the collimating lens 22 a, the focal position of the collimating lens 22 a is set near the light emitting portion 13 of the semiconductor light emitting element 12.

  FIG. 4 is a view schematically showing the first illumination light 4a composed of the plurality of first light beams 2a collimated by the first collimating optical system 20a. In FIG. 4, a cross section (a cross section in the YZ plane) of the first illumination light 4 a is illustrated. Further, in FIG. 4, except for the line representing the outline of the first light flux 2a, the color is darker as the light intensity is larger.

  The first illumination light 4a emitted from the first collimating optical system 20a is composed of a plurality of first light beams 2a arranged in an array (4 rows and 3 columns) in the YZ plane. As shown in FIG. 4, the first light beam 2a is collimated by the collimating optical system 20a, thereby generating a streak-like light and dark distribution including one or more bright lines along the Z axis in the first light beam 2a. .

  Since the light component emitted from the narrow region (Y-axis direction) of the light emitting portion 13 of the semiconductor light emitting device 12 has a small phase difference, the light component spreading in the Y-axis direction tends to cause interference. Therefore, when light is collected in the Y-axis direction by the collimating lens 22a, interference fringes are generated in the first light beam 2a, and a streaky light-dark distribution including one or more bright lines is generated. Further, for this reason, the direction of the emission angle of the first luminous flux 2a corresponds to the direction of the bright line (the Z-axis direction in the example shown in FIG. 4). However, depending on the intervening optical element such as a lens, the generation of the bright line is different.

The cross-sectional shape of the first light beam 2a collimated by the first collimating optical system 20a depends on the positional relationship between the configuration of the collimating lens 22a and the semiconductor light emitting element 12 (light emitting portion 13). In this embodiment, a collimating lens 22 having one refracting surface for collimating light components in the direction of a wide radiation angle.
a is assumed, and as shown in FIG. 4, the shape has a longitudinal direction in the Y-axis direction and a lateral direction in the Z-axis direction. In the illustrated example, the cross-sectional shape of the first light flux 2a is an elliptical shape having a major axis in the Y-axis direction and a minor axis in the Z-axis direction. In addition, by using the collimating lens 22a having two refracting surfaces having different focal lengths at an appropriate position from the semiconductor light emitting element 12 (light emitting portion 13), it is possible to obtain a substantially circular cross section. .

  The second array light source 10 b has a plurality of semiconductor light emitting elements, and emits a second illumination light 4 b composed of the second luminous flux 2 b emitted from each of the plurality of semiconductor light emitting elements.

  FIG. 5 is a plan view schematically showing the second array light source 10b. As shown in FIG. 5, the second array light source 10 b includes a plurality of semiconductor light emitting devices 12 (an example of a second semiconductor light emitting device), a thermally conductive support substrate 14, and a common substrate 16. The second array light source 10 b is disposed such that the second illumination light 4 b travels in the + Z axis direction.

  The configuration of the semiconductor light emitting element 12 configuring the second array light source 10 b is the same as the configuration of the semiconductor light emitting element 12 configuring the first array light source 10 a described above. In the second array light source 10b, the orientation of the semiconductor light emitting element 12 (light emitting unit 13) is different from that of the first array light source 10a.

  In the second array light source 10b, as shown in FIG. 5, the light emitting portion 13 of the semiconductor light emitting element 12 is on the XY plane, the longitudinal direction is along the Y axis, and the lateral direction is along the X axis There is. Therefore, the second light flux 2b emitted from the light emitting portion 13 has a wide radiation angle in the X-axis direction as compared to other directions, and a narrow radiation angle in the Y-axis direction as compared to the other directions. In the second array light source 10b, the second light beam 2b emitted from the semiconductor light emitting element 12 is P-polarized (the polarization direction is the X-axis direction) with respect to the light combining surface 3 of the light combining optical system 30.

  The second array light source 10 b forms a single light source by arraying the plurality of semiconductor light emitting elements 12. Although the number of the semiconductor light emitting elements 12 constituting the second array light source 10 b is 12 in the illustrated example, the number is not particularly limited. The plurality of semiconductor light emitting elements 12 constituting the second array light source 10 b are arranged in a two-dimensional array. The plurality of semiconductor light emitting elements 12 are arranged in a plurality of rows and a plurality of columns (in a matrix) along the X axis and the Y axis. In the illustrated example, three semiconductor light emitting devices 12 are arranged along the X axis, and four semiconductor light emitting devices 12 are arranged along the Y axis. That is, the semiconductor light emitting elements 12 are arranged in four rows and three columns. It is desirable that the specifications of each of the plurality of semiconductor light emitting elements 12 constituting the second array light source 10 b be in alignment. Further, it is preferable that the specifications be uniform among each of the plurality of semiconductor light emitting elements 12 constituting the first array light source 10 a and each of the plurality of semiconductor light emitting elements 12 constituting the second array light source 10 b.

  The semiconductor light emitting device 12 is supported by a thermally conductive support substrate 14. In the illustrated example, four semiconductor light emitting devices 12 are supported by one thermally conductive support substrate 14.

  The thermally conductive support substrate 14 is disposed on the common substrate 16. In the illustrated example, three thermally conductive support substrates 14 are arranged side by side in the X-axis direction. Thereby, in the second array light source 10b, the semiconductor light emitting elements 12 are arranged in an array (4 rows and 3 columns).

  The second illumination light emitted from the second array light source 10b is composed of the second light beam 2b emitted from the semiconductor light emitting elements 12 arranged in an array. That is, the second illumination light 4b is a light in which a plurality of (12 in the illustrated example) second light beams 2b are arranged in an array (4 rows and 3 columns). The second illumination light 4b emitted from the second array light source 10b travels in the + Z-axis direction.

  The second illumination light 4b enters the second collimating optical system 20b.

  The second collimating optical system 20 b collimates the second light beam 2 b constituting the second illumination light 4 b. The second collimating optical system 20 b is configured of a lens array in which a plurality of collimating lenses 22 b are arranged in an array. The configuration of the collimating lens 22b for collimating the second light flux 2b is similar to the configuration of the collimating lens 22a for collimating the first light flux 2a. The plurality of collimating lenses 22 b constituting the second collimating optical system 20 b are arranged in an array (4 rows and 3 columns), similarly to the plurality of semiconductor light emitting elements 12 constituting the second array light source 10 b.

  FIG. 6 is a view schematically showing the second illumination light 4b composed of the second light beam 2b collimated by the second collimating optical system 20b. In FIG. 6, the cross section (cross section in the XY plane) of the second illumination light 4b is illustrated. Further, in FIG. 6, except for the line representing the outer edge of the second light flux 2b, the darker the color, the greater the light intensity.

  The second illumination light 4b emitted from the second collimating optical system 20b is composed of a plurality of second light beams 2b arranged in an array (4 rows and 3 columns) in the XY plane, as shown in FIG. ing. As shown in FIG. 6, when the second light beam 2b is collimated by the collimating optical system 20b, a streaky light-dark distribution including one or more bright lines along the Y-axis is generated in the second light beam 2b. .

  The cross-sectional shape of the second light beam 2b collimated by the second collimating optical system 20b is a shape having a longitudinal direction in the X-axis direction and a lateral direction in the Y-axis direction, as shown in FIG. In the illustrated example, the cross-sectional shape of the second light flux 2b is an elliptical shape having a major axis in the X-axis direction and a minor axis in the Y-axis direction.

  The light combining optical system 30 includes the first illumination light 4a composed of the first light beam 2a collimated by the first collimating optical system 20a shown in FIG. 4 and the second illuminating optical system 20b shown in FIG. And the second illumination light 4b composed of the converted second light flux 2b. Although described later, combining in this case means that the first illumination light 4a and the second illumination light 4b are emitted in the same direction (+ Z-axis direction).

  The light combining optical system 30 is disposed at a position where the first illumination light 4a and the second illumination light 4b intersect (or substantially intersect). The light combining optical system 30 is a position where the light combining surface 3 where the first illumination light 4a and the second illumination light 4b are combined intersects the optical axis of the first illumination light 4a and the optical axis of the second illumination light 4b (or approximately It is arranged at the crossing position). The light combining surface 3 of the light combining optical system 30 is disposed at an angle of 45 degrees with respect to the optical axis of the first illumination light 4a and the optical axis of the second illumination light 4b.

  FIG. 7 is a perspective view schematically showing the light combining optical system 30. As shown in FIG. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7 schematically showing the photosynthetic optical system 30. As shown in FIG.

  As shown in FIGS. 7 and 8, the light combining optical system 30 includes a plate-like member 34 having a plurality of light transmitting regions 32 and a plurality of light reflecting portions 36 provided on the major surface 34 a of the plate-like member 34. have. In the light combining optical system 30, the surfaces (reflecting surfaces) of the plurality of light reflecting portions 36 and the main surface 34a (the surface of the light transmitting area 32) of the plate member 34 constitute the light combining surface 3.

  The plate member 34 is a translucent flat plate. The plate member 34 has major surfaces 34a and 34b facing in opposite directions. The main surfaces 34a and 34b of the plate-like member 34 are disposed at an angle of 45 degrees with respect to the first light flux 2a and the second light flux 2b. It is preferable that an anti-reflection film (not shown) be provided on the main surfaces 34 a and 34 b of the plate-like member 34.

The light transmitting area 32 is an area of the plate-like member 34 which does not overlap with the light reflecting portion 36 when viewed from the traveling direction (Z-axis direction) of the second light flux 2b. The second light flux 2 b is transmitted through the light transmission region 32 and emitted from the plate member 34.

  A plurality of light reflecting portions 36 are provided on the major surface 34 a of the plate-like member 34. A plurality of light reflecting portions 36 are provided on the main surface 34 a at predetermined intervals. As the light reflecting portion 36, a light reflecting film such as a dielectric multilayer film which efficiently reflects the first light flux 2a is preferable.

The width W _R of the light reflecting portion 36 is, for example, equal to or greater than the width of the first light flux 2 a incident on the light reflecting portion 36 (the size in the width W _R direction of the first light flux 2 a, hereinafter also referred to as “width W 1”) . The width W _T of the light transmission region 32 is, for example, the width of the second light flux 2b emitted from the light transmitting region 32 (the width W _T direction size of the second light flux 2b, also referred to as "width W2" below) It is above. The width W _R of the light reflecting portion 36 is equal to or more than the width W 1 of the first light flux 2 a, and the width W _T of the light transmission region 32 is equal to or more than the width W 2 of the second light flux 2 b. The combined light 6 can be obtained in a state where the matching first light flux 2a and the second light flux 2b do not overlap.

  The flat plate used as the plate member 34 is preferably as thin as possible. The main surfaces 34a and 34b of the plate-like member 34 are disposed at an angle of 45 degrees with respect to the optical axis of the second light flux 2b. Therefore, the second light flux 2 b shifts in parallel when passing through the plate-like member 34. When a parallel shift occurs, the position of the light beam emitted from the plate member 34 may be shifted to cause uneven intensity or to decrease the light utilization efficiency. Therefore, it is preferable that the flat plate used as the plate member 34 be thin in order to reduce the amount of parallel shift. In addition, it is preferable to shift the position of the second light beam 2b to be incident on the light combining optical system 30 in the direction opposite to the direction of the parallel shift in consideration of the parallel shift amount in advance.

  As shown in FIG. 7, the second illumination light 4 b travels in the + Z-axis direction, and is incident on the plate member 34 (main surface 34 b) at an angle of 45 degrees. Then, the second illumination light 4 b passes through the light transmission region 32 for each row of the second light flux 2 b and is emitted from the main surface 34 a of the plate-like member 34 in the + Z-axis direction.

  On the other hand, the first illumination light 4 a travels in the −X axis direction, and enters the light reflecting portion 36 of the plate member 34 from a direction inclined 45 degrees. Then, the first illumination light 4a is reflected by the light reflecting portion 36 for each row of the first light flux 2a to change the traveling direction in the + Z-axis direction. That is, the light reflecting portion 36 reflects the first light flux 2a in the same direction as the traveling direction (Z-axis direction) of the second light flux 2b.

  As described above, the light combining optical system 30 sets the traveling direction of the first illumination light 4a (the first luminous flux 2a) and the traveling direction of the second illumination light 4b (the second luminous flux 2b) on the light synthesizing surface 3 in the same direction. Thus, the first illumination light 4 a and the second illumination light 4 b are combined into a combined light 6. Note that combining the first illumination light 4a and the second illumination light 4b means that the traveling direction of the first illumination light 4a and the traveling direction of the second illumination light 4b are the same direction, and are not necessarily integrated. The first light flux 2a constituting the first illumination light 4a and the second light flux 2b constituting the second illumination light 4b may not overlap.

  In the illumination device 100, in the light combining surface 3, the radiation angle of the first light beam 2a is wider than the other directions (hereinafter, referred to simply as the “direction in which the radiation angle is wide”, the first direction) The radiation angle intersects with the direction (second direction) wider than the other directions. In other words, in the light combining surface 3, the direction in which the radiation angle of the first light beam 2a is wide and the direction in which the radiation angle of the second light beam 2b is wide are not the same direction but different from each other.

  FIG. 9 is a view schematically showing the first illumination light 4 a and the second illumination light 4 b (combined light 6) combined by the light combining surface 3 of the light combining optical system 30. In FIG. 9, the cross section (cross section in the XY plane) of the combined light 6 is illustrated. Further, in FIG. 9, except for lines representing the outer edges of the light fluxes 2a and 2b, the light intensity is represented as darker as the light intensity is larger.

  As described above, the radiation angle of the first luminous flux 2a emitted from the semiconductor light emitting element 12 constituting the first array light source 10a is wide in the Y-axis direction. Further, the radiation angle of the second light beam 2b emitted from the semiconductor light emitting element 12 constituting the second array light source 10b is wide in the X-axis direction. Therefore, when the first illumination light 4a and the second illumination light 4b are combined on the light combining surface 3, as shown in FIG. 9, the radiation angle of the first light beam 2a is wide (Y-axis direction), and A direction (X-axis direction) where the radiation angle of the light flux 2b is wide intersects. In the illustrated example, the direction (Y-axis direction) in which the radiation angle of the first light flux 2a is wide and the direction (X-axis direction) in which the radiation angle of the second light flux 2b is wide are orthogonal. That is, in the illustrated example, the angle formed by the direction in which the radiation angle of the first light beam 2a is wide and the direction in which the radiation angle of the second light beam 2b is wide is 90 degrees.

  As described above, by making the radiation angle of the first light beam 2a be wider and the radiation angle of the second light beam 2b be wider (orthogonal), the light and dark distribution of the light intensity of the first light beam 2a appears in the combined light 6 The direction of one or more bright lines crosses (orthogonalizes) the direction of one or more bright lines appearing in the light-dark distribution of the light intensity of the second light flux 2b. Therefore, the brightness distribution of the combined light 6 can be reduced.

  In the light combining surface 3, the direction in which the radiation angle of the first light beam 2a is wide refers to the direction in which the radiation angle of the first light beam 2a after being combined in the light combining surface 3 (after the traveling direction is changed) is wide. Say. For example, in the example shown in FIG. 4, the wide direction of the radiation angle of the first light beam 2a before entering the light combining surface 3 is the Y axis direction, and the wide direction of the radiation angle of the first light beam 2a is also the light combining surface 3 It is the Y-axis direction. Although not illustrated, if the wide direction of the radiation angle of the first light beam 2a before entering the light combining surface 3 is the Z-axis direction, the direction in which the radiation angle of the first light beam 2a is wide in the light combining surface 3 is It becomes the X axis direction.

  Since the radiation angle of the first light beam 2a on the light combining surface 3 is wide in the Y-axis direction, as shown in FIG. 9, the cross-sectional shape of the first light beam 2a has a shape having a longitudinal direction in the Y-axis direction. Further, since the radiation angle of the second light flux 2b in the light combining surface 3 is wide in the X-axis direction, the cross-sectional shape of the second light flux 2b has a shape having a longitudinal direction in the X-axis direction. As described above, the direction in which the radiation angles of the light beams 2a and 2b are wide in the light combining surface 3 corresponds to the cross-sectional shape of the light beams 2a and 2b of the combined light 6.

  In the combined light 6 shown in FIG. 9, the first light flux 2 a and the second light flux 2 b do not overlap on the light combining surface 3. In the example of illustration, the row | line | column of the 2nd light beam 2b which comprises the 2nd illumination light 4b is located between the row | lines of the 1st light beam 2a which comprises the 1st illumination light 4a. The line of the first light flux 2a and the line of the second light flux 2b are alternately arranged in the X-axis direction.

  The combined light 6 combined by the light combining optical system 30 enters the polarization conversion element 40.

  The polarization conversion element 40 aligns the polarization directions of the first light flux 2 a and the second light flux 2 b that constitute the combined light 6.

  FIG. 10 is a plan view schematically showing the polarization conversion element 40. As shown in FIG. FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 10 schematically showing the polarization conversion element 40. As shown in FIG. As shown in FIGS. 10 and 11, the polarization conversion element 40 includes a plate-like member 44 having a plurality of light transmitting regions 42 and a plurality of λ / 2 retardation films provided on the main surface 44 a of the plate-like member 44. And 46.

  The plate member 44 is a translucent flat plate. It is preferable that an anti-reflection film (not shown) is provided on the main surfaces 44 a and 44 b of the plate-like member 44.

The light transmitting region 42 is a region of the plate member 44 which does not overlap with the λ / 2 retardation film 46 when viewed from the perpendicular direction (Z-axis direction) of the main surface 44 a of the plate member 44. The light transmission regions 42 and the λ / 2 retardation film 46 are alternately arranged in the X-axis direction. The first luminous flux 2 a is incident on the light transmission region 42.

  A plurality of λ / 2 retardation films 46 are provided on the main surface 44 a of the plate-like member 44. The second light beam 2 b is incident on the λ / 2 phase difference film 46. The λ / 2 retardation film 46 rotates the polarization direction of the incident second light beam 2 b by 90 degrees to convert the second light beam 2 b from p-polarization to s-polarization. The λ / 2 retardation film 46 is, for example, a crystal plate having birefringence, an organic film, a dielectric multilayer film, or the like.

The width W _P (size in the X-axis direction) of the λ / 2 phase difference film 46 is, for example, equal to or greater than the width (size in the X-axis direction) of the second light beam 2 b incident on the λ / 2 phase difference film 46 . Further, the width W _S (size in the X-axis direction) of the light transmission area 42 is, for example, equal to or greater than the width (size in the X-axis direction) of the first light flux 2 a incident on the light transmission area 42. In the polarization conversion element 40, the width W _P of the λ / 2 retardation film 46 is equal to or greater than the width of the second light flux 2b, and the width W _S of the light transmission region 42 is equal to or greater than the width of the first light flux 2a. The polarization direction of the first luminous flux 2a and the polarization direction of the second luminous flux 2b can be aligned.

  As shown in FIG. 1, the first light beam 2a constituting the combined light 6 is incident on the light transmission region 42 of the polarization conversion element 40, and the light transmission region 42 is s-polarized without conversion of the polarization direction. Pass (permeate). On the other hand, the second light beam 2b constituting the combined light 6 is incident on the λ / 2 retardation film 46 of the polarization conversion element 40, and the polarization direction is rotated by 90 degrees by the λ / 2 retardation film 46. It is converted to polarized light. Thus, in the polarization conversion element 40, the polarization directions of the first light flux 2a and the second light flux 2b can be aligned.

  The combined light 6 emitted from the polarization conversion element 40 is incident on the light diffusion optical system 50.

  The light diffusion optical system 50 has an optical path of the first light beam 2a between the first collimating optical system 20a and the integrator optical system 60, and a second light flux between the second collimating optical system 20b and the integrator optical system 60. It is placed in the 2b light path. In the example shown in FIG. 1, the light diffusion optical system 50 is disposed in the optical path of the combined light 6 between the polarization conversion element 40 and the integrator optical system 60.

  The light diffusion optical system 50 diffuses the combined light 6. As the light diffusion optical system 50, for example, an optical element such as a light diffusion plate can be used. The light diffusion plate used as the light diffusion optical system 50 includes, for example, a minute diffusion structure having a size of several hundred μm or less, and can finely divide the first and second light beams 2a and 2b. As a result, since the adjacent light speeds overlap, the light intensity distribution of the combined light 6 is made uniform, and the light and dark distribution of the inherent light intensity can be effectively reduced. As the light diffusion plate, for example, ground glass, a light diffusion film, a micro lens array or the like can be used. The light diffusion optical system 50 is not limited to the light diffusion plate, and may be an optical element capable of diffusing the combined light 6.

  The combined light 6 emitted from the light diffusion optical system 50 is incident on the integrator optical system 60. The distance between the light diffusion optical system 50 and the integrator optical system 60 is preferably such a distance that the adjacent light beams 2a and 2b can enter the integrator optical system 60 in a partially overlapped state. Thereby, the light intensity of the combined light 6 can be made more uniform.

  The integrator optical system 60 makes the light intensity of the combined light 6 combined by the light combining optical system 30 uniform. The integrator optical system 60 has a pair of lens arrays 62 and 64.

  The first lens array 62 is composed of a plurality of lens cells. The shape of the lens cell viewed in the Z-axis direction is, for example, a shape similar (or substantially similar) to an illumination target (for example, a liquid crystal light valve described later). The plurality of lens cells are arranged in an array (matrix) in the X-axis direction and the Y-axis direction. The first lens array 62 splits the incident light (combined light 6) by a plurality of lens cells and guides the split light to the second lens array 64.

  Similar to the first lens array 62, the second lens array 64 is configured of a plurality of lens cells. The plurality of lens cells constituting the first lens array 62 and the plurality of lens cells constituting the second lens array 64 are paired with each other. Each of the plurality of lens cells constituting the second lens array 64 projects the shape of the lens cell of the corresponding first lens array 62 onto the illumination target. Thereby, the light divided into a plurality by the first lens array 62 is superimposed on the illumination target. Therefore, the integrator optical system 60 can illuminate the illumination target with uniform light intensity (or substantially uniform light intensity).

  Next, the operation of the lighting device 100 will be described.

  In the illumination device 100, the first illumination light 4a is emitted from the first array light source 10a. The first illumination light 4a is constituted by the first luminous flux 2a emitted from each of the plurality of semiconductor light emitting elements 12 (see FIG. 2) constituting the first array light source 10a. The first light flux 2a is S-polarized light. Each of the plurality of first light beams 2a constituting the first illumination light 4a is collimated (or substantially collimated) by the first collimating optical system 20a. The first illumination light 4a (see FIG. 4) composed of the collimated (or substantially collimated) first luminous flux 2a enters the light combining optical system 30.

  On the other hand, the second illumination light 4b is emitted from the second array light source 10b. The second illumination light 4b is composed of the second luminous flux 2b emitted from each of the plurality of semiconductor light emitting elements 12 (see FIG. 5) constituting the second array light source 10b. The second light flux 2b is P polarized light. Each of the plurality of second light fluxes 2b constituting the second illumination light 4b is collimated (or substantially collimated) by the second collimating optical system 20b. The second illumination light 4 b (see FIG. 6) composed of the collimated (or substantially collimated) second light beam 2 b is incident on the light combining optical system 30.

  The first illumination light 4a and the second illumination light 4b incident on the light combining optical system 30 are combined by the light combining optical system 30 (see FIG. 9). In the light combining surface 3 of the light combining optical system 30, the direction in which the radiation angle of the first light beam 2a is wide (Y-axis direction) and the direction in which the radiation angle of the second light beam 2b is wide (X-axis direction) intersect (orthogonal) .

  The first illumination light 4 a and the second illumination light 4 b (combined light 6) combined by the light combining optical system 30 enter the polarization conversion element 40. The combined light 6 emitted from the polarization conversion element 40 becomes (S-polarized) light having the same polarization direction.

  The combined light 6 having the same polarization direction is diffused by the light diffusion optical system 50, and then enters the integrator optical system 60. The light intensity of the combined light 6 is equalized by the light diffusion optical system 50 and the integrator optical system 60, and the synthetic light 6 is irradiated on the illumination target.

  The lighting device 100 according to the present embodiment can be applied to, for example, a light source such as a projector, a display, a lighting fixture, and a measuring device.

  The lighting device 100 has, for example, the following features.

In the illumination device 100, on the light combining surface 3 of the light combining optical system 30, the radiation angle of the first light beam 2a is wider than in the other direction, and the radiation angle of the second light beam 2b is wider than the other direction. Crosses. Therefore, in the illumination device 100, the directions of one or more bright lines appearing in the contrast of the light intensity of the first light beam 2a in the combined light 6 and the directions of one or more bright lines appearing in the light-dark distribution of the light intensity of the second beam 2b. As compared with the case where the direction of the bright line of the first light flux 2a and the direction of the bright line of the second light flux 2b are the same, the light-dark distribution of the light intensity of the combined light 6 can be reduced. Therefore, in the illumination device 100, the illumination uniformity of the illumination light flux with respect to the illumination target can be improved.

  In the illumination device 100, the light diffusion optical system 50 is disposed in the optical path of the combined light 6 between the light combining optical system 30 and the integrator optical system 60. Therefore, in the illumination device 100, the combined light 6 combined by the light combining optical system 30 can be diffused and incident on the integrator optical system 60. Therefore, in the illumination device 100, the illumination uniformity of the illumination light flux can be improved.

  In the illumination device 100, on the light combining surface 3 of the light combining optical system 30, the radiation angle of the first light beam 2a is wider than in the other direction, and the radiation angle of the second light beam 2b is wider than the other direction. Are orthogonal. Therefore, in the illumination device 100, when the illumination lights 4a and 4b from the two array light sources 10a and 10b are combined to form the combined light 6, for example, the emission angle of the first light beam 2a is wide in the light combining surface 3. The brightness distribution of the light intensity of the combined light 6 can be further reduced as compared with the case where the radiation angle of the second light flux 2b is not orthogonal to the wide direction.

  In the illumination device 100, the first light beam 2a and the second light beam 2b do not overlap on the light combining surface 3 of the light combining optical system 30. Therefore, in the illumination device 100, as described above, the polarization direction of the second light flux 2b constituting the combined light 6 can be rotated to obtain the combined light 6 in which the polarization directions are uniform. Therefore, in the illumination device 100, light having the same polarization direction can be irradiated to the illumination target, which is suitable for illuminating a display element (for example, a liquid crystal display element) that requires polarization for display.

1.2. Modified Example of Lighting Device Next, a modified example of the lighting device according to the first embodiment will be described. In the illumination device according to each modification described below, the members having the same functions as the constituent members of the illumination device 100 according to the above-described first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

(1) First Modification First, an illumination device according to a first modification will be described with reference to the drawings. FIG. 12 is a view schematically showing a configuration of a lighting device 200 according to a first modification.

  In the illumination apparatus 100 described above, as shown in FIG. 1, the light diffusion optical system 50 has one light diffusion element disposed in the optical path of the combined light 6 between the light combining optical system 30 and the integrator optical system 60. Was.

  On the other hand, in the illumination device 200, as shown in FIG. 12, the light diffusion optical system 50 has the first light diffusion element 50a, the second light diffusion element 50b, and the third light diffusion element 50c. doing.

  The first light diffusing element 50a diffuses the first light flux 2a. The first light diffusing element 50 a is disposed in the optical path of the first light beam 2 a between the first collimating optical system 20 a and the light combining optical system 30. The first light diffusion element 50a is, for example, an anisotropic diffusion element that diffuses the first light flux 2a in the Y-axis direction.

  The second light diffusing element 50b diffuses the second light flux 2b. The second light diffusing element 50 b is disposed in the optical path of the second light beam 2 b between the second collimating optical system 20 b and the light combining optical system 30. The second light diffusion element 50b is, for example, an anisotropic diffusion element that diffuses the second light flux 2b in the Y-axis direction.

  The light diffusion elements 50a and 50b diffuse the light beams 2a and 2b before entering the light combining optical system 30, but do not affect the light combination in the light combining optical system 30 because the diffusion direction is the Y-axis direction. This is because, in the light combining optical system 30, as shown in FIG. 9, the illumination beams 4a and 4b are combined by arranging the light beams 2a and 2b in the X-axis direction.

  The third light diffusing element 50 c diffuses the combined light 6. The third light diffusing element 50 c is disposed in the optical path of the combined light 6 between the light combining optical system 30 and the integrator optical system 60. The third light diffusing element 50c is different from the light diffusing elements 50a and 50b in the direction in which light is diffused.

  The anisotropic diffusion elements used as the light diffusion elements 50a, 50b, and 50c are elements that diffuse light in a predetermined direction. As an anisotropic diffusion element, for example, a diffraction element can be used. The diffraction element is an element using diffraction of light, and includes, for example, a diffraction grating using diffraction by a lattice pattern, a hologram element, and the like.

  The illumination device 200 has, for example, the following features.

  In the illumination device 200, the light diffusion optical system 50 includes the first light diffusion element 50a disposed in the light path between the first collimating optical system 20a and the light combining optical system 30, the second light collimating optical system 20b, and the light synthesizing. And a second light diffusing element 50 b disposed in the optical path between the optical system 30 and the optical system 30. Therefore, in the illumination device 200, for example, the light path between the light diffusion elements 50a and 50b and the integrator optical system 60 can be made longer as compared with the case where the light diffusion element is disposed downstream of the light combining optical system 30, and the adjacent light speed Since the overlap between the two can be increased, the light intensity of the combined light 6 can be made more uniform.

  For example, in the illumination device 100 described above, the distance between the light diffusion optical system 50 and the integrator optical system 60 is set to the integrator optical system 60 in a state where the adjacent first and second light beams 2a and 2b are partially overlapped. The light intensity is made uniform by setting the distance that can be made incident. For this reason, the optical path between the array light sources 10a and 10b and the integrator optical system 60 may be long. On the other hand, in the illumination device 200, the light diffusion elements 50a and 50b are disposed in the light path between the collimating optical systems 20a and 20b and the light combining optical system 30, and therefore, compared with the illumination device 100, the array light sources The distance between 10a and 10b and the integrator optical system 60 can be shortened. Therefore, in the lighting device 200, the device can be miniaturized.

  In the illumination device 200, the light diffusion optical system 50 is a diffractive element that diffuses light in a predetermined direction. Therefore, in the illumination device 200, even if the light diffusing elements 50a and 50b are disposed in the optical path between the collimating optical systems 20a and 20b and the light combining optical system 30, the light combining in the light combining optical system 30 is not affected. . As described above, in the illumination device 200, light can be diffused in a desired direction in the light diffusion optical system 50, and therefore, the degree of freedom in the arrangement of the light diffusion optical system 50 can be increased.

In the above embodiment, an example in which the light diffusion elements 50a and 50b are anisotropic diffusion elements has been described, but the light diffusion elements 50a and 50b do not interfere with light synthesis in the light combining optical system 30 It may be a light diffusion element (fine diffusion element) that diffuses the first and second light beams 2a and 2b at the corners. Even in such a case, the light intensity of the combined light 6 can be made more uniform as in the above embodiment. In this case, an isotropic light diffusion element may be used as the third light diffusion element 50c, or the third light diffusion element 50c may not be provided.

(2) Second Modified Example Next, an illumination device according to a second modified example will be described with reference to the drawings. FIG. 13 is a view schematically showing a configuration of a lighting device 300 according to a second modification. FIG. 14 is a perspective view schematically showing the light combining optical system 30 of the illumination device 300. As shown in FIG. Hereinafter, in the illumination device according to the second modification, members having the same functions as the constituent members of the illumination device according to the first modification described above are given the same reference numerals, and the description thereof will be omitted.

  In the illumination apparatus 100 described above, as shown in FIG. 1, the light diffusion optical system 50 has one light diffusion element disposed in the optical path of the combined light 6 between the light combining optical system 30 and the integrator optical system 60. Was.

  On the other hand, in the illumination device 300, as shown in FIGS. 13 and 14, the light diffusion optical system 50 includes the first light diffusion element 50a, the second light diffusion element 50b, and the third light diffusion element 50c. ,have.

  The first light diffusing element 50a diffuses the first light flux 2a. The first light diffusing element 50 a is provided in the light reflecting portion 36 of the light combining optical system 30. The first light diffusing element 50 a is, for example, an element in which a diffusing surface is formed on the surface of a light reflecting film to be the light reflecting portion 36 of the light combining optical system 30. The diffusion surface is constituted of, for example, a concavo-convex structure formed on the surface of the light reflection film. That is, the first light diffusing element 50a is a surface relief type light diffusing element.

  The second light diffusing element 50b diffuses the second light flux 2b. The second light diffusion element 50 b is provided in the light transmission region 32 of the light combining optical system 30. The second light diffusion element 50b is, for example, an element in which a diffusion surface is formed on the surface of the light transmission region 32 (plate member 34). The diffusion surface is configured by, for example, a concavo-convex structure formed on the surface of the plate-like member 34. That is, the second light diffusing element 50b is a surface relief type light diffusing element.

  The third light diffusing element 50 c diffuses the combined light 6. The third light diffusing element 50 c is disposed in the optical path of the combined light 6 between the light combining optical system 30 and the integrator optical system 60. The light diffusion elements 50a, 50b, and 50c may be anisotropic diffusion elements, or may be fine diffusion elements having a small diffusion angle.

  In the illumination device 300, the light combining optical system 30 includes the light transmitting area 32 and the light reflecting portion 36, and the light diffusing optical system 50 includes the first light diffusing element 50a provided in the light reflecting portion 36, and the light transmission. And the second light diffusing element 50 b provided in the region 32. Therefore, in the lighting device 300, as in the lighting device 200 described above, the light path between the light diffusion elements 50a and 50b and the integrator optical system 60 can be lengthened, and overlapping of the adjacent light speeds can be increased. Light intensity can be made more uniform. Further, in the lighting device 300, the device can be miniaturized similarly to the lighting device 200 described above.

  In the above embodiment, the light diffusing elements 50a and 50b are provided in both the light reflecting portion 36 and the light transmitting area 32, but the light diffusing element is provided in one of the light reflecting portion 36 and the light transmitting area 32. You may provide. Even in such a case, the same effect as described above can be obtained.

(3) Third Modified Example Next, an illumination device according to a third modified example will be described with reference to the drawings. The illumination device according to the present modification is the same as the illumination device 100 except that the configuration of the light combining optical system 30 is different. Hereinafter, only differences from the lighting apparatus 100 will be described, and the other descriptions will be omitted.

  FIG. 15 is a perspective view schematically showing the light combining optical system 30 of the illumination device according to the third modification. FIG. 16 is a cross-sectional view schematically showing a light combining system 30 according to a third modification.

  In the illumination device 100 described above, as shown in FIGS. 7 and 8, the light combining optical system 30 includes the plate-like member 34 and the plurality of light reflecting portions 36 provided on the main surface 34 a of the plate-like member 34. I had it.

  On the other hand, in the illumination device according to the present modification, as shown in FIGS. 15 and 16, the light combining optical system 30 is provided in the plate member 34 having the plurality of openings 33 and the plate member 34. And a plurality of light reflecting portions 36.

  The plate-like member 34 is a flat plate. The plate member 34 may not have the light transmitting property. A light reflecting film 38 constituting the light reflecting portion 36 is formed on the entire surface of the plate-like member 34. The light reflecting film 38 can be formed of a dielectric multilayer film or the like. The plate-like member 34 is provided with an opening 33 penetrating between the main surfaces 34 a and 34 b. A plurality of (three in the illustrated example) openings 33 are provided.

  The flat plate used as the plate member 34 is preferably as thin as possible. The main surfaces 34a and 34b of the plate-like member 34 are disposed at an angle of 45 degrees with respect to the optical axis of the second light flux 2b. Therefore, the effective opening width (the size of the opening in the X-axis direction) of the opening 33 is narrowed, and when the flat plate is thick, light loss may occur at the edge portion of the opening 33. Note that, in order to prevent the effective opening width of the opening 33 (the size of the opening in the X-axis direction) from being narrowed, as shown in FIG. You may use the light combining optical system 30 provided with the part 33. FIG. As described later, the second illumination light 4b enters the opening 33 from a direction inclined 45 degrees with respect to the major surface 34b of the plate member 34, but the cross-sectional shape of the opening 33 in the XZ plane is a parallelogram. If so, since the width of the opening 33 does not change along the direction in which the second illumination light 4 b is incident, the occurrence of light loss at the edge portion of the opening 33 can be prevented.

  In the light combining optical system 30, the light combining surface 3 includes the surfaces (reflecting surfaces) of the plurality of light reflecting portions 36 and the opening of the opening 33 (an opening on the side from which the second light beam 2b is emitted).

  As shown in FIG. 15, the second illumination light 4b travels in the + Z-axis direction, and enters the opening 33 from a direction inclined 45 degrees with respect to the major surface 34b of the plate-like member 34. Then, the second illumination light 4 b passes through the opening 33 for each row of the second light flux 2 b and is emitted in the + Z-axis direction.

  On the other hand, the first illumination light 4 a travels in the −X axis direction, and enters the light reflecting portion 36 of the plate member 34 from a direction inclined 45 degrees. Then, the first illumination light 4a is reflected by the light reflecting portion 36 for each row of the first light flux 2a to change the traveling direction in the + Z-axis direction. Thus, in the light combining optical system 30, the first illumination light 4a and the second illumination light 4b are combined.

  According to this modification, the same operation and effect as the above-described lighting device 100 can be achieved.

  A light diffusing element may be formed in the light reflecting portion 36 of the light combining optical system 30 according to this modification. That is, the second modification described above may be applied to the present modification.

(4) Fourth Modified Example Next, a lighting device according to a fourth modified example will be described with reference to the drawings. The illumination device according to the present modification is the same as the illumination device 100 except that the configuration of the light combining optical system 30 is different. Hereinafter, only differences from the lighting apparatus 100 will be described, and the other descriptions will be omitted.

  FIG. 18 is a perspective view schematically showing the light combining optical system 30 of the illumination device according to the fourth modification.

  In the illumination device 100 described above, as shown in FIGS. 7 and 8, the light combining optical system 30 includes the plate-like member 34 and the plurality of light reflecting portions 36 provided on the main surface 34 a of the plate-like member 34. I had it.

  On the other hand, in the illumination device according to the present modification, as shown in FIG. 18, the light combining optical system 30 has two prisms 30a and 30b made of a translucent material, and a light reflecting portion 36. ing.

  The prisms 30a and 30b are, for example, triangular prism-shaped right-angle prisms whose bottom surfaces are right-angled isosceles triangles. The two prisms 30a and 30b are fixed by using a transparent adhesive or the like so that the slopes face each other. A light reflecting portion 36 for reflecting the first light flux 2a and a light passing portion 31 for transmitting (transmitting) the second light flux 2b are provided on the slope of the first prism 30a or the slope of the second prism 30b. . A plurality of light passing portions 31 and light reflecting portions 36 are provided. The light passing portions 31 and the light reflecting portions 36 are alternately provided in the in-plane direction of the slopes of the prisms 30a and 30b.

  An anti-reflection film is formed on the side surface of the first prism 30a on which the second light flux 2b is incident, the side surface on which the first light flux 2a of the second prism 30b is incident, and the side surface on which the combined light 6 of the second prism 30b is emitted. Is preferred.

  In the light combining optical system 30, the slope on which the light reflecting portion 36 is formed in the first prism 30a or the second prism 30b constitutes the light combining surface 3.

  As shown in FIG. 18, the second illumination light 4b travels in the + Z-axis direction and is incident on the first prism 30a. Then, the second illumination light 4 b passes through the light passing portion 31 for each row of the second light flux 2 b and is emitted in the + Z-axis direction.

  On the other hand, the first illumination light 4a travels in the −X-axis direction and enters the second prism 30b. Then, the first illumination light 4a is reflected by the light reflecting portion 36 for each row of the first light flux 2a, changes its traveling direction in the + Z axis direction, and is emitted from the second prism 30b in the + Z axis direction. Thus, in the light combining optical system 30, the first illumination light 4a and the second illumination light 4b are combined.

  According to this modification, the same operation and effect as the above-described lighting device 100 can be achieved.

  Furthermore, according to the present modification, by causing the light beams 2a and 2b to vertically enter the side surfaces of the prisms 30a and 30b, the parallel shift of the light beams due to the light beams 2a and 2b entering the light combining optical system 30 is eliminated (or Can be reduced). In addition, since the prisms 30a and 30b are less likely to bend than, for example, a plate-like member, according to the present modification, the light reflecting portion 36 can be maintained at a good flatness.

2. Second Embodiment 2.1. Lighting Device Next, a lighting device according to a second embodiment will be described with reference to the drawings. FIG. 19 is a view schematically showing a configuration of a lighting device 400 according to the second embodiment. FIG. 20 is a view schematically showing the first illumination light 4a and the second illumination light 4b (combined light 6) combined by the light combining surface 3 of the light combining optical system 30 of the lighting device 400. As shown in FIG. In FIG. 20, the cross section (cross section in the XY plane) of the combined light 6 is illustrated. Further, in FIG. 20, except for lines representing the outer edges of the light fluxes 2a and 2b, the light intensity is represented as darker as the light intensity is larger.

  Hereinafter, in the illuminating device 400 which concerns on 2nd Embodiment, the code | symbol same about the member which has a function similar to the structural member of the illuminating device 100 which concerns on 1st Embodiment mentioned above is attached | subjected, and the description is abbreviate | omitted.

  The illumination device 100 described above is configured such that the first luminous flux 2a and the second luminous flux 2b do not overlap on the light combining surface 3 of the light combining optical system 30, as shown in FIGS.

  On the other hand, as shown in FIGS. 19 and 20, the illumination device 400 is configured such that the first light flux 2a and the second light flux 2b overlap on the light combining surface 3 of the light combining optical system 30.

  FIG. 21 is a perspective view schematically showing the light combining optical system 30 of the illumination device 400. As shown in FIG.

  The light combining optical system 30 has a light transmitting plate-like member 34 and a polarization separation film 39 formed on the plate-like member 34. The polarization separation film 39 reflects the first light flux 2a which is S-polarization and transmits the second light flux 2b which is P-polarization. In the light combining optical system 30, the surface 39 a of the polarization separation film 39 is the light combining surface 3.

  As shown in FIG. 21, the second illumination light 4 b travels in the + Z-axis direction, and is incident on the plate member 34 at an angle of 45 degrees. Then, the second illumination light 4 b passes through the polarization separation film 39 and is emitted in the + Z-axis direction.

  On the other hand, the first illumination light 4 a travels in the −X axis direction, and enters the polarization separation film 39 of the plate member 34 from a direction inclined 45 degrees. Then, the first illumination light 4a is reflected by the polarization separation film 39 and changes the traveling direction in the + Z axis direction.

  Here, in the illumination device 400, the first array light source 10a and the second array light source 10b are disposed such that the first light beam 2a and the second light beam 2b overlap on the light combining surface 3. Therefore, the first illumination light 4a and the second illumination light 4b travel in the same direction on the light combining surface 3, and the first light flux 2a and the second light flux 2b overlap.

  Thus, in the light combining optical system 30, the first illumination light 4a and the second illumination light 4b are combined.

  In the combined light 6, as shown in FIG. 20, the direction in which the radiation angle of the first light beam 2a is wide (Y-axis direction) intersects the direction (X-axis direction) in which the radiation angle of the second light beam 2b is wide )doing. Further, in the light combining surface 3, the first light flux 2a and the second light flux 2b overlap. In the illustrated example, in the XY plane, the light axis of the first light flux 2a and the light axis of the second light flux 2b overlap so as to coincide with each other. In the combined light 6, one or more bright lines appearing in the light-dark distribution of the light intensity of the first light flux 2a overlap with one or more bright lines appearing in the light-dark distribution of the light intensity of the second light flux 2b. In the illustrated example, in the XY plane, the direction of the bright line of the first light flux 2a and the direction of the bright line of the second light flux 2b are orthogonal to each other.

  Next, the operation of the lighting device 400 will be described.

  In the illumination device 400, the first illumination light 4a is emitted from the first array light source 10a. The first illumination light 4a is constituted by the first luminous flux 2a emitted from each of the plurality of semiconductor light emitting elements 12 (see FIG. 2) constituting the first array light source 10a. The first light flux 2a is S-polarized light. Each of the plurality of first light beams 2a constituting the first illumination light 4a is collimated (or substantially collimated) by the first collimating optical system 20a. The first illumination light 4a (see FIG. 4) composed of the collimated (or substantially collimated) first luminous flux 2a enters the light combining optical system 30.

  On the other hand, the second illumination light 4b is emitted from the second array light source 10b. The second illumination light 4b is composed of the second luminous flux 2b emitted from each of the plurality of semiconductor light emitting elements 12 (see FIG. 5) constituting the second array light source 10b. The second light flux 2b is P polarized light. Each of the plurality of second light fluxes 2b constituting the second illumination light 4b is collimated (or substantially collimated) by the second collimating optical system 20b. The second illumination light 4 b (see FIG. 6) composed of the collimated (or substantially collimated) second light beam 2 b is incident on the light combining optical system 30.

  The first illumination light 4a and the second illumination light 4b incident on the light combining optical system 30 are combined by the light combining optical system 30 (see FIG. 20). In the light combining surface 3 of the light combining optical system 30, the direction in which the radiation angle of the first light beam 2a is wide (Y-axis direction) and the direction in which the radiation angle of the second light beam 2b is wide (X-axis direction) intersect (orthogonal) . At this time, in the light combining surface 3, the first light flux 2a and the second light flux 2b overlap, and two types of polarized light (S-polarized light and P-polarized light) are mixed.

  The combined light 6 in which two types of polarized light are mixed is diffused by the light diffusion optical system 50, and then enters the integrator optical system 60. The light intensity of the combined light 6 is made uniform by the light diffusion optical system 50 and the integrator optical system 60, and the combined light 6 is irradiated to the illumination target.

  The illumination device 400 has, for example, the following features.

  In the illumination device 400, on the light combining surface 3 of the light combining optical system 30, the radiation angle of the first light beam 2a is wider than in the other direction, and the radiation angle of the second light beam 2b is wider than the other direction. Crosses (orthogonal). Therefore, in the illumination device 400, as in the illumination device 100, the illumination uniformity of the illumination light flux can be improved.

  In the illumination device 400, since the first light flux 2a and the second light flux 2b overlap on the light combining surface 3, the density of the bright line (bright and dark distribution) in the combined light 6 can be increased compared to the illumination device 100. Therefore, in the illumination device 400, even when the light diffusion optical system 50 having a small diffusion angle is used, an illumination light flux having uniform light intensity can be obtained. Therefore, the number of lenses constituting the integrator optical system 60 can be reduced (the size of the lens cell can be increased), and the light transmission efficiency in the integrator optical system can be improved. Therefore, in the lighting device 400, the lighting efficiency (light utilization efficiency) can be improved.

  Moreover, in the illumination device 400, the polarization conversion element 40 (see FIG. 1) is unnecessary, so the number of parts of the device can be reduced. The illumination device 400 of this embodiment is suitable for illuminating a display element (for example, a digital micro mirror device) which does not require polarization for display.

2.2. Modified Example of Lighting Device Next, a modified example of the lighting device according to the second embodiment will be described. The illumination device according to this modification is the same as the illumination device 400 except that the configuration of the light combining optical system 30 is different. Hereinafter, only differences from the lighting device 400 will be described, and the other descriptions will be omitted.

  FIG. 22 is a perspective view schematically showing the light combining optical system 30 of the illumination device according to this modification. Hereinafter, in the illumination device according to the present modification, members having the same functions as the constituent members of the illumination devices 100, 200, 300, and 400 described above are given the same reference numerals, and descriptions thereof will be omitted.

  In the illumination device 400 described above, as shown in FIG. 21, the light combining optical system 30 includes the plate-like member 34 and a plurality of polarization splitting films 39 provided on the major surface 34 a of the plate-like member 34. The

  On the other hand, in the illumination device according to this modification, as shown in FIG. 22, the light combining optical system 30 is a polarization splitting film disposed between the two prisms 30a and 30b and the two prisms 30a and 30b. And 39.

  The two prisms 30a and 30b are fixed by using a transparent adhesive or the like so that the slopes face each other. A polarization separation film 39 is formed between the slope of the first prism 30a and the slope of the second prism 30b.

  As shown in FIG. 22, the second illumination light 4b which is P-polarized light travels in the + Z-axis direction, and is incident on the first prism 30a. Then, the second illumination light 4 b passes through the polarization separation film 39 and is emitted in the + Z-axis direction.

  On the other hand, the first illumination light 4a that is S-polarized travels in the −X-axis direction and enters the second prism 30b. Then, the first illumination light 4 a is incident on the polarization separation film 39 from a direction inclined 45 degrees. Then, the first illumination light 4a is reflected by the polarization separation film 39, changes its traveling direction in the + Z axis direction, and is emitted from the second prism 30b. Thus, in the light combining optical system 30, the first illumination light 4a and the second illumination light 4b travel in the same direction, and the first light flux 2a and the second light flux 2b overlap on the light combining surface 3. It can be synthesized.

  According to this modification, the same operation and effect as the above-described lighting device 400 can be achieved.

  Furthermore, according to the present modification, by causing the light beams 2a and 2b to vertically enter the side surfaces of the prisms 30a and 30b, the parallel shift of the light beams due to the light beams 2a and 2b entering the light combining optical system 30 is eliminated (or Can be reduced). In addition, since the prisms 30a and 30b are less likely to bend than, for example, a plate-like member, according to this modification, the polarization separation film 39 can be maintained at a good flatness.

3. Third Embodiment Next, a projector according to a third embodiment will be described with reference to the drawings. FIG. 23 is a view schematically showing a projector 600 according to the third embodiment.

  As shown in FIG. 23, the projector 600 includes a red light source 100R that emits red light, green light, and blue light, a green light source 100G, and a blue light source 100B. The red light source 100R, the green light source 100G, and the blue light source 100B are lighting devices according to the present invention. Below, the example using the illuminating device 100 as an illuminating device which concerns on this invention is demonstrated. Note that for the sake of convenience, in FIG. 23, the housing that constitutes the projector 600 is omitted, and the lighting device 100 is illustrated in a simplified manner.

  The projector 600 includes transmissive liquid crystal light valves (light modulation devices) 604R, 604G, and 604B, and a projection lens (projection device) 608.

  The lights emitted from the light sources 100R, 100G, and 100B enter the liquid crystal light valves 604R, 604G, and 604B. The liquid crystal light valves 604R, 604G, and 604B modulate incident light according to image information. In the liquid crystal light valves 604R, 604G, and 604B, it is preferable that light (polarized light) having the same polarization direction be incident. Therefore, the illumination device 100 capable of emitting light whose polarization directions are uniform is suitable as the light sources 100R, 100G, and 100B.

  The projector 600 can include a cross dichroic prism (color light combining unit) 606 that combines the light emitted from the liquid crystal light valves 604R, 604G, and 604B and guides the combined light to the projection lens 608.

  The three color lights modulated by the liquid crystal light valves 604 R, 604 G and 604 B enter the cross dichroic prism 606. The prism is formed by bonding four right-angle prisms, and the dielectric multilayer film reflecting red light and the dielectric multilayer film reflecting blue light are disposed orthogonally to the inner surface of the prism. The three color lights are combined by these dielectric multilayer films to form light representing a color image. Then, the combined light is projected onto the screen 610 by the projection lens 608 which is a projection optical system, and the image (image) formed by the liquid crystal light valves 604R, 604G, 604B is enlarged and displayed.

  The configuration of the projection optical system is appropriately changed according to the type of light valve used.

  The projector 600 includes, as a light source, an illumination device capable of improving the illumination uniformity of the illumination light flux, so that unevenness in brightness of a projected image can be reduced and a high quality image can be displayed.

4. Fourth Embodiment Next, a projector according to a fourth embodiment will be described with reference to the drawings. FIG. 24 is a view schematically showing a projector 700 according to the fourth embodiment. Hereinafter, in the projector according to the fourth embodiment, members having the same functions as the constituent members of the projector 600 described above are denoted by the same reference numerals, and the description thereof will be omitted.

  In the projector 600 described above, as shown in FIG. 23, transmission type liquid crystal light valves 604R, 604G, and 604B are used as light modulation devices.

  On the other hand, in the projector 700, as shown in FIG. 24, a digital micromirror device (DMD) 704 is used as the light modulation device.

  As shown in FIG. 24, the projector 700 includes a red light source 400R that emits red light, green light, and blue light, a green light source 400G, and a blue light source 400B. The red light source 400R, the green light source 400G, and the blue light source 400B are lighting devices according to the present invention. Below, the example using the illuminating device 400 as an illuminating device which concerns on this invention is demonstrated. Note that for the sake of convenience, in FIG. 24, the housing that constitutes the projector 700 is omitted, and the lighting device 400 is illustrated in a simplified manner.

  The projector 700 includes a cross dichroic prism 606, a reflection mirror 702, a DMD 704, and a projection lens 608.

The light sources 400R, 400G, and 400B emit red light, green light, and blue light in time division. Light emitted from the light sources 400R, 400G, and 400B enters the DMD 704 via the cross dichroic prism 606 and the reflection mirror 702. That is, red light, green light and blue light are incident on the DMD 704 in a time division manner.

  The DMD 704 is a reflective light valve. The DMD 704 includes a plurality of micro mirrors arranged in a matrix. The DMD 704 can display an image according to image data by time-divisionally driving each micro mirror based on the image data. The illumination device 400 is suitable as the light sources 400R, 400G, and 400B because the DMD 704 does not require polarization.

  The color light modulated by the DMD 704 is projected onto the screen 610 by the projection lens 608 which is a projection optical system, and the image (image) formed by the DMD 704 is enlarged and displayed.

  The projector 700 includes, as a light source, an illumination device capable of improving the illuminance uniformity of the illumination light flux, so that unevenness in brightness of a projected image can be reduced and a high quality image can be displayed.

5. Others The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

  For example, in each of the above-described embodiments, the semiconductor light emitting elements 12 constituting the first and second array light sources 10a and 10b are semiconductor lasers, but the semiconductor light emitting elements 12 are super luminescent diodes (SLDs) It is also good. The SLD has a device structure similar to that of a semiconductor laser, but is a light-emitting device in which laser oscillation is suppressed by not including a resonator structure. The SLD can emit light with reduced speckle noise as compared to a semiconductor laser, and can achieve higher output compared to an LED. For example, when using a lighting device as a light source for a projector, etc. It is suitable.

  Further, for example, in each of the above-described embodiments, one semiconductor light emitting element 12 has one light emitting portion 13 in the first and second array light sources 10a and 10b, but as shown in FIG. One semiconductor light emitting element 12 may have a plurality of light emitting parts 13. Thereby, for example, the number of parts of the device can be reduced.

  Further, for example, in the above-described embodiment, the case where the first and second illumination lights 4a and 4b emitted from the first and second array light sources 10a and 10b are combined to obtain the combined light 6 has been described. Illumination light emitted from one or more array light sources may be combined to obtain combined light. In this case, illumination light emitted from a plurality of array light sources may be combined using a plurality of light combining optical systems.

  Furthermore, for example, the illumination device according to the present invention is also applied to a light source of a scanning image display device (projector) that displays an image of a desired size on a screen by scanning light from the light source. Is also possible. Moreover, the illuminating device which concerns on this invention can also be applied to the back light of a liquid crystal display.

  In addition, the embodiment and modification which were mentioned above are an example, and are not necessarily limited to these. For example, each embodiment and each modification can be combined suitably.

The present invention includes configurations substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method and result, or configurations having the same purpose and effect). Further, the present invention includes a configuration in which a nonessential part of the configuration described in the embodiment is replaced. The present invention also includes configurations that can achieve the same effects as the configurations described in the embodiments or that can achieve the same purpose. Further, the present invention includes a configuration in which a known technology is added to the configuration described in the embodiment.

2a: first light flux, 2b: second light flux, 3: light combining surface, 4a: first illumination light, 4b: second illumination light, 6: combined light, 10a: first array light source, 10b: second array light source, 12: semiconductor light emitting element, 13: light emitting portion, 14: heat conductive supporting substrate, 16: common substrate, 20a: first collimating optical system, 20b: second collimating optical system, 22a: collimating lens, 22b ... Parallelizing lens, 30: light combining optical system, 30a: first prism, 30b: second prism, 31: light passing portion, 32: light transmitting region, 33: opening, 34: plate member, 34a: main surface , 34b: principal surface, 36: light reflection portion, 38: light reflection film, 39: polarization separation film, 39a: surface, 40: polarization conversion element, 42: light transmission region, 44: plate member, 44a: principal surface , 44b: principal surface, 46: λ / 2 retardation film, 50: light diffusion optical system, 50a 1st light diffusing element 50b second light diffusing element 50c third light diffusing element 60 integrator optical system 62 first lens array 64 second lens array 100 illumination device 100R red Light source, 100 G: green light source, 100 B: blue light source, 200: lighting device, 300: lighting device, 400: lighting device, 400 R: red light source, 400 G: green light source, 400 B: blue light source, 600: projector, 604 R: liquid crystal light Bulb, 604G: liquid crystal light valve, 604B: liquid crystal light valve, 606: cross dichroic prism, 608: projection lens, 610: screen, 700: projector, 702: reflection mirror, 704: digital micro mirror device

Claims (7)

A first array light source having a plurality of first semiconductor light emitting elements and emitting a first illumination light composed of a first luminous flux emitted from each of the plurality of first semiconductor light emitting elements;
A second array light source having a plurality of second semiconductor light emitting elements and emitting a second illumination light composed of a second light beam emitted from each of the plurality of second semiconductor light emitting elements;
A first collimating optical system that collimates the first light flux;
A second collimating optical system that collimates the second light flux;
The first illumination light composed of the first beam collimated by the first collimating optical system, and the second beam composed of the second beam collimated by the second collimating optical system A light combining optical system that combines illumination light;
An integrator optical system for equalizing the light intensity of the light synthesized by the light synthesizing optical system;
A light diffusion optical system disposed in an optical path between the first collimating optical system and the integrator optical system, and an optical path between the second collimating optical system and the integrator optical system;
Including
The first semiconductor light emitting device and the second semiconductor light emitting device are edge-emitting light emitting devices,
In the light combining surface of the light combining optical system in which the first illumination light and the second illumination light are combined, the radiation direction of the first light beam is wider in the first direction than in the other direction, and the radiation of the second light beam is emitted. Crosses the second direction, whose corners are wider than the other directions ,
The light diffusion optical system is
A first light diffusing element disposed in a light path between the first collimating optical system and the light combining optical system;
A second light diffusing element disposed in a light path between the second collimating optical system and the light combining optical system;
A lighting device characterized by having . A first array light source having a plurality of first semiconductor light emitting elements and emitting a first illumination light composed of a first luminous flux emitted from each of the plurality of first semiconductor light emitting elements;
A second array light source having a plurality of second semiconductor light emitting elements and emitting a second illumination light composed of a second light beam emitted from each of the plurality of second semiconductor light emitting elements;
A first collimating optical system that collimates the first light flux;
A second collimating optical system that collimates the second light flux;
The first illumination light composed of the first beam collimated by the first collimating optical system, and the second beam composed of the second beam collimated by the second collimating optical system A light combining optical system that combines illumination light;
An integrator optical system for equalizing the light intensity of the light synthesized by the light synthesizing optical system;
A light diffusion optical system disposed in an optical path between the first collimating optical system and the integrator optical system, and an optical path between the second collimating optical system and the integrator optical system;
Including
The first semiconductor light emitting device and the second semiconductor light emitting device are edge-emitting light emitting devices,
In the light combining surface of the light combining optical system in which the first illumination light and the second illumination light are combined, the radiation direction of the first light beam is wider in the first direction than in the other direction, and the radiation of the second light beam is emitted. Crosses the second direction, whose corners are wider than the other directions ,
The light combining optical system has a light transmitting region for transmitting the second light beam, and a light reflecting portion for reflecting the first light beam in the same direction as the traveling direction of the second light beam transmitted through the light transmitting region. And
The light diffusion optical system includes a light diffusion element provided in at least one of the light transmission region and the light reflection portion . Wherein the first light flux and the second light flux, does not overlap in the combining surface lighting device according to claim 1 or 2, characterized in that. Wherein the first light flux and the second light flux lighting device according to claim 1 or 2, wherein the overlap in combining surface, it is characterized. The illumination device according to any one of claims 1 to 4 , wherein the light diffusion optical system is a diffractive element that diffuses light in a predetermined direction. The lighting device according to any one of claims 1 to 5 , wherein the first direction and the second direction are orthogonal to each other in the light combining surface. A lighting device according to any one of claims 1 to 6 ,
A light modulation device that modulates light emitted from the lighting device according to image information;
A projection device for projecting an image formed by the light modulation device;
A projector characterized in that.