JP2016145973A - Light source device and projector having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device including a light source using multiple semiconductor lasers, capable of preventing reduction in the luminous efficiency of phosphors, and obtaining a shape of a focus of a desired size and a desired aspect ratio, at low cost, and to provide a projector.SOLUTION: A light source device 1 includes: multiple light sources 10A, 10B each having semiconductor lasers 12 and collimating lenses 13; a focusing lens 20; an optic 70 disposed between the light sources 10A, 10B and the focusing lens 20, for transmitting light from the light sources 10A, 10B; and a transmissive phosphor wheel 30 having phosphors 32. The optic 70 includes a tilted optical surface 74. The semiconductor lasers 12 include: first semiconductor lasers 12A disposed in a first direction; and second semiconductor lasers 12B disposed in a second direction different from the first direction. On the optic 70, a diffusive layer 72 is formed only in optical paths of emission light from one of a set of the first semiconductor lasers 12A and a set of the second semiconductor lasers 12B.SELECTED DRAWING: Figure 1a

Description

  The present invention relates to a light source device and a projector including the light source device.

  2. Description of the Related Art In recent years, time division projectors that take out light of a plurality of wavelengths in a time division manner and form and project an image by sequentially modulating the extracted light of the plurality of wavelengths have become widespread. As a light source device used for such a time-division projector, for example, a light source that outputs white light and a rotating wheel to which a plurality of color filters are attached are used to convert white light emitted from the light source at a constant speed. The light is made incident on a rotating wheel that rotates in order to extract light of a plurality of wavelengths (for example, blue, green, and red light) in a time-sharing manner.

  In addition, by using a rotating wheel having a phosphor layer instead of a color filter with a light source that outputs light of a single wavelength such as a semiconductor laser, light of a single wavelength emitted from a light source such as a semiconductor laser is applied to the rotating wheel. There has also been proposed a light source device that extracts light of a plurality of wavelengths in a time division manner by making it incident. For example, light emitted from a blue semiconductor laser can be wavelength-converted into green or red light by a phosphor.

Among them, as shown in Patent Document 1, by arranging a plurality of laser light sources sequentially rotated around the optical axis, the condensing shape when condensing on the phosphor is expanded into a substantially elliptical shape. Thus, a method for obtaining uniform brightness during projector projection has been proposed.
Moreover, as shown in Patent Document 2, the focal point on the phosphor differs for each semiconductor laser by shifting the arrangement interval of the plurality of laser light sources and the lens interval of the collimator lens installed on the exit surface side. In this way, a method for exciting the phosphor by lowering the light density has been proposed.
Further, as shown in Patent Document 3, by providing a diffractive optical element between the laser light source and the phosphor wheel, a plurality of beam condensing positions on the phosphor surface can be provided, and the light density can be lowered. A method for exciting a phosphor has been proposed.

JP2011-133382A JP 2012-215633 A JP 2012-159603 A

When a plurality of semiconductor lasers are arranged around the optical axis as in the light source device disclosed in Patent Document 1, it is necessary to adjust the rotation direction of each laser. Moreover, since the condensing point positions are the same, there is a problem that the light density at the center is high and the luminous efficiency of the phosphor is lowered.
Further, in the case of the light source device disclosed in Patent Document 2, the condensing point position can be changed because the condensing point position differs for each laser light source, but the parallel light emitted from the collimator lens has a small condensing diameter. There is a problem that the light density is high and the luminous efficiency of the phosphor is lowered. Furthermore, in the light source devices disclosed in Patent Documents 1 and 2, the beam shape in the condensing region of the condensing lens depends on the far field pattern or near field pattern of the semiconductor laser. It is difficult to obtain a beam shape having a desired aspect ratio.

  Moreover, in the case of the light source device shown in Patent Document 3, there is a problem that the cost is high because a diffractive optical element is used.

  In order to solve the above problems, in a light source device according to one embodiment of the present invention, a plurality of light sources having a semiconductor laser and a collimator lens, a condensing lens for condensing light from the light sources, and the light sources And an optical component disposed between the condensing lens and a phosphor wheel that has a phosphor and transmits light collected by the condensing lens, and the optical component includes the collimating lens. The light source has a different inclined optical surface inclined from a plane perpendicular to the optical axis, and the short axis direction of the condensing point shape is arranged in the first direction in the semiconductor laser. And a second semiconductor laser disposed in a second direction in which the direction of the short axis of the condensing point shape is different from the first direction, the first semiconductor laser and the second semiconductor laser One of the semiconductor lasers in the optical path of the emitted light Diffusion layer is formed.

  In a projector according to an embodiment of the present invention, light that forms an image by sequentially modulating light in a plurality of wavelength bands emitted from the light source device based on the light source device of the above embodiment and image data. Modulation means and projection means for enlarging and projecting the image.

  As described above, in the light source device according to one embodiment of the present invention, in the light source device using a plurality of semiconductor lasers, it is possible to suppress a decrease in the luminous efficiency of the phosphor, and in the light condensing region, a desired size. In addition, it is possible to provide a light source device capable of obtaining a condensing point shape (beam shape) having a desired aspect ratio at a low manufacturing cost, and to provide a projector using the light source device at a low manufacturing cost.

It is a figure including the typical top view for demonstrating the light source device which concerns on one Embodiment of this invention. It is a figure containing the typical side view for demonstrating the light source device which concerns on one Embodiment of this invention. It is a figure which shows the shape of a condensing area | region and light intensity distribution (sectional light intensity) in the light source device which concerns on embodiment of this invention. It is a figure which shows the condensing point shape and cross-sectional light intensity at the time of changing the position of the lens array comprised from a some collimating lens, and a case where a diffused layer is provided. It is a mimetic diagram showing a phosphor wheel concerning one embodiment of the present invention. It is a graph which shows the relationship between the excitation light intensity | strength and fluorescent substance output intensity in the light source device which concerns on embodiment of this invention. It is a schematic diagram which shows the optical component which concerns on other embodiment of this invention. It is a schematic diagram which shows the structure of the projector provided with the light source device which concerns on one Embodiment of this invention. It is a figure containing the typical top view for demonstrating the light source device which concerns on other embodiment of this invention.

  In the light source device according to the first embodiment of the present invention, a plurality of light sources including a semiconductor laser and a collimator lens, a condensing lens that condenses light from the light source, and the light source and the condensing lens An optical component that is disposed; and a phosphor wheel that has a phosphor and transmits light collected by the condenser lens, the optical component being inclined from a plane perpendicular to the optical axis of the collimating lens. A first semiconductor laser having a different inclined optical surface for each light source, the short axis direction of the condensing point shape being arranged in the first direction in the semiconductor laser, and a condensing point There is a second semiconductor laser arranged in a second direction in which the direction of the minor axis of the shape is different from the first direction, and either one of the first semiconductor laser and the second semiconductor laser is emitted. A diffusion layer is formed in the optical path of the incident light.

According to this embodiment, the optical component disposed between the light source and the condensing lens has different inclined optical surfaces for each light source inclined from the surface perpendicular to the optical axis of the collimating lens. The light emitted from the light source is condensed at different positions on the phosphor wheel (that is, on the phosphor) by the condenser lens. Therefore, since the light density in the condensing area | region on fluorescent substance can be suppressed, it becomes possible to utilize the emitted light from fluorescent substance efficiently.
Further, the first semiconductor laser in which the direction of the short axis of the condensing point shape is arranged in the first direction, and the direction of the short axis of the condensing point shape is arranged in the second direction different from the first direction. Since the diffusion layer is formed in the optical path of one of the first semiconductor laser and the second semiconductor laser, the condensing point shape (at the condensing point) The size of the beam shape (hereinafter abbreviated as the beam shape) is different, and a condensing point shape (beam shape) having a desired size and a desired aspect ratio can be obtained in the condensing region of the condensing lens.
In addition, since it is not necessary to use expensive parts such as a diffractive optical element, in this embodiment, in the light source device using a plurality of semiconductor lasers, it is possible to suppress a decrease in the luminous efficiency of the phosphor, and in the light collecting region, A light source device capable of obtaining a condensing point shape (beam shape) having a desired size and a desired aspect ratio can be provided at a low manufacturing cost.

  In addition, the above-mentioned “the optical component has a different inclined optical surface for each light source” may have different inclination angles, or may have the same inclination angle arranged in different directions. In addition, in some light sources, ones having the same inclination angle may be arranged in the same direction. Furthermore, when the thing of the same inclination angle is arrange | positioned adjacent to the same direction, it is possible to shape | mold the adjacent inclination optical surface integrally. Moreover, although the optical component should just be formed for every light source, those optical components may be integral with respect to several light sources. Since the optical component is formed for each light source, an optimal condensing point shape (beam shape) can be obtained, and fine adjustment can be performed.

  In the light source device according to the second embodiment of the present invention, in the first embodiment, the diffusion layer is formed on the optical surface of the optical component.

According to this embodiment, since the diffusion layer is formed on the optical surface of the optical component, a condensing point shape (beam shape) having a desired aspect ratio can be efficiently obtained with a compact light source device.
The diffusion layer may be provided on the inclined optical surface of the optical component or may be provided on the optical surface perpendicular to the optical axis of the collimating lens of the optical component.

  In the light source device according to Embodiment 3 of the present invention, in the above Embodiment 1 or 2, the plurality of light sources includes two first light sources in which the inclined optical surfaces are inclined in opposite directions by 180 degrees, And at least two second light sources in which the inclination of the inclined optical surface is 180 degrees opposite to each other.

  According to this embodiment, the two first light sources with the inclined optical surfaces inclined 180 degrees opposite to each other, and the two second light sources with the inclined optical surfaces inclined 180 degrees opposite to each other, Therefore, two condensing point shapes (beam shape) by the first light source and two condensing point shapes (beam shape) by the second light source are provided at positions symmetrical to the optical axis of the condensing lens. Can be obtained. Therefore, it is possible to obtain a condensing point shape (beam shape) that spreads in a predetermined manner around the optical axis of the condensing lens.

  In the light source device according to Embodiment 4 of the present invention, in any one of Embodiments 1 to 3, the inclination of the inclined optical surface of the optical component is centered on the major axis of the condensing point shape of the semiconductor laser. It is attached in the direction of rotation.

  According to this embodiment, the inclination of the inclined optical surface of the optical component is a rotation direction around the major axis of the condensing point shape of the semiconductor laser (also referred to as “the minor axis direction of the condensing point shape”). Therefore, the area where the light emitted from each semiconductor laser overlaps with each other can be reduced, and the light density can be appropriately suppressed in the condensing area.

  In the light source device according to Embodiment 5 of the present invention, in any one of Embodiments 1 to 4, the first direction and the second direction are different by 90 degrees.

  According to this embodiment, since the first direction and the second direction are different by 90 degrees, a condensing point shape (beam shape) having a desired aspect ratio can be reliably obtained by the diffusion layer.

  In the light source device according to Embodiment 6 of the present invention, in any one of Embodiments 1 to 5, the light source is fixed on the same plane of the support member.

  According to this embodiment, since the light source is fixed on the same plane of the support member, the heat generated from the light source can be dissipated using a larger plane, thus contributing to the extension of the life of the light source device. it can.

  In the light source device according to Embodiment 7 of the present invention, in any one of Embodiments 1 to 6, the inclined optical surface has an inclination angle of 0.25 to 2 degrees with respect to a vertical plane of the optical axis of the collimating lens. Is formed.

  According to this embodiment, since the inclined optical surface is formed at an inclination angle of 0.25 to 2 degrees from the vertical surface of the optical axis of the collimating lens, it can be condensed at different positions within an appropriate range. it can.

In the light source device according to Embodiment 8 of the present invention, in any one of Embodiments 1 to 7,
The collimating lens is arranged at a position different from the arrangement position in the optical axis direction for emitting parallel light.

  According to this embodiment, since the collimating lens is arranged at a position different from the arrangement position in the optical axis direction for emitting parallel light, the light density in the condensing region on the phosphor can be suppressed. The size of the condensing point shape (beam shape) can also be adjusted.

In the light source device according to Embodiment 9 of the present invention, in any one of Embodiments 1 to 8,
The support member is a heat dissipation member.

  According to this embodiment, since the support member is a heat radiating member, the light source can be efficiently cooled, and the number of components can be suppressed, thereby reducing the size of the light source device.

In the light source device according to Embodiment 10 of the present invention, in any one of Embodiments 1 to 9, the wavelength band of the emitted light from the light source is 370 to 500 nm.
In the light source device according to Embodiment 11 of the present invention, in any one of Embodiments 1 to 10, one of the phosphors is a phosphor that emits light including light including red light.

  Even if the phosphor that emits light including red light tends to have a large decrease in wavelength conversion efficiency due to an increase in temperature, according to the present embodiment, the light density in the condensing region on the phosphor is suppressed. Therefore, it is possible to suppress a decrease in long conversion efficiency.

  In the projector according to the first embodiment of the present invention, the light source device according to any one of the above embodiments 1 to 11 and light of a plurality of wavelength bands emitted from the light source device based on image data. Light modulation means for sequentially modulating the image to form an image, and projection means for enlarging and projecting the image.

According to this embodiment, a light source device using a plurality of semiconductor lasers and a phosphor wheel is provided, and in the light source device, a decrease in luminous efficiency of the phosphor can be suppressed, and further in a light collection region of output light from the light source device. A projector capable of obtaining a condensing point shape (beam shape) having a desired aspect ratio can be provided at a low manufacturing cost.
Next, a light source device according to an embodiment of the present invention and a projector including the light source device will be described in detail with reference to the drawings.

(Description of the outline of the light source device)
First, a light source device according to an embodiment of the present invention will be described with reference to FIGS. 1a and 1b. FIG. 1a is a schematic plan view for showing a light source device according to one embodiment of the present invention, showing a plan view of the light source device 1 and light sources 10A and 10B from the condenser lens 20 side. When the semiconductor lasers 12A and 12B are viewed, a front view of the semiconductor laser or the like is shown on the left of FIG. 1a, and further, a far field pattern and a near field pattern of laser light emitted from one semiconductor laser will be described. For this purpose, an axis explanatory diagram defining the axis is shown in the lower center of FIG. 1a. FIG. 1B is a schematic side view for showing a light source device according to one embodiment of the present invention, showing a side view of the light source device, and a semiconductor laser of the light sources 10A and 10B from the condenser lens 20 side. FIGS. 12A and 12B are views as a front view of a semiconductor laser or the like on the left side of FIG. 1B, and axes for explaining a far field pattern and a near field pattern of laser light emitted from one semiconductor laser. An explanatory view of the axis that defines is shown in the lower center of FIG. 1b. 1a and 1b, the light source device 1 viewed from the arrow A corresponds to the plan view (FIG. 1a) of the light source device of the present embodiment, and the light source device 1 viewed from the arrow B. Corresponds to the side surface (FIG. 1 b) of the light source device of the present embodiment.

First, an outline of a light source device according to one embodiment of the present invention will be described with reference to FIG. 1a showing a plan view of the light source device. As shown in FIG. 1 a, the light source device 1 according to this embodiment includes light sources 10 </ b> A and 10 </ b> B attached to a heat dissipation member 60, a diffusion layer 72, an optical component 70, a condenser lens 20, a phosphor wheel 30, and a light receiving lens 40. And a rotation drive unit 50.
In the present embodiment, blue light is emitted from the light sources 10 </ b> A and 10 </ b> B, and the emitted blue light passes through the diffusion layer 72 and the optical component 70 and enters the condenser lens 20 and is condensed by the condenser lens 20. Then, the light enters the phosphor wheel 30 that is rotated by the rotation driving unit 50. The phosphor wheel 30 is made of a material that transmits light, and a dielectric film 31 is formed on the incident side surface, and a phosphor 32 is formed concentrically on the emission side surface. More specifically, a green phosphor region, a red phosphor region, and a blue transmission region are provided concentrically on the exit side surface. The green phosphor emits green light when blue light is incident, and the red phosphor emits red light when blue light is incident. Therefore, when blue light enters the phosphor wheel 30 from the condenser lens 20, green light, red light, and blue light are emitted from the phosphor wheel 30 in a time-sharing manner and enter the light receiving lens 40. Then, the traveling direction of the light is changed to a predetermined direction by the light receiving lens 40, and the light is output from the light source device 1. Specifically, the light receiving lens 40 can emit light in the direction in which the light spreads, it can emit parallel light, or it can be condensed at a predetermined position.
Note that the wavelengths of the semiconductor lasers 12A and 12B used in this embodiment desirably emit light within a range of 370 to 500 nm, and more desirably emit light within a range of 420 to 500 nm.

The light sources 10A and 10B will be described in more detail. As shown in FIGS. 1a and 1b, two light sources (hereinafter referred to as “first light sources”) 10A and 2 are attached to the mounting surface of the heat radiating member 60 as a support member. A total of four light sources, one light source (hereinafter referred to as “second light source”) 10B, are attached.
In each of the two first light sources 10A, one housing 11 and four first semiconductor lasers 12A that emit blue light provided in each housing 11 and each first semiconductor laser. It has four collimating lenses 13 corresponding to 12A. Similarly, in the second light source 10B, one housing 11, the second semiconductor laser 12B that emits blue light provided in each of the four housings 11, and each second semiconductor. It has four collimating lenses 13 corresponding to the laser 12B. Note that the first light source 10A and the second light source 10B only need to have at least one first semiconductor laser 12A and second semiconductor laser 12B, respectively. In addition, as shown in FIGS. 1a and 1b, each of the light sources has one housing for the housing 11, but there may be one housing for four light sources.

As described above, the two first light sources 10 </ b> A and the two second light sources 10 </ b> B are mounted adjacent to one mounting surface of the heat dissipation member 60 (side surfaces are in contact with each other).
That is, since the light source 10 is fixed on the same plane of the support member, heat generated from the light source 10 can be radiated using a larger plane of the heat radiating member 60, and the light source device 1 has a long life. Can contribute to
Furthermore, since the supporting member is the heat radiating member 60, the light sources 10A and 10B can be efficiently cooled, and the number of components can be suppressed, thereby reducing the size of the light source device 1.

Next, it demonstrates still in detail using FIG. 1a (plan view of a light source). In the front view of the semiconductor laser or the like on the left side of FIG. 1 a, the long axis (X axis in the lower diagram) of the near field pattern of the first semiconductor laser 12 </ b> A provided in the first light source 10 </ b> A is perpendicular to the light source device 1. The major axis of the near field pattern of the second semiconductor laser 12B provided in the second light source 10B is in the horizontal direction of the light source device 1 (that is, up and down in the drawing). Direction).
In the present embodiment, in the front view of the semiconductor laser or the like of FIG. 1a, the left-right direction is referred to as a first direction in the drawing, and the up-down direction is referred to as a second direction in the drawing. That is, in the present embodiment, the first direction and the second direction are different by 90 degrees. In other words, the angle formed by the first direction and the second direction is 90 degrees. In FIG. 1, the first direction and the second direction are shown in the vertical direction of the drawing and the horizontal direction of the drawing, but any other direction can be adopted. In addition, the first direction and the second direction are different by 90 degrees in the present embodiment. However, the first direction and the second direction are not limited to this, and may be different at other arbitrary angles.

Further, in the present embodiment, the collimating lens 13 is arranged so as to be shifted from the arrangement position (that is, the focal position) in the optical axis direction for emitting parallel light. Thereby, as will be described later, the area of the condensing region can be increased and the light density of the condensed light can be suppressed. Therefore, the direction of the short axis of the condensing point shape (the direction of the short axis of the far field pattern) and the direction of the long axis of the near field pattern of the semiconductor lasers 12A and 12B (the X axis in the lower figure) coincide with each other. The direction of the long axis of the condensing point shape in the light region (the direction of the long axis of the far field pattern) coincides with the direction of the short axis of the near field pattern of the semiconductor lasers 12A and 12B (Y axis in the lower diagram).
However, the arrangement is not limited to this, and the collimating lens 13 may be arranged at the focal position. In this case, the direction of the major axis of the far field pattern in the condensing region and the direction of the major axis of the near field pattern of the semiconductor lasers 12A and 12B coincide, and the direction of the minor axis of the far field pattern in the condensing region The minor axis directions of the near field patterns of the semiconductor lasers 12A and 12B coincide with each other.

  The optical axis of the light emitted from the first semiconductor laser 12 </ b> A coincides with the optical axis of the corresponding collimating lens 13, and is parallel to the optical axis 21 of the condenser lens 20. Similarly, the optical axis of the light emitted from the second semiconductor laser 12 </ b> B coincides with the optical axis of the corresponding collimator lens 13 and is parallel to the optical axis 21 of the condenser lens 20.

An optical component 70 is provided corresponding to each of the first light source 10A and the second light source 10B. The optical component 70 has an inclined optical surface 74 that is inclined from a surface perpendicular to the optical axis of the collimating lens 13. The direction of inclination of the inclined optical surface 74 will be described with reference to the front view of the left semiconductor laser and the like in FIG. 1a. In addition, in order to clearly show the inclination direction of the inclined optical surface 74, the side shape of the optical component 70 is schematically shown around the front view of the semiconductor laser or the like.
Specifically, in the front view of the semiconductor laser or the like of FIG. 1a, the optical component 70 corresponding to the first semiconductor laser 12A in the lower left is the direction of the short axis of the condensing point shape (far field pattern) in the condensing region. That is, it has an inclined optical surface 74 inclined in the direction of the major axis of the near field pattern of the semiconductor laser 12A (left / right direction / first direction in the figure). More specifically, the left side of the drawing is inclined (ie, thick) and the right side of the drawing is low (ie, thin). The inclination in the direction of the short axis of the condensing point shape (far field pattern) means that it is attached in the rotation direction around the long axis of the condensing point shape (far field pattern). be able to.
If the collimating lens 13 is disposed at the focal position, the inclination of the inclined optical surface 74 of the optical component 70 is in the direction of the short axis of the condensing point shape (near field pattern) in the condensing region. Attached.

In the front view of the semiconductor laser or the like in FIG. 1a, the optical component 70 corresponding to the first semiconductor laser 12A in the upper right is the direction of the short axis of the condensing point shape (far field pattern) in the condensing region (that is, the semiconductor laser 12A). In contrast to the first semiconductor laser 12A in the lower left of the front view, the right side of the drawing is higher and the left side of the drawing is inclined, in the direction of the major axis of the near field pattern (left / right direction / first direction in the figure). Has a low slope.
The optical component 70 corresponding to the second semiconductor laser 12B in the lower right has a short axis direction (that is, a long axis direction of the near field pattern of the semiconductor laser 12B) (see FIG. In the vertical direction / second direction)), the lower side of the drawing is higher and the upper side of the drawing is lower.
In the front view of the semiconductor laser or the like of FIG. 1a, the optical component 70 corresponding to the second semiconductor laser 12B in the upper left is the direction of the short axis of the condensing point shape (far field pattern) in the condensing region (that is, the semiconductor laser 12B). In the direction of the major axis of the near field pattern (vertical direction / second direction in the figure), the upper side of the drawing is high and the lower side of the drawing is low, contrary to the second semiconductor laser 12B in the lower right. Is attached.

  As described above, in the present embodiment, the two first light sources 10A in which the inclined optical surface 74 is inclined 180 degrees in the opposite direction and the inclined optical surface 74 are inclined in the opposite direction 180 degrees. Two second light sources 10B. An optical component 70 is formed for each of the light sources 10A and 10B, and each optical component 70 has a different inclined optical surface 74 for each of the light sources 10A and 10B.

  As shown in the plan view of FIG. 1 a, in this embodiment, an inclined optical surface 74 is formed on the exit side of the optical component 70, that is, on the surface away from the light source 10. However, the present invention is not limited to this, and the inclined optical surface 74 may be formed on the incident side of the optical component 70, that is, on the side close to the light source 10, or on the incident side and the emission side of the optical component 70. Sometimes formed on both sides. When the inclined optical surfaces are formed on both the incident side and the exit side of the optical component 70, the case where the flat optical component 70 without a taper is disposed obliquely is also included.

  Further, in the front view of the semiconductor laser or the like on the left side of FIG. 1a, as schematically shown by a plurality of points, the diffusion layer 72 is provided only in the optical component 70 corresponding to the first semiconductor laser 12A. As shown in the plan view of FIG. 1 a, in this embodiment, a diffusion layer 72 is formed on the optical surface on the incident side of the optical component 70, that is, on the side close to the light source 10. However, the present invention is not limited to this, and the diffusion layer 72 may be formed on the emission side of the optical component 70, that is, on the optical side far from the light source 10. Further, the diffusion layer 72 can be disposed at any position on the optical path of the emitted light from the first semiconductor laser 12 </ b> A between the collimating lens 13 and the condenser lens 20. When the diffusion layer 72 is formed at a position away from the optical component 70, it is only necessary that the diffusion layer 72 has a strength capable of supporting itself.

Next, FIG. 1b (side view of the light source) will be described. FIG. 1B is a side view of the light source device as seen from the arrow B in the front view of the left semiconductor laser or the like, and corresponds to a view when rotated 90 degrees from the plan view of FIG.
In the front view of the left semiconductor laser or the like in FIG. 1b, the optical component 70 corresponding to the lower right first semiconductor laser 12A is in the direction of the short axis of the condensing point shape (far field pattern) in the condensing region (that is, The major axis direction (vertical direction / first direction in the figure) of the near field pattern of the semiconductor laser 12A is inclined, the lower side of the drawing is high (that is, the thickness is high), and the upper side of the drawing is low (that is, the thickness is thin). ) Inclined.
In the front view of the left semiconductor laser or the like in FIG. 1B, the optical component 70 corresponding to the first semiconductor laser 12A in the upper left is the direction of the short axis of the condensing point shape (far field pattern) in the condensing region (that is, the semiconductor). In the direction of the major axis of the near field pattern of the laser 12A (vertical direction / first direction in the figure), the upper side of the drawing is high, contrary to the lower right first semiconductor laser 12A, and the lower side of the drawing. The side has a low slope.

In the front view of the left semiconductor laser and the like in FIG. 1b, the optical component 70 corresponding to the second semiconductor laser 12B in the lower left is the direction of the short axis (that is, the semiconductor) of the condensing point shape (far field pattern) in the condensing region. The direction of the major axis of the near-field pattern of the laser 12B (left / right direction / second direction in the drawing) is inclined, and the left side of the drawing is high and the right side of the drawing is low.
The optical component 70 corresponding to the second semiconductor laser 12B in the upper right has a short axis direction (that is, a long axis direction of the near field pattern of the semiconductor laser 12B) (see FIG. In the left / right direction / second direction)), the right side of the drawing is high and the left side of the drawing is low, contrary to the second semiconductor laser 12B in the lower left of the front view.
The inclination in the direction of the short axis of the condensing point shape (far field pattern) means that it is attached in the rotation direction around the long axis of the condensing point shape (far field pattern). be able to.

With the configuration as described above, the light emitted in parallel with the optical axis 21 of the condenser lens 20 from the first light source 10A and the second light source 10B has a low inclination due to the inclined optical surface of the optical component 70. The traveling direction is bent in the direction (that is, the thickness is reduced), and the light enters the condenser lens 20 with the optical axis 21 having a predetermined inclination angle. As described above, in the four light sources 10 </ b> A and 10 </ b> B, the inclination directions of the inclined optical surfaces 74 are different from each other, and thus the light is condensed at different positions on the phosphor 32. In FIG. 1a and FIG. 1b, it is drawn so as to be condensed at the surface position of the dielectric film 31 provided on the incident side surface of the phosphor wheel 30, but the dielectric film 31 is very thin, Since the light is not condensed or diffused by the phosphor wheel 30, it can be said that “the light is condensed at different positions on the phosphor 32”.
Further, when the light passes through the diffusion layer 72, the light becomes diffused light, so that the shape at the condensing position is widened. The description regarding the optical component 70 and the diffusion layer 72 will be described later.

As described above, the phosphor wheel 30 has the dielectric film 31 formed on the incident side surface and the phosphor 32 formed concentrically on the output side surface. FIG. 4 shows a schematic diagram of one embodiment of the phosphor wheel. 4A shows the incident side of the phosphor wheel 30, and FIG. 4B shows the emission side of the phosphor wheel 30. The phosphor wheel 30 is provided with a green phosphor region, a red phosphor region, and a blue transmission region. In the green phosphor region, a dielectric film 31G that transmits blue light and reflects green light is formed on the incident side, and a phosphor 32G having a green wavelength band is applied on the emission side of the substrate. . Similarly, in the red phosphor region, a dielectric film 31R that transmits blue light and reflects red light is formed on the incident side, and a phosphor 32R having a red wavelength region is applied on the emission side. ing. In the blue transmissive region, a dielectric film 31B that transmits blue light is formed on the incident side, and a phosphor is not applied on the output side, but a dielectric that transmits blue light as in the incident side. A film 32B may be formed. Further, in order to improve luminance unevenness and chromaticity unevenness, it is desirable that a diffuser, for example, particles such as SiO ₂ , TiO ₂ , and Ba ₂ SO ₄ be applied.

  The dielectric films 31G and 31R formed in the green and red phosphor areas of the phosphor wheel 30 are films that transmit blue light and reflect wavelengths according to the colors of the respective areas. The phosphor light emitted from the phosphors 32G and 32R to the semiconductor laser 12 side can be reflected to the light receiving lens 40 side, whereby the phosphor light can be used efficiently.

The phosphor 32G applied to the green phosphor region of the phosphor wheel 30 desirably generates green fluorescence including a wavelength band of about 500 to 560 nm. An example of a specific _{material, β-Si 6-Z AB} Z O Z N 8-Z: EA, BA 3 AB 5 O 12: Ce, Ca 8 MgSi 4 O 16 C B2: EA, Ba 3 Si 6 Examples include O ₁₂ N ₂ : EA, (Sr, Ba, Ca) Si ₂ O ₂ N ₂ : EA.

The phosphor 32R applied to the red phosphor region of the phosphor wheel desirably generates a red tendency in which the wavelength band includes 600 to 800 nm. Specific examples of the material include (Sr, Ca) ABSiN ₃ : EA, CaABSiN ₃ : EA, SrABSiN ₃ : EA, and K ₂ SiF ₆ : Mn.

The ratio of the green / red phosphor region and the blue transmission region in the phosphor wheel 30 can be arbitrarily determined. For example, it can be calculated from the white chromaticity required for the projector and the efficiency of each phosphor. Here, the green and red phosphor regions green are each 150 degrees, and the blue transmission region is 60 degrees.
In the present embodiment, three regions of green, red, and blue are used, but four or more regions may be used. It is also possible to increase the white light area by blue and yellow and the green, red, and blue areas, respectively.

The phosphor wheel 30 is made of a transparent disk-shaped member that transmits light, and the center thereof is fixed to the drive shaft 50 a of the rotation drive unit 50. Here, glass, resin, sapphire, or the like can be used as the material of the phosphor wheel 30 as long as the material has high light transmittance. In FIG. 4A, an area indicated by “SP” indicates an area (condensing area) where incident light from the light source 10 condensed by the condenser lens 20 is incident. Further, an area indicated by “FL” in FIG. 4B indicates an area (fluorescent area) in which the phosphor layer emits light by incident light from the light source 10.
Note that one more substrate may be added to the emission side of the phosphor wheel 30 and a band pass filter may be provided there (not shown). Thereby, more pure green and red can be obtained.

  Returning to the description of FIG. 1A and FIG. 1B, the rotation drive unit 50 is a brushless DC motor, and is arranged such that the drive shaft 50a and the optical axis 21 of the condenser lens 20 are parallel to each other. Further, the surface of the phosphor wheel 30 is fixed so as to be perpendicular to the drive shaft 50a. The rotation speed of the rotation drive unit 50 is a rotation speed based on the frame rate of the moving image to be reproduced (the number of frames per second. The unit is [fps]). For example, when it is possible to reproduce a moving image of 60 [fps], the rotation speed of the rotation drive unit 50 (that is, the phosphor wheel 30) may be set to an integral multiple of 60 rotations per second.

The light emitted from the phosphor wheel 30 is output from the light source device 1 by changing the traveling direction in a predetermined direction by the light receiving lens 40. The light receiving lens 40 can emit light in a direction in which light spreads, can emit parallel light, or can collect light at a predetermined position. When this light source device 1 is used as a light source of a projector, the emitted light from the light source device 1 is condensed on the modulation means, and the image formed by the modulation means is enlarged by the projection means and projected onto the screen. At this time, Etendue calculated from the relationship between the image size formed by the modulation means and the spread angle of the light projected from the projection means is the NA of the light receiving lens 40 and the size of the light emitting area of the phosphor. Affect.
That means
(Image size formed by modulation means) × (projection angle) = (fluorescence region FL) × (light receiving lens NA)
It becomes. Therefore, since the light emission of the phosphor is substantially Lambertian, it is desirable that the light receiving lens 40 has as high NA as possible. Further, it is desirable that the fluorescent region FL is small. When the Etendue on the phosphor side is larger than the Etendue on the projection side, the difference is reduced in efficiency.

  As described above, since the NA of the light receiving lens 40 is high, it is desirable that the fluorescent region FL be as small as possible. However, in that case, the light density from the light source 10 becomes high. In the present embodiment, since the size of the fluorescent region FL is desirably about 1.5 to 2 mm, the light from the light source 10 is desirably 2 mm or less as the size of the condensing region SP. Note that this shape is not the size of the light condensing region of each light source 10, but the size of the entire light condensing region in a state where a plurality of light sources 10 are attached.

Next, the optical component will be described. An optical component 70 according to an embodiment of the present invention will be described in detail with reference to FIG. As described above, the direction of the short axis (the direction of the long axis of the near field pattern of the semiconductor laser) of the condensing spot shape (far field pattern) is the first direction (in the front view of the semiconductor laser or the like on the left in FIG. 1a). The light emitted from the first light source 10 </ b> A (that is, the first semiconductor laser 12 </ b> A) arranged in the left-right direction passes through the corresponding collimating lens 13 and enters the diffusion layer 72 formed on the incident surface of the optical component 70. Incident. At this time, the light emitted from the collimating lens 13 is parallel to the optical axis 21 of the condenser lens 20, and the incident surface of the optical component 70 and the incident surface of the diffusion layer 72 formed on the incident surface are the condensing lens. The light emitted from the collimating lens 13 is incident on the incident surface of the diffusion layer 72 perpendicularly. The light incident on the diffusion layer 72 becomes diffused light while passing through the diffusion layer 72 and enters the optical component 70. The effect of the diffusion layer 72 will be described later in detail.
At this time, the optical component 70 has a surface on the emission side in the direction of the short axis of the condensing point shape (far field pattern) of the first semiconductor laser 12A (the direction of the long axis of the near field pattern of the semiconductor laser). It has the inclined optical surface 74 inclined in a certain first direction. Therefore, the optical component is inclined from the optical axis 21 of the condensing lens 20 by a predetermined angle, is emitted from the optical component 70, and enters the condensing lens 20 while maintaining the angle (see the side view of FIG. 1b). ). That is, the light enters the condenser lens 20 at a predetermined angle (for example, 0.25 to 2 degrees) that is not parallel to the optical axis 21 of the condenser lens 20. Further, as shown in the front view of the left semiconductor laser and the like in FIG. 1a, the two optical components 70 corresponding to the first light source 10A have the inclined optical surface 74 inclined in the opposite direction by 180 degrees.
Therefore, the light emitted from the two optical components 70 corresponding to the two first light sources 10A is condensed at different positions on the phosphor wheel 30 (that is, on the phosphor 32) by the condenser lens 20. It will be.

Similarly, the front view of the semiconductor laser or the like on the left side in FIG. 1A is the second direction (the direction of the long axis of the near field pattern of the semiconductor laser) in the short axis direction of the focal spot shape (far field pattern). The light emitted from the second light source 10 </ b> B (that is, the second semiconductor laser 12 </ b> B) arranged in the vertical direction in FIG. 1 enters the optical component 70 through the corresponding collimator lens 13. At this time, the light emitted from the collimating lens 13 is parallel to the optical axis 21 of the condenser lens 20, and the incident surface of the optical component 70 is disposed perpendicular to the optical axis 21 of the condenser lens 20. Therefore, the outgoing light from the collimating lens 13 enters the incident surface of the optical component 70 perpendicularly.
At this time, the optical component 70 has a second direction whose surface on the emission side is the short axis direction of the condensing point shape of the second semiconductor laser 12B (the long axis direction of the near field pattern of the semiconductor laser). And an inclined optical surface 74 inclined at. Therefore, the optical component is inclined from the optical axis 21 of the condenser lens 20 by a predetermined angle, is emitted from the optical component 70, and enters the condenser lens 20 while maintaining the angle (see the plan view of FIG. 1a). ). That is, the light enters the condenser lens 20 at a predetermined angle (for example, 0.25 to 2 degrees) that is not parallel to the optical axis 21 of the condenser lens 20. Further, as shown in the front view of the left semiconductor laser or the like in FIG. 1a, the two optical components 70 have the inclined optical surface 74 inclined 180 degrees in opposite directions.
Therefore, the light emitted from the two optical components 70 corresponding to the two second light sources 10B is condensed at different positions on the phosphor wheel 30 (that is, on the phosphor 32) by the condenser lens 20. It will be.

  In addition, since the inclined optical surface 74 is attached in the direction of the short axis of the condensing point shape, it is possible to reduce the area where the light emitted from each semiconductor laser 12 overlaps each other, and the light density in the condensing area appropriately. Can be suppressed. When the collimating lens 13 is arranged out of the focal position as in the present embodiment, the inclined optical surface 74 is attached in the direction of the major axis of the near field pattern of the semiconductor laser 12. When the collimating lens 13 is disposed at the focal position, the inclined optical surface 74 is attached in the direction of the minor axis of the near field pattern of the semiconductor laser 12.

The light emitted from the two first light sources 10A and the two second light sources 10B with the optical component 70 having such an inclined optical surface 74 is condensed on the phosphor wheel 30 by the condenser lens 20. An example of the shape of the condensing point in the case of the above will be described with reference to FIG.
FIG. 2A shows a condensing point shape and cross-sectional light intensity in a flat plate-like optical component 70 that does not have the inclined optical surface 74 and whose incident-side optical surface and output-side optical surface are parallel. FIG. 2B shows the condensing point shape and cross-sectional light intensity when two optical components 70 corresponding to the second semiconductor laser 12B are arranged. FIG. 2C shows a case corresponding to the embodiment shown in FIG. 1A and FIG. 1B, and includes two optical components 70 corresponding to the first semiconductor laser 12A and the second semiconductor laser 12B. The condensing point shape and cross-sectional light intensity when two corresponding optical components 70 are arranged are shown.
2B and 2C, the two optical components 70 corresponding to the second semiconductor laser 12B form an elliptical condensing point shape that is vertically long and aligned in the left-right direction in the drawing. It is formed. As a result, as shown in the lower cross-sectional light intensity graphs of FIGS. 2B and 2C, the emitted light from the second light source 10B is concentrated at one point (the cross-sectional light intensity in FIG. 2A). (See graph) without being dispersed into a light intensity curve having two peaks.

In FIG. 2C, in addition to the vertically elongated elliptical condensing point shape arranged in the left-right direction by the two optical components 70 corresponding to the second semiconductor laser 12B, the first semiconductor laser 12A By the two optical components 70 corresponding to, a long elliptical condensing point shape is formed on the left and right sides, which are arranged in the vertical direction of the drawing. Thereby, the light emitted from the first light source 10A is also dispersed into a light intensity curve having two peaks. Therefore, in the condensing point shape shown in FIG.
In FIGS. 1a and 1b, the optical component 70 has the inclined optical surface 74 inclined in the opposite direction by 180 degrees at the same angle, but the present invention is not limited to this, and each has a different inclination angle. It can also have an inclined optical surface.

Here, assuming that the original light peak intensity in the case where the light collecting area is one is Po, the light peak intensity in the case of FIG. 2B and FIG.
P = Po / (the number of condensing areas = 2 in the case of FIG. 2B, 4 in the case of FIG. 2C)
It becomes. In other words, since the original light peak intensity Po is divided by the number of condensing regions, in this example, 1/2 in the case of FIG. 2B and 1/4 in the case of FIG. 2C. Light peak intensity.

  The optical component 70 having the inclined optical surface 74 is incident on the condensing lens 20 from the collimating lens 13 with a predetermined angle with respect to the optical axis of the condensing lens 20. The angle is an absolute value. 0.25 to 2 degrees is desirable. If the inclination angle is in the range of 0.25 to 2 degrees as an absolute value, the area of the light collection region SP (see FIG. 4A) in the phosphor wheel 30 (phosphor) will not be too large. In one embodiment shown in FIGS. 1 a and 1 b, the optical component 70 is not limited to having the same inclination angle, and each optical component 70 may have a different inclination angle.

  Next, the diffusion layer will be described. In the present embodiment, as described above, the diffusion layer 72 is formed on the incident surface of the optical component 70 corresponding to the first light source 10A, that is, the diffusion layer 72 on the optical path of the emitted light from the first light source 10A. Therefore, the diffusion layer 72 becomes diffused light. Therefore, in the light condensing area, the light is condensed in a wider area than in the case where there is no diffusion layer. As shown in FIG. 2 (c), the light emitted from the first light source 10 </ b> A passes through the diffusion layer 72 and the optical component 70, and the condensing lens 20 forms an elliptical condensing point shape that is long on the left and right. The emitted light from the second light source 10B is transmitted through the optical component 70, and the condensing lens 20 forms an elliptical condensing point shape that is long vertically. At this time, the length of the major axis of the ellipse by the first light source 10A is longer than the length of the major axis of the ellipse by the second light source 10B. This is because light is diffused by the diffusing layer 72, so that a larger image is drawn in the condensing region (the condensing point shape becomes larger).

Therefore, in the present embodiment, a condensing point shape (beam shape) having a horizontally long (or vertically long) spectral ratio on the phosphor wheel 30 (that is, on the phosphor 32) that is a light condensing region of the condensing lens 20 is used. Can be obtained. Therefore, by appropriately selecting the diffusion intensity of the diffusion layer 72, a condensing point shape (beam shape) having a desired size and a desired aspect ratio can be obtained.
In addition, since it condenses in a different position with the optical component 70 which has the inclination optical surface 74, the magnitude | size of a condensing point shape (beam shape) can also be adjusted by this. As an example of a condensing point shape (beam shape) having a desired size and a desired aspect ratio, a condensing point shape (beam shape) of 1.5 mm in length × 2 mm in width can be exemplified, but is not limited thereto. is not. In addition, if the shape is 1.5 mm long × 2 mm wide, it can be realized by using a diffusion layer having a diffusion coefficient such that an aspect ratio of about 1.33 (= 2 mm / 1.5 mm) can be obtained.

Examples of the diffusion layer 72 include a layer including a diffusion material made of particles such as SiO ₂ , TiO ₂ , and Ba ₂ SO ₄ . The particle size of the diffuser is preferably in the range of 0.1 to 100 μm, more preferably in the range of 1 to 50 μm. Such a layer can be provided on the surface of the optical component 70 by coating or the like. Note that the present invention is not limited thereto, and a diffusion layer can be formed by a large number of bubbles, and any material and configuration can be adopted as long as the layer has a function of diffusing light. Other embodiments relating to the diffusion layer will be described in detail later.
In the present embodiment, the size and content of the diffuser and the bubbles can be set so as to obtain the optimum diffusion intensity, that is, the diffusion angle, according to the aspect ratio required for the condensing point shape. . Furthermore, the intensity of light from the light source, the characteristics of the phosphor layer (for example, the degree of influence on the wavelength conversion efficiency when the light having a high light density is incident, the intensity of the visibility, etc.), between the diffusion layer 72 and the phosphor 32 It is also possible to determine the optimum diffusion intensity according to the distance.

  As described above, in the light source device 1 of the embodiment shown in FIGS. 1 a and 1 b, the plurality of light sources 10 including the semiconductor laser 12 and the collimator lens 13, and the condensing lens 20 that condenses the light from the light source 10. An optical component 70 disposed between the light source 10 and the condensing lens 20, and a phosphor wheel 30 having a phosphor 32 and transmitting the light condensed by the condensing lens 20. 70 has a different inclined optical surface 74 for each light source inclined from a surface perpendicular to the optical axis of the collimating lens 13, and the short axis direction of the condensing point shape is the first in the semiconductor laser 12. A first semiconductor laser 12A arranged in a direction, and a second semiconductor laser 12B arranged in a second direction in which the direction of the short axis of the condensing point shape is different from the first direction, Semiconductor laser 12A and second semiconductor laser On one optical path of the light emitted out of 2B, the diffusion layer 72 is formed.

According to this embodiment, the optical component 70 disposed between the light sources 10A and 10B and the condenser lens 20 has different inclined optical surfaces 74 for each light source inclined from the surface perpendicular to the optical axis of the collimating lens 13. Therefore, the light emitted from the plurality of light sources 10 </ b> A and 10 </ b> B is condensed at different positions on the phosphor wheel 30 (that is, on the phosphor 32) by the condenser lens 20. Therefore, since the light density in the condensing region SP (see FIG. 4A) on the phosphor 32 can be suppressed, the emitted light from the phosphor 32 can be used efficiently.
Furthermore, the first semiconductor laser 12A in which the direction of the short axis of the condensing point shape is arranged in the first direction, and the direction of the short axis of the condensing point shape is arranged in the second direction different from the first direction. Since the diffusion layer 72 is formed in the optical path of one of the first semiconductor laser 12A and the second semiconductor laser 12B, the condensing point shape is obtained. The size of (beam shape) is different, and a condensing point shape (beam shape) having a desired size and a desired aspect ratio can be obtained in the condensing region SP of the condensing lens. In addition, since it condenses in a different position with the inclination optical surface 74 of the optical component 70, the magnitude | size of a condensing point shape (beam shape) can also be adjusted by this.
Also, as shown in FIG. 8, a diffusion layer 72 is provided between the light sources 10A and 10B and the condenser lens 20 in the optical paths of the emitted light of the first semiconductor laser 12A and the second semiconductor laser 12B. Thus, the diffusion coefficient of the diffusion layer 72 can be made different between the first semiconductor laser 12A and the second semiconductor laser 12B. This also makes it possible to obtain a condensing point shape (beam shape) having a desired size and a desired aspect ratio in the condensing region SP of the condensing lens.
In addition, since it is not necessary to use expensive parts such as a diffractive optical element, in this embodiment, in the light source device using a plurality of semiconductor lasers 12A and 12B, a decrease in the luminous efficiency of the phosphor 32 can be suppressed. In the light region SP, the light source device 1 capable of obtaining a condensing point shape (beam shape) having a desired size and a desired aspect ratio can be provided at a low manufacturing cost.

  In addition, the above-mentioned “the optical component has a different inclined optical surface for each light source” may have different inclination angles, or may have the same inclination angle arranged in different directions. In addition, in some light sources, ones having the same inclination angle may be arranged in the same direction. When those having the same inclination angle are arranged adjacent to each other in the same direction, it is possible to integrally form adjacent inclined optical surfaces.

Furthermore, according to the present embodiment, since the optical component 70 is formed for each light source 10, fine adjustment can be performed in order to obtain an optimum condensing point shape (beam shape). Further, since the diffusion layer 72 is formed on the optical surface of the optical component 70, the compact light source device 1 can efficiently obtain a condensing point shape (beam shape) having a desired aspect ratio.
The diffusion layer 72 may be provided on the optical surface perpendicular to the optical axis of the collimating lens 13 of the optical component 70 as in FIGS. 1a and 1b, or may be provided on the inclined optical surface of the optical component 70. Sometimes. Further, the diffusion layer 72 may be provided as an independent component and disposed at any position between the light condensing lens 20 on the optical path of the light emitted from the light source 10.

  In addition, according to the present embodiment, the two first light sources 10A in which the inclination optical surface 74 is inclined in the opposite direction by 180 degrees and the two first light sources 10A in which the inclination optical surface 74 is inclined in the opposite direction by 180 degrees are provided. At least the second light source 10B, two condensing point shapes (beam shapes) by the first light source 10A and two by the second light source 10B are located symmetrically with respect to the optical axis of the condensing lens 20. A condensing point shape (beam shape) can be obtained. Therefore, it is possible to obtain a condensing point shape (beam shape) that spreads in a predetermined manner around the optical axis of the condensing lens 20.

  Further, according to the present embodiment, the inclination of the inclined optical surface 74 of the optical component 70 is centered on the short axis direction of the condensing point shape of the semiconductor laser 12, that is, the long axis of the condensing point shape of the semiconductor laser 12. Therefore, the region where the light emitted from each semiconductor laser 12 overlaps with each other can be reduced, and the light density can be appropriately suppressed in the condensing region.

According to the present embodiment, since the first direction and the second direction are different by 90 degrees, the light condensing point shape (beam shape) having a desired aspect ratio can be reliably obtained by the diffusion layer 72.
In addition, according to the present embodiment, the inclined optical surface 74 is formed at an inclination angle of 0.25 to 2 degrees from the vertical surface of the optical axis of the collimating lens 13, so that it is concentrated at different positions within an appropriate range. Can be light.
Furthermore, even if the phosphor 32R having the red wavelength region tends to have a large decrease in wavelength conversion efficiency due to an increase in temperature, according to the present embodiment, the light density in the condensing region on the phosphor is suppressed. Therefore, a decrease in wavelength conversion efficiency can be suppressed.

  Next, the relationship between the position of the collimating lens 13 and the light intensity will be described with reference to FIG. The arrangement of the semiconductor laser 12, the collimating lens 13, the optical component 70, etc. is schematically shown on the upper side of FIG. 3, and the condensing point shape (beam shape) and the sectional light intensity are shown on the lower side. 3A and 3B show the semiconductor laser 12, the collimating lens 13, and the optical component 70. In FIG. 3A, the collimating lens 13 is arranged in the optical axis direction for emitting parallel light. FIG. 3B shows a case where the collimating lens 13 is arranged so as to deviate from the focal position (arrangement position in the optical axis direction for emitting parallel light). . FIG. 3C shows a case where a diffusion layer 72 is further arranged in the state of FIG.

  As shown in FIG. 3A, when the collimating lens 13 is disposed at the focal position (arrangement position in the optical axis direction for emitting parallel light), the condensing point shape in the condensing region is small, and the light Peak intensity is high (light density is high). On the other hand, as shown in FIG. 3B, when the collimating lens 13 is arranged shifted from the focal position (arrangement position in the optical axis direction for emitting parallel light), the shape of the condensing point in the condensing region. The area of the light increases and the light peak intensity decreases (the light density decreases). Therefore, by shifting the collimating lens 13 from the focal position (arrangement position in the optical axis direction for emitting parallel light), the area of the condensing region can be increased and the light density of the condensed light can be suppressed. it can.

  As described above, since the collimating lens 13 is disposed at a position different from the focal position (arrangement position in the optical axis direction for emitting parallel light), the light density in the condensing region on the phosphor is suppressed. It is also possible to adjust the size of the condensing point shape (beam shape).

Further, as shown in FIG. 3C, the collimating lens 13 is shifted from the focal position (arrangement position in the optical axis direction for emitting parallel light), and the optical component 70 having the inclined optical surface 74 is used in the light collection region. In addition to condensing light at different positions, it is also possible to suppress the light density on the phosphor by widening the light traveling angle by the diffusion layer 72 and increasing the area of the light collecting region. Further, by providing the diffusion layer 72 in at least one of the first direction and the second direction, a condensing point shape (beam shape) having a desired aspect ratio can be formed.
In FIG. 3 (a), the condensing point shape when the collimating lens 13 is arranged at the arrangement position in the optical axis direction for emitting the parallel light at the focal position is drawn small. Depending on the case, in the embodiment of the present invention, it is possible to arrange the collimating lens 13 at the arrangement position in the optical axis direction for emitting the focal position parallel light.

(Explanation of the effect on the output efficiency of the phosphor due to the presence of the inclined optical surface and the diffusion layer)
Next, the output efficiency of the phosphor with and without the inclined optical surface 74 and with or without the diffusion layer 72 will be described using the graph of FIG.
The graph of FIG. 5 shows the relationship between the light output of the phosphor and the excitation light output of the light source. A fine dotted line shown in (A) shows a case where neither the inclined optical surface 74 nor the diffusion layer 72 is provided, and a dotted line shown in (B) shows a case where the inclined optical surface 74 is provided but the diffusion layer 72 is not provided. The solid line shown in FIG. 8C shows the case where the inclined optical surface 74 and the diffusion layer 72 are provided.
In the case where neither the inclined optical surface 74 nor the diffusing layer 72 shown by the fine dotted line in (A) is present, when the excitation output is increased, the phosphor output reaches a peak and conversely decreases. In the case where the inclined optical surface 74 shown by the dotted line (B) is provided but the diffusion layer 72 is not provided, when the excitation output is increased, the phosphor output increases, but gradually becomes saturated.
On the other hand, in the case of having the inclined optical surface 74 and the diffusion layer 72 shown by the solid line in (C), saturation of the phosphor output is suppressed, and the phosphor is effectively used even when the light output from the light source 10 is high. Can be used. This is because the light density in the light condensing region can be kept low, so that a decrease in the luminous efficiency of the phosphor is suppressed.
Therefore, by combining the inclined optical surface 74 and the diffusion layer 72, the light emitted from the plurality of light sources 10 is condensed at different positions on the phosphor, and the light from each light source 10 is condensed. Since the diameter is large, the light density can be sufficiently reduced, and a decrease in the luminous efficiency of the phosphor can be sufficiently suppressed.

  As described above, in the light source device 1 according to the embodiment of the present invention, the optical components 70 having the inclined optical surfaces 74 are used to shift the light condensing regions of the plurality of light sources 10, so that the light density in the light condensing regions of the phosphors is increased. Can be reduced. Further, by performing defocusing by shifting the position of the collimating lens 13, the shape of the phosphor in the light condensing region can be increased without sacrificing etendue, and the light density can be reduced. Furthermore, the diffusion layer can increase the shape of the phosphor in the light condensing region without sacrificing etendue, thereby reducing the light density. Thereby, the fall of the light conversion efficiency of fluorescent substance can be suppressed and fluorescent substance can be used efficiently. Furthermore, the arrangement of the light sources 10 having the same shape can be changed and incorporated, and mass productivity is not sacrificed.

Note that the number of the light sources 10 is not limited to the above-described embodiment, and may be any number as long as it is at least four, and the number of the semiconductor lasers 12 in one light source 10 may be any number. It's okay.
In the description of the above-described embodiment, the first direction and the second direction differ by 90 degrees are synonymous with the angle formed by the first direction and the second direction being 90 degrees.

(Description of other embodiments of optical component)
In the above-described embodiment, both the optical component 70 having the inclined optical surface 74 and the member of the diffusion layer 72 are included. However, the present invention is not limited to this, and the first semiconductor does not have the diffusion layer 72. There may be a case where an optical component 70 that functions as a diffusion layer is provided in the optical path of one of the emitted light of the laser 12A and the second semiconductor laser 12B. Other embodiments of such an optical component will be described with reference to FIG. FIG. 6 is a schematic view showing another embodiment of the optical component according to the embodiment of the present invention.

FIG. 6A shows a case where both the optical component 70 and the diffusion layer 72 are included. On the other hand, in the embodiment shown in FIG. 6B, there is no individual diffusion layer. Instead, bubbles are included in the optical component 70A, or particles such as SiO ₂ , TiO ₂ , Ba ₂ SO _4, etc. The light passing therethrough can be dispersed by including a diffusing material made of Also in this embodiment, the size and content of the diffuser and the bubbles can be set so as to obtain the optimal diffusion strength, that is, the diffusion angle, according to the aspect ratio required for the condensing point shape. . Regarding the size of the bubbles and the particle size of the diffuser, the same ones as in the above-described embodiment can be applied.

  In the embodiment shown in FIG. 6 (c), there is no individual diffusion layer, and instead, in the optical component 70B made of glass, the light passing therethrough can be diffused by making the refractive index different. Also in the present embodiment, it is possible to adjust according to a required aspect ratio in the condensing point shape.

  In the embodiment shown in FIG. 6 (d), there is no individual diffusion layer. Instead, light can be diffused by providing an uneven surface on the entrance surface or exit surface of the optical component 70C. Also in the present embodiment, the size and pitch of the unevenness can be set so that an optimum diffusion coefficient can be obtained according to the aspect ratio required for the condensing point shape.

(Description of projector according to one embodiment of the present invention)
Next, the case where the light source device 1 shown in the above-described embodiment is used as a light source device in a so-called one-chip DBP projector will be described with reference to FIG. FIG. 7 is a schematic diagram for illustrating the configuration of the projector 100 including the light source device 1 shown in the above-described embodiment, and is a schematic plan view of the light source device 1 and the projector 100 as viewed from above. is there.
In FIG. 7, light emitted from the light source device 1 is reflected by a DMD (Digital Micromirror Device) element 110 which is an optical spatial modulator, condensed by a projection lens 120 which is a projection means, and projected onto a screen SC. The The DMD element is a matrix in which fine mirrors corresponding to each pixel of an image projected on a screen are arranged in a matrix, and the light emitted to the screen by changing the angle of each mirror is turned on / off in units of microseconds. Can be turned off.
In addition, by changing the gradation of light incident on the projection lens according to the ratio of the time when each mirror is turned on and the time when it is turned off, gradation display based on the image data of the image to be projected becomes possible. Become.

  In the present embodiment, the DMD element is used as the light modulation means. However, the present invention is not limited to this, and any other light modulation element can be used depending on the application. In addition, the light source device 1 and the projector using the light source device 1 according to the present invention are not limited to the above-described embodiments, and various other embodiments are included in the present invention.

  As described above, according to the present embodiment, the light source device 1 using a plurality of semiconductor lasers and phosphor wheels is provided. In the light source device 1, a decrease in the luminous efficiency of the phosphor can be suppressed. It is possible to provide the projector 100 that can obtain a condensing point shape (beam shape) having a desired aspect ratio in the condensing region of the output light at a low manufacturing cost.

  Although the embodiments of the present invention have been described, the disclosure may vary in the details of the configuration, and combinations of elements and changes in the order in the embodiments depart from the scope and spirit of the claimed invention. It can be realized without.

DESCRIPTION OF SYMBOLS 1 Light source device 10 Light source 11 Housing | casing 12 Semiconductor laser 13 Collimating lens 20 Condensing lens 21 Optical axis 30 of condensing lens Phosphor wheel 31 Dielectric film 32 Phosphor 40 Light receiving lens 50 Rotation drive part 50a Drive shaft 60 Heat radiation member ( Support member)
70 Optical component 72 Diffusion layer 74 Inclined optical surface 100 Projector 110 DMD element 120 Projection lens SC Screen SP Condensing area FL Phosphor light emitting area

Claims (13)

A plurality of light sources having a semiconductor laser and a collimating lens;
A condensing lens for condensing light from the light source;
An optical component disposed between the light source and the condenser lens and transmitting light from the light source;
A phosphor wheel having a phosphor and transmitting the light collected by the condenser lens;
With
The optical component has a different inclined optical surface for each of the light sources inclined from a surface perpendicular to the optical axis of the collimating lens;
In the semiconductor laser, the first semiconductor laser in which the direction of the short axis of the condensing point shape is arranged in the first direction, and the direction of the short axis of the condensing point shape is different from the first direction. And a second semiconductor laser arranged in the direction of
A light source characterized in that a diffusion layer is formed between the light source and the condenser lens in an optical path of one of the emitted light of the first semiconductor laser and the second semiconductor laser. apparatus. A plurality of light sources having a semiconductor laser and a collimating lens;
A condensing lens for condensing light from the light source;
An optical component disposed between the light source and the condenser lens and transmitting light from the light source;
A phosphor wheel having a phosphor and transmitting the light collected by the condenser lens;
With
The optical component has a different inclined optical surface for each of the light sources inclined from a surface perpendicular to the optical axis of the collimating lens;
In the semiconductor laser, the first semiconductor laser in which the direction of the short axis of the condensing point shape is arranged in the first direction, and the direction of the short axis of the condensing point shape is different from the first direction. And a second semiconductor laser arranged in the direction of
Of the optical paths of the emitted light of each of the first semiconductor laser and the second semiconductor laser, a diffusion layer is provided between the light source and the condenser lens, and the diffusion coefficient of the diffusion layer is A light source device, wherein the light source device is different between the first semiconductor laser and the second semiconductor laser.   The light source device according to claim 1, wherein the diffusion layer is formed on an optical surface of the optical component. The plurality of light sources are
And having at least two first light sources with tilted optical surfaces inclined at 180 degrees opposite to each other and two second light sources with tilted optical surfaces inclined at 180 degrees opposite to each other. The light source device according to claim 1, wherein the light source device is a light source device.   The inclination of the inclined optical surface of the optical component is attached in a rotation direction around the major axis of the condensing point shape of the semiconductor laser. The light source device according to 1.   6. The light source device according to claim 1, wherein the first direction and the second direction are different from each other by 90 degrees.   The light source device according to claim 1, wherein the light source is fixed on the same plane of the support member.   8. The light source device according to claim 1, wherein the inclined optical surface is formed at an inclination angle of 0.25 to 2 degrees with respect to a vertical surface of the optical axis of the collimating lens.   9. The light source device according to claim 1, wherein the collimating lens is arranged at a position different from an arrangement position in an optical axis direction for emitting parallel light.   The light source device according to claim 1, wherein the support member is a heat dissipation member.   11. The light source device according to claim 1, wherein a wavelength band of light emitted from the light source is 370 to 500 nm.   The optical device according to claim 1, wherein one of the phosphors is a phosphor that emits light including light including red light. The light source device according to any one of claims 1 to 12,
A light modulation unit that sequentially modulates light of a plurality of wavelength bands emitted from the light source device to form an image based on image data;
Projection means for enlarging and projecting the image;
A projector comprising: